Association of caffeine intake with all-cause and cardiovascular mortality in diabetes and prediabetes

Abstract

Backgroud: The association between caffeine intake and mortality in prediabetes and diabetes is not well defined. This study was designed to investigate the association between caffeine intake and all-cause mortality and cardiovascular disease (CVD) mortality in adults with prediabetes and diabetes in the United States.

Methods: This analysis included 18,914 adult patients with diabetes and prediabetes from the National Health and Nutrition Examination Survey (NHANES) 2003-2018. Follow-up extended to December 31, 2019. Weighted Cox proportional hazards regression models were used to estimate the hazard ratios (HR) and 95% confidence intervals (CI) for all-cause mortality and CVD mortality.

Results: During 142,460 person-years of follow-up, there were 3,166 cases of all-cause mortality and 1,031 cases of CVD mortality recorded. In the fully adjusted models, caffeine intake showed a significant dose-response association with the risk of all-cause mortality and CVD mortality in individuals with diabetes and prediabetes. When comparing extreme quartiles of caffeine intake, the multivariable-adjusted hazard ratio for all-cause mortality was 0.78 (0.67-0.91) (P for trend = 0.007); however, there was no significant association with the risk of CVD mortality. Results remained consistent in stratified analyses by sex, age, race/ethnicity, education level, family income-poverty ratio, BMI, hypertension, smoking status, alcohol intake, and HEI-2015.

Conclusions: This study suggests that caffeine intake is significantly inversely associated with the risk of all-cause mortality in individuals with diabetes and prediabetes. In individuals with prediabetes, there is also a significant inverse association between caffeine intake and CVD events, but this association is not present in those with diabetes.

Keywords: Caffeine; Diabetes; Mortality; NHANES; Predibetes.

Fig. 1

Flowchart of participants in this study

Fig. 2

Multivariable adjusted restricted cubic splines forassociations of caffeine intake with all-cause and cardiovascular mortality among diabetes and prediabetes from NHANES 2003–2018. A: Dose-response relationship between caffeine intake and all-cause mortality among diabetes and prediabetes in NHANES 2003–2018. P for non linear < 0.001. B: Dose-response relationship between caffeine intake and cardiovascular mortality among diabetes and prediabetes in NHANES 2003–2018. P for non linear = 0.1010. The four nodes of the restricted cubic spline (RCS) are set at the 5th, 35th, 65th, and 95th percentiles of caffeine intake distribution. To determine whether the optimal model is linear or non-linear, we conducted a likelihood ratio test and calculated the p-value for non-linearity. Complete model were adjusted for sex (female or male), age (continuous), race/ethnicity (non-Hispanic white, non-Hispanic black, Mexican American, and other races), BMI (< 25.0, 25.0-29.9, ≥ 30), education level (less than high school, high school or equivalent, university or higher), family income-to-poverty ratio (≤ 1.3, 1.3–3.5, > 3.5), smoking status (never smoked, former smoker, current smoker), alcohol intake (non-drinker, moderate drinker, heavy drinker), hypertension (yes or no), eGFR (continuous), HbA1c (< 7%, ≥ 7%), HDL-C (continuous), TC (continuous), SUA (continuous), HEI-2015 (continuous), red meat intake (oz. eq./d, continuous), white meat intake (oz. eq./d, continuous), total protein (continuous), carbohydrate intake (continuous), total sugars (continuous), total energy (continuous), total saturated fatty acids (continuous), total polyunsaturated fatty acids (continuous), dietary fiber (continuous), vitamin E (continuous), vitamin A (continuous). The pale pink shaded area represents a 95% confidence interval