Noncholesterol sterols are both products of cholesterol synthesis and plant origin. Sitosterol and campesterol are indicators of cholesterol absorption and they are not produced in the organism. The ratio of endogenous cholesterol absorption and synthesis may be assessed by sitosterol and campesterol in conjunction with lathosterol and squalene examination. Three groups of patients were formed and relationships serum noncholesterol sterols, cholesterol and triacylglycerides, glycosylated hemoglobin and statins effect were studied. In 38 Type 2 diabetics (59.9 years, BMI 29.8 kg/m2, HbA1c 7.6 %, C-peptide 0.82 nmol/l) and in 40 non-diabetics (37.2 years, BMI 25.4 kg/m2, HbA1c 5.2%, C-peptide 0.85 nmol/l) plant sterols serum concentration were measured: lathosterol (diabetics 10.64, non-diabetics 6.04 µmol/l, P = 0.09), squalene (diabetics 3.42, non-diabetics 1.78 µmol/l,P< 0.01), sitosterol (diabetics 3.91, non-diabetics 3.80 µmol/l,P = 0.60) and campesterol (diabetics 7.91, non-diabetics 8.85 mmol/l, P = 0.09). In 56 Type 2 diabetics (15 of them on statin therapy) were found relationships of sterols to HbA1c, BMI, statin therapy, CRP, serum cholesterol and the constant rate for glucose disappearance from plasma after intravenous insulin tolerance test (KITT; P = 0.001) in regression model. Lathosterol (cholesterol synthesis, not cholesterol absorption) is influenced by statin therapy. Campesterol and sitosterol are negatively influenced by diabetes compensation. Decompensation of diabetes probably decreased cholesterol absorption. BMI influences cholesterol synthesis positively and cholesterol absorption negatively. Cholesterol synthesis is therefore increased and absorption decreased in obesity as an insulin-resistant state. Sqalene levels and therefore cholesterol synthesis is increased by insulin-resistance state degree. Systemic inflammation decreases plant sterols level (sitosterol and campesterol), and therefore cholesterol absorption. Any significant diferrences in noncholesterol sterols levels were not found in 72 nondiabetics with cardiovascular disease on statin therapy or without statins. In 63 Type 2 diabetics on diet significantly higher lathosterol and lower sitosterol and campesterol level were found; the same result being detected by index sterol/cholesterol. In 15 Type 2 diabetics on statin therapy were significantly lower lathosterol level and latosterol/cholesterol ratio. Even though total cholesterol is not higher in diabetics, the endogenous cholesterol synthesis may be increased. Our results show that diabetics with higher lathosterol and triacylglycerides level could be appropriate for more intesive statin therapy. Low cholesterol absorption and increased cholesterol endogenous production are probably components of the metabolic syndrome with relatively normal cholesterol level.

        Key words: plant sterols, lathosterol, squalene, sitosterol, campesterol, cholesterol, C peptide, glycosylated hemoglobin (HbA1c), insulin resistance, statins, Type 2 diabetes, metabolic syndrome.