Obesity has been shown to be associated with increased left ventricular mass (LVM) and heart sympathetic activity even in nonhypertensive subjects. These factors are predictors of cardiovascular morbidity and mortality independent of other traditional risk factors. We evaluated the effect of losartan and spironolactone on LVM and heart sympathetic activity in prehypertensive obese subjects. A 16-week blinded randomized trial was performed in middle-aged men selected from a Health Public program. Anthropometric and clinical variables were measured at baseline and after losartan (50 mg/day; n ¼ 25) or spironolactone (25 mg/day; n ¼ 25) treatment. Heart sympathetic activity was evaluated with 60-min electrocardiograph monitoring, and spectral analysis was carried out. LVM was measured by echocardiography according to Devereux and Reicheck's formula indexed for body height (m 2.7 ) to account for obesity. Anthropometric variables, systolic, and diastolic blood pressure levels decreased in both groups of treatment without statisticall difference between them. Losartan increased heart rate variability (from 70.0 to 82.3 ms; P ¼ 0.01), and decreased low frequency-high frequency index (from 6.6 to 4.9; P ¼ 0.001), and LVM (from 49.2 to 45.2 g; P ¼ 0.004). In the multiple regression analysis for factors associated with reduction in LVM; treatment with losartan, and decrease in SBP were the only factors included in the model (R 2 ¼ 0.60; P ¼ 0.003). To conclude losartan, but not spironolactone, decreased LVM and heart sympathetic overactivity in prehypertensive obese subjects after 16 weeks of treatment. Regression on LVM was associated with reduction on SBP levels.

No abstract

An improved method of inducing diabetes in dogs was developed. This method included 90% pancreatectomy, 2 mg/kg streptozotocin (STZ) perfused into pancreaticoduodenal artery, and the fixation suture of the duodenum to the costo-abdominal wall. Vasopressin injection administered to the animals before surgery reduced bleeding. All dogs used in this procedure survived and became diabetic. One month after the procedure the pancreatic islets were reduced in volume and the number compared with pancreas tissue obtained during the surgery. Acinar tissue remained with a normal histology, and exocrine function maintained the physiological parameters, except for a soft faecal consistency. We conclude that this procedure is effective in inducing experimental diabetes in dogs.