Associations of Serum Carotenoids With Risk of Cardiovascular Mortality Among Individuals With Type 2 Diabetes: Results From NHANES
Methods: This analysis included 3107 individuals with T2D from the Third National Health and Nutrition Examination Survey (NHANES III) and NHANES 2001–2006. Cardiovascular mortality was ascertained by linkage to National Death Index records through 31 December 2015. Cox proportional hazards regression models were used to estimate hazard ratios (HRs) and 95% confidence intervals (CIs).
Result: During an average of 14 years of follow-up, 441 cardiovascular deaths occurred. After multivariate adjustment including lifestyles, dietary factors, glucose control, and other major carotenoids, higher serum β-carotene concentrations were significantly associated with an elevated risk of cardiovascular mortality in a dose-response manner. Comparing extreme quartiles of β-carotene, the multivariable-adjusted HR (95% CI) was 2.47 (1.62, 3.76) for cardiovascular mortality (P trend =0.002); and per one-unit increment in natural log-transformed serum β-carotene was associated with a 46% higher risk of cardiovascular mortality (P=0.001). Other individual carotenoids (α-carotene, β-cryptoxanthin, lycopene, and lutein/zeaxanthin) were not significantly associated with risk of cardiovascular mortality. Consistent results were observed when stratifying by age, sex, race, body mass index, smoking status, diabetes duration, and HbA1c levels.
Conclusion: Higher concentrations of serum β-carotene, but not other individual carotenoids, were significantly associated with an increased risk of cardiovascular mortality among individuals with T2D. Our findings, if replicated, underscore the need to estimate the optimal serum β-carotene concentrations in individuals with T2D.