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

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.Oksidatif stres, diabetes mellitusun (DM) patofizyolojisinde önemli rol oynamaktadır. Kolestrolün spontan veya enzimatik oksidasyonundan kaynaklanan oksisteroller, oksidatif stresin invazif olmayan potansiyel biyobelirteçleridir. Bu çalışmanın amacı diyabetik hastalarda oksidatif stresin biyobelirteçleri olarak oksisterol türlerini (7-ketokolesterol ve cholestan-3β, 5α, 6β-triol) değerlendirmektir. Plasma 7-ketokolesterol ve kolestan-3β, 5α, 6β-triol düzeyleri tip 1 (n = 26), tip 2 (n = 80) DM hastalarında ve sağlıklı kontrollerde (n=205) güvenilir, duyarlı ve spesifik LC-MS/MS yöntemi kullanılarak kantite edildi. Oksisteroller ile diabetik hastaların klinik/biyokimyasal özellikleri arasında korelasyonlar belirlendi. Tip 1 DM (42.75 ± 11.54 ng/mL) ve belirgin olarak tip 2 DM (84.80 ± 43.71 ng/mL) hastalarında plazma 7-ketokolesterol düzeyleri, kontrol gubuna göre (18.97 ± 3.83 ng/mL) anlamlı derecede yüksek bulundu (p < 0.001). Tip 1 ve belirgin şekilde tip 2 DM hastalarında, sağlıklı kontrollere (10.106 ± 3.94 ng/mL) göre yüksek kolestan-3β, 5α, 6β triol (32.30 ± 8.93 ng/mL ve 65.69 ± 35.34 ng/mL) değerleri saptandı (p<0,001). Plazma oksisterol düzeyleri ile HbA1c, serum total kolesterol, LDL, VLDL, trigliserit, risk faktörlerinin sayısı ve VKİ düzeyleri arasında pozitif korelasyon tespit edildi (p