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Background: Our population‐based study has previously shown that being born in winter or spring was associated with adult‐onset asthma. The aim was to study if season of birth (SOB) is associated with airway allergy and related diseases: NSAID exacerbated respiratory disease (N‐ERD), asthma, allergic rhinitis (AR), nonallergic rhinitis (NAR), chronic rhinosinusitis with nasal polyps (CRSwNP) and CRS without nasal polyps (CRSsNP) in Finland. Methods: A randomly sampled retrospective registry‐based follow‐up data (n = 74,868) of patients visiting Hospital District of Helsinki and Uusimaa (HUS) in Finland was used. The birth date, sex, visit date and comorbidities were collected from electronic health record data during visits from 2005 to 2019. Results: The mean (SD, range) age of the sample was 34.53 (25.47, 0–102) years, with 48.7 % being men. We divided the whole population in four groups based on the season they were born (SOB‐groups). When observing these four SOB‐groups, the proportion of those having asthma was 43.1%, 42.1%, 41.1%, 42.7%, in winter, spring, summer, and autumn SOB‐groups, respectively. The proportion of those having AR was 12.6%, 12.0%, 10.7%, 12.1%, respectively. When having summer as a reference, being born in any other time of year was significantly associated with AR and, being born in autumn or winter was associated with asthma. No significant association was observed in CRS or N‐ERD or NAR groups in adjusted models. Conclusions: The study suggests that early life immunological events may have a role a role in pathogenesis of asthma and AR. As no association was observed between SOB and CRSsNP, CRSwNP, N‐ERD or NAR, further studies on this are warranted. [ABSTRACT FROM AUTHOR]

Background: Type 2 Diabetes Mellitus (T2D) is a chronic disease with a high prevalence worldwide. Human literature suggests factors beyond well‐known risk factors (e.g., age, body mass index) for T2D: cytomegalovirus serostatus, season of birth, maternal age, birth weight, and depression. Nothing is known, however, about whether these variables are influential in primate models of T2D. Methods: Using a retrospective methodology, we identified 22 cases of spontaneously occurring T2D among rhesus monkeys at our facility. A control sample of n = 1199 was identified. Results: Animals born to mothers that were ≤5.5 years of age, and animals that showed heightened Activity and Emotionality in response to brief separation in infancy, had a greater risk for development of T2D in adulthood. Conclusions: Knowledge of additional risk factors for T2D could help colony managers better identify at‐risk animals and enable diabetes researchers to select animals that might be more responsive to their manipulations. [ABSTRACT FROM AUTHOR]

Introduction: Balavata Kala janm (~birth in a season when people naturally gain strength) is one of an individual's Bala (~strength) enhancing factors, according to Ayurveda. Coronavirus disease 2019 (COVID-19) showed heterogeneous clinical manifestations in the global population, and the role of innate immunity in COVID-19 pathogenesis came up. The objective of this study was to see the association between the season of birth (SOB) and COVID-19 clinical manifestations. The association of ABO blood group systems was studied as a secondary objective. Methods: A retrospective observational study was conducted from October 2020 to January 2021 at an Ayurveda research center in India. Confirmed patients of COVID-19 from 0 to 80 years of age group were telephonically contacted and interviewed through a structured questionnaire prepared in Google Forms after obtaining informed verbal consent. Based on the Ayurvedic concept of strength in Adana (~Northern solstice) and Visarga Kala (~Southern solstice), the categorization of participants according to their SOB was done. Results: The study included 402 participants and analyzed data through IBM SPSS. The odds ratio (OR) of COVID-19 clinical outcomes and SOB was analyzed using a multivariate logistic regression model to control confounding variables. Birth in the season of maximum strength was significantly associated with a lower percentage (22.1%) of symptomatic cases (crude OR = 0.54, 95% confidence intervals = 0.33–0.87). Maximum participants (55.1%) had B blood group, and the percentage of symptomatic participants was the highest among them, being 22.9%. However, this association was insignificant in the multivariate logistic regression model. Conclusion: Study outcomes indicate that SOB has a significant effect on COVID-19 clinical outcomes.

The number of births varies by season. Research on birth seasonality has shown that women's season of birth somehow influences that of their children, but factors underlying the intergenerational transmission of birth seasonality remain unknown. With data from Spain and France, we analysed the possibility of transmission of birth season between generations, testing whether relatives tended to be born in the same season. Results indicated that there was an association—a similarity—between parents' and children's birth seasons, partially explaining the stability of seasonal patterns over time. This association also existed between parents' birth seasons. While parents' association is directly explained by an excess of marriages with spouses born in the same month, the overall association may be explained by two facts: different socio-demographic groups show differentiated birth patterns, and relatives share socio-demographic features. Birth season seems to be related to family characteristics, which should be controlled for when assessing birth-month effects on subsequent social/health outcomes. [ABSTRACT FROM AUTHOR]

Catatonia is a neuropsychiatric syndrome associated with both psychiatric disorders and medical conditions. Understanding of the pathophysiology of catatonia remains limited, and the role of the environment is unclear. Although seasonal variations have been shown for many of the disorders underlying catatonia, the seasonality of this syndrome has not yet been adequately explored. Clinical records were screened to identify a cohort of patients suffering from catatonia and a control group of psychiatric inpatients, from 2007 to 2016 in South London. In a cohort study, the seasonality of presentation was explored fitting regression models with harmonic terms, while the effect of season of birth on subsequent development of catatonia was analyzed using regression models for count data. In a case-control study, the association between month of birth and catatonia was studied fitting logistic regression models. In total, 955 patients suffering from catatonia and 23,409 controls were included. The number of catatonic episodes increased during winter, with a peak in February. Similarly, an increasing number of cases was observed during summer, with a second peak in August. However, no evidence for an association between month of birth and catatonia was found. The presentation of catatonia showed seasonal variation in accordance with patterns described for many of the disorders underlying catatonia, such as mood disorders and infections. We found no evidence for an association between season of birth and risk of developing catatonia. This may imply that recent triggers may underpin catatonia, rather than distal events. [ABSTRACT FROM AUTHOR]

In European populations, the birth season significantly correlates with many biological features. It is thus possible that the observed clinical effects of bone metabolism disorders are a partial consequence of bone mineral density (BMD), modified by the season of prenatal development (the birth season). The aim of this study was to evaluate the relationship between the birth season and BMD among Polish women in perimenopausal age. A total of 653 Polish women aged 50.0–59.9 years were included in the study. BMDs of lumbar vertebrae were measured by dual-energy x-ray absorptiometry. Statistical analyses were based on measured lumbar BMD values, age, and body mass index (BMI). The analysis of variance (ANOVA) was applied to evaluate the season-related differentiation of mineral density of lumbar vertebrae. BMDs of lumbar vertebrae negatively correlated with age and positively with BMI. We regressed BMD on age and BMI and used the residuals as a measure of age- and BMI-independent lumbar BMD values. The ANOVA results showed that women born in summer had significantly lower BMD of the L1 vertebra compared to those born in autumn, regardless of age and BMI. The results of our study indicate the need to extend the group of risk factors for osteoporosis in Central Europeans with the season of woman’s birth.

