[Hypertension in hemodialysis patients in Andalucia]

Hypertension is a common and difficult clinic problem in patients undergoing cronical hemodialysis and exerts a deleterious effect on mordibidy and mortality in end stage renal disease. Identification of potentially reversible factors associated with hypertension would be rational fist step in designing and effective therapeutic strategy. Our study aimed to document the prevalence of hypertension in hemodialysis patients in Andalucia and identify and characterise the demographic, epidemiological, clinical factors and dialysis regimens associated with hypertension.

The study population included 2,789 patients enrolled in 46 hemodialysis centers in Andalucia on 2002. Hypertension was defined as requiring the use of antihypertensive drugs. Patients wre classified as hypertensive and no hypertensive. Demographic, comorbidity, anaemia, inflammatory and nutritional data were collected in both groups. Hypertensive patients were divided into 4 groups of severity according to the number of antihypertensive drugs received. Comparisons between groups were done.

Our results show a hypertension prevalence of 53.8% in comparing clinical data of no hypertensive and hypertensive patients, we observed that patients with hypertension were significantly younger (60.2 +/- 15.6 vs 63.5 +/- 15 years; p < 0.001) and had shorter time on dialysis (months) (56.5 +/- 60 vs 67.3 +/- 68.2; p = 0.001). Coronary heart disease (p < 0.001) and diabetes (p < 0.001) were associated with hypertension. Hypertensive patients had higher levels of creatinine (mg/dl) (8.8 +/- 2.3 vs 8.5 +/- 2.3; p = 0.006) and serum albumin (g/dl