Pressor Responses to Voluntary Breathhold is Exaggerated in African Americans with Sleep Apnea and With Hypertension

Introduction: Previously, we demonstrated that the chemo-reflex control of sympathetic nerve activity (SNA) is exaggerated in patients with obstructive sleep apnea (OSA), in that the SNA and systolic arterial pressure (SAP) response to a voluntary breath hold was greater than in individuals without OSA. This previous study did not distinguish ethnic differences, nor was the response in hypertensive patients assessed systematically. In this pilot study, we hypothesized that the SAP response to apnea (as an index of the chemo-reflex sensitivity), is exaggerated in African-Americans (AA) with OSA compared to healthy AA individuals, and that the presence of hypertension exacerbated this response. Methods: Standard auscultatory blood pressure was measured in triplicate during quiet rest and immediately following a 20 sec voluntary end-expiratory breath hold (apnea) in the following groups of AA volunteers: 18 normotensive (7 with OSA) and 28 hypertensive (16 with OSA). Results: Post-apnea change in SAP increased significantly more in patients with OSA than those without OSA, p Conclusions: These data demonstrate that measurement of the SAP response to a voluntary breath hold can distinguish AA subjects with OSA from those without OSA, and that the presence of hypertension may exaggerate these responses.