Dietary carbohydrate intake and high-sensitivity C-reactive protein in at-risk women and men

Background The quality and quantity of dietary carbohydrate intake, measured as dietary glycemic load (GL), are associated with a number of cardiovascular disease (CVD) risk factors and, in healthy young women, are related to increased high-sensitivity C-reactive protein (hsCRP) concentrations. Our objective was to determine if GL is related to hsCRP and other measures of CVD risk in a population of sedentary, overweight, dyslipidemic middle-aged women and men enrolled in an exercise intervention trial (STRRIDE). Methods This was a cross-sectional evaluation of the relationships between measures of dietary carbohydrate intake, calculated from food frequency questionnaire data, and CVD risk factors, including plasma hsCRP, measured in 171 subjects. Results After adjusting for energy intake, GL and other measures of carbohydrate intake were not independently related to hsCRP (P > .05 for all). In the analyses performed separately for each sex, only the quantity of carbohydrate intake was independently related to hsCRP (R2 = 0.28, P < .04), and this relationship was present for women but not for men. The strongest relationship identified between GL and any CVD risk factor was for cardiorespiratory fitness (R2 = 0.12, P < .02); an elevated GL was associated with a lower level of fitness in all subjects, and this relationship persisted even when the findings were adjusted for energy intake and sex (R2 = 0.48, P < .03). Conclusions In middle-aged, sedentary, overweight to mildly obese, dyslipidemic individuals, consuming a diet with a low GL is associated with better cardiorespiratory fitness. Our findings suggest that the current literature relating carbohydrate intake and hsCRP should be viewed with skepticism, especially in the extension to at-risk populations that include men.