Changes in body weight from young adulthood to middle age and its association with blood pressure and hypertension : a cross-sectional study in Hong Kong Chinese women

Abstract

Background-Few studies have examined the associations of weight changes from young adulthood to middle age with blood pressure (BP) and hypertension among Hong Kong Chinese women. Methods and Results-Weight at age 18 (W18), current weight (Wcurrent), height, BP, demographics, and lifestyle factors were obtained from 1253 female nurses (35-65 years) by a self-administered questionnaire through mail survey in Hong Kong. The conditional relative weight (CRW; a residual of Wcurrent regressed on W18) was used to express the relative weight change from age 18 to current age. The study results show that from young adulthood to middle age, 76.9%, 15.1%, and 8.0% of women had weight gain, weight loss, and stable weight, respectively. Women in the weight loss group had heavier W18 than those in the weight gain group (P < 0.05). Higher weight gain was associated with higher BP (P for trend < 0.01). Women who belonged to the heaviest 10% both at age 18 and at present had highest BP than women in other weight categories. By giving W18, a 1-kg increase in weight change predicted 0.63 and 0.42 mm Hg increases in systolic and diastolic BP, respectively (both P < 0.001) and 12% greater odds of being hypertension (95% confidence interval, 1.08, 1.17). The CRW was positively associated with BP and hypertension; no interaction was found between CRW and Wcurrent on BP/hypertension. Conclusions-A majority of Chinese women tended to become heavier throughout adult life. More weight gain led to the higher BP. Weight change is an independent predictor for later-life BP and hypertension.