Hypertension in obese black women is not caused by increased sympathetic vascular tone

Alejandro Marinos, Alfredo Gamboa, Jorge E. Celedonio, Brock A. Preheim, Luis E. Okamoto, Claudia E. Ramirez, Amy C. Arnold, Andre Diedrich, Italo Biaggioni, Cyndya A. Shibao

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Abstract

Background--Black women have one of the highest prevalence rates of hypertension and obesity in the United States. We previously reported that sympathetic activation induced by obesity is a significant contributor to hypertension in white patients. It is unknown whether sympathetic activity similarly contributes to hypertension in obese black women. Methods and Results--We studied 42 obese women (16 white, body mass index 36±4 kg/m2, 44% with hypertension; 26 black, body mass index 35±4 kg/m2, 46% with hypertension). Antihypertensive medications were discontinued for 2 weeks before the day of the study. All patients underwent complete autonomic blockade with trimethaphan at a dosage of 4 mg/min. Resting sympathetic activity determined from muscle sympathetic nerve recordings was similar between obese black women with hypertension and those with normotension. In whites, sympathetic activity was elevated in obese patients with hypertension compared with normotension; the decrease in mean arterial blood pressure produced by trimethaphan was greater in obese white patients with hypertension compared with those with normotension (-26.8±9.7 mm Hg versus -14.8±7.9 mm Hg, P=0.02). In contrast, there was no difference in the depressor responses induced by trimethaphan between obese black women with hypertension and those with normotension (-15.5±10.5 mm Hg versus -12.3±10.2 mm Hg, P=0.45). Mean arterial blood pressure remained elevated in obese blacks with hypertension compared with those with normotension during trimethaphan infusion (83.7±15.0 mm Hg versus 71.7±9.8 mm Hg, P=0.02). Heart rate increased similarly with trimethaphan between white (P=0.11) and black (P=0.76) women with hypertension and normotension. Conclusions--These findings suggest that sympathetic activity does not contribute to hypertension in obese black women and provide further evidence for racial differences in hypertension mechanisms.

Original languageEnglish (US)
Article numbere006971
JournalJournal of the American Heart Association
Volume6
Issue number11
DOIs
StatePublished - Nov 1 2017

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All Science Journal Classification (ASJC) codes

  • Cardiology and Cardiovascular Medicine

Cite this

Marinos, A., Gamboa, A., Celedonio, J. E., Preheim, B. A., Okamoto, L. E., Ramirez, C. E., Arnold, A. C., Diedrich, A., Biaggioni, I., & Shibao, C. A. (2017). Hypertension in obese black women is not caused by increased sympathetic vascular tone. Journal of the American Heart Association, 6(11), [e006971]. https://doi.org/10.1161/JAHA.117.006971