Associations of Diet Quality and Blood Serum Lipoprotein Levels in a Population at High Risk for Diabetes: The Strong Heart Family Study

BACKGROUND/OBJECTIVES: Previous studies consistently report that diet quality is inversely associated with risk of cardiovascular disease (CVD) and type 2 diabetes. However, few studies have assessed the association of diet quality with serum lipoproteins, an intermediate-marker of cardio-metabolic health, or assessed whether type 2 diabetes modifies these associations. This study assessed associations of diet quality (evaluated using the Alternative Healthy Eating Index (AHEI)), and the interaction of diet quality with diabetes, on total cholesterol (TC), triglycerides (TG), low density lipoprotein (LDL-C), high density lipoprotein (HDL-C), apolipoprotein A (apoA1) and apolipoprotein B (apoB) among American Indians (AIs). SUBJECTS/METHODS: Participants comprised AIs who participated in the Strong Heart Family Study (SHFS)--a study of CVD and its risk factors in 12 AI communities. Generalized estimated equations (GEE) were used to examine the: (1) cross-sectional associations of diet quality (as determined by AHEI) with serum lipoproteins (n=2 200); and (2) the prospective associations of the AHEI measured at baseline with serum lipoproteins (n=1 899). RESULTS: The association of AHEI with TC, LDL-C, and ApoB differed according to diabetes status. In prospective analysis, AHEI was associated with more favorable levels of TC (p=0.029) and LDL-C (p=0.008) among participants with diabetes independent of other demographic, behavioral, and health factors. The association of diet quality with TC, LDL-C, and ApoB were much weaker among participants without diabetes. There was no association of diet quality with TG, HDL-C, or ApoA. CONCLUSIONS: The associations of diet quality with TC, LDL-C, and ApoB differ according to diabetes status.