DOES OBESITY IMPAIR THE RELEVANCE OF THE SECONDARY HYPERTENSION SCREENING INDICATIONS PROPOSED BY THE GUIDELINES?

Objective: Hypertension is one of the main cardiovascular risk factors. Prevalence of obesity is increasing as is the prevalence of hypertension. Secondary hypertension is frequent but is believed to be rare in obese patients. The prevalence of secondary causes of hypertension in obese patients is unknown, and therefore there is no consensus regarding the indication of screening of secondary hypertension in this population. Our objective was to compare the prevalence and the causes of secondary hypertension in obese and non-obese patients, admitted for secondary hypertension screening according to the guidelines. Design and method: 1066 patients with confirmed hypertension aged 18 to 84 years referred between January 2019 and December 2023 to Bordeaux University hospital, Hypertension Unit, France, with full work-up for secondary hypertension screening, were included in this cross-sectional study. We assessed the prevalence of essential and secondary hypertension and analyzed factors associated with the presence of secondary hypertension in obese patients. Results: In the total cohort, 331 patients (31%) presented with secondary hypertension, the most frequent diagnosis being primary aldosteronism (n = 228; 21,3%). We found no difference in the prevalence of secondary hypertension in patients with a BMI below or above 30 kg/m2(33,2% vs 27,2%, p = 0.184), and no association between BMI as a continuous variable and secondary hypertension diagnosis in univariate logistic regression, despite a clear tendency (OR = 0,98 [0,96-1,00], p = 0,08). In obese patients, multivariate analysis demonstrates that number of antihypertensive drugs above or equal to 2 (OR = 1,75, IC [1.05 – 2,93], p = 0.033) and kalemia below 3,5 mmol/l (OR = 2,56, IC [1.42 – 4,64], p = 0.002) were independently associated with secondary hypertension diagnosis. Conclusions: The prevalence of secondary hypertension is high among hypertensive patients with obesity admitted for secondary hypertension screening in our center, and no different from the prevalence found in non-obese patients. Obesity should not preclude patients from accessing guideline-indicated screening for secondary hypertension.