(HealthDay News) — For patients with hypertension and obstructive sleep apnea (OSA), treatment with losartan does not lead to significant reductions in aldosterone, but the treatment is tied to aldosterone reductions in patients with hypertension but without OSA, according to a study published online Aug. 22 in the Annals of the American Thoracic Society.
Erik Thunström, M.D., Ph.D., from the University of Gothenburg in Sweden, and colleagues treated newly diagnosed patients with hypertension and with (54 patients) or without OSA (35 patients) with losartan daily for six weeks. In a second six-week study, all subjects with OSA continued to receive losartan and were randomized to CPAP or no CPAP. Subjects without OSA continued to take losartan.
The researchers found that in the first six-week study losartan significantly increased renin and reduced aldosterone levels in patients without OSA. Among patients with OSA there was no significant decrease in aldosterone levels. Add-on CPAP treatment was associated with lower aldosterone levels; reductions were more pronounced in measures of sympathetic activity. After treatment with losartan and CPAP there were no significant changes in inflammatory markers.
“Hypertensive patients with OSA responded to losartan treatment with smaller reductions in aldosterone compared to hypertensive patients without OSA,” the authors write. “Sympathetic system activity seemed to respond primarily to add-on CPAP treatment in patients with newly-discovered hypertension and OSA.”
The study was partially funded by ResMed Sweden, which supplied some of the CPAP devices.