Search

G David Batty,1 Catharine R Gale2 1Department of Epidemiology and Public Health, University College London, London, UK; 2Medical Research Council Lifecourse Epidemiology Unit, University of Southampton, Southampton, UKCorrespondence: G David BattyDepartment of Epidemiology and Public Health, University College London, 1-19 Torrington Place, London, WC1E 6BT, UKEmail david.batty@ucl.ac.ukAim: In the absence of effective treatments for amyotrophic lateral sclerosis (ALS), a neurodegenerative disorder with high case fatality, there is a clear need to identify its primary risk factors.Methods: UK Biobank is a prospective cohort study in which baseline data were captured between 2006 and 2010 in 502,649 participants aged 37 to 73 years. Follow-up for ALS hospitalisations and death was made via national registries.Results: Eleven years of event surveillance gave rise to 301 hospitalisations and 279 deaths due to ALS. After adjustment for selected confounding factors, being older (hazard ratio per 10 year increase; 95% confidence interval: 1.92; 1.58, 2.33) and male (1.37; 1.00, 1.87) were associated with elevated rates of hospitalisation for ALS. Similar effects were apparent when death ascribed to the disorder was the outcome of interest. Of the remaining 23 social, biological, and behavioural risk indices, however, there was only a suggestion that taller people experienced an increased risk of hospitalisation (per SD increase: 1.31; 1.09, 1.59).Conclusion: In the present, large-scale study, other than well known associations, we did not find convincing evidence of links with ALS for other risk indices.Keywords: risk factors, amyotrophic lateral sclerosis, cohort study, UK Biobank

Background: Reported associations between psychiatric disorders and cancer incidence are inconsistent, with cancer rates in psychiatric patients that are variously higher than, similar to, or lower than the general population. Understanding these associations is complicated by difficulties in establishing the timing of onset of psychiatric disorders and cancer, and by the possibility of reverse causality. Some studies have dealt with this problem by excluding patients with cancers predating their psychiatric illness; others have not considered the issue.Methods: We examined associations between psychiatric hospitalization and cancer incidence in a cohort of 1,165,039 Swedish men, and we explored the impact of different analytic strategies on these associations using real and simulated data.Results: Relative to men without psychiatric hospitalization, we observed consistent increases in smoking-related cancers in those with psychiatric hospitalizations, regardless of analytic approach (eg, hazard ratio = 1.73 [95% confidence interval = 1.52-1.96]). However, associations with cancers unrelated to smoking were highly dependent on analytic strategy. In analyses based on the full cohort, we observed no association or a modest increase in cancer incidence in those with psychiatric hospitalizations (1.14 [1.07-1.22]). In contrast, when men whose cancer predated their psychiatric hospitalizations were excluded, future cancer incidence was lower in psychiatric patients (0.72 [0.67-0.78]). Results from simulated data suggest that even modest exclusions of this type can lead to strong artifactual associations.Conclusions: Psychiatric disorder-cancer incidence associations are complex and influenced by analytic strategy. A better understanding of the temporal relationship between psychiatric disorder and cancer incidence is required. [ABSTRACT FROM AUTHOR]

BACKGROUND: There is growing evidence of an inverse association between intelligence (IQ) and unintentional injuries. METHODS: Analyses are based on a cohort of 1 109 475 Swedish men with IQ measured in early adulthood. Men were followed up for an average 24 years, and hospital admissions for unintentional injury were recorded. RESULTS: 198 133 (17.9%) men had at least one hospital admission for any unintentional injury during follow-up. The most common cause of unintentional injury was falling, followed by road accidents, poisoning, fire and drowning. In addition, 14 637 (1.3%) men had at least one admission for complications of medical care. After adjusting for confounding variables, lower IQ scores were associated with an elevated risk of any unintentional injury (HR (95% CI) per SD decrease in IQ: 1.15 (1.14 to 1.15)) and of cause-specific injuries other than drowning (poisoning (1.53 (1.49 to 1.57)), fire (1.36 (1.31 to 1.41)), road traffic accidents (1.25 (1.23 to 1.26)), medical complications (1.20 (1.18 to 1.22)) and falling (1.17 (1.16 to 1.18))). These gradients were stepwise across the full IQ range. CONCLUSIONS: Low IQ scores in early adulthood were associated with a subsequently increased risk of unintentional injury. A greater understanding of mechanisms underlying these associations may provide opportunities and strategies for prevention. [ABSTRACT FROM AUTHOR]

