[Predictive factors of hypertension in patients with diagnostic doubts of persistent hypertension]. / Factores predictivos de hipertensión arterial en pacientes con dudas diagnósticas de hipertensión mantenida.

ABSTRACT

BACKGROUND: White coat hypertension (WCH) is a prevalent clinical situation which requires a therapeutic management different from persistent hypertension (PH). To distinguish between patients with WCH and uncertain hypertension from patients with PH, an ambulatory blood pressure monitoring (ABPM) is usually indicated, yet it is not available in primary care. Thereby, predictors of WCH on the basis of pre-test (pre-ABPM) clinical characteristics have been suggested. However, little is known about the predictors of PH. The aim of this study was to ascertain predictors of PH in patients referred from the primary care due to suspicion of WCH or uncertain hypertension. PATIENTS AND METHOD: A 24-hours ABPM was performed in 230 consecutive patients referred from primary care because of suspicion of WCH or uncertain hypertension. WCH was defined as an increased office BP with a mean daytime BP, as measured by ABPM, < 135/85 mmHg. Uncertain hypertension was diagnosed when patients had had episodic (2 or more) office BP >140 and/or 90 mmHg together with normal BP determinations. Patients with increased office BP with a mean daytime BP [by ABPM]3 135/85 mmHg were considered as having PH. RESULTS: In 178 patients, ABPM was successful. Eighty-six patients (48.3%) had PH and the remainder (92 patients; 51.7%) were considered as having WCH. In the PH group, there were more males (67.4% vs 43.5%; p < 0.001), patients were older (42.8 [11.8] years vs 35.7 [11.2] years), there were more smokers (39.5 vs 26.1%; p = 0.056), they consumed more alcohol (p = 0.001) and coffee (p < 0.001) and they had higher levels of hemoglobin (p = 0.001) and creatinine (p = 0.003) and lower levels of uric acid (p<0.001) than the WCH group. Also they had an office BP and an ambulatory BP higher than WCH patients. A multivariate logistic regression analysis revealed that PH was significantly associated with a male gender (odds ratio [OR] = 3.26; confidence interval [CI] 1.54-6.88; p = 0.001), office systolic BP > 145 mmHg (OR = 6.53; CI, 2.67-16.11; p < 0.001), age (> 35 years) (OR = 5.03; CI, 2.35-10.78; p < 0.001) and smoking (OR = 3.07; CI, 1.38-6.84; p = 0.005). CONCLUSIONS: Our findings indicate that in patients referred from primary care due to suspicion of WCH or uncertain hypertension, the prevalence of PH was 48.3%. PH was more frequent among men older than 35 years, smokers and those with an ambulatory systolic BP > 145 mmHg.