Poor school performance is associated with a larger gain in body mass index during puberty.

AIM: Social inequalities in type 2 diabetes and coronary heart disease may be established in formative school years. We investigated whether school performance is associated with adiposity and increase in body mass index (BMI) between 10 and 15 years of age. METHODS: A community sample of 2633 school children had height and weight measured in school at the ages of 10 and 15. Percentages of body fat and waist circumference were measured at the age of 15. Mean grades in several school subjects at the age of 15 (ninth school year) were divided into quartiles. A linear regression analysis with BMI as the main outcome took into account parental education and ethnicity, obtained from registers, and children's living habits, collected by questionnaires. RESULTS: In adjusted models, longitudinal changes in BMI between the ages of 10 and 15 were larger in the lowest quartiles of school grades compared with the highest: for girls, they were ß = 0.45 (p = 0.007) and for boys they were ß = 0.45 (p = 0.016). Cross-sectional regression analyses, with percentage of body fat and waist circumference as outcomes, showed similar results. CONCLUSION: Our results suggest that school performance is one pathway to social inequalities in obesity in school children.

Obesity status and risk of disability pension due to psychiatric disorders.

OBJECTIVE: The aim of this study was to investigate associations between underweight, overweight and obesity in young adult men and risk of disability pension (DP) due to psychiatric disorders. DESIGN AND SUBJECTS: In this nationwide study of 1 110 139 Swedish men (mean age 18.3+/-0.5 years), weight, height and muscular strength were measured at mandatory military conscription testing (1969-1994). Information on DP (1971-2006), residential area, parental socioeconomic position and education and preexisting psychiatric disorders was obtained by record linkage of national registers. RESULTS: During 26 million person-years of follow-up, 19 684 men received DP due to psychiatric disorders. After adjustment, hazard ratios (HRs) due to any psychiatric disorder were 1.20 (95% CI: 1.15-1.26) for underweight, 1.14 (95% CI: 1.08-1.21) for overweight and 1.43 (95% CI: 1.28-1.60) for obesity compared to normal weight. For affective disorders, HRs were elevated for underweight (1.24, 95% CI: 1.16-1.32), overweight (1.19, 95% CI: 1.10-1.28) and obesity (1.55, 95% CI: 1.33-1.81), whereas for substance abuse increased risks were seen only for underweight (1.41, 95% CI: 1.23-1.61) and obesity (1.50, 95% CI: 1.07-2.12). For nonaffective disorders (including schizophrenia) overweight (HR=0.87, 95% CI: 0.76-1.00) and obesity (HR=0.79, 95% CI: 0.57-1.10) seemed to be protective, although not statistically significant. HRs for personality disorders were increased for underweight (1.18, 95% CI: 1.04-1.34), overweight (1.16, 95% CI: 1.00-1.30) and obesity (1.40, 95% CI: 1.03-1.90). CONCLUSION: Underweight and overweight were associated with small risk increases, whereas higher risks for DP were generally found for obesity.

Association between obesity status in young adulthood and disability pension.

OBJECTIVE: Obesity and underweight in young adulthood are associated with greater risk of future disability pension. Neither underlying causes of disability pension nor whether overweight confers excess risk is established in this age group. The aim of this study was to investigate risk of future disability pension according to body mass index (BMI) in young adulthood. DESIGN: BMI was measured at military conscription (1969-1994; n=1 191 027; mean age 18.3+/-0.5 years). Date and cause of disability pension, death and emigration dates were collected from national registers (1971-2006). Muscular strength, age, municipality, socioeconomic position, testing center and year were adjusted for in Cox regressions. RESULTS: During 28.4 million person-years, 60 024 subjects were granted disability pension. The hazard ratios (HRs) for underweight (1.14, CI 95% 1.11-1.17), overweight (1.36, 1.32-1.40), moderate (BMI 30-34.9; 1.87, 1.76 to 1.99) and morbid obesity (BMI>or=35; 3.04, 2.72-3.40) were elevated compared to normal weight. Not adjusting for muscular strength led to overestimation of the risk in underweight (1.27, 1.24-1.31), but underestimation in overweight (1.29, 1.25-1.33), moderately (1.72, 1.62-1.82) and morbidly obese subjects (2.77, 2.48-3.09). For circulatory and musculoskeletal causes, respectively, HRs were elevated only for overweight (2.06; 1.82-2.34; 1.47; 1.39-1.55) and obesity (3.51; 2.79-4.40; 2.15; 1.94-2.38). The same applied for tumors and nervous system, but not psychiatric causes, for which underweight (1.20; 1.16-1.24) displayed similar HR as overweight (1.21; 1.16-1.27), whereas the risk in obese subjects was higher (1.60; 1.46-1.75). CONCLUSION: The risks in overweight and obese, but not underweight, subjects were significantly elevated for each cause investigated. Although causality cannot be inferred, productivity losses associated with adverse BMI in young adulthood appear to be large.

Obesity status and sick leave: a systematic review.

This review identified 36 studies on the relation between obesity status and sick leave. Pooling of effect estimates was not possible due to great heterogeneity between studies regarding definition of sick leave (short-term/long-term), measure of obesity (body mass index/waist circumference/percentage body fat), definition of obesity status (World Health Organization standards/other), study population (sex/age/occupation/country) and exposure and outcome ascertainment (self-reported/objectively assessed). Nevertheless, a clear trend towards greater sick leave among obese compared with normal weight workers could be discerned, especially for spells of longer duration. In studies from the USA, which consistently reported about five times lower number of sick leave days per person-year than European, obese workers had about 1-3 extra days of absence per person-year compared with their normal weight counterparts. In European studies, the corresponding difference was about 10 d. For overweight workers the data were conflicting, indicating either increased or neutral level of sick leave compared with normal weight. Regarding underweight, the studies were very few and concerns regarding direction of causality were greater. Finally, in all four interventional studies identified substantial weight loss in obese subjects resulted in reduced sick leave, at least temporarily. In conclusion, increasing obesity in children and adults is likely to negatively affect future productivity as obesity increases the risk of sick leave, disability pension and death.

Overweight among international adoptees in Sweden: a population-based study.

UNLABELLED: This study investigated the prevalence of overweight [body mass index (BMI) > or = 25 kg m-2] in young adulthood among international adoptees. The prevalence of overweight among adoptees from various countries of origin was compared with that in a large group of non-adopted individuals. All 275,026 young men born in 1973-1977 and living in Sweden at 17 y of age were included. A record linkage was made between the Military Service Conscription Register and several population registers. Data on BMI at 18 y of age were obtained from military conscription examinations conducted in 1991-1995. BMI was missing for 12.7% of 2400 adoptees and 10.8% of 263,173 non-adoptees. Among 623 adoptees from Latin America 21.5% (95% confidence interval 18.3-24.7) were overweight, with a particularly high prevalence of overweight among the 266 adoptees from Chile (28.6%, 23.1-34.0). Among 502 adoptees from the Indian subcontinent 8.4% (5.9-10.8) were overweight and the prevalence of overweight was 8.8% (5.7-12.0) among 317 adoptees from India. Among 817 adoptees from the Far East 12.0% (9.8-14.2) were overweight and the prevalence of overweight was 10.9% (7.9-13.9) among 404 from South Korea. The corresponding figure was 14.1% (14.0-14.2) among the non-adopted individuals. CONCLUSION: These differences in prevalence of overweight between various groups of adoptees and between adopted and non-adopted subjects are remarkable and are probably due to diversity in genetic susceptibility to overweight.