BMI in adolescence predicts CHD and diabetes risk later in life
MedWire News: An elevated body mass index (BMI) in adolescence, but within the range currently considered normal, increases the risk for coronary heart disease (CHD) and diabetes later in life, US researchers report.
These findings "support concerns about the association between increasing cardiometabolic morbidity in early adulthood and the increase in BMI in adolescence," says the team.
Amir Tirosh (Harvard Medical School, Boston, Massachusetts) and colleagues used data from the Metabolic, Lifestyle, and Nutrition Assessment in Young Adults (MELANY) study of the Israel Defense Forces (IDF) Medical Corps to assess the association between BMI and obesity-related diseases in 37,674 apparently healthy men, whose BMI at 17 years was between 15 and 36 kg/m2.
During a mean follow-up period of 17.4 years, 327 new cases of heart disease and 1173 new cases of diabetes were diagnosed.
Tirosh and team report that adolescent men with a BMI in the 8th, 9th, and 10th deciles (22.35-23.39, 23.40-25.06, and >25.07 kg/m2, respectively) had a 2.96-, 3.58-, or 5.43-fold higher risk for CHD and a 1.47-, 1.79-, or 2.76-fold higher risk for diabetes later in life, respectively, compared with men in the lowest BMI decile (<18.11 kg/m2), after adjusting for age, family history, blood pressure, lifestyle factors, and CHD biomarkers in blood.
However, adjustment for BMI in young adulthood (between 25 and 45 years of age) completely attenuated this effect for diabetes, but not for CHD, such that the respective risk for CHD was 3.41-, 4.27-, and 6.85-fold greater for men in the 8th, 9th, 10th BMI deciles in young adulthood, compared with lowest decile.
"Diabetes is influenced mainly by recent BMI and weight gain, whereas for CHD, both elevated BMI in adolescence and recent BMI are independent risk factors," explain the authors.
Therefore, "the natural history of CHD, in contrast with that of diabetes, is probably the consequence of gradually increasing atherosclerosis during adolescence and early adulthood that leads to clinically important disease in midlife," they say.
Tirosh et al note that these results were observed among men with BMI values within the range that is now defined as 'normal'.
"Our study may help to redefine what constitutes a 'normal' or 'healthy' BMI in adolescence," the team concludes in The New England Journal of Medicine.
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By Nikki Withers