Background: The relationship between the season of birth, allergen sensitization, and allergic rhinitis have been inconsistent, and there are no studies that simultaneously consider vitamin D and allergen exposure. This study aimed to determine the associations between the season of birth, house dust mite (HDM) and Japanese cedar pollen (JCP) sensitization, and allergic rhinitis and pollinosis, while taking vitamin D levels and allergen exposure into account. Methods: This study included 4323 participants in the Sub-Cohort Study of the Japan Environment and Children's Study. A logistic regression model was used to analyze the association between the season of birth and sensitization to JCP or HDM (judged by specific immunoglobulin E) at age 2 and allergic rhinitis or pollinosis at age 3, adjusted for HDM or JCP exposure and vitamin D levels with potential confounders. Results: Participants born in spring or summer were more likely to have pollinosis than were those born in winter (adjusted odds ratio [aOR]: 2.08, 95% confidence interval [CI]: 1.13–3.82 for spring; aOR: 1.89, 95% CI: 1.03–3.47 for summer). Participants born in summer were more likely to have HDM sensitization than were those born in winter (Der p 1, aOR: 1.53, 95% CI: 1.10–2.15; Der f 1, aOR: 1.44, 95% CI: 1.03–2.01). Exposure to JCP and HDM were associated with pollinosis and HDM sensitization, respectively. Conclusions: Spring and summer births were associated with the development of pollinosis, and summer birth was associated with HDM sensitization, even when vitamin D and allergen exposure were considered. Further studies on mechanisms other than vitamin D and allergen exposure are required.

Developmental disability rates may vary by the season or month in which children are born. However, the seasonal mechanisms, such as climate, underlying these variations are unclear. Previous studies focused on high-latitude regions, leaving this climate hypothesis only partially tested. We analyzed rates of developmental disabilities in 3- to 5-year-old children from a tropical climate—South Florida—from 2004 to 2015 (N = 79,047) using a time-series analysis to identify peaks in diagnoses based on birth months. Children with speech impairments were more likely to be born in March, April, and September, a novel finding. Children with developmental delays were more likely to be born in September and October, consistent with studies in colder regions. In contrast to prior studies, there were no effects of birth month for language impairment or autism spectrum disorder. We highlight potential prenatal mechanisms that may contribute to the seasonal variations in some developmental disabilities. [ABSTRACT FROM AUTHOR]

Objective: An excess of schizophrenia births in the winter or spring is a well-known finding in Western studies; however, few studies from equatorial regions have been done. Our purpose is to investigate the seasonality of schizophrenia births in Thailand. Methods: This was a retrospective study in which patients with schizophrenia were identified from computerized records at Thammasat University Hospital. The Edwards test was used to detect any birth seasonality patterns among the patients with schizophrenia. Subsequently, the data were compared against the general population birth month data to examine potential seasonal effects using the Walter--Elwood seasonality test. Results: There are 949 patients with schizophrenia, with a mean age of 39.3 years. The results demonstrate no evidence of distinctive seasonality in birth patterns among patients with schizophrenia (P = .329). The overall monthly distribution of births did not differ between the general population and patients with schizophrenia (P = .365). Conclusion: In Thailand, a tropical country, there does not appear to be an effect of season of birth and the later development of schizophrenia. [ABSTRACT FROM AUTHOR]

The relationship between the season of birth, allergen sensitization, and allergic rhinitis have been inconsistent, and there are no studies that simultaneously consider vitamin D and allergen exposure. This study aimed to determine the associations between the season of birth, house dust mite (HDM) and Japanese cedar pollen (JCP) sensitization, and allergic rhinitis and pollinosis, while taking vitamin D levels and allergen exposure into account. This study included 4323 participants in the Sub-Cohort Study of the Japan Environment and Children's Study. A logistic regression model was used to analyze the association between the season of birth and sensitization to JCP or HDM (judged by specific immunoglobulin E) at age 2 and allergic rhinitis or pollinosis at age 3, adjusted for HDM or JCP exposure and vitamin D levels with potential confounders. Participants born in spring or summer were more likely to have pollinosis than were those born in winter (adjusted odds ratio [aOR]: 2.08, 95% confidence interval [CI]: 1.13–3.82 for spring; aOR: 1.89, 95% CI: 1.03–3.47 for summer). Participants born in summer were more likely to have HDM sensitization than were those born in winter (Der p 1, aOR: 1.53, 95% CI: 1.10–2.15; Der f 1, aOR: 1.44, 95% CI: 1.03–2.01). Exposure to JCP and HDM were associated with pollinosis and HDM sensitization, respectively. Spring and summer births were associated with the development of pollinosis, and summer birth was associated with HDM sensitization, even when vitamin D and allergen exposure were considered. Further studies on mechanisms other than vitamin D and allergen exposure are required. [ABSTRACT FROM AUTHOR]

In European populations, the birth season significantly correlates with many biological features. It is thus possible that the observed clinical effects of bone metabolism disorders are a partial consequence of bone mineral density (BMD), modified by the season of prenatal development (the birth season). The aim of this study was to evaluate the relationship between the birth season and BMD among Polish women in perimenopausal age. A total of 653 Polish women aged 50.0-59.9 years were included in the study. BMDs of lumbar vertebrae were measured by dual-energy x-ray absorptiometry. Statistical analyses were based on measured lumbar BMD values, age, and body mass index (BMI). The analysis of variance (ANOVA) was applied to evaluate the season-related differentiation of mineral density of lumbar vertebrae. BMDs of lumbar vertebrae negatively correlated with age and positively with BMI. We regressed BMD on age and BMI and used the residuals as a measure of age- and BMI-independent lumbar BMD values. The ANOVA results showed that women born in summer had significantly lower BMD of the L1 vertebra compared to those born in autumn, regardless of age and BMI. The results of our study indicate the need to extend the group of risk factors for osteoporosis in Central Europeans with the season of woman's birth. [ABSTRACT FROM AUTHOR]

