Glycemic and lipid responses to glucomannan in Thais with type 2 diabetes mellitus.
OBJECTIVE
To evaluate the benefits of glucomannan supplement on glycemic and lipid controls in type 2 diabetic patients.


METHODS
A single-blind, placebo-controlled, crossover trial with two treatments separated by a 2-week washout period was performed in 10 men and 10 women with type 2 diabetes mellitus. Two separated protocols of experiments were sequentially followed. Initially, purified glucomannan (1 g) or placebo was ingested 30 min before 75-g glucose load to evaluate their effects on glucose absorption and insulin secretion in oral glucose tolerance test (OGTT). Later, the glycemic and lipid changes after 4-week intervention with 3 g/day glucomannan comparing to the placebo were determined. The standard OGTT was performed before and after ending of each intervention.


RESULTS
Glucomannan taken before performing the OGTT can lower the rise of blood glucose and insulin from 1 to 2 hour in comparison with the placebo, though a statistically significance of insulin was not achieved. Long-term glucomannan supplement significantly reduced the 120-min glucose area under the curve of OGTT. Glucomannan also decreased the rise of low-density lipoprotein cholesterol (LDL-C). Reductions of HOMA-insulin resistance index and body mass index were detected in glucomannan-treated group though the former was shown only in females. No within- and between-group differences of insulin, fructosamine, and other lipids were observed in glucomannan- nor placebo- treated groups.


CONCLUSIONS
In type 2 diabetes, pre-prandial glucomannan ingestion attenuated a rise of blood glucose without significantly affecting insulin levels. Long-term supplement of glucomannan to the regular diabetic regimen lessened post challenge glucose AUC and impeded the rise of LDL-C. Supplement of glucomannan may be beneficial to the glycemic and lipid controls in type 2 diabetes mellitus.
Department of Physiology, Faculty of Medicine, Siriraj Hospital, Mahidol University, Bangkok, Thailand. sisch@mahidol.ac.th
Supornpim
S
Chearskul
Somkiat
S
Sangurai
Wannee
W
Nitiyanant
Wantanee
W
Kriengsinyos
Suwattanee
S
Kooptiwut
Tasma
T
Harindhanavudhi
D000328:Adult; D000368:Aged; D019540:Area Under Curve; D001786:Blood Glucose / Q000187:drug effects*; D015992:Body Mass Index; D002400:Cathartics / Q000494:pharmacology*; D008078:Cholesterol, LDL / Q000187:drug effects; D003924:Diabetes Mellitus, Type 2 / Q000503:physiopathology*; D005260:Female; D005951:Glucose Tolerance Test; D038321:Glycemic Index; D006305:Health Status Indicators; D006801:Humans; D007328:Insulin; D007333:Insulin Resistance; D008055:Lipids / Q000097:blood*; D008297:Male; D008351:Mannans / Q000494:pharmacology*; D008875:Middle Aged; D013785:Thailand
D001786:Blood Glucose; D002400:Cathartics; D008078:Cholesterol, LDL; D007328:Insulin; D008055:Lipids; D008351:Mannans; C022901:(1-6)-alpha-glucomannan