BACKGROUND - High glycemic index (GI) and glycemic load (GL) are associated with increased levels of oxidative stress and systemic inflammation in the general population. Maintenance hemodialysis (MHD) patients are known to have excessive oxidative stress burden and inflammation. In this study, we examined the relationship between dietary GI or GL and markers of oxidative stress or inflammation among prevalent MHD patients.
METHODS - A registered dietitian obtained GI, GL and other dietary data from 58 MHD patients. Two separate 24-h diet recalls (a hemodialysis day and a non-hemodialysis day) were analyzed using the Nutrition Data System for Research (NDS-R) software. Plasma or serum concentrations of F2-isoprostanes, high sensitivity C-reactive protein (hsCRP), leptin and adiponectin (ADPN) were measured in fasting state. Fat mass was measured by dual-energy X-ray absorptiometry (DEXA). Cross-sectional associations between GI, GL and markers of interest were examined by multiple regression analysis with adjustment for potential covariates.
RESULTS - Mean (±SD) age, body mass index (BMI) and total trunk fat were 47 ± 12 years, 29.5 ± 6.8 kg/m(2) and 16.4 ± 8.8 kg, respectively. Dietary GI was associated with trunk fat (r = -0.182, P = 0.05) but not with F2-isoprostanes and hsCRP. In contrast, GL was significantly associated with F2-isoprostanes (P = 0.002), in unadjusted analysis, which remained in adjusted analyses, adjusting for age and sex (P = 0.005), and after adjusting for BMI, trunk fat and waist/hip ratio (P = 0.004). Addition of leptin or ADPN did not alter the significance of the association. GL also correlated with hsCRP (P = 0.03), but this association was modified by BMI and trunk fat.
CONCLUSIONS - Dietary GL is significantly associated with markers of oxidative stress and inflammation among prevalent MHD patients, independent of the body composition and adipocytokines. These data indicate the importance of the contents of dietary nutrient intake composition and its potential role in determining the metabolic disturbances in MHD patients.