We examined whether higher levels of neuroticism in adolescence were associated with poorer cognitive function in midlife in 2,071 members of the British 1946 birth cohort. Higher neuroticism at age 13 was associated with poorer performance on tests of verbal ability, verbal fluency, and verbal memory at age 53 in sex-adjusted analyses. However, higher neuroticism was also associated with poorer cognitive performance at age 8. After adjustment for childhood cognition or educational attainment, the associations between neuroticism at age 13 and midlife cognition ceased to be statistically significant. The link between neuroticism and subsequent cognitive ability may be a reflection of a long-standing correlation between the stable aspects of these traits since childhood, but further measurements of both traits are needed to confirm this. [ABSTRACT FROM AUTHOR]

BACKGROUND: The health and social impact of drinking in excess of internationally recognized weekly (>21 units in men; >14 units in women) and daily (>4 units in men; >3 units in women) recommendations for 'sensible' alcohol intake are largely unknown. METHODS: A prospective cohort study of 1551 men and women aged around 55 years in 1988 when typical alcohol consumption was recalled using a 7-day grid. An average of 3.4 years later (1990/92), study participants were re-surveyed (n = 1259; 84.7% of the target population) when they responded to nurse-administered enquiries regarding minor psychiatric morbidity, self-perceived health, hypertension, accidents, overweight/obesity and financial difficulties. Study members were followed up for mortality experience over 18 years. RESULTS: In fully adjusted analyses, surpassing guidelines for sensible alcohol intake was associated with an increased risk of hypertension [daily guidelines only: P-value(trend): 0.012], financial problems [weekly guidelines: P-value(difference): 0.046] and, to a lesser degree, accidents [weekly guidelines: P-value(difference): 0.065]. There was no association between either indicator of alcohol intake and mortality risk. CONCLUSIONS: In the present study, there was some evidence for a detrimental effect on health and social circumstances of exceeding current internationally recognized weekly and daily guidelines for alcohol intake. [ABSTRACT FROM AUTHOR]

The authors evaluated the little-examined association between intelligence (IQ) and injury mortality and, for the first known time, explored the extent to which IQ might explain established socioeconomic inequalities in injury mortality. A nationwide cohort of 1,116,442 Swedish men who underwent IQ testing at about 18 years of age was followed for mortality experience for an average of 22.6 years. In age-adjusted analyses in which IQ scores were classified into 4 groups, relative to the highest scoring category, the hazard ratio in the lowest was elevated for all injury types: poisonings (hazard ratio (HR) = 5.82, 95% confidence interval (CI): 4.25, 7.97), fire (HR = 4.39, 95% CI: 2.51, 7.77), falls (HR = 3.17, 95% CI: 2.19, 4.59), drowning (HR = 3.16, 95% CI: 1.85, 5.39), and road injury (HR = 2.17, 95% CI: 1.91, 2.47). Dose-response effects across the full IQ range were evident (P-trend < 0.001). Control for potential covariates, including socioeconomic position, had little impact on these gradients. When socioeconomic disadvantage -- indexed by parental and subject's own occupational social class -- was the exposure of interest, IQ explained a sizable portion (19%-86%) of the relation with injury mortality. These findings suggest that IQ may have an important role both in the etiology of injuries and in explaining socioeconomic inequalities in injury mortality. [ABSTRACT FROM AUTHOR]

