Sympathetic activity and response to ACE inhibitor (enalapril) in normotensive obese and non-obese subjects

Background. Angiotensinogen has been proposed as a possible link between obesity and hypertension because the adipocyte produces angiotensinogen and contains the enzymes required for its conversion. Moreover, sympathetic overactivity has been reported in obese subjects. The aim of this study was to compare heart sympathetic activation and serum angiotensinogen levels in obese and non-obese normotensive subjects, their relationship, and the effect of a drug that modifies the renin-angiotensin system. Methods. Serum angiotensinogen, leptin, lipids, glucose, and insulin levels were measured and 24-h electrocardiograph monitoring was carried out in 41 (20 non-obese and 21 obese) volunteers before and after administration of 5 mg enalapril twice/day for 7 days. Results. Obese subjects had higher values than non-obese subjects for % body fat (35.1±4.6 vs. 30.5±5.2; p = 0.005), triglycerides (1.93±0.9 vs. 1.25±0.7 g/L, p = 0.002), insulin (114.8±82. 5 vs. 45.9±22.2 pmol/L), leptin (31.4±20.4 vs. 14.1±11.2 ng/mL, p = 0.002), and LF/HFn index (4.3±2.9 vs. 2.2±1.3, p