Body Mass Index and Angiotensin-Dependent Control of the Renal Circulation in Healthy Humans

• Published in: Hypertension (Dallas, Tex. 1979) Vol. 46; no. 6; pp. 1316 - 1320
• Main Authors: Ahmed, Sofia B, Fisher, Naomi D.L, Stevanovic, Radomir, Hollenberg, Norman K
• Format: Journal Article
• Language: English
• Published: Philadelphia, PA American Heart Association, Inc 01.12.2005; Hagerstown, MD Lippincott
• Subjects: Adult; Aging - physiology; Angiotensin-Converting Enzyme Inhibitors - pharmacology; Angiotensins - physiology; Arterial hypertension. Arterial hypotension; Biological and medical sciences; Blood and lymphatic vessels; Body Mass Index; Captopril - pharmacology; Cardiology. Vascular system; Clinical manifestations. Epidemiology. Investigative techniques. Etiology; Dose-Response Relationship, Drug; Endocrine kidney. Renin-angiotensin-aldosterone system; Experimental diseases; Female; Fundamental and applied biological sciences. Psychology; Hemodynamics - drug effects; Humans; Linear Models; Male; Medical sciences; Middle Aged; Multivariate Analysis; Reference Values; Renal Circulation - drug effects; Renal Circulation - physiology; Renin - blood; Sodium Chloride, Dietary - administration & dosage; Sodium Chloride, Dietary - pharmacology; Vasodilation; Vertebrates: endocrinology; Vertebrates: urinary system; Peptide hormone; Body mass index; kidney; Octapeptide; Renin; Peptidyl-dipeptidase A; Aspartic endopeptidases; Angiotensin II; Nutritional status; Human; Kidney disease; Obesity; Urinary system disease; Enzyme; Captopril; Nutrition disorder; Weight loss; Enzyme inhibitor; Peptidases; Renin angiotensin system; Risk factor; Hydrolases; Peptidyl-dipeptidases; Antihypertensive agent; Hemodynamics; ACE inhibitor; Comparative study; renin-angiotensin system
• ISSN: 0194-911X; 1524-4563
• DOI: 10.1161/01.HYP.0000190819.07663.da

Obesity is increasingly recognized as a risk factor for renal disease, but the mechanism is unclear. Renal plasma flow response to captopril, as an index of renin-angiotensin system activity, was measured by para-aminohippurate clearance technique in 100 healthy, normotensive subjects in balance on a high-salt diet. Of the 100 subjects, body mass index exceeded 25 in 56 and exceeded 30 in 22. The average vasodilator response to captopril was 27±7 mL/min per 1.73 m (P<0.0001). After adjustment for other predictors of the renal plasma flow response to captopril using a multivariate linear regression model, there was a highly significant relationship between age- and plasma renin activity–adjusted body mass index and the renal plasma flow response to captopril; however, a quadratic model provided a substantially better fit (r=0.55; P<0.0001; P=0.03 versus linear correlation). The strong association between increasing body mass index and angiotensin-dependent control of the renal circulation suggests that this may be a mechanism by which obesity contributes to renal disease. Weight loss should be considered in the overweight or obese patient for renal protection.