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ObjectivePeople with diabetes are more likely to have obstructive sleep apnea, but there are few studies examining sleep architecture in people with diabetes, especially in the absence of moderate-severe sleep apnea. Therefore, we compared sleep architecture among people with diabetes, prediabetes or neither condition, whilst excluding people with moderate-severe sleep apnea.Research design and methodsThis sample is from the Baependi Heart Study, a prospective, family-based cohort of adults in Brazil. 1,074 participants underwent at-home polysomnography (PSG). Diabetes was defined as 1) FBG>125 OR 2) HbA1c>6.4 OR 3) taking diabetic medication, and prediabetes was defined as 1) [(5.7≤HbA1c≤6.4) OR (100≤FBG≤125)] AND 2) not taking diabetic medication. We excluded participants that had an apnea-hypopnea index (AHI)>30 from these analyses to reduce confounding due to severe sleep apnea. We compared sleep stages among the 3 groups.ResultsCompared to those without diabetes, we found shorter REM duration for participants with diabetes (−6.7min, 95%CI -13.2, -0.1) or prediabetes (−5.9min, 95%CI -10.5, -1.3), even after adjusting for age, gender, BMI, and AHI. Diabetes was also associated with lower total sleep time (−13.7min, 95%CI -26.8, -0.6), longer slow-wave sleep (N3) duration (+7.6min, 95%CI 0.6, 14.6) and higher N3 percentage (+2.4%, 95%CI 0.6, 4.2), compared to those without diabetes.ConclusionsPeople with diabetes and prediabetes had less REM sleep after taking into account potential confounders, including AHI. People with diabetes also had more N3 sleep. These results suggest that diabetes is associated with different sleep architecture, even in the absence of moderate-severe sleep apnea.

Objectives Prior studies have examined sleep during the coronavirus disease 2019 (COVID-19) pandemic, but have few compared sleep measured both during and prior to COVID. We examined the impact of the COVID-19 pandemic on subjective sleep quality in general and separately by gender and age (

Studying communities at different stages of urbanisation and industrialisation can teach us how timing and intensity of light affect the circadian clock under real-life conditions. We have previously described a strong tendency towards morningness in the Baependi Heart Study, located in a small rural town in Brazil. Here, we tested the hypothesis that this morningness tendency is associated with early circadian phase based on objective measurements (as determined by dim light melatonin onset, DLMO, and activity) and light exposure. We also analysed how well the previously collected chronotype questionnaire data were able to predict these DLMO values. The average DLMO observed in 73 participants (40 female) was 20:03 ± 01:21, SD, with an earlier average onset in men (19:38 ± 01:16) than in women (20:24 ± 01:21; P ≤ .01). However, men presented larger phase angle between DLMO and sleep onset time as measured by actigraphy (4.11 hours vs 3.16 hours; P ≤ .01). Correlational analysis indicated associations between light exposure, activity rhythms and DLMO, such that early DLMO was observed in participants with higher exposure to light, higher activity and earlier light exposure. The strongest significant predictor of DLMO was morningness-eveningness questionnaire (MEQ) (beta=-0.35, P ≤ .05), followed by age (beta = -0.47, P ≤ .01). Sex, light exposure and variables derived from the Munich chronotype questionnaire were not significant predictors. Our observations demonstrate that both early sleep patterns and earlier circadian phase have been retained in this small rural town in spite of availability of electrification, in contrast to metropolitan postindustrial areas.

Cardiometabolic risk factors influence white matter hyperintensity (WMH) development: in metabolic syndrome (MetS), higher WMH load is often reported but the relationships between specific cardiometabolic variables, WMH load and cognitive performance are uncertain. We investigated these in a Brazilian sample (aged 50–85) with (N = 61) and without (N = 103) MetS. Stepwise regression models identified effects of cardiometabolic and demographic variables on WMH load (from FLAIR MRI) and verbal recall performance. WMH volume was greater in MetS, but verbal recall performance was not impaired. Age showed the strongest relationship with WMH load. Across all participants, systolic blood pressure (SBP) and fasting blood glucose were also contributors, and WMH volume was negatively associated with verbal recall performance. In non-MetS, higher HbA1c, SBP, and number of MetS components were linked to poorer recall performance while higher triglyceride levels appeared to be protective. In MetS only, these relationships were absent but education exerted a strongly protective effect on recall performance. Thus, results support MetS as a construct: the clustering of cardiometabolic variables in MetS alters their individual relationships with cognition; instead, MetS is characterised by a greater reliance on cognitive reserve mechanisms. In non-MetS, strategies to control HbA1c and SBP should be prioritised as these have the largest impact on cognition.

