Systematic review of the effect of telmisartan on insulin sensitivity in hypertensive patients with insulin resistance or diabetes.

WHAT IS KNOWN AND OBJECTIVE Telmisartan is an angiotensin receptor blocker (ARB) originally developed for the treatment of hypertension. It can also partially activate peroxisome proliferator-activated receptor (PPAR)-γ, which may improve insulin sensitivity. This effect may prove useful in hypertensive patients with insulin resistance or diabetes mellitus. Such activity is more marked than that observed with other ARBs. This systematic review and meta-analysis evaluated the benefit of telmisartan on insulin sensitivity compared with that of other ARBs in hypertensive patients who had either insulin resistance or diabetic states. METHODS Clinical trials of telmisartan were identified through electronic searches (MEDLINE, CINAHL, Scopus, and The Cochrane Library) up to and including May 2011. Studies were included if they met the following inclusion criteria: (i) randomized controlled trials that compared telmisartan with other ARBs in hypertensive patients who had insulin resistance or type 2 diabetes mellitus; (ii) using telmisartan as an add-on therapy or a monotherapy for treating hypertension; and (iii) reporting fasting plasma glucose (FPG) and fasting plasma insulin (FPI), or homeostasis model assessment of insulin resistance (HOMA-IR), or adiponectin as an outcome measure. Treatment effect was estimated with the mean difference in the final value of FPG, FPI, HOMA-IR and adiponectin between the telmisartan and the control groups. RESULTS AND DISCUSSION Eight trials involving a total of 763 patients met the inclusion criteria. Telmisartan was superior to other ARBs in reducing FPG level (mean difference, -8·63 mg/dL; 95% CI -12·29 mg/dL to -4·98 mg/dL; P < 0·00001) and increasing adiponectin level (mean difference, 0·93 μg/dL; 95% CI 0·28 μg/dL to 1·59 μg/dL; P = 0·005). At 80 mg dose, telmisartan may reduce FPI level and HOMA-IR. WHAT IS NEW AND CONCLUSIONS The available evidence suggests a beneficial effect of telmisartan in improving insulin sensitivity in hypertensive patients with insulin resistance or diabetes as demonstrated by the decrease in FPG and increase in adiponectin levels. The effect in decreasing FPG was greater with 80 mg dose than with the 40 mg dose. FPI and insulin resistance may be improved with 80 mg of telmisartan.