Association of long-term dynamic change in body weight and incident hypertension: The Rural Chinese Cohort Study.

OBJECTIVES: The association of long-term dynamic change in body weight and incident hypertension among general Chinese adults is still unknown. The aim of this study was to evaluate the hypertension risk in a large prospective study of rural Chinese adult using relative weight gain or loss. METHODS: A total of 10 149 nonhypertensive Chinese adults 18 to 75 y of age completed a questionnaire interview and anthropometric and laboratory measurements at both baseline (2007-2008) and follow-up (2013-2014). Participants were divided into five categories based on relative weight change. Logistic regression analysis was used to estimate odds ratios (ORs) and 95% confidence intervals (CIs) for hypertension risk by categories of weight change. RESULTS: During 6 y of follow-up, about one-third of the participants retained a stable weight (33.3%) or gained >6% (32.7%). Only 7.9% lost >6% weight. For every 1% increase in relative body weight, systolic and diastolic blood pressures increased 0.27 and 0.22 mm Hg, respectively. Risk for hypertension was reduced and increased with weight loss >6% (OR, 0.78; 95% CI, 0.61-0.99) and gain >6% (OR, 2.08; 95% CI, 1.79-2.42), respectively, compared with weight loss or gain ≤3%. With baseline prehypertension, compared with maintaining a stable weight, weight loss >6% reduced the risk for hypertension (OR, 0.71; 95% CI, 0.54-0.95). With baseline overweight, compared with maintaining the overweight status during follow-up, changing to normal weight reduced the risk for hypertension (OR, 0.67; 95% CI, 0.49-0.92), but changing to general obesity increased the risk (OR, 1.73; 95% CI, 1.35-2.22). CONCLUSIONS: Long-term excessive weight gain is positively associated with increased risk for incident hypertension. Losing weight by lifestyle modification could be helpful for the primary prevention of hypertension in the general rural Chinese population.