VITAMIN-C INTAKE AND CARDIOVASCULAR-DISEASE RISK-FACTORS IN PERSONS WITH NON-INSULIN-DEPENDENT DIABETES-MELLITUS - FROM THE INSULIN-RESISTANCE ATHEROSCLEROSIS STUDY AND THE SAN-LUIS VALLEY DIABETES STUDY

Background. Persons with non-insulin-dependent diabetes mellitus (NIDD M) are at increased risk for cardiovascular disease, partly due to con comitant worsening of traditional risk factors including dyslipidemia and hypertension. Based on evidence from small, controlled clinical tr ials, we hypothesized that increased intake of vitamin C would be asso ciated with improved cardiovascular disease (CVD) risk factor status a mong community-dwelling persons with NIDDM. Methods. In separate but p arallel statistical analyses, hypotheses were evaluated among persons with NIDDM confirmed by WHO criteria from the Insulin Resistance Ather osclerosis Study (IRAS, n = 520) and from the San Luis Valley Diabetes Study (SLVDS, n = 422). For IRAS, diet and vitamin supplement use was assessed by food frequency interview and for SLVDS, by 24-hr dietary recall interview. Results. Mean vitamin C intake (mg/day) was 275 for IRAS and 133 for SLVDS, including supplements. In cross-sectional regr ession models from each data set, vitamin C intake was not associated with systolic or diastolic blood pressure nor with HDL-C, LDL-C, or tr iglycerides (P values >0.10; adjusted for calories, demographic and li festyle variables, obesity, diabetes duration, and medications). In pr ospective analyses including 285 SLVDS participants, baseline vitamin C intake was not related to any of these CVD risk factors measured an average of 4 years later nor to change in CVD risk factor status durin g the follow-up period. Conclusions: We conclude that, across a wide r ange of intake, vitamin C does not appear to be associated with improv ed CVD risk factor status among community-dwelling persons with diabet es. (C) 1997 Academic Press.