Effects of Dietary l-Arginine on Nitric Oxide Bioavailability in Obese Normotensive and Obese Hypertensive Subjects

Obesity related hypertension is a major risk factor for resistant hypertension. We do not completely understand the mechanism(s) underlying the development of obesity related hypertension which hinders the development of novel treatment strategies for this condition. Data from experimental studies and small clinical trials indicate that transport of l-arginine, the substrate for nitric oxide (NO), and subsequent NO production are reduced in obesity induced hypertension. Reduced NO bioavailability can induce hypertension via multiple mechanisms. Mirmiran et al. recently analyzed data from a large population study and found that the association between dietary l-arginine and serum nitrate and nitrite was weakened in obese hypertensive subjects compared to obese normotensives. These data suggest that l-arginine dependent NO production is impaired in the former group compared to the latter which may represent a novel mechanism contributing to hypertension in the setting of obesity.