No sex difference was found for different variables between the diabetic and control groups (data not shown). In the diabetic group, treatment of diabetes had no effect on the different variables. The two groups were similar according to demographic variables ( Table 1 ) and apoE phenotype distribution (data not shown), but blood glucose level was higher in the diabetic group than in the control group. The average serum insulin level was 19.7 ± 1.2 mU/l in the diabetic group and 8.0 ± 0.8 mU/l in the control group (measured randomly in six subjects; P <0.001 from the diabetic group). The reference values of our hospital laboratory were 2-20 mU/l. The dietary variables, fat intake, dietary plant sterols, and cholesterol intake did not differ between the study groups.
Serum total cholesterol was similar between the groups, whereas LDL and HDL cholesterol levels were lower and VLDL cholesterol was higher in the diabetic group than in the control group ( Table 2 ). Serum total and VLDL triglycerides were higher and LDL triglycerides were lower in the diabetic group than in the control group.
Percent cholesterol absorption and the absorbed mass of dietary, total, and biliary cholesterol were ~30% (P < 0.01) lower in the diabetic group than in the control group ( Table 3 ). Cholesterol synthesis was significantly higher in the diabetic group than in the control group. Cholesterol excretion as neutral and total steroids, bile acid synthesis, and cholesterol turnover tended to be higher in the diabetic group than in the control group.
In the diabetic group, percent cholesterol absorption was unrelated to serum or LDL cholesterol concentrations, but tended to relate inversely to serum and VLDL triglyceride levels (r = -0.486 for serum and r = -0.492 for VLDL, P = 0.06 for both). Cholesterol absorption efficiency and the total mass of cholesterol absorbed were significantly related to serum total and HDL cholesterol only in the control group (HDL: r = +0.7098 and r = +0.7187, P <0.01 for both). Cholesterol absorption efficiency was negatively associated with fecal neutral sterols only in the control group (r = -0.641, P < 0.01), less consistently with cholesterol synthesis (diabetic group: r = -0.242 control group: r = -0.331, NS for both). Blood glucose was associated with fecal bile acids and fecal neutral sterols (r = +0.603 and r = +0.501, P <0.05 for both) and cholesterol synthesis (Fig. 1); in the control group, it was associated with fecal neutral steroids (r = +0.551, P <0.05), but was unrelated to cholesterol absorption efficiency (diabetic group: r = -0.210; control group: r = -0.140, NS for both).
Correlation between blood glucose and cholesterol synthesis. Diabetic group: y = 0.005x - 0.042, r = 0.663, P < 0.01; control group: y = 0.001x + 3.296, r = 0.590, P < 0.05.
Diabetes Care. 2002;25(9) © 2002 American Diabetes Association, Inc.
Cite this: Diabetes Contributes to Cholesterol Metabolism Regardless of Obesity - Medscape - Sep 01, 2002.