BMI change during puberty and the risk of heart failure.

AIM: Hospitalization for heart failure amongst younger men has increased. The reason for this is unknown but it coincides with the obesity epidemic. The aim of this study was to evaluate the association between childhood BMI (Body Mass Index) and BMI change during puberty for risk of adult heart failure in men. METHODS: Using the BMI Epidemiology Study (BEST), a population-based study in Gothenburg, Sweden, we collected information on childhood BMI at age 8 years and BMI change during puberty (BMI at age 20 - BMI at 8) for men born 1945-1961, followed until December 2013 (n = 37 670). BMI was collected from paediatric growth charts and mandatory military conscription tests. Information on heart failure was retrieved from high-quality national registers (342 first hospitalizations for heart failure). RESULTS: BMI change during puberty was independently of childhood BMI associated with risk of heart failure in a nonlinear J-shaped manner. Subjects in the upper quartile of BMI change during puberty (Q4) had more than twofold increased risk of heart failure compared with subjects in Q1 [HR (Hazard Ratio) = 2.29, 95% CI (Confidence Interval) 1.68-3.12]. Childhood BMI was not independently associated with risk of heart failure. Boys developing overweight during puberty (HR 3.14; 95% CI 2.25-4.38) but not boys with childhood overweight that normalized during puberty (HR 1.12, 95% CI 0.63-2.00) had increased risk of heart failure compared with boys without childhood or young adult overweight. CONCLUSION: BMI change during puberty is a novel risk factor for adult heart failure in men.

The rise and the recent decline of childhood obesity in Swedish boys: the BEST cohort.

BACKGROUND/OBJECTIVES: Childhood obesity increases the risk for adult obesity and diseases. The aim of this study was to investigate secular changes of childhood body mass index (BMI), overweight and obesity in boys born during 1946-2006, using the population-based BMI Epidemiology STudy (BEST) cohort in Gothenburg, Sweden. SUBJECTS/METHODS: We collected height and weight from archived school health records for boys born every 5 years 1946-2006 (birth cohort 1946 n=1584, each birth cohort 1951-2006 n=425). Childhood BMI at 8 years of age was obtained for all the participants. RESULTS: Childhood BMI increased 0.18 kg m-2 (95% confidence interval: 0.16-0.20) per decade increase in birth year, during 1946-2006. The increase was significant from birth year 1971, peaked 1991 and was then followed by a stabilization or tendency to a reduction. Next, we aimed to thoroughly explore the trend after birth year 1991 and therefore expanded birth cohorts 1991 (n=1566), 2001 (n=6478) and 2006 (n=6515). Importantly, decreases in mean BMI (P<0.01), prevalences of overweight (P<0.01) and obesity (P<0.05) were observed after birth year 1991. For boys born in Sweden and with parents born in Sweden, a substantial reduction in the prevalences of overweight (-28.6%, P<0.001) and obesity (-44.3%, P<0.001) were observed between birth year 1991 and birth year 2006. CONCLUSIONS: This long-term study captures both the rise and the recent decline of childhood obesity. As childhood obesity is strongly associated with subsequent adult obesity, we anticipate a similar reduction in adult obesity during the coming decades in Swedish men.