OBJECTIVES: We examined the viability and efficacy of a known quantity of exercise in facilitating weight loss among previously sedentary or irregularly active overweight and obese adult women residing in a slum (favela) in Brazil. METHODS: In this randomized controlled trial, 156 women were randomized to a control or intervention group (78 in each group). Exercise was supervised, consisting of three 50-minute aerobic sessions each week for 6 months. RESULTS: Ninety-one percent (71) of the participants in the intervention group completed 6 months of the exercise program. At 6 months, women in the treatment group showed significant reduction in weight (mean=-1.69 kg; 95% confidence interval [CI]=-2.36,-1.03) and body mass index (mean=-0.63 kg/m2; 95% CI=-0.97, -0.30) compared with controls (P for both<.001). CONCLUSIONS: A moderately intense, structured exercise program resulted in modest weight loss in women when sustained for 6 months. [ABSTRACT FROM AUTHOR]

Background: Several studies show that children who were breastfed as babies gain higher scores on intelligence tests than those who were bottlefed. Although these findings suggest that breastfeeding in early life may promote cognitive development, their interpretation is complicated by the current association between breastfeeding and higher social class. We investigated the relation between method of feeding in infancy and adult intelligence in a setting where breastfeeding was not linked with socioeconomic advantage.Methods: We followed up 994 men and women, born between 1920 and 1930 in Hertfordshire, UK, for whom information on infant feeding had been recorded by health visitors. Intelligence was measured by the AH4 IQ test, taken on a computer. Factors significantly linked with IQ were investigated by multivariate analysis.Findings: Study participants who had been exclusively breastfed gained slightly higher scores on the IQ test than those who had been exclusively bottlefed, or fed with both breast and bottle. IQ was lower in participants who had used a dummy (pacifier) in infancy, in those whose fathers were in manual occupations at the time of their birth, and in those whose mothers were young at the time they were born. Scores on the IQ test fell as the number of older siblings increased. In multivariate analysis, after adjustment for the effect of all other variables, no association was found between adult intelligence and method of feeding. Dummy use in infancy, number of older siblings, maternal age at birth of the participant, and father's occupational class remained independent predictors of adult intelligence.Interpretation: The mechanisms that link type of feeding in early life with later intelligence may have more to do with the child's social environment that with the nutritional qualities of the milk. [ABSTRACT FROM AUTHOR]

Question: Are gestational age and low birth weight associated with depressive symptoms in adult life? People: 752 women and 619 men who were born at full term (gestational age 259--294 days), selected from a larger random sample of all those born at Helsinki University Central Hospital in 1934-44 for whom birth and child welfare records were available and who could be identified by personal ID numbers in Finland in 1971.Setting: Community setting in Finland; cohort born 1934-44, date of analyses not reported.Risk factors: Length of gestation, birth weight, newborn length and head circumference from birth records. Father's occupation was also extracted to determine social class. Analyses of the effect of body size were adjusted for gender and length of gestation, and analyses of length of gestation adjusted for gender and birth weight. Analyses also adjusted for other potential confounders.Outcomes: Depressive symptom score of >/= 10 on the Beck Depression Inventory (BDI; higher score indicates more severe symptoms) or '16 on the Center for Epidemiological Studies Depression (CES-D) scale (higher score indicates greater frequency of symptoms). Depressive symptoms were assessed by postal survey at average age 61.5 years (time point 1), and again at average age 63.4 years (time point 2). The EDI was administered at both time points, while the CES-D was only assessed at the second time point.METHODSDesign: Cohort study.Follow-up period: Two years' prospective follow-up (between mean ages 61.5 and 63.4 years); birth weight and gestation were assessed retrospectively.MAIN RESULTSDecreased length of gestation increased the risk of having a BDI score of 10 or greater at both follow up time points (OR per day decrease in gestational length: 0.97, 95% CI 0.94 to 0.99), and the risk of having BDI and CES-D scores both above the cut-off at the second follow-up time point (OR per day decrease in gestational length: 0.97, 95%, CI 0.95 to 0.99). Average BDI score over both time points decreased by 0.9% per day increase in gestation (95% CI -1.4 to -0.4; p = 0.001), and CES-D score at time point 2 decreased by 0.8% per day increase in gestation (95% CI -1.3 to -0.2; p = 0.01). Birth weight, length or head circumference were not associated with depressive symptoms (see online table).CONCLUSIONSShorter gestational age, within the range of full-term gestation, seems to be associated with depressive symptoms in later life, independently of birth weight. [ABSTRACT FROM AUTHOR]