Consistent visit-to-visit variability of fasting plasma glucose (FPG) represents a significant independent risk factor for cardiovascular disease (CVD) and all-cause mortality, according to study findings published in the Journal of the American Heart Association.
Investigators assessed the association between FPG visit-to-visit variability over a 4-year period and incident CVD and all-cause mortality in 53,607 CVD-free Chinese participants. The researchers stratified patients into 4 groups according to quartiles of FPG variability: quartile 1 (<5.27 mmol/L), quartile 2 (5.27-8.48 mmol/L), quartile 3 (8.49-13.11 mmol/L), and quartile 4 (>13.11 mmol/L).
A total of 4261 participants developed CVD within the mean follow-up period of 4.93 years, and 1545 participants died during this period. Per 1000 person-years, the incidence of both CVD and all-cause mortality was 5.04 and 5.85, respectively. The investigators adjusted for mean FPG as well as other possible confounders and found that participants in the highest quartile of FPG variability had a 26% higher risk for CVD compared with participants in the lowest quartile (hazard ratio [HR], 1.26; 95% CI, 1.08-1.47). Also, the participants in the highest quartile had a 46% greater risk for all-cause mortality than participants in the lowest quartile (HR, 1.46; 95% CI, 1.25-1.70).
The findings are limited in that the investigators did not determine the types of CVD experienced by patients and their associations with FPG visit-to-visit variability. Also, investigators suggested the potential for residual confounding nonpharmacological factors may have further limited the findings.
Although oxidative stress, inflammatory cytokines, and endothelial dysfunction are plausible underlying mechanisms for the association between visit-to-visit FPG variability and CVD risk, another explanation could be that “individuals with a higher variability of FPG tend to have a higher prevalence of traditional risk factors for CVD and all-cause mortality.”
Wang A, Liu X, Xu J, et al. Visit-to-visit variability of fasting plasma glucose and the risk of cardiovascular disease and all-cause mortality in the general population [published online November 29, 2017]. J Am Heart Assoc. doi:10.1161/JAHA.117.006757