Outstanding Improvement of the Advanced Lipoprotein Profile in Subjects with New-Onset Type 1 Diabetes Mellitus After Achieving Optimal Glycemic Control
Abstract Background: An altered lipoprotein profile is often hidden in normolipidemic subjects with uncontrolled type 1 diabetes mellitus (T1D). Conceivably, its amelioration after glycemic control may be overlooked in controlled T1D subjects. In this regard, we investigated the influence of glycemic optimization on lipoprotein subfraction parameters in normolipidemic new-onset T1D subjects.Methods: Twelve subjects at onset of T1D (5 women and 7 men) were studied. Serum lipid and advanced lipoprotein profiles were determined by routine laboratory methods and 1H-NMR spectroscopy shortly after diabetes diagnosis (baseline), and after achieving optimal glycemic control (HbA1c<7%) at a follow-up of 11.3 to 25.6 weeks.Results: Advanced lipoprotein analysis revealed a significant reduction from baseline in plasma concentrations of triglycerides (TG) and cholesterol (C), and in apolipoprotein (Apo)B-containing lipoproteins of treated subjects (VLDL-TG: -21%, LDL-TG: -36%, IDL-TG: -32%, LDL-TG: -36%, P<0.05; VLDL-C: -46%, IDL-C: -46%, LDL-C: -16%; P<0.05). Additionally, neither VLDL-TG and LDL-TG nor LDL-C of T1D subjects at follow-up differed from those of non-diabetic subjects. Decreased VLDL and LDL lipids were mainly attributed to concomitant reductions in the concentration of medium-sized VLDL (-39%) and medium-sized LDL (34%) and, to a lesser extent, to large-sized LDL (13%), respectively. Notably, proatherogenic IDL characteristics and related surrogates of atherogenicity were resolved upon intensive glycemic control. However, neither the concentration of HDL-P, nor the relative proportion of HDL sizes was influenced by the glucose-lowering therapy.Conclusions: In otherwise normolipidemic T1D subjects according to the conventional lipid profile, the achievement of optimal glycemic control after diabetes onset is associated with normalization of profound derangements in ApoB-containing lipoproteins (VLDL, IDL, and LDL). Whether higher cardiovascular risk in poorly controlled T1D is partially mediated by these proatherogenic lipid alterations should be elucidated by further studies.
