Issue 141 Item 11 Rosiglitazone Improves Insulin Sensitivity, Lowers Blood Press

Insulin sensitizers may benefit nondiabetic patients with hypertension. In nondiabetic hypertensive patients, treatment with rosiglitazone improves insulin sensitivity, reduces systolic and diastolic blood pressure, and leads to improvements in several markers of cardiovascular risk, according to a report in the January issue of Diabetes Care.

First, any patients on ACE inhibitors were switched to other hypertensives. After 10 weeks, the patients were taken off antihypertensive medication for a 2-week period at which point ambulatory blood pressure was monitored and blood tests for cardiovascular risk factors were completed. They also received a euglycemic-hyperinsulinemic clamp with 6.6-[2H2] glucose infusion.

The patients were then given 4 mg rosiglitazone b.i.d. and their usual antihypertensive medication for 14 weeks. A 2-week period on rosiglitazone only followed, after which the baseline tests were repeated.

Between the two tests, fasting plasma glucose did not change (83 mg/dL versus 82 mg/dL, p = 0.60), according to the investigators. However, fasting insulin decreased from 16.1 to 12.5 U/mL (p < 0.001). There was an increase in total glucose disposal during the clamp (p < 0.001), "with no change in suppression of hepatic glucose output."

Mean 24-h systolic and diastolic blood pressure were significantly decreased (-4 mm Hg and -5mm Hg, p < 0.02 and p < 0.0001, respectively). The investigators observed a correlation between the decline in systolic blood pressure and the improvement in insulin sensitivity (p < 0.005).

"Markers of cardiovascular risk including triglycerides, plasminogen activator inhibitor-I, and C-reactive protein declined significantly in both groups after rosiglitazone treatment," Dr. Raji and colleagues note. "Both LDL and HDL cholesterol declined, resulting in no change in the LDL-to-HDL ratio."

They conclude that insulin sensitizers may benefit nondiabetic patients with hypertension, even though the mechanism is not fully understood. Diabetes Care 2003;26:172-178