Analysis Of Oxysterol Species In Type 1 And Type 2 Diabetes Mellitus By Lc-ms/ms Method

Abstract

Oxidative stress plays an important role in the pathophysiology of diabetes mellitus (DM). Oxysterols, which resulted from spontaneous or enzymatic oxidation of cholesterol, are potentially non-invasive biomarkers of oxidative stress in vivo. The aim of the present study was to evaluate oxysterol species (7-ketocholesterol and cholestan-3β,5α,6β-triol) as biomarkers of oxidative stress in diabetic patients. 7-ketocholesterol and were quantified by using a reliable, sensitive and specific LC-MS/MS method in type 1 (n=26) and type 2 (n=80) DM patients as well as in healthy controls (n=205). The correlation between oxysterols and clinical/biochemical characteristics of the DM patients were also determined. Plasma 7-ketocholesterol levels in type 1 DM (42.75±11.54 ng/mL) and more clearly in type 2 DM (84.80±43.71 ng/mL) patients were significantly higher than those in control subjects (18.97±3.83 ng/mL) (p<0,001). Type 1 and more significantly type 2 DM patients also demonstrated high levels of (32.30±8.93 ng/mL and 65.69±35.34 ng/mL) compared to healthy controls (10.106±3.94 ng/mL) (p<0,001). Positive correlations of oxysterol levels with glucose, HbA1c, serum total cholesterol, LDL, VLDL, triglyceride, number of risk factors and BMI were observed (p<0,001). Strong significant relations between oxysterols and microvascular complications as well as usage of drugs were determined. In conclusion, plasma oxysterol levels in DM, particularly in type 2 diabetic patients, may yield complementary information in oxidative stress. Oxidative stress is likely a causative factor in the development of insulin resistance. Furthermore, our LC-MS/MS method for determining oxysterols is the only study in diabetic patients so far. It is more sensitive and reliable method when compared to GC-MS method. More effort is needed to establish the clinical utility of oxysterols as sensitive biomarkers of oxidative stress to foresee and monitor the potential complications of DM.