Introduction Insomnia significantly impacts lifetime morbidity and thus has substantial socioeconomic costs. In developed, high-income countries insomnia prevalence is increasing. However, little is known about insomnia in less urbanised, lower-income populations. Baependi is a Brazilian rural town, which has been shown to maintain sleep cycles synchronised to natural daylight, in spite of electrification. We aimed to investigate the components of insomnia in the family-based Baependi Heart Study cohort, using the Insomnia Severity Index (ISI) questionnaire. Methods and materials Descriptive analysis was performed on data collected from the Baependi population (n=1,202) using R software. Heritability analysis was calculated using polygenic mixed modelling. Genome-wide association analysis (GWAS) was subsequently performed on the Baependi data, in order to interrogate for associations with polymorphisms previously related with insomnia symptoms (n= 811). Results Descriptive regression analysis categorised 7.6% of the participants as suffering from ‘clinical insomnia’ based on their ISI scores, with an average total score of 6.5±5.0 (SD). Heritability of ISI score, based on the best-fit model adjusted for sex, age, education, and depression, was 19%. GWAS yielded four associations of genome-wide significance with single-nucleotide polymorphisms (SNP) rs869481, rs62037617 and rs3747579, which are located in the CORO7 gene, and rs3789038, located on the neighbouring HMOX2 gene on chromosome 16. Conclusion This is one of the first studies of ISI score distribution in a general population. The heritability value observed is consistent with previously published literature, which have used different measures of insomnia symptoms. In addition, this is the first reported GWAS analysis for ISI score, identifying the first significant genome-wide genetic associations of ISI score. Thus, this study confirms the reliability and suitability of ISI as a measure for genetic studies in population. Acknowledgements This study was supported by the Santander Universities Researcher Mobility Award and CNPq (PVE 400791/2014-5).

Sleep is modulated by several factors, including sex, age, and chronotype. It has been hypothesised that contemporary urban populations are under pressure towards shorter sleep duration and poorer sleep quality. Baependi is a small town in Brazil that provides a window of opportunity to study the influence of sleep patterns in a highly admixed rural population with a conservative lifestyle. We evaluated sleep characteristics, excessive daytime sleepiness, and chronotype using the Pittsburgh Sleep Quality Index, Epworth Sleepiness Scale and Morningness-Eveningness Questionnaire questionnaires, respectively. The sample consisted of 1,334 subjects from the Baependi Heart study (41.5% male; age: 46.5 ± 16.2 y, range: 18–89 years). Average self-reported sleep duration was 07:07 ± 01:31 (bedtime 22:32 ± 01:27, wake up time: 06:17 ± 01:25 hh:min), sleep quality score was 4.9 + 3.2, chronotype was 63.6 ± 10.8 and daytime sleepiness was 7.4 ± 4.8. Despite a shift towards morningness in the population, chronotype remained associated with reported actual sleep timing. Age and sex modulated the ontogeny of sleep and chronotype, increasing age was associated with earlier sleep time and shorter sleep duration. Women slept longer and later, and reported poorer sleep quality than men (p

PURPOSE: Cardiovascular disease (CVD) is a major challenge to global health. The same epidemiological transition scenario is replayed as countries develop, but with variations based on environment, culture and ethnic mixture. The Baependi Heart Study was set up in 2005 to develop a longitudinal family-based cohort study that reflects on some of the genetic and lifestyle-related peculiarities of the Brazilian populations, in order to evaluate genetic and environmental influences on CVD risk factor traits. PARTICIPANTS: Probands were recruited in Baependi, a small rural town in the state of Minas Gerais, Brazil, following by first-degree and then increasingly more distant relatives. The first follow-up wave took place in 2010, and the second in 2016. At baseline, the study evaluated 1691 individuals across 95 families. Cross-sectional data have been collected for 2239 participants. FINDINGS TO DATE: Environmental and lifestyle factors and measures relevant to cardiovascular health have been reported. Having expanded beyond cardiovascular health outcomes, the phenotype datasets now include genetics, biochemistry, anthropometry, mental health, sleep and circadian rhythms. Many of these have yielded heritability estimates, and a shared genetic background of anxiety and depression has recently been published. In spite of universal access to electricity, the population has been found to be strongly shifted towards morningness compared with metropolitan areas. FUTURE PLANS: A new follow-up, marking 10 years of the study, is ongoing in 2016, in which data are collected as in 2010 (with the exception of the neuropsychiatric protocol). In addition to this, a novel questionnaire package collecting information about intelligence, personality and spirituality is being planned. The data set on circadian rhythms and sleep will be amended through additional questionnaires, actimetry, home sleep EEG recording and dim light melatonin onset (DLMO) analysis. Finally, the anthropometric measures will be expanded by adding three-dimensional facial photography, voice recording and anatomical brain MRI.

