Diabetes Care, Vol 19, Issue 2 160-164, Copyright © 1996 by American Diabetes Association
The effect of metformin on adipose tissue metabolism and peripheral blood flow in subjects with NIDDM
PA Jansson, HS Gudbjornsdottir, OK Andersson and PN Lonnroth
Department of Internal Medicine, Sahlgrenska University Hospital, Goteborg, Sweden.
OBJECTIVE: To examine the effect of metformin on net lactate and glycerol
release in NIDDM subjects, we used abdominal subcutaneous microdialysis
combined with 133Xe clearance. Skeletal muscle blood flow (MBF) was
assessed simultaneously both before and after metformin treatment. RESEARCH
DESIGN AND METHODS: Nine male patients with NIDDM (age 53 +/- 2 years [mean
+/- SE]; BMI 30.2 +/- 1.4 kg/m2; body fat 23.0 +/- 2.6 kg; diabetes
duration 4.6 +/- 1.5 years; six of nine receiving sulfonylurea treatment)
were recruited into an open study. They were studied after an overnight
fast, both before and after 1 week of additional treatment with 500 mg
metformin three times daily. Nine weight- and age-matched nondiabetic
subjects served as a control group. RESULTS: Postabsorptive net
subcutaneous lactate release increased (149 +/- 50 vs. 475 +/- 127 nmol.100
g-1.min-1, P < 0.05) whereas plasma lactate was unchanged after
metformin treatment in the NIDDM patients. The net decrease of glycerol
release 90 min after an oral glucose tolerance test was more pronounced
(110 +/- 30 vs. 199 +/- 20 nmol.100 g-1.min-1, P < 0.05) after metformin
treatment. Both adipose tissue blood flow (ATBF) (1.5 +/- 0.1 vs. 2.3 +/-
0.2 ml.100 g-1.min-1, P < 0.01) and MBF (3.2 +/- 0.4 vs. 4.2 +/- 0.5
ml.100 ml-1.min-1, P < 0.05) increased after metformin treatment.
CONCLUSIONS: In this open study, postabsorptive net lactate release in
abdominal subcutaneous adipose tissue was clearly increased in NIDDM
patients after metformin treatment. Basal ATBF as well as MBF was improved
after metformin treatment. Whether this reflects enhanced metabolic control
or is a drug-specific effect remains to be established.