Role of body mass index history in predicting risk of the development of hypertension in Japanese individuals: Toranomon Hospital Health Management Center Study 18 (TOPICS 18).

It has not been clarified whether overall adiposity in early adulthood or at the lifetime maximum weight would confer a residual risk of hypertension after considering the risk associated with current adiposity. Studied were 6121 Japanese without hypertension. The risk of developing hypertension 4 years after a baseline examination was investigated using the body mass index in the early 20s, at the lifetime maximum, or at the baseline examination. An elevated body mass index at baseline or at the maximum rather than in the early 20s was strongly associated with future hypertension. Compared with individuals with low body mass index both at baseline and in the early 20s, those with an elevated body mass index at the baseline alone had an odds ratio of 1.89 (95% confidence interval, 1.58­2.27) and those with an elevated body mass index both at baseline and in the early 20s had the highest odds ratio of 2.26 (1.76­2.89). Individuals with an elevated body mass index both at baseline and at the maximum had a 2.26-fold (1.87­2.72) increased risk of hypertension compared with those without the 2 factors. An elevated body mass index at the baseline examination weakened the favorable influence of a low body mass index in early adulthood on developing hypertension. Adding information on body mass index in early adulthood or at the maximum in addition to that at the baseline examination contributed to differentiating the risk of hypertension among Japanese, particularly among those with an elevated overall adiposity at present.