Winter birth has been hypothesized to be associated with increased schizophrenia risk for nearly a century. Major hypotheses regarding the potential etiological risk factors for schizophrenia such as vitamin D deficiency and virus exposure in utero are predicated based on the observation that risk of schizophrenia is higher in children born in winter months. We conducted a systematic review and meta-analysis to examine the association between season and month of birth and risk of schizophrenia. We further investigated this relationship stratified by hemisphere. Forty-three studies spanning 30 countries and territories and 440,039 individuals with schizophrenia were included in this meta-analysis. Winter births were associated with a small but statistically significant increased risk of schizophrenia (OR 1.05, 95 % CI 1.03–1.07, p < 0.0001) and summer births were associated with a small but statistically significant decreased risk of schizophrenia (OR 0.96, 95 % CI 0.94–0.98, p = 0.0001). Stratified subgroup analysis demonstrated no significant difference between hemispheres in the risk of schizophrenia for either winter or summer births. Analysis using birth month data demonstrated a clear seasonal trend towards increased risk of schizophrenia being associated with winter birth months and decreased risk of schizophrenia in summer-to-fall months in the Northern but not Southern Hemisphere. These data suggest a small-but-substantial increased risk of schizophrenia in winter birth month. Further research needs to examine potential etiologic causes for this association. [ABSTRACT FROM AUTHOR]

Abstract Introduction Chronic malnutrition is highly prevalent in Sub-Saharan Africa and a severe public health problem in Ethiopia.At country level in the past three decades,the prevalence of stunting is above 40%.Different researchs and intervention were implemented in the past;but the progresss is non-remarkable.Despite; the effect of birth season on childhood chronic malnutrition was not studied yet in Ethiopia. Methods This research was extracted from the 2016 demographic health survey of Ethiopia. The data was collected based on national and international scientific protocols. A total of 645 enumeration areas were selected for the national survey.The surevey uses two stage stratified sampling technique to gather data from the sampling unit. After excluding non eligible children a total of 8855 participants were included for final analysis.Height and weight were measured based on the standards nutritional assessment procedure.SPSS version 20 was used to analyze the data.Descriptive statistics were used to present the data. Binary and multivariable logistic regression models were regressed to identify the potential predictors.A p-value of less than 0.05 with 95% CI were used to declare an association. Result The prevalence of stunting in Ethiopia was 38.7% (95% CI: 36.8, 40.6). Season of birth had a significant association with stunting. The odds of being stunted among children born in the spring season were decreased by 16% as compared to children born in the winter season. Conclusion Children born in the spring season were less likely to be stunted (the so called October effect). The clear scientific relation between the season of birth and child anthropometric indicator is not well understood. Nutritional interventions and policies are better to consider the birth season of the child.

This study examines the effects of birth month on reproduction and mating behavior using historical and contemporary census data from 1820 to 1970. The research examines the effect of birth month on the number of children for women and their male spouses, finding a monthly cycle for both men and women. In addition, the study examines whether birth month influences whether a person has ever been married. In support of previous research, we find clear birth month effects on the number of children for both women and their spouses, while the time series of ever being married shows a 60-month and a 10-year cycle, the latter possibly related to the solar cycle. Although the effects are small, both results, based on a large and representative dataset, indicate the importance of early life factors on mating and reproduction. • We examined the effects of month and year of birth using two large US Census data sets. • A woman's month of birth, as well as the month of birth of her spouses, influences the number of children a woman has, as well as her mating success. • The time series of birth year shows a periodicity in ever being married of 10 years for men, presumably indicating solar cycle effects on mating. [ABSTRACT FROM AUTHOR]

Psychiatric disorders share an excess of seasonal birth in winter and spring, suggesting an increase of neurodevelopmental risks. Evidence suggests season of birth can serve as a proxy of harmful environmental factors. Given that prenatal exposure of these factors may trigger pathologic processes in the neurodevelopment, they may consequently lead to brain volume alterations. Here we tested the effects of season of birth on gray matter volume in a transdiagnostic sample of patients with schizophrenia and depression compared to healthy controls (n = 192). We found a significant effect of season of birth on gray matter volume with reduced right hippocampal volume in summer-born compared to winter-born patients with depression. In addition, the volume of the right hippocampus was reduced independent from season of birth in schizophrenia. Our results support the potential impact of season of birth on hippocampal volume in depression. [ABSTRACT FROM AUTHOR]

Perinatal light exposure predisposes towards health and behaviour in adulthood. Season of birth is associated with psychiatric, allergic, cardiovascular and metabolic problems. It has been proposed that early-life environmental light disrupts the development of biological rhythms which, in turn, influence later-life health. However, the mechanisms linking perinatal seasonal light to later-life biological rhythm and health in humans are unknown. In this study, we investigated the association between season of birth and epigenome-wide DNA methylation of two postmortem human brain regions (16 hypothalamus, 14 temporal cortex). We did not find statistically significant differences at the whole epigenome level, either because we lacked statistical power or that no association exists. However, when we examined 24 CpG sites that had the highest significance or differential methylation, we identified regions which may be associated with circadian rhythm entrainment, cholinergic neurotransmission and neural development. Amongst methylation of the core clock genes, we identified that hypothalamus Neuronal PAS Domain Protein 2 (NPAS2) gene has hypermethylated regions in long photoperiod-born individuals. In addition, we found nominal associations between season of birth and genes linked to chronotype and narcolepsy. Season of birth-related brain DNA methylation profile was different than a previously reported blood methylation profile, suggesting a tissue-specific mechanism of perinatal light programming. Overall, we are the first to analyse the relationship between season of birth and human brain DNA methylation. Further studies with larger sample sizes are required to confirm an imprinting effect of perinatal light on the circadian clock. [ABSTRACT FROM AUTHOR]

Introduction: Chronic malnutrition is highly prevalent in Sub-Saharan Africa and a severe public health problem in Ethiopia.At country level in the past three decades,the prevalence of stunting is above 40%.Different researchs and intervention were implemented in the past;but the progresss is non-remarkable.Despite; the effect of birth season on childhood chronic malnutrition was not studied yet in Ethiopia.Methods: This research was extracted from the 2016 demographic health survey of Ethiopia. The data was collected based on national and international scientific protocols. A total of 645 enumeration areas were selected for the national survey.The surevey uses two stage stratified sampling technique to gather data from the sampling unit. After excluding non eligible children a total of 8855 participants were included for final analysis.Height and weight were measured based on the standards nutritional assessment procedure.SPSS version 20 was used to analyze the data.Descriptive statistics were used to present the data. Binary and multivariable logistic regression models were regressed to identify the potential predictors.A p-value of less than 0.05 with 95% CI were used to declare an association.Result: The prevalence of stunting in Ethiopia was 38.7% (95% CI: 36.8, 40.6). Season of birth had a significant association with stunting. The odds of being stunted among children born in the spring season were decreased by 16% as compared to children born in the winter season.Conclusion: Children born in the spring season were less likely to be stunted (the so called October effect). The clear scientific relation between the season of birth and child anthropometric indicator is not well understood. Nutritional interventions and policies are better to consider the birth season of the child. [ABSTRACT FROM AUTHOR]

