The Effect of Glycemic Index and Glycemic Load on Glucose Control, Lipid Profiles and Anthropometrics Among Low-Income Latinos With Type 2 Diabetes: A Dissertation

Abstract

Background The incidence of type 2 diabetes has increased dramatically, particularly among Latinos. While several studies suggest the beneficial effect of lowering glycemic index and glycemic load in patients with type 2 diabetes, no data exists regarding this issue in the Latino population. The purpose of this study was to determine the effect of lowering glycemic index and glycemic load on diabetes control, lipid profiles and anthropometrics among Latinos with type 2 diabetes. Methods Subjects participated in a 12 month randomized clinical trial. The intervention targeted diabetes knowledge, attitudes and behavioral capabilities related to diabetes self management with content including nutrition and physical activity. The nutrition protocol emphasized reduction in glycemic index, fat, salt and portion size and increase in fiber. The control group was given usual care. Measurements included Hba1c, fasting glucose, total cholesterol (TC), low density lipoproteins (LDL) and high density lipoproteins (HDL), HDL:LDL ratio, TC:HDL ratio, waist circumference and BMI and were collected at baseline, 4 and 12-months. Results Two hundred fifty two Latino adults with type 2 diabetes participated in the study. Baseline mean HbA1C was 8.98% (SD=1.87), BMI was 34.76 kg/cm (SD=6.94), age was 56 (SD=11.18) years and 76% were female. Reduction in glycemic index was positively associated with a reduction in logHbA1c (p=0.006), HDL:LDL ratio (p=0.037) and waist circumference (p=0.003) overtime, but not with fasting glucose, TC, LDL and HDL, TC:HDL ratio, body weight or BMI. No significant associations were found between glycemic load and any measures. Conclusion Results suggest that lowering glycemic index may have a positive effect on some markers of diabetes control, lipid profiles and anthropometrics among Latinos with type 2 diabetes, but not others. While statistically significant reductions in GI and GL were noted, the actual reduction was small. Thus, greater reduction in GI and GL may be needed for clinical significance and greater effect on metabolic outcomes. Future research should target populations with higher baseline GI and GL.