Prevalence and determinants of resistant hypertension in a sample of patients followed in Italian hypertension centers: results from the MINISAL-SIIA study program.

ABSTRACT

The aim of this study was to detect the prevalence of resistant hypertension (RH), allowing for adherence to appropriate lifestyle measures according to European Society of Hypertension-European Society of Cardiology (ESH-ESC) 2013 guidelines, in a sample of 1284 hypertensive subjects participating at the MINISAL-SIIA study. Hypertensive patients were recruited in 47 Italian centres, recognised by the Italian Society of Hypertension. Anthropometric indexes, blood pressure and 24-h urinary sodium (Na24h) and potassium (K24h) excretion were measured. Data on antihypertensive therapy were available for 1177 (92%) subjects. The population was divided into three groups (North, Central and South), according to their geographical location. Accounting only at the treatment criteria, the prevalence of RH was 8.2% (96/1177). RH prevalence in the southern, central and northern regions was respectively 1, 3.8 and 3.3% (P<0.001). Participants with RH were older and showed a higher body mass index (BMI) and waist circumference compared with other subjects (P<0.005). RH risk was statistically significant (P<0.01) increased of 1.52-fold (95% confidence interval (CI)1.20-1.92) for one unit increase in s.d. score of age (11 years), and 1.50-fold (95% CI1.22-1.83) for one unit increase in s.d. score of BMI (4.5 kg m-2). Including in RH diagnosis also the adherence to appropriate lifestyle measures, such as dietary salt restriction (Na24h <100 mmol) and normal BMI (18-25 kg m-2), RH prevalence felt respectively to 2.2% (26/1177) and 0.8% (9/1177). In conclusion in this national sample of Italian hypertensive population, among participants following both drug treatment and lifestyle modifications advises, the 'true' RH prevalence appears to be particularly low.