Various environmental exposures have been associated with psychosis spectrum disorder. However, the role of gender in this association has received little attention. Therefore, we conducted a systematic review to evaluate gender-related differences and identified 47 research articles investigating the associations of psychosis with childhood adversity, substance use, urbanicity, migration, season of birth, and obstetric complication in the PubMed database. The findings suggest that childhood abuse may be more strongly associated with a risk to develop psychosis and an earlier age at onset of illness in women than in men. Furthermore, childhood adversity has been associated with the severity of different symptom dimensions in men and women. Growing up in an urban environment and immigration are more strongly associated with psychosis risk in men than in women. Despite a higher prevalence of substance abuse comorbidity in men diagnosed with psychotic disorders, it appears that the association between substance use and psychosis risk may be stronger in women. These findings should be evaluated with caution considering several methodological limitations, limited number of studies, and lack of consistency across results. Overall, although further investigation is needed, our review shows that gender-related differences in the associations of environmental exposures with psychosis expression may exist. [ABSTRACT FROM AUTHOR]

Psychiatric disorders share an excess of seasonal birth in winter and spring, suggesting an increase of neurodevelopmental risks. Evidence suggests season of birth can serve as a proxy of harmful environmental factors. Given that prenatal exposure of these factors may trigger pathologic processes in the neurodevelopment, they may consequently lead to brain volume alterations. Here we tested the effects of season of birth on gray matter volume in a transdiagnostic sample of patients with schizophrenia and depression compared to healthy controls (n = 192). We found a significant effect of season of birth on gray matter volume with reduced right hippocampal volume in summer-born compared to winter-born patients with depression. In addition, the volume of the right hippocampus was reduced independent from season of birth in schizophrenia. Our results support the potential impact of season of birth on hippocampal volume in depression.

Objective: To examine whether perinatal factors are associated with low-grade inflammation measured by high-sensitivity C-reactive protein levels during adolescence. Methods: Nested case-control study of 125 teenagers who were born by Cesarean delivery and had high-sensitivity C-reactive protein levels determined at 15-17 years. Data on obstetric and perinatal factors were recorded prospectively at the time of their birth. Results: Median values of high-sensitivity C-reactive protein were significantly higher in teenagers, who were born as large for gestational age or with maternal diabetes compared to others (2.54 vs 0.34 mg/L; p < 0.024), and born during spring or summer compared to those born during winter or autumn (0.48 vs 0.27 mg/L; p < 0.023). No other perinatal associations were detected (for ex. such as electivity of operation, onset of labor, rupture of fetal membranes, cervical dilatation at delivery, gestational age, Apgar scores at 5 min, umbilical blood pH value, administration of neonatal antibiotics or need of neonatal intensive care treatment) in CRP levels. Further, teenagers with current body mass index in the highest tertile, regular medication for chronic disease and girls using oral contraceptives had significantly higher high-sensitivity C-reactive protein levels than others. Conclusion: Prenatal exposures such as maternal metabolic environment and seasonality may have longterm effects on the low-grade inflammation and later cardiometabolic risks. Seasonality might be partly explained by maternal vitamin D levels during pregnancy, and thus future efforts are warranted to ensure sufficient vitamin D availability during pregnancy. Surprisingly, no other significant associations were detected between perinatal characteristics and high-sensitivity C-reactive protein levels. [ABSTRACT FROM AUTHOR]

Abstract Background Several epidemiological studies have examined the possibility of a relationship between season of birth and atopic dermatitis (AD) and food allergy (FA), yet their results are contradictory. We investigated the association between season of birth and risk of AD and FA in Japanese infants. Methods Study subjects were 612 newborn infants born at a single obstetric/pediatric clinic without perinatal diseases. Season of birth was classified as spring (March–May), summer (June–August), autumn (September–November) or winter (December–February). AD was diagnosed according to the United Kingdom Working Party’s criteria. FA was defined as present if there was a history of immediate allergic symptoms within 2 h after ingestion of a food. Specific IgE to the corresponding food was also assessed to support the diagnosis. We assessed the association between season of birth and risk of AD and FA using Cox proportional hazard models. Results We identified a total of 365 cases of AD occurring during 3659 person-months of follow-up. Compared with summer birth, autumn, winter, and spring birth were significantly positively associated with the risk of AD: adjusted HRs (95% CIs) were 2.67 (1.96–3.63), 1.42 (1.03–1.95), and 1.43 (1.04–1.98), respectively. We identified a total of 23 cases of physician-diagnosed FA occurring during 6815 person-months of follow-up. Conclusions Being born in the summer is associated with a lower risk of AD compared to other seasons of birth. The low incidence of FA in our cohort group made it difficult to establish a valid association between FA and season of birth as the statistical power was low.

Schizophrenia is a severe mental disorder characterized by positive and negative symptoms. The negative symptoms are highly relevant to the disease course and outcome. Because negative symptoms show considerable heterogeneity, there is substantial interest in elucidating the negative symptom domains that are characteristic of patient subgroups. It has been proposed that patients with schizophrenia should be classified into deficit and non-deficit groups based on the severity of their negative symptoms. Another method suggested the assessment of the factor structure of negative symptoms to understand its mechanisms. Factor analysis of the different negative symptom rating scales reveals two distinct negative symptom subdomains: diminished expression (DE) and avolition/apathy (AA). These characteristics suggest different pathophysiological mechanisms for the development of AA and DE. We present a large dataset of negative symptom factors calculated for 3006 patients with schizophrenia in the Russian population. Sex, age, age at disease onset and data of birth, including season of birth (SOB), family history of schizophrenia are presented. Negative symptoms were assessed with the Positive and Negative Syndromes Scale (PANSS). We calculated negative symptoms factors as suggested by Liemburg et al. (2013). The data will be useful in assessing the impact of such factors as sex, season of birth (SOB) and family history on the scores of negative symptoms subdomains; such data can help us to better understand the heterogeneity of the negative symptoms of schizophrenia.

