Even high normal BMIs in adolescents increase midlife CHD risk
An elevated body-mass index (BMI) at age 17, even when in the range considered to be at the high end of normal, is strongly correlated with an increased risk for coronary heart disease (CHD) by age 40 but has less influence in the development of midlife type 2 diabetes mellitus, according to a study published in the New England Journal of Medicine.
In the study, 37,674 apparently healthy 17-year-old Israeli men had their BMI and other health measures documented at the beginning of military service; height and weight were measured at regular intervals thereafter. The mean adolescent BMI values were between 20 and 21 kg/m2.
After a mean follow-up of 17.4 years, 327 incident cases of angiographically proven CHD (at least 50% stenosis in at least 1 major coronary artery) were diagnosed between 25 and 45 years of age. An elevated adolescent BMI was independently associated with a higher risk for CHD. The association between elevated adolescent BMI and CHD was apparent even at BMIs between 19 and 20 kg/m2, which are considered within normal limits. After adjusting for adult BMI, adolescents with a BMI in the highest decile (>25 kg/m2) had a risk of midlife CHD that was nearly 7 times greater than adolescents with a BMI in the lowest decile (mean BMI, 17.3 kg/m2).
Adolescents with a BMI greater than 20.7 kg/m2 were about 3 times as likely to develop CHD by midlife compared with those with a BMI in the lowest decile. The risk for heart disease increased 12% with every 1 U increase in BMI.
Adolescent weight had no effect on the risk for diabetes among those who were not overweight as adults. Only men with adolescent BMIs in the 3 highest deciles had a significantly higher risk of incident diabetes than those in the lowest decile.
The investigators write that their research may help to redefine normal or healthy BMI in adolescence.
Tirosh A, Shai I, Afek A, et al. Adolescent BMI trajectory and risk of diabetes versus coronary disease. N Engl J Med. 2011;364(14):1315-1325.