PREVALENCE AND ETIOLOGY OF SECONDARY HYPERTENSION IN YOUNG HYPERTENSIVE TERTIARY CARE PATIENTS

Objective: Secondary hypertension prevalence varies widely across studies, and scarce data exist on the clinical characteristics of young adults with secondary hypertension. Current European guidelines recommend screening hypertensive patients under 30 years old for secondary hypertension, but the evidence behind this recommendation is limited. Our objective was to assess the etiology of hypertension among young adults and to determine the characteristics linked with secondary hypertension in these patients. Design and method: We retrospectively studied 243 Finnish young hypertensive adults aged <30 years (mean age 25.5 years; 49% women). The initial examination of these patients was performed at the Internal Medicine Department of the University Central Hospital between 2002 and 2023. Clinical data, including medical history, medication use, and laboratory test results were collected from electronic health records. We classified the patients under three hypertension subtypes: primary hypertension, secondary hypertension, or exogenic hypertension. Using logistic regression, we examined the association between participants characteristics and hypertension subtype (primary versus secondary). Results: A total of 127 patients had primary hypertension, while 104 patients had secondary hypertension. The most common cause for secondary hypertension was renal disease (n=77), most frequently due to diabetic nephropathy (n=22). Other causes of secondary hypertension were rare, with sleep apnea being the second most common (n=13). Individuals with a history of diabetes mellitus had odds of 3.20 (95% confidence interval [95% CI], 1.11–5.90; P=0.007) for having secondary hypertension. A plasma creatinine increase of 1 mmol/l was associated with 1.03-fold (95% CI 1.01–1.04; P=0.002) odds of secondary hypertension. Conclusions: In this population, renal parenchymal disease and diabetes mellitus emerged as the most important risk factors for secondary hypertension. Apart from renal disease and sleep apnea that can be easily screened in primary care, other forms of secondary hypertension are extremely rare in young adults with hypertension. Extensive universal screening for secondary hypertension for all hypertensive patients <30 years may be unnecessary.