Objective: Winter birth has consistently been identified as a risk factor for schizophrenia. This study aimed to determine whether individuals born during this season are also at higher risk for early psychosis and whether this is associated with distinct functional and clinical outcomes., Methods: We conducted a prospective study on 222 patients during their early phase of psychosis in Switzerland, nested in the Treatment and Early Intervention in Psychosis (TIPP) cohort. We compared the birth trimesters of these patients with those of the general Swiss population. Additionally, we evaluated the Global Assessment of Functioning scale (GAF) and the Positive and Negative Syndrome Scale (PANSS) scores among patients born in winter (January to March) versus those born during the rest of the year during a three-year follow-up period., Results: A significantly higher proportion of patients experiencing early psychosis were born in winter compared to the general Swiss population. Patients born in winter had significantly lower GAF scores at 6 months, 24 months, and 36 months of follow-up, compared to patients born during the rest of the year. They also manifested fewer positive symptoms, as indicated by the PANSS positive subscale., Conclusion: Birth in winter appears to be associated with a lower functional outcome and potentially distinct symptomatology in the early phase of psychosis., Competing Interests: Declaration of competing interest None., (Copyright © 2024 The Authors. Published by Elsevier B.V. All rights reserved.)

The data pertaining to 6785 lambs born to a total of 459 sires spanning over a period of 47 years (1974 to 2020) were collected from Central Sheep and Wool Research Institute, Bikaner, Rajasthan for a comprehensive evaluation of the growth performance of Chokla sheep under semi arid conditions to assess the random effect of sire and fixed effects of period, season, sex and weight of dam at lambing on its performance. The overall least-squares means of body weight at different age were estimated as 2.89±0.008, 13.64±.051, 19.32±.083, 21.30±.092 and 24.36±.099 kg for birth, 3, 6, 9, and 12 months of age, respectively. The effect of sire, period of lambing and sex of lamb was found highly significant (P<0.01) on all the studied traits. Males were heavier than females in all age groups. The effect of season of lambing was reported highly significant (P<0.01) on all growth traits except nine month body weight. The regression of these traits on weight of ewe at lambing was significant on all body weight traits. [ABSTRACT FROM AUTHOR]

In vivarium conditions, the growth and attainment of puberty of the offspring of constant parental pairs have been studied in relation to the calendar month of birth (May or September) and the characteristics of the family environment (identification number of the parental pair, body mass of parents, litter size, and sex ratio at birth). The results of multiple regression analysis show that intra-annual changes in the duration of the light period play the key role in the regulation of growth and reproductive development in the water vole. At the end of the winter period, the onset of puberty of individuals of the spring cohort, based on the cellular composition of vagina smears in females, the testosterone content in the blood of males, and their anogenital distance, occurs faster than in individuals of the autumn cohort. Body weight is shown to be more important to the onset of reproductive activity than age, because individuals of the spring and autumn cohorts that reached puberty did not differ in body weight. The growth dynamics are significantly affected by the identification number of parents. The age of puberty of water voles decreases with an increasing body mass of the mother and the proportion of males in the litter at birth. [ABSTRACT FROM AUTHOR]

In many human populations, especially those living in regions with pronounced climatic differences between seasons, the most sensitive (prenatal and neonatal) developmental stages occur in contrasting conditions depending on the season of conception. The difference in prenatal and postnatal environments may be a factor significantly affecting human development and risk for later life chronic diseases. Factors potentially contributing to this kind of developmental programming include nutrition, outdoor temperature, infectious exposures, duration of sunlight, vitamin D synthesis, etc. Month of birth is commonly used as a proxy for exposures which vary seasonally around the perinatal period. Season-of-birth patterns have been identified for many chronic health outcomes. In this review, the research evidence for the seasonality of birth in adult-life disorders is provided and potential mechanisms underlying the phenomenon of early life seasonal programming of chronic disease and longevity are discussed. [ABSTRACT FROM AUTHOR]

Background: Several early-life factors have been associated with higher risk of developing dementia. It is unclear whether season of birth (SOB) can affect cognitive aging in older adults or not.Objective: We aimed to study the association of SOB with the level of cognitive performance as well as with the rate of cognitive decline.Methods: We studied 70,203 individuals who participated in the Survey of Health, Aging and Retirement in Europe. Cognition was measured with tests on verbal fluency and immediate and delayed recall. We assessed the association of SOB with the level of cognitive performance using multiple linear regression and with the rate of cognitive decline using linear mixed-effects models.Results: When compared to individuals born in winter and adjusted for sociodemographic and health-related characteristics, being born in summer was associated with a higher level of delayed recall (B 0.05; 95%CI 0.01 to 0.09) and verbal fluency (B 0.15; 95%CI 0.00 to 0.29) and being born in fall with a higher level of immediate recall (B 0.04; 95%CI 0.01 to 0.08) and verbal fluency (B 0.15; 95%CI 0.01 to 0.29). Individuals born in summer had a higher yearly decline in delayed recall (B -0.005; 95%CI -0.009 to 0.000), while the scores in delayed recall in participants born in spring showed an inverse trend (B 0.005; 95%CI 0.000 to 0.010).Conclusion: Individuals born in winter seem to carry a life-long disadvantage in a lower level of cognitive performance; however, being born in winter does not seem to affect the rate of cognitive decline. [ABSTRACT FROM AUTHOR]

The month and season of birth have been found to be associated with cardiovascular mortality, but the mechanisms are not fully explained. We planned a study to examine the relationship between SYNTAX score, which shows the severity of coronary artery disease (CAD), and the month and season of birth. 346 patients who underwent coronary angiography between October 2019 and January 2020 were evaluated. Birth month, birth seasons and demographic data of patients were recorded. SYNTAX scores were calculated from patients' coronary angiographies. Patients with birth months September, October, November and December had the lowest SYNTAX score (6.42±8.78, 5.61±8.42, 8.93±12.07, 6.35±8.02, respectively). SYNTAX score of patients who were born in October was statistically significantly lower compared to other months (p= 0.005). Coronary artery disease was highest in those born in June (%81.2) and July (%82.6). The presence of CAD in patients born in fall was 46.5% (p <0.001) and the mean of SYNTAX was 7.08 ± 10.03, which was significantly lower compared to other seasons (p = 0.003). There was a correlation between the month and season of birth and the severity of CAD. Being born in the fall season, and especially in October, can be a protective factor for CAD. Compared to other months, being born in June and July is more risky for CAD. The correlation between the month and season of birth and psychiatric diseases, and also seasonal variation in maternal vitamin D exposure may be the main trigger of CAD. [ABSTRACT FROM AUTHOR]

