Causes of weight gain during insulin therapy with and without metformin in patients with Type II diabetes mellitus.
OBJECTIVE
To determine causes of weight gain during insulin therapy with and without metformin in Type II (non-insulin-dependent) diabetes mellitus.


METHODS
Twenty-six patients with Type II diabetes (body mass index 28+/-1 kg/m2) were treated with insulin alone (n = 13) or insulin and with metformin (n = 13). Components of energy balance (basal metabolic rate, energy intake, glucosuria) were measured at 0 and 12 months.


RESULTS
Glycaemic control improved similarly in patients using (HbA1c 10.5+/-0.3 vs 7.6+/-0.2%, p<0.001) and not using (10.2+/-0.3 vs 7.8+/-0.3%, p < 0.001) metformin. The metformin group required 47 % less insulin than the group not using metformin (p < 0.001). Body weight increased by 3.8+/-0.8 and 7.5+/-1.6 kg (p < 0.05), respectively. Basal metabolic rate and glucosuria were similar at 0 and 12 months in both groups but the metformin group decreased energy intake by 1.12+/-0.46 MJ/day, whereas it remained unchanged in the other group (0.15+/-0.42 MJ/day). Changes in body weight and glycaemia were statistically significant independent determinants of basal metabolic rate. Their change in opposite directions explained why basal metabolic rate remained unchanged.


CONCLUSIONS
Improved glycaemia promotes weight gain by decreasing both basal metabolic rate and glucosuria. Use of metformin decreases weight gain by reducing energy intake and is therefore a useful adjunct to insulin therapy in patients with Type II diabetes.
Mäkimattila
S
S
Department of Medicine, Helsinki University Central Hospital, Finland.
Nikkilä
K
K
Yki-Järvinen
H
H
D000328:Adult; D000368:Aged; D001786:Blood Glucose / Q000378:metabolism; D001823:Body Composition; D003924:Diabetes Mellitus, Type 2 / Q000188:drug therapy* / Q000503:physiopathology; D004359:Drug Therapy, Combination; D002149:Energy Intake; D004734:Energy Metabolism; D005260:Female; D006442:Glycated Hemoglobin / Q000378:metabolism; D006801:Humans; D007004:Hypoglycemic Agents / Q000627:therapeutic use*; D007328:Insulin / Q000097:blood / Q000627:therapeutic use*; D008297:Male; D008687:Metformin / Q000627:therapeutic use*; D008875:Middle Aged; D015430:Weight Gain / Q000187:drug effects
D001786:Blood Glucose; D006442:Glycated Hemoglobin; D007004:Hypoglycemic Agents; D007328:Insulin; D008687:Metformin