title: Prevalence and prognostic role of resistant hypertension in chronic kidney disease patients.
abstract: OBJECTIVE
  This study sought to evaluate in chronic kidney disease (CKD) prevalence and prognosis of true resistant hypertension (RH) (i.e., confirmed by ambulatory blood pressure [ABP] monitoring).
  
  
  BACKGROUND
  In CKD, uncontrolled hypertension is a major risk factor, but no study has properly investigated the role of RH.
  
  
  METHODS
  We prospectively studied 436 hypertensive CKD patients under nephrology care. Four groups were constituted by combining 24-h ABP with diagnosis of RH (office blood pressure ≥130/80 mm Hg, despite adherence to ≥3 full-dose antihypertensive drugs including a diuretic agent or ≥4 drugs): control (ABP <125/75 mm Hg without RH); pseudoresistance (ABP <125/75 mm Hg with RH); sustained hypertension (ABP ≥125/75 mm Hg without RH); and true resistance (ABP ≥125/75 mm Hg with RH). Endpoints of survival analysis were renal (end-stage renal disease or death) and cardiovascular events (fatal and nonfatal cardiovascular event).
  
  
  RESULTS
  Age was 65 ± 14 years, men 58%, diabetes 36%, cardiovascular disease 30%, median proteinuria 0.24 (interquartile range 0.09 to 0.83) g/day, estimated glomerular filtration rate 43 ± 20 ml/min/1.73 m(2), office blood pressure 146 ± 19/82 ± 12 mm Hg, and 24-h ABP 129 ± 17/72 ± 10 mm Hg. True resistant patients were 22.9%, and pseudoresistant patients were 7.1%, whereas patients with sustained hypertension were 42.9%, and control subjects were 27.1%. Over 57 months of follow-up, 109 cardiovascular events and 165 renal events occurred. Cardiovascular risk (hazard ratio [95% confidence interval]) was 1.24 (0.55 to 2.78) in pseudoresistance, 1.11 (0.67 to 1.84) in sustained hypertension, and 1.98 (1.14 to 3.43) in true resistance, compared with control subjects. Corresponding hazards for renal events were 1.18 (0.45 to 3.13), 2.14 (1.35 to 3.40), and 2.66 (1.62 to 4.37).
  
  
  CONCLUSIONS
  In CKD, pseudoresistance is not associated with an increased cardio-renal risk, and sustained hypertension predicts only renal outcome. True resistance is prevalent and identifies patients carrying the highest cardiovascular risk.
authors.affiliation: Department of Nephrology, Second University of Naples, Naples, Italy.
authors.forename: Luca
authors.initials: L
authors.lastname: De Nicola
authors.affiliation: Department of Medicine, Veterans Administration San Diego Healthcare System and University of California at San Diego Medical School, San Diego, California.
authors.forename: Francis B
authors.initials: FB
authors.lastname: Gabbai
authors.affiliation: Division of Nephrology, Department of Medicine, Indiana University School of Medicine and Richard L. Roudebush Veterans Administration Medical Center, Indianapolis, Indiana.
authors.forename: Rajiv
authors.initials: R
authors.lastname: Agarwal
authors.affiliation: Medicine and Public Health, Second University of Naples, Naples, Italy.
authors.forename: Paolo
authors.initials: P
authors.lastname: Chiodini
authors.affiliation: Department of Nephrology, Second University of Naples, Naples, Italy.
authors.forename: Silvio
authors.initials: S
authors.lastname: Borrelli
authors.affiliation: Department of Nephrology, Salerno Hospital, Salerno, Italy.
authors.forename: Vincenzo
authors.initials: V
authors.lastname: Bellizzi
authors.affiliation: Department of Nephrology, Nola Hospital, Nola, Italy.
authors.forename: Felice
authors.initials: F
authors.lastname: Nappi
authors.affiliation: Department of Nephrology, Second University of Naples, Naples, Italy.
authors.forename: Giuseppe
authors.initials: G
authors.lastname: Conte
authors.affiliation: Department of Nephrology, Second University of Naples, Naples, Italy. Electronic address: roberto.minutolo@unina2.it.
authors.forename: Roberto
authors.initials: R
authors.lastname: Minutolo
mesh_terms: D000368:Aged; D001794:Blood Pressure; D018660:Blood Pressure Monitoring, Ambulatory / Q000379:methods; D015897:Comorbidity; D005260:Female; D006801:Humans; D006973:Hypertension / Q000150:complications* / Q000175:diagnosis / Q000453:epidemiology*; D008297:Male; D008875:Middle Aged; D010349:Patient Compliance; D015995:Prevalence; D011379:Prognosis; D016016:Proportional Hazards Models; D011446:Prospective Studies; D051436:Renal Insufficiency, Chronic / Q000150:complications* / Q000175:diagnosis / Q000453:epidemiology*; D012307:Risk Factors; D016896:Treatment Outcome