Telmisartan partially activates the peroxisome proliferator-activated receptor gamma (PPAR gamma), which may ameliorate the accumulation of visceral adipose tissues and sensitise insulin action. Nineteen patients with essential hypertension and metabolic syndrome were randomly assigned to receive 40 mg of telmisartan (TELMI group) once daily or 80 mg of valsartan (VAL group) once daily for 24 weeks. The visceral fat area (VFA) measured by computed tomography (CT) was significantly reduced from 150.4 +/- 15.5 to 127.7 +/- 16.7 cm(2) in the TELMI group (p=0.049). Although VFA was also reduced in the VAL group from 169.8 +/- 14.8 to 155.3 +/- 14.8 cm(2), the change was not significant (p=0.173). There were no significant changes in body weight, body mass index (BMI), waist circumference, subdermal fat area (SFA), fasting plasma glucose, and homeostasis model assessment of insulin resistance (HOMA-IR) in comparison to the baseline and follow-up data in both groups. In conclusion, telmisartan may have a benefit in the reduction of visceral adipose tissues in comparison to valsartan.