Prevalence of hypertension in renal disease

Hypertension (HTN) is very frequent in patients with renal disease and its prevalence increases as renal failure progresses.

We studied the prevalence of HTN in 1921 patients with different nephropathies. Patients on dialysis and renal transplant patients were not included in the study. HTN was defined as SBP>140 and/or DBP>90 mmHg, or requiring antihypertensive therapy.

The prevalence of HTN in the total group of patients with renal diseases was 60.5%, but this prevalence varied widely depending upon the type of underlying nephropathy. The prevalence of HTN was practically universal in patients with renal vascular disease (93%) and in patients with established diabetic nephropathy (87%), and 74% of the patients with polycystic kidney disease, 63% of the patients with chronic pyelonephritis and 54% of the patients diagnosed with glomerulonephritis were hypertensive. The prevalence of HTN in patients with renal insufficiency (80%) is significantly higher than that in patients without renal insufficiency (43% P<0.001). In a multiple logistic regression analysis, the independent risk factors defining HTN in renal patients were: renal failure, age, the presence of diabetes, hypertriglyceridaemia and proteinuria. Antihypertensive treatment consisted of diet alone in 4% of the patients, one drug in 45%, two drugs in 36%, three medications in 13% and more than three drugs in 2.5%. The angiotensin-converting enzyme (ACE) inhibitors were the most frequently prescribed drug (39% of the patients treated in monotherapy) followed by calcium channel blockers (27%), diuretics (18%) and beta-blockers (9%). The most common combined therapy was a diuretic plus an ACE inhibitor. The percentage of patients with BP controlled according to current recommendations for renal patients (BP<130/85) was very low; SBP in only 49% and DBP in 24%. Control of both was only achieved in 10% of the patients.

There is a high prevalence of HTN in renal patients, which depends on the type of nephropathy and the degree of renal failure. Other independent risk factors for HTN in patients with renal disease are: advanced age, the presence of diabetes, hypertriglyceridaemia and the severity of proteinuria. BP control in renal patients is quite poor and should be improved to reduce progression of the renal disease.