Diabetes Care, Vol 20, Issue 9 1430-1434, Copyright © 1997 by American Diabetes Association
Glibenclamide, but not acarbose, increases leptin concentrations parallel to changes in insulin in subjects with NIDDM
SM Haffner, M Hanefeld, S Fischer, K Fucker and W Leonhardt
Department of Medicine, University of Texas Health Science Center at San Antonio 78284-7873, USA.
OBJECTIVE: To hypothesize if glibenclamide, which increases insulin levels,
also increases leptin concentrations. RESEARCH DESIGN AND METHODS: Leptin
is a hormone that regulates weight in mice. In obese humans, leptin
concentrations are increased, suggesting resistance to the effects of this
hormone. Although short-term infusion of insulin during the
hyperinsulinemiceuglycemic clamp does not increase leptin concentration,
the effect of oral antidiabetic agents on leptin concentration is unknown.
Differing effects can be expected, since glibenclamide acts via stimulation
of insulin secretion, whereas acarbose inhibits alpha-glucosidases of the
small intestine and has no direct effect on insulin levels. We examined the
effect of acarbose (n = 4), glibenclamide (n = 6), and placebo (n = 6) on
insulin and leptin levels during 24-h periods before and after 16 weeks of
therapy. RESULTS: We observed a significant diurnal variation in leptin
concentrations. This was inversely related to insulin levels during the
24-h follow-up with usual diet. Neither the placebo nor acarbose altered
leptin concentrations. However, glibenclamide increased leptin
concentrations parallel to insulin levels. There were only minor changes in
body weight during the l6-week follow-up: decrease in the placebo group
(change -0.5 kg/m2, P = 0.07) and acarbose (change -0.7 kg/m2, P = 0.046)
and increase in the glibenclamide group (change 0.8 kg/m2, P = 0.27).
However, individual subjects who gained weight had increases in their
leptin concentrations. The diurnal variation in leptin concentrations was
preserved after glibenclamide. CONCLUSIONS: Glibenclamide increases
circadian leptin and insulin concentrations, whereas acarbose does not.
This observation may help to explain weight gain in subjects treated with
glibenclamide and stable weight in those treated with acarbose in the long
run.