abstract available at the link http://www.medwire-news.md/57/83466/Diabetes/Type_2_diabetes_imbalances_cholesterol_homeostasis.html Type 2 diabetes imbalances cholesterol homeostasis By Jenny Grice 13 July 2009 Diabetes Res Clin Pract 2009; Advance online publication MedWire News: The reciprocal relationship between cholesterol absorption and cholesterol synthesis in men with metabolic syndrome is lost in the presence of Type 2 diabetes, indicating that diabetes causes an imbalance in cholesterol homeostasis, researchers report. The contribution of abnormalities in lipoprotein metabolism to metabolic syndrome-associated dyslipidemia has been well described, but the role of cholesterol metabolism has been less extensively characterized. Gerald Watts (University of Western Australia, Perth, Australia) and co-workers explored the associations between cholesterol metabolism and features of the metabolic syndrome in men with or without Type 2 diabetes, using serum levels of lathosterol and campesterol as indirect measures of cholesterol synthesis and cholesterol absorption, respectively. They recruited 140 men with features of the metabolic syndrome as defined by the National Cholesterol Education Program (NCEP) criteria, and 10 age- and gender-matched, normolipidemic, non-obese men as controls. Plasma lathosterol and campesterol were measured by gas chromatography mass spectrometry, and their ratios to total cholesterol were used to estimate cholesterol metabolism. Reporting in the journal Diabetes Research and Clinical Practice, the authors confirmed previous findings that men with the metabolic syndrome, regardless of Type 2 diabetes status, have higher cholesterol synthesis and lower cholesterol absorption rates compared with non-obese control individuals. They then compared measures of cholesterol metabolism between the subsets of men with (n=58) and without Type 2 diabetes (n=82). They found that the lathosterol-to-cholesterol ratio (an index of cholesterol synthesis) was not altered by diabetes status. In contrast, the campesterol-to-cholesterol ratio (an index of cholesterol absorption) was 36% lower in men with the metabolic syndrome and Type 2 diabetes than in those without diabetes. The results suggest that there is a significant negative association between cholesterol synthesis and cholesterol absorption in men with just the metabolic syndrome, but that this association is lost in men with both the metabolic syndrome and Type 2 diabetes. Age and fasting insulin were independent predictors of the campesterol-to-cholesterol ratio in men with metabolic syndrome and Type 2 diabetes. ?We demonstrated that the homeostatic balance between cholesterol synthesis and absorption is, on average, present in metabolic syndrome in the absence of Type 2 diabetes, and that diabetes nullifies this inverse relationship,? conclude the authors. ?This supports the notion that Type 2 diabetes tends to disturb whole body cholesterol balance, with more profound alterations of cholesterol metabolism,? they add.