RENAL DISEASE AND ASSOCIATED CARDIOVASCULAR RISK FACTORS IN RESISTANT HYPERTENSION: THE I-DEMAND STUDY

Background: Resistant hypertension (RH) is defined by most guidelines as blood pressure that remains above goal despite use of at least three antihypertensive agents of different classes, including a diuretic, prescribed at optimal doses. Few data are available on the clinical characteristics and on the prevalence of different forms of organ damage in these patients.
Aim: This analysis is to evaluate the prevalence of RH in the large population of the “Italy Developing Education and awareness on MicroAlbuminuria in patients with hyperteNsive Disease (I-DEMAND) study”, an observational, cross-sectional, multicenter study aimed at determining prevalence of microalbuminuria and its correlates among Italian hypertensive patients attending out-patient referral clinics. CKD was defined as glomerular filtration rate (GFR) less than 60 ml/min per 1.73 m (Modification of Diet in Renal Disease equation) or urine albumin to creatinine ratio of at least 2.5 mg/mmol in men and of at least 3.5 mg/mmol in women or both.
Results: A total of 3,754 study treated patients with renal data available were considered for this analysis: 47% women, mean age was 62 ± 11 years and 38% had diabetes mellitus. Resistant hypertension was observed in 271 patients (7.1%). Patients with RH were older (mean age 67 ± 9 vs. 61 ± 11 years, p < 0.01), had higher glucose values (129 ± 41 vs. 117 ± 39 mg/dl, p < 0.001), BMI (29 ± 45 vs. 28.5 ± 5 mg/dl, p < 0.005) and triglycerides (169 ± 107 vs. 145 ± 94 mg/dl, p < 0.001). Estimated glomerular filtration rate (MDRD) was lower in RH (59 ± 23 ml/min/1.73 m2 vs. 74 ± 24, p < 0.001), while albuminuria was higher; in addition the prevalence of CKD and of LVH (diagnosed by either ECG or echocardiography) was greater in patients with resistant hypertension.
Conclusion: In a groups of treated hypertensive patients participating to the Italy Developing Education and awareness on MicroAlbuminuria in patients with hyperteNsive Disease (I-DEMAND), the prevalence of RH was relatively high. Patients with RH were older, had higher glucose values and a higher prevalence of cardiac and renal organ damage.