Relative age effects (RAE) describe the unintended side effect of annual age grouping such that athletes born close to a specific cutoff date are more likely to be associated with attaining higher performance status than athletes born later. One factor suggested to override the RAE is handedness. Given the left-handers' rarity and their proposed performance advantage in interactive sports, left-handedness may be associated with a lower likelihood of suffering from selection inequalities like RAE in those sports compared with right-handedness. Here, in a two-study approach, we tested that hypothesis by examining male and female athletes from various interactive individual sports sampled over a 10-year period from 2007 to 2016. Study 1 investigated distributions of birth and handedness of senior athletes listed in the top 200 of year-end world rankings in table tennis, tennis, squash, and fencing (épée, foil, and saber). Study 2 followed a similar design but focused on junior athletes in the fencing disciplines and tennis. Unlike the above prediction, in both studies, birth distribution was not found to be reliably associated with handedness in any of the sports or disciplines considered. Left-handers were consistently overrepresented in épée, foil, and table tennis, occasionally in saber and tennis, and not at all in squash. Birth frequencies decreased from quartile Q1 (January to March) to Q4 in almost any sporting domain at the junior level, whereas such trend was rarely found at the senior level. In conclusion, while providing novel insight on the role handedness may play at the junior level, our findings do not support the hypothesis that left-handedness helps override birth-related inequalities in high sporting achievement in elite interactive individual sports.

The relative age effect (RAE) is associated with (dis)advantages in competitive sports. While the RAE in elite male soccer reveals a skewed birthdate distribution in relation to a certain cut-off date, research of RAE in elite female soccer is affected by small number of samples and conflicting results. The purpose of this study was to investigate the RAE in elite adult German soccer regarding gender and competition level. The sample comprised 680 female and 1,083 male players of the two top German leagues during the 2019/20 season and German national teams (A-Team to Under 19). Differences between the observed and expected birthdate distributions were analyzed using chi-square statistics and effect sizes followed by calculating odds ratios. Results showed a statistically significant RAE with small effect size across all players included for both genders (female players: P < 0.001, W = 0.16, male players: P < 0.001, W = 0.23). The identified RAE was based on an over-representation of players born at the beginning of the year. According to gender and competition level, RAEs were more pronounced in German male soccer. While significant RAEs were found among males in the first two leagues (first league: P < 0.001, W = 0.19, second league: P < 0.001, W = 0.26), the RAE of females was more pronounced in the second league (first league: P = 0.080, W = 0.16, second league: P = 0.002, W = 0.20). The analysis of RAE regarding the national teams revealed a statistically significant RAE with large effect size for only the youngest investigated age group of male players (Under 19: P = 0.022, W = 0.52). Our data show an RAE in female and male German adult soccer, which could be accompanied by a loss of valuable elite players during the youth phase of the career. Consequently, the pool of talented players at the adult level would be limited.

By modulating the immunological relationship between the mother and the fetus, as well as interacting with various environmental factors, HLA-G plays an important role in the development of the brain of the embryo and is therefore considered as one of the risk factors for schizophrenia. We studied the relationship of INDEL HLA-G gene polymorphism with schizophrenia and its clinical features, taking into account the season of birth. The sample of patients included 1171 people with schizophrenia; the control group consisted of 575 mentally healthy people without a family history of mental disorders. The interaction of INDEL polymorphism and the season of birth was revealed. It has been found that, in men with the D/D genotype born in the summer, the risk of schizophrenia increases (OR = 1.95, 95% CI: 1.01–3.78). Our analysis has shown that the INDEL polymorphism does not interact with the season of birth as an environmental factor and does not affect the clinical features of schizophrenia: the age of onset of the disease and the severity of symptoms. [ABSTRACT FROM AUTHOR]

The relative age effect (RAE) is associated with (dis)advantages in competitive sports. While the RAE in elite male soccer reveals a skewed birthdate distribution in relation to a certain cut-off date, research of RAE in elite female soccer is affected by small number of samples and conflicting results. The purpose of this study was to investigate the RAE in elite adult German soccer regarding gender and competition level. The sample comprised 680 female and 1,083 male players of the two top German leagues during the 2019/20 season and German national teams (A-Team to Under 19). Differences between the observed and expected birthdate distributions were analyzed using chi-square statistics and effect sizes followed by calculating odds ratios. Results showed a statistically significant RAE with small effect size across all players included for both genders (female players: P < 0.001, W = 0.16, male players: P < 0.001, W = 0.23). The identified RAE was based on an over-representation of players born at the beginning of the year. According to gender and competition level, RAEs were more pronounced in German male soccer. While significant RAEs were found among males in the first two leagues (first league: P < 0.001, W = 0.19, second league: P < 0.001, W = 0.26), the RAE of females was more pronounced in the second league (first league: P = 0.080, W = 0.16, second league: P = 0.002, W = 0.20). The analysis of RAE regarding the national teams revealed a statistically significant RAE with large effect size for only the youngest investigated age group of male players (Under 19: P = 0.022, W = 0.52). Our data show an RAE in female and male German adult soccer, which could be accompanied by a loss of valuable elite players during the youth phase of the career. Consequently, the pool of talented players at the adult level would be limited. [ABSTRACT FROM AUTHOR]

Data on 26 bulls of Kankrej cattle (birth date from 2006 to 2017) inducted at a semen station from 2010 to 2020 were analyzed to study the effects of season and year of birth on age, body weight and scrotal circumference of bull at first semen collection. The overall leastsquares means for age, body weight, and scrotal circumference of bulls at first semen collection were 1122.36 ± 86.9 days, 537.69 ± 10.51 kg and 30.86 ± 1.60 cm. Non-genetic factors like season and year of birth did not contribute significantly (p>0.05) to these parameters' variations. Results of the study revealed well adaptation of Kankrej cattle breed to seasonal changes and farm management took care of yearly variation in such a way that age, body weight and scrotal circumference of Kankrej bulls at first semen collection did not vary significantly. [ABSTRACT FROM AUTHOR]

Season of birth is considered to be associated with multiple sclerosis (MS) although some findings opposing to this assumption raise doubts about the seasonality pattern in MS births. The present work synthesizes the evidence of previous published studies aiming at examining whether the month of birth is associated with a higher number of MS births. Pubmed and Scopus were systematically searched and a multivariate meta-analysis of case–control studies was conducted. Data of healthy controls births were retrieved from census reports when not included in the studies. For comparisons, October was set as a reference month and autumn (September–October–November) as a reference season. The meta-analysis included studies that provided the number of MS births for each month or season. Twenty-two eligible studies were included in the meta-analysis involving twenty-four different populations and overall 145,672 MS patients and 75,169,550 healthy controls. The multivariate analysis supports that MS births in spring are higher compared to autumn [odds ratio (OR) 1.14, 95% confidence interval (CI) 1.04, 1.24]. Univariate analyses confirm the same for April (OR 1.12, 95% CI 1.05, 1.21), March (OR 1.05, 95% CI 1.00, 1.11) and May (OR 1.07, 95% CI 1.00, 1.14). A reduction of MS births was found in November (OR 0.96, 95% CI 0.93, 0.99). The month and the season of birth are significantly associated with MS births. [ABSTRACT FROM AUTHOR]

