Characteristics of patients resistant to antihypertensive drug therapy.

In order to determine the features that characterize refractory hypertension (RH), patients aged less than 65 years in a hypertension clinic were screened. Thirty-six patients on triple drug therapy with a supine diastolic blood pressure (DBP) of greater than or equal to 5 mmHg above an identified target pressure (90-100 mmHg), or a systolic blood pressure (SBP) greater than or equal to 170 mmHg for the last 6 months (greater than or equal to 3 measurements) underwent a thorough clinical investigation. The frequency of renal artery stenosis (RAS) in the RH patients was 30%. The non-RAS patients had a low occupational status, 76% being either manual workers or unskilled non-manual workers (reference group: 42%; P less than 0.01). They were more obese (body mass index (BMI) 28.8 vs. 25.8; P less than 0.01), and had a longer duration of hypertensive disease. RH patients had a higher prevalence of non-insulin-dependent diabetes mellitus (18 vs. 6%; P less than 0.05), and showed a higher prevalence of nervous complaints and mental distress (44% vs. 12%; P less than 0.001) and musculo-skeletal pain (39% vs. 7%: P less than 0.001). It is suggested that refractory hypertension should be investigated and treated bearing psychosocial factors in mind, concurrently with a screening for secondary hypertension.