Body Mass Index Predicts Aldosterone Production in Normotensive Adults on a High-Salt Diet

Bentley-Lewis, Rhonda
Adler, Gail K.
Perlstein, Todd
Seely, Ellen W.
Hopkins, Paul N.
Williams, Gordon H.
Garg, Rajesh

Divisions of Endocrinology, Diabetes, and Hypertension (R.B.-L., G.K.A., E.W.S., G.H.W., R.G.) and Cardiology (T.P.), Brigham and Women’s Hospital and Harvard Medical School, Boston, Massachusetts 02115; and Division of Cardiology and Cardiovascular Genetics (P.N.H.), University of Utah, Salt Lake City, Utah 84112

Received May 15, 2007. Accepted August 21, 2007.

Address all correspondence and requests for reprints to: Rajesh Garg, M.D., Brigham and Women’s Hospital, Division of Endocrinology, Diabetes, and Hypertension, 221 Longwood Avenue, Boston, Massachusetts 02115. E-mail: [email protected].

This work was supported by NIH Grants HL47651, HL59424, and DK63214; Specialized Center of Research in Molecular Genetics of Hypertension Grant P50HL055000; and General Clinical Research Centers Grants M01RR02635, M01RR00095, and M01RR00064. R.B.-L. was supported by NIH Grant 5K30RR22292-9. T.P. was supported by National Heart, Lung, and Blood Institute Training Grant T32 HL07604.

Disclosure Statement: The authors have no disclosures.

First Published Online August 28, 2007

Abbreviations: AngII, Angiotensin II; BMI, body mass index; HDL, high-density lipoprotein; HOMA, homeostasis model assessment; LDL, low-density lipoprotein; PRA, plasma renin activity.

Journal of Clinical Endocrinology & Metabolism 92(11):p 4472-4475, November 2007.

Context:

The mechanisms underlying obesity-mediated cardiovascular disease are not fully understood. Aldosterone and insulin resistance both are associated with obesity and cardiovascular disease.

Objectives:

The objectives of this study were to test the hypotheses that aldosterone production is elevated and associated with insulin resistance in overweight adults on a high-sodium diet.

Participants/Interventions:

Healthy normotensive adults were categorized as lean body mass index (BMI) less than 25 kg/m² (n = 63) or overweight BMI 25 kg/m² or greater (n = 57). After 7 d of a high-sodium diet, participants fasted overnight and remained supine throughout hemodynamic and laboratory assessments and angiotensin II (AngII) stimulation.

Results:

The overweight group, compared with the lean group, had higher 24-h urinary aldosterone (9.0 ± 0.8 vs. 6.6 ± 0.5 μg per 24 h; P = 0.003) and higher AngII-stimulated serum aldosterone (11.4 ± 1.0 vs. 9.0 ± 0.6 ng/dl; P = 0.04). There were no differences in 24-h urinary cortisol or sodium or supine measurements of plasma renin activity, serum aldosterone, or serum potassium. The homeostasis model assessment of insulin resistance was predicted by urinary aldosterone excretion (r = 0.32, P = 0.03) and serum aldosterone response to AngII stimulation (r = 0.28, P = 0.02) independent of age and BMI.

Conclusion:

Urinary aldosterone excretion and AngII-stimulated aldosterone are increased in overweight, compared with lean, normotensive adults. The correlation of these measures of aldosterone production with insulin resistance suggests a potential role for aldosterone in the pathophysiology of obesity-mediated insulin resistance.