Body mass index trajectories during mid to late life and risks of mortality and cardiovascular outcomes: Results from four prospective cohorts

Abstract

Background: Our understanding of the weight-outcome association mainly comes from single-time body mass index (BMI) measurement. However, data on long-term trajectories of within-person changes in BMI on diverse study outcomes are sparse. Therefore, this study is to determine the associations of individual BMI trajectories and cardiovascular outcomes.

Methods: The present analysis was based on data from 4 large prospective cohorts and restricted to participants aged ≥45 years with at least two BMI measurements. Hazard ratios (HR) and 95% confidence intervals(95%CI) for each outcome according to different BMI trajectories were calculated in Cox regression models.

Findings: The final sample comprised 29,311 individuals (mean age 58.31 years, and 77.31% were white), with a median 4 BMI measurements used in this study. During a median follow-up of 21.16 years, there were a total of 10,192 major adverse cardiovascular events (MACE) and 11,589 deaths. A U-shaped relation was seen with all study outcomes. Compared with maintaining stable weight, the multivariate adjusted HR for MACE were 1.53 (95%CI 1.40-1.66), 1.26 (95%CI 1.16-1.37) and 1.08 (95%CI 1.02-1.15) respectively for rapid, moderate and slow weight loss; 1.01 (95%CI 0.95-1.07), 1.13 (95%CI 1.05-1.21) and 1.29 (95%CI 1.20-1.40) respectively for slow, moderate and rapid weight gain. Identical patterns of association were observed for all other outcomes. The development of BMI differed markedly between the outcome-free individuals and those who went on to experience adverse events, generally beginning to diverge 10 years before the occurrence of the events.

Interpretation: Our findings may signal an underlying high-risk population and inspire future studies on weight management.

Funding: National Natural Science Foundation of China, Guangdong Natural Science Foundation.

Keywords: Body mass index; Cardiovascular events; Mid-to-late life; Mortality; Trajectories.

Fig. 1

U-shaped association between annual change in BMI and different study outcomes. Associations were examined by multivariable Cox regression models based on restricted cubic splines. Solid line represents estimates of hazard ratios and dashed line represents 95%CI. Each color represents one outcome of interest. A. Association between annual change in BMI and cardiovascular outcomes. MACE (purple), stroke (light grey), heart failure (light green) and myocardial infarction (orange). B. Association between annual change in BMI and death outcomes. All-cause death (red), non-cardiovascular death (blue), cardiovascular death (dark green) and death due to coronary heart disease (dark grey). MACE, major adverse cardiovascular events. (For interpretation of the references to colour in this figure legend, the reader is referred to the web version of this article.)

Fig. 2

Distinct trajectory patterns of BMI between the outcome-free individuals (dashed line) and those who went on to experience adverse events (solid line). The corresponding shaded area represents 95%CI. Each color represents one outcome of interest. A. Major adverse cardiovascular events (purple). B. Myocardial infarction (orange). C. Chronic heart failure (light green). D. Stroke (light grey). E. All-cause death (red). F. Cardiovascular death (dark green). G. Non-cardiovascular death (blue). H. CHD death (dark grey). CHD, coronary heart disease. (For interpretation of the references to colour in this figure legend, the reader is referred to the web version of this article.)

Fig. 3

Associations of BMI trajectories with major adverse cardiovascular events (MACE) and all-cause mortality, stratified by age group, sex, race, smoking status and baseline BMI. Hazard ratios are adjusted for age, gender, race, smoking status, current alcoholic use, education level, marital status, income, physical activity, consumption of fruits and vegetables, history of hypertension, diabetes, HF, CHD, cancer, COPD and stroke, baseline BMI, serum level of glucose, total cholesterol, LDLC, HDLC and triglyceride.