Variability in cardiometabolic parameters and all-cause and cause-specific mortality in older adults: evidence from 2 prospective cohorts

Introduction: To assess the individual and joint associations of variability in multiple cardiometabolic parameters with mortality risk across older populations.

Methods: A total of 51,551 Chinese elderly participants (aged ≥60 years) with ≥3 measurements of systolic blood pressure (SBP), visceral adiposity index (VAI), fasting blood glucose (FBG) and low-density lipoprotein cholesterol (LDL-C) during 2018-2022 were included. Variability metrics included standard deviation, coefficient of variation, average real variability and variability independent of the mean (VIM, used in primary analysis). Participants were classified based on the number of high-variability (highest quartile of variability) parameters into four categories: with 0, 1, 2 and 3-4 high-variability cardiometabolic parameters. Cox regression analyses were performed in 2024. Findings were then externally validated using the Health and Retirement Study (HRS, wave 8-15).

Results: Higher SBP, VAI, FPG and LDL-C variability were associated with greater all-, cardiovascular- and other-cause mortality risk. Compared with subjects with no high-variability parameters measured as the VIM, the hazard ratios (95% confidence interval) of all-cause mortality were 1.30 (1.16-1.44) for one parameter, 1.86 (1.66-2.09) for two parameters and 2.02 (1.75-2.32) for three/four parameters. Consistent results were noted for cardiovascular-, cancer- and other-cause mortality, using other variability indices and in various sensitivity and subgroup analyses. These associations were validated in the HRS (n=1,991).

Conclusions: Increased variability in cardiometabolic parameters is associated with elevated risks of all-cause and cause-specific mortality amongst older adults in China. Reducing variability of these parameters could serve as a target to increase life expectancy in older populations.