The effect of metformin on blood glucose control in overweight patients with Type 1 diabetes.
OBJECTIVE
In a randomized, double-blind, cross-over study, we investigated the effect of metformin on blood glucose control and daily insulin dose in overweight patients with Type 1 diabetes.


METHODS
We studied 15 C-peptide-negative patients, aged 48 +/- 12 years, with a body mass index of 31.3 +/- 2.6 kg/m(2). Each patient had a 'screening visit', followed by a 4-week 'run-in' period. This was followed by two separate 16-week 'study' (treatment) periods, separated by a 4-week 'wash-out' period. Patients received either metformin or placebo during the 'study' periods, in random order.


RESULTS
HbA(1c) was significantly lower following 16 weeks of treatment with metformin (7.8 +/- 1.1%) compared with baseline (8.5 +/- 1.4%; P < 0.005) and placebo (8.6 +/- 1.2%; P < 0.005). Fasting plasma glucose, following 16 weeks of metformin treatment, was significantly lower (8.3 +/- 2.8 mmol/l) compared with baseline (12.4 +/- 3.0 mmol/l; P < 0.01) and placebo (12.6 +/- 3.4 mmol/l; P < 0.01). Compared with baseline (60 +/- 14 units), total daily insulin dose was significantly lower following the addition of metformin (50 +/- 13 units; P < 0.05) and this final total daily insulin dose in the metformin group was lower compared with placebo (58 +/- 12 units, P < 0.05). Body weight did not change following metformin or placebo treatment.


CONCLUSIONS
Metformin can effectively improve glycaemic control and reduce the total daily insulin dose in overweight people with Type 1 diabetes.
Khan
A S A
AS
Department of Diabetes and Endocrinology, Blackpool Victoria Hospital, Blackpool, UK.
McLoughney
C R
CR
Ahmed
A B
AB
D001786:Blood Glucose / Q000378:metabolism*; D018592:Cross-Over Studies; D003922:Diabetes Mellitus, Type 1 / Q000097:blood / Q000188:drug therapy* / Q000378:metabolism; D004311:Double-Blind Method; D005260:Female; D006442:Glycated Hemoglobin / Q000378:metabolism; D006801:Humans; D007004:Hypoglycemic Agents / Q000627:therapeutic use*; D007328:Insulin / Q000008:administration & dosage*; D008297:Male; D008687:Metformin / Q000627:therapeutic use*; D008875:Middle Aged; D050177:Overweight / Q000502:physiology*
D001786:Blood Glucose; D006442:Glycated Hemoglobin; D007004:Hypoglycemic Agents; D007328:Insulin; D008687:Metformin