Season of birth, a surrogate of seasonal variation of environmental exposures, has been associated with increased risk of several cancers. In the context of a Southern‐Eastern Europe (SEE) consortium, we explored the potential association of birth seasonality with childhood (0–14 years) central nervous system (CNS) tumors. Primary CNS tumor cases (n = 6,014) were retrieved from 16 population‐based SEE registries (1983–2015). Poisson regression and meta‐analyses on birth season were performed in nine countries with available live birth data (n = 4,987). Subanalyses by birth month, age, gender and principal histology were also conducted. Children born during winter were at a slightly increased risk of developing a CNS tumor overall [incidence rate ratio (IRR): 1.06, 95% confidence intervals (CI): 0.99–1.14], and of embryonal histology specifically (IRR: 1.13, 95% CI: 1.01–1.27). The winter peak of embryonal tumors was higher among boys (IRR: 1.24, 95% CI: 1.05–1.46), especially during the first 4 years of life (IRR: 1.33, 95% CI: 1.03–1.71). In contrast, boys <5 years born during summer seemed to be at a lower risk of embryonal tumors (IRR: 0.73, 95% CI: 0.54–0.99). A clustering of astrocytomas was also found among girls (0–14 years) born during spring (IRR: 1.23, 95% CI: 1.03–1.46). Although the present exploratory results are by no means definitive, they provide some indications for age‐, gender‐ and histology‐related seasonal variations of CNS tumors. Expansion of registration and linkage with cytogenetic reports could refine if birth seasonality is causally associated with CNS tumors and shed light into the complex pathophysiology of this lethal disease. What's new? Does the risk of developing childhood central nervous system (CNS) tumors depend on the season of birth? The answer is yes. Age‐, gender‐ and histology‐related seasonal variations of CNS tumors were found, namely a winter birth clustering among boys with embryonal tumors, mostly marked in the course of the first four years of life. The authors recommend an expansion of cancer registration and linkage with cytogenetics that could refine if birth seasonality is a potential indicator of early‐life exposures associated with CNS tumor risk. [ABSTRACT FROM AUTHOR]

Background: Several epidemiological studies have examined the possibility of a relationship between season of birth and atopic dermatitis (AD) and food allergy (FA), yet their results are contradictory. We investigated the association between season of birth and risk of AD and FA in Japanese infants. Methods: Study subjects were 612 newborn infants born at a single obstetric/pediatric clinic without perinatal diseases. Season of birth was classified as spring (March–May), summer (June–August), autumn (September–November) or winter (December–February). AD was diagnosed according to the United Kingdom Working Party's criteria. FA was defined as present if there was a history of immediate allergic symptoms within 2 h after ingestion of a food. Specific IgE to the corresponding food was also assessed to support the diagnosis. We assessed the association between season of birth and risk of AD and FA using Cox proportional hazard models. Results: We identified a total of 365 cases of AD occurring during 3659 person-months of follow-up. Compared with summer birth, autumn, winter, and spring birth were significantly positively associated with the risk of AD: adjusted HRs (95% CIs) were 2.67 (1.96–3.63), 1.42 (1.03–1.95), and 1.43 (1.04–1.98), respectively. We identified a total of 23 cases of physician-diagnosed FA occurring during 6815 person-months of follow-up. Conclusions: Being born in the summer is associated with a lower risk of AD compared to other seasons of birth. The low incidence of FA in our cohort group made it difficult to establish a valid association between FA and season of birth as the statistical power was low. [ABSTRACT FROM AUTHOR]

Objective: Pathogenic airway bacteria colonizing the neonatal airway increase the risk of childhood asthma, but little is known about the determinants of the establishment and dynamics of the airway microbiota in early life. We studied associations between perinatal risk factors and bacterial richness of the commensal milieu in the neonatal respiratory tract. Methods: Three hundred and twenty-eight children from the Copenhagen Prospective Studies on Asthma in the Childhood2000 (COPSAC2000) at-risk birth cohort were included in this study. The bacterial richness in each of the nasopharynxes of the 1-month old, asymptomatic neonates was analyzed by use of a culture-independent technique (T-RFLP). Information on perinatal risk factors included predisposition to asthma, allergy and eczema; social status of family; maternal exposures during pregnancy; mode of delivery; and postnatal exposures. The risk factor analysis was done by conventional statistics and partial least square discriminant analysis (PLSDA). Results: The nasopharyngeal bacterial community at 1-month displayed an average of 35 (IQR: 14-55, range 1-161) phylogenetically different bacteria groups. Season of birth was associated with nasopharyngeal bacterial richness at 1-month of age with a higher bacterial richness (p = 0.003) and more abundant specific bacterial profiles representing Gram-negative alpha-proteobacteria and Gram-positive Bacilli in the nasopharynx of summer-born children. Conclusion: Early postnatal bacterial colonization of the upper airways is significantly affected by birth season, emphasizing a future focus on the seasonality aspect in modelling the impact of early dynamic changes in airway bacterial communities in relation to later disease development. [ABSTRACT FROM AUTHOR]

According to "the energy balance mechanism" theory, female ovarian function is strongly hindered by even a modest negative energy balance (the difference between calorie intake and calorie consumption). Agriculture-based economies were characterized by periods of extremely intense workload (especially in summer when grain was harvested) without sufficient nutrition. We analyze the role of the intensity of agricultural workload (proxied by marriage seasonality) on seasonal oscillations in births. Using data at the regional level, from Italian Unification to the eve of the World War I, we find some empirical support for the energy balance theory. In particular, we find the strength of the relationship between marriage seasonality and birth seasonality to be lower in the more developed Northern part of the Italian country, in which some signs of industrialization had already been present. [ABSTRACT FROM AUTHOR]

