Antihypertensive treatment is frequently needed in
type 2 diabetes. In this study we measured the rates of total, oxidative, and nonoxidative
glucose disposal,
glycogen synthesis, glycolysis, endogenous
glucose production, and
lipid oxidation using a 4-h euglycemic (approximately 5 mmol/L) hyperinsulinemic (approximately 300 pmol/L) clamp in combination with a dual
glucose tracer infusion ([3-(3)H]- and [U-14C]
D-glucose) and indirect calorimetry in 40 nonobese subjects with
type 2 diabetes. Subjects were studied twice: after a 4-week run-in period and after a 16-week period of double blind, randomized treatment with 4-6 mg/day
lacidipine, a
calcium channel blocker (n = 19), or 10-20 mg/day
lisinopril, an
angiotensin-converting enzyme inhibitor (n = 21).
Antihypertensive treatment resulted in a significant increase in total
glucose disposal during
insulin clamp as well as in basal and
insulin-stimulated nonoxidative
glucose disposal rates. On the contrary, oxidative
glucose disposal was significantly decreased by
antihypertensive treatment, mainly in the basal state. The changes in
glucose disposal rates were not significantly different in subjects treated with
lacidipine and in those treated with
lisinopril. The suppression of endogenous
glucose production during
insulin clamp was significantly greater after
lacidipine than after
lisinopril. These results suggest that treatment of subjects with
type 2 diabetes with either
lacidipine or
lisinopril has no adverse effect on
glucose metabolism. Conversely, both drugs seem to improve
insulin sensitivity.