Background Semantic verbal fluency is broadly used in both clinical and non-clinical research, mainly because its sensitivity to several neurobiological conditions associated with cognitive impairment. In order to provide additional insights into genetic component contributing to normal variation on speech production, we conducted a Genome-Wide Association Study (GWAS) of semantic verbal fluency in a family-based cohort from the Baependi Heart Study. Cognitive performance was analysed considering not only the total number of words produced in 60 s but also subdivided into four 15-s time-quartiles because of the involvement of different cognitive processes- predominantly automatic at the beginning and controlled/executive at the end of the task. Methods We analysed cognitive performance of 1,735 participants from 134 extended families (mean age±SD 46±16.2, 60% female). Participants were asked to orally name as many animals as possible within 60 s avoiding repetitions and variations of the same animal. Scores were the numbers of exemplars produced in 60 s, which were broken down into four 15-s time-quartiles [0–15 s (T1), 16–30 s (T2), 31–45 s (T3), 46–60 s (T4)]. Heritability estimates were obtained by an adjusted variance component model. The Baependi cohort was genotyped using different GWAS platforms (custom arrays to capture the tri-ancestry genetic structure of the Brazilian population; Affymetrix Axiom Incor array and Affymetrix SNP chip 6.0; Affymetrix, Santa Clara, CA). Results All performed analysis were adjusted for sex, age, education and time of day since these sociodemographic variables affected means. Heritability calculations showed an estimate of: 60 s=0.21 (p Discussion Using a family-based cohort with a wide distribution of schooling years and, partitioning word production along time-quartiles contributed to the finding of specific genetic markers for verbal fluency at 60 s, T1, T2 e T3. Importantly, the gene influencing score for 60 s (RIMS1) has been previously reported to play a role in cognitive performance and schizophrenia. Our findings provide, on a biological level, grounds for the presence of distinct cognitive processes recruited during semantic verbal fluency since different loci are implicated with each one of the time-intervals.

Background There is a significant interest in the contribution of the circadian timing system to individual differences in a wider range of behaviour. This is in part because sleep complaints and disturbances of the circadian timing system are common in psychiatric disorders. Based on diurnal preference, people can be divided into chronotypes with demonstrated differences in sleep-wake patterns and a variety of circadian rhythms, behavioral rhythms, and diurnal variation in mood. Specifically, greater eveningness has been related to greater depression. The human PER3 gene contains a variable number tandem repeat (VNTR) which is associated with diurnal preference: the longer allele (five tandem repeats) has been reported to associate with greater morningness, and the shorter allele (four tandem repeats) with greater eveningness. We have investigated the PER3 polymorphism and its relationship to sleep, circadian and depression characteristics in a Brazilian family-based cohort. Methods Baependi is a small rural town in Brazil that provides a window of opportunity to study the influence of sleep circadian patterns in a highly admixed rural population with a conservative lifestyle. Here, we studied 786 subjects (mean age±SD 46.5±16.2, 42% female). Blood samples were collected from all participants. The Per3 length polymorphism was genotyped using PCR followed by gel electrophoresis. We tested for associations between the PER3 polymorphism and sleep characteristics, daytime sleepiness, and chronotype using the Pittsburgh Sleep Quality Index, Epworth Sleepiness Scale and Morningness-Eveningness Questionnaire, respectively. Depressive symptoms were assessed using the Beck Depression Inventory [BDI-II]). Results Our genotyping data showed that 36% of the subjects were homozygous for the shorter allele (4/4), 51% of the participants were heterozygous (4/5) and 12% of the subjects were homozygous for the longer allele (5/5). Allele frequency was 0.62 for the 4-repeat and a 0.38 for the 5-repeat. The percentages of the chronotypes Morning type (M-type), Neither type (N-type) and Evening type (E-type) were 5%, 46% and 7%, respectively. We observed an increase of the depression symptoms in evening types [F(2, 1014)=4.8, p=0.007]. On the other hand, no such associations were observed the PER3 genotype. There were no significant differences in the MEQ score [F(2, 317)=0.46, p=0.63], daytime sleepiness [(F(2, 317)=0.23, p=0.79)], sleep efficiency [(F(2, 317)=2.59, p=0.07)] and sleep characteristics [(F(2, 317)=1.92, p=0.14)] between the PER3 genotypes. Discussion We observed an association between eveningness and depression. Identifying factors contributing to individual differences in sleep and to describe how these factors are associated with physiological and psychological profiles may aid our understanding of the role of sleep and the circadian system in mental health. On the other hand, we were not able to replicate the association between the PER3 VNTR polymorphism and chronotype, which has been confirmed independently in multiple populations worldwide (including in Brazil). Neither did we observe any association with depression. CNPq – PVE 400791/2014-5.