Public health nutrition | 2021
Body mass index and risk of all-cause mortality in normotensive and hypertensive adults: The Rural Chinese Cohort Study.
Abstract
OBJECTIVE\nThe impact of baseline hypertension status on the BMI-mortality association is still unclear. We aimed to examine the moderation effect of hypertension on the BMI-mortality association using a rural Chinese cohort.\n\n\nDESIGN\nIn this cohort study, we investigated the incident of mortality according to different BMI categories by hypertension status.\n\n\nSETTING\nLongitudinal population-based cohort.\n\n\nPARTICIPANTS\n17,262 adults ≥18 years were recruited from July to August of 2013 and July to August of 2014 from a rural area in China.\n\n\nRESULTS\nDuring a median 6-year follow-up, we recorded 1109 deaths (610 with and 499 without hypertension). In adjusted models, as compared with BMI 22-24 kg/m2, with BMI ≤18, 18-20, 20-22, 24-26, 26-28, 28-30 and >30 kg/m2, the HRs (95% CI) for mortality in normotensive participants were 1.92 (1.23-3.00), 1.44 (1.01-2.05), 1.14 (0.82-1.58), 0.96 (0.70-1.31), 0.96 (0.65-1.43), 1.32 (0.81-2.14), and 1.32 (0.74-2.35) respectively, and in hypertensive participants were 1.85 (1.08-3.17), 1.67 (1.17-2.39), 1.29 (0.95-1.75), 1.20 (0.91-1.58), 1.10 (0.83-1.46), 1.10 (0.80-1.52), and 0.61 (0.40-0.94) respectively. The risk of mortality was lower in individuals with hypertension with overweight or obesity versus normal weight, especially in older hypertensives (≥60 years old). Sensitivity analyses gave consistent results for both normotensive and hypertensive participants.\n\n\nCONCLUSIONS\nLow BMI was significantly associated with increased risk of all-cause mortality regardless of hypertension status in rural Chinese adults, but high BMI decreased the mortality risk among individuals with hypertension, especially in older hypertensives.