Elevated 1-h post-load plasma glucose levels in subjects with normal glucose tolerance are associated with a pro-atherogenic lipid profile

Background and aims Evidence suggests that plasma glucose concentration ≥155 mg/dl at 1h during an oral glucose tolerance test (OGTT) (NGT 1 h-high) predicts both development of type 2 diabetes (T2DM) and cardiovascular events, among adults with normal glucose tolerance (NGT). An atherogenic lipid profile is detectable in subjects with impaired glucose tolerance (IGT) and T2DM. Whether individuals with NGT-1h-high also exhibit a pro-atherogenic lipid profile is still uncertain. Methods The study cohort includes 1011 non-diabetic Caucasian adults participating in the CATAMERI study. All participants were submitted to anthropometrical evaluation before undergoing an OGTT. Subjects were categorized into NGT 1 h-low (1 h glucose < 155 mg/dl), NGT 1 h-high, IGT, and newly diagnosed T2DM. Lipid profile includes triglycerides, total and HDL cholesterol, apolipoprotein B (ApoB) and ApoA-1. Results 510 subjects were NGT 1 h-low, 211 NGT 1 h-high, 232 IGT and 58 were newly diagnosed T2DM. Triglyceride and ApoB levels were significantly higher in NGT 1 h-high, IGT and T2DM subjects compared to NGT 1 h-low, and HDL cholesterol was significantly lower. Triglycerides-to-HDL cholesterol ratio was significantly higher in NGT 1 h-high, IGT and T2DM groups compared with NGT 1 h-low individuals. The ApoB/ApoA-1 ratio was significantly higher in NGT 1 h-high, IGT and T2DM groups than in the NGT 1 h-low group. NGT 1 h-high, IGT and T2DM subjects exhibited reduced LDL/ApoB ratio compared with NGT 1 h-low. Noticeably, there were no significant differences in ApoB/ApoA-1 and LDL/ApoB ratios when comparing NGT 1 h-high with IGT and T2DM. Conclusions Individuals with NGT 1-h-high exhibited an atherogenic lipid pattern qualitatively and quantitatively similar to that observed in individuals with IGT and newly diagnosed T2DM.