Objectives: The present study was designed to evaluate effects of konjac glucomannan (KGM) supplement (3.6 g/day) for 28 days on blood lipid and glucose levels in hyperlipidemic type 2 diabetic patients and the possible mechanism for the reductions in blood lipid levels.
Methods: Twenty-two diabetic subjects (age 64.2 + 8.4 years, BMI 25.5 + 3.2 kg/m(2)) with elevated blood cholesterol levels (fasting glucose between 6.7-14.4 mmol/L), but currently not taking lipid-lowering medication, were recruited to participate in a two 28-day period, randomized, double-blind, crossover clinical trial. Fasting blood samples drawn on the initial and final days of each period were determined for plasma lipids and glucose levels. Feces collected at the end of each experimental period were analyzed for neutral sterol and bile acid contents.
Results: Compared with placebo, KGM effectively reduced plasma cholesterol (11.1%, p = 0.0001, adjusted alpha = 0.006), LDL-cholesterol (20.7%, p = 0.0004, adjusted alpha = 0.006), total/HDL cholesterol ratio (15.6%, p = 0.0005, adjusted alpha = 0.007), ApoB (12.9%, p = 0.0001, adjusted alpha = 0.006) and fasting glucose (23.2%, p = 0.002, adjusted alpha = 0.008). Plasma triglyceride, HDL-cholesterol, LDL/HDL cholesterol, postprandial glucose and body weight were not significant after adjustment by the Bonferroni-Hochberg procedure. Fecal neutral sterol and bile acid concentrations were increased by 18.0% (p = 0.004) and 75.4% (p < 0.001), respectively, with KGM supplement.
Conclusions: The KGM supplement improved blood lipid levels by enhancing fecal excretion of neutral sterol and bile acid and alleviated the elevated glucose levels in diabetic subjects. KGM could be an adjunct for the treatment of hyperlipidemic diabetic subjects.