Background: Despite much evidence that season of birth (SOB) my influence the vulnerability to psychiatric disorders, divergence has been reported, in particular between populations born in the northern and southern hemispheres. We analyzed the potential modified risk by SOB to psychiatric disorder or drug addiction comorbidity in a population born in the Triângulo Mineiro region, a southern hemisphere Köppen tropical savanna region in Brazil. Method: We accessed the records of 98,457 of patients and healthy controls of the National Datacenter of Medical Promptuary to evaluate the influence of SOB as a modifying factor on the occurrence of mental disorders and drug abuse conditions among individuals born from the year 2000 to 2016. Results: The data revealed significant modification of the relative incidence of major depressive disorder (MDD) (F11, 72 = 2.898; p = 0.003; eta-squared, ES = 0.313; ⍺ = 0.97), anxiety-related disorder (ARD) (F11, 81 =2.389; p = 0.013; ES = 0.241; ⍺ = 0.932), and schizophrenia (SZ) (F11, 83 = 2.764; p = 0.005; ES = 0.303; α = 0.963), while there was no increase in the number of healthy controls born in any month of the year (F11, 71 = 1.469; p = 0.163). Post hoc analyses indicated a significant higher vulnerability to MDD or ARD if the patient was born in August, or October to December, respectively. A relative increase in the incidence of SZ was also observed in patients born from August to October, compared to patients born from November to January. Conclusions: SOB may influence the risk for psychiatric disorders in the TMR population. Regional particularities associated with the climatic regime may account for the apparent divergence between studies. [ABSTRACT FROM AUTHOR]

Background: The fetal origins hypothesis have associated early life exposures with the development of adverse health outcomes in adulthood. Season of birth has been shown to be associated with overall and cardiovascular mortality. Methods: We performed a retrospective database study to explore the association between season of birth and mortality in patients with atrial fibrillation. Results: A total of 8962 patients with AF were identified in the database with 1253 deaths recorded. AF patients born in spring and summer had a higher mortality rate when compared to those born in autumn and winter (hazard ratio (HR) 1.13, 95% confidence interval (CI) 1.01–1.26, p = 0.03). This effect was consistent in the male subgroup (HR 1.25, 95% CI 1.03–1.51, p = 0.02 for males born in spring; HR 1.24, 95% CI 1.03–1.51, p = 0.03 for males born in summer when compared to winter as the reference) but not in females (HR 1.02, 95% CI 0.79–1.31, p = 0.88 for females born in spring; HR 1.11, 95% CI 0.87–1.42, p = 0.39 for females born in summer when compared to winter as the reference). Results persisted after adjustment for baseline characteristics and clinical risk profile. A similar pattern was observed with cardiovascular mortality. Conclusion: Birth in spring or summer is associated with a higher risk of cardiovascular mortality in male AF patients, but not in females. This could be related to the underlying differences in rates of major adverse clinical events between genders. Further studies should aim at clarifying the mechanisms behind this association, which may help us understand the higher level of risk in female patients with AF.

Data of 544 kids born during 2000 to 2017 maintained at the institute were analysed to study the factors affecting the sex ratio and mortality rate in Andaman local goat under semi-intensive system. Frequency and percentage of kidding and mortality rate of kids under different years (2000 to 2017), months (January to December) and seasons (wet and dry season) were calculated. Relative female ratio (RFR) as well as secondary sex ratio (SSR) was also calculated to assess the sex ratio of the kids in the organised goat farm. Result revealed that birth rate, sex ratio, mortality rate, kidding pattern such as singles, twins and triplets varied with months, seasons and years. Birth rate, mortality rate, single and twine birth were higher in monsoon than dry season whereas triplets, quadruplet and sex ratio were higher in dry season than monsoon. In conclusion, sex ratio, birth rate and mortality rate differed significantly between months/seasons/years and wet season/months were most conducive for breeding of goat under semi-intensive system in Andaman and Nicobar Islands.

Seasonal patterns of neonatal mortality and stillbirths have been found around the world. However, little is known about the association between season of birth and infant mortality of pre-industrial societies in a subarctic environment. In this study, we compared how season of birth affected the neonatal and stillbirth risk among the Sami and non-Sami in Swedish Sápmi during the nineteenth century. Using digitised parish records from the Demographic Data Base at Umeå University, we applied logistic regression models for estimating the association of season of birth with stillbirths and neonatal mortality, respectively. Higher neonatal mortality was found among the winter- and autumn-born Sami, compared to summer-born infants. Stillbirth risk was higher during autumn compared to summer among the Sami, whereas we found no seasonal differences in mortality among the non-Sami population. We relate the higher neonatal mortality risk among winter-born Sami to differences in seasonality of living conditions associated with reindeer herding.

Background: There is strong evidence that people born in winter and in spring have a small increased risk of schizophrenia. As this 'season of birth' effect underpins some of the most influential hypotheses concerning potentially modifiable risk exposures, it is important to exclude other possible explanations for the phenomenon. Methods: Here we sought to determine whether the season of birth effect reflects gene-environment confounding rather than a pathogenic process indexing environmental exposure. We directly measured, in 136 538 participants from the UK Biobank (UKBB), the burdens of common schizophrenia risk alleles and of copy number variants known to increase the risk for the disorder, and tested whether these were correlated with a season of birth. Results: Neither genetic measure was associated with season or month of birth within the UKBB sample. Conclusions: As our study was highly powered to detect small effects, we conclude that the season of birth effect in schizophrenia reflects a true pathogenic effect of environmental exposure. [ABSTRACT FROM AUTHOR]

Evening-oriented sleep timing preferences have been associated with risk of diabetes, cardiovascular diseases, obesity, psychiatric disorders, and increased mortality. This research aims to explore the relationship between diurnal preferences (chronotype), daily habits, metabolic health, and mortality, using longitudinal data from The University of Manchester Longitudinal Study of Cognition in Normal Healthy Old Age (6375 participants at inception, recruited in the North of England) with a long follow-up period (up to 35.5 years). Mixed models were used to investigate the influence of aging, socio-demographic, and seasonal factors on sleep timing. Results show that sleep timing shifted towards earlier time with aging. Test seasons influence chronotype of older adults but working schedules challenge seasonality of sleep timing. Moreover, the season of birth may set chronotype in adulthood. Individual chronotype trajectories were clustered using latent class analysis and analyzed against metabolic health and mortality. We observed a higher risk of hypertension in the evening-type cluster compared to morning-type individuals (Odds ratio = 1.88, 95%CI = 1.02/3.47, p =.04). Evening-type cluster was also associated with traits related to lower health such as reduced sport participation, increased risk of depression and psychoticism personality, late eating, and increased smoking and alcohol usage. Finally, Cox regression of proportional hazards was used to study the effects of chronotype on longevity after adjusting for sleep duration, age, gender, smoking, alcohol usage, general health, and social class. The survival analysis (82.6% censored by death) revealed that evening-type chronotype increased the likelihood of mortality (Hazard ratio = 1.15, 95%CI = 1.04/1.26, p =.005). Taken together, chronotype is influenced by aging and seasonal effects. Evening-type preference may have detrimental outcomes for human well-being and longevity. [ABSTRACT FROM AUTHOR]