Comprehensive evaluation of secondary causes of hypertension: Integrated screening for obstructive sleep apnea and...

Obstructive sleep apnea (OSA) and primary aldosteronism (PA) are common and treatable conditions that are often overlooked in the evaluation of hypertension. We assessed the prevalence and relative contribution of identifiable causes of hypertension using a comprehensive diagnostic approach.

In this cross-sectional study, consecutive adults (aged 18-80 years) with hypertension from the endocrinology OPD were screened for secondary causes. All participants underwent standardized blood pressure assessment and systematic evaluation for major causes of secondary hypertension (biochemical screening with plasma aldosterone and renin concentrations, with confirmatory testing among screen-positive individuals, level I polysomnography for OSA, renal Doppler ultrasonography for renal artery stenosis, echocardiographic assessment for coarctation of the aorta, and biochemical testing for pheochromocytoma and other endocrine causes, when indicated).

131 patients were included (mean age, 47.8 ± 12.5 years; 63.4% male; mean body mass index, 29.9 ± 6.3 kg/m²). Moderate-to-severe obstructive sleep apnea (apnea-hypopnea index ≥15 events/h) was present in 84.5% of patients and represented the most frequent identifiable contributor to hypertension. PA was diagnosed in 8.4% of patients and was more common among leaner individuals and those with resistant hypertension. Other causes, including renovascular disease, pheochromocytoma, and coarctation of the aorta, were rare (<2% each). OSA, PA, and resistant hypertension frequently coexisted in patients.

OSA was the predominant identifiable contributor to hypertension, whereas PA remained an important complementary diagnosis. Comprehensive screening for both sleep-related and endocrine causes may improve etiologic classification and management of hypertension, particularly in younger and resistant cases.