Blood pressure control and comorbidity in a nephrology clinic.

Background: Many patients with established hypertension have poorly controlled blood pressure (BP). We studied demographic and clinical characteristics related to hypertension and analyzed the relationships between BP control and comorbidity.

Methods: This study was based on 414 consecutive hypertensive out-patients referred to our nephrology clinic. We recorded systolic and diastolic BP, age, gender, body mass index, total cholesterol, family history of hypertension, glomerular filtration rate (GFR), 24-hr proteinuria, diabetes, coronary artery disease, smoking habits and antihypertensive drug treatment. BP control was considered optimal if BP was < 130/80 mmHg in patients with diabetes or chronic kidney disease (CKD), if BP was < 125/75 mmHg in CKD with proteinuria > 1 g/24 hr and if BP was < 140/90 mmHg in patients with no comorbidity. Multivariate logistic regression analysis was used to investigate the association between BP control and predictors.

Results: Only 26.6% of patients had adequately controlled BP. Eighty-five percent of patients aged > 65 yrs had uncontrolled systolic hypertension. Univariate analysis showed a significant association between poor BP control and age >65 yrs, family history of hypertension, diabetes, CKD with or without proteinuria > 1 g/24 hr and total cholesterol > 220 mg/dL. Multivariate logistic regression showed that age > 65 yrs, diabetes and CKD with or without proteinuria > 1 g/24 hr were significantly and independently associated with poor BP control.

Conclusions: Inadequate hypertension control is a common cause for referral to our out-patient nephrology clinic. Our data confirm that elderly patients, diabetic patients and nephropathic patients are difficult to treat; and therefore, deserve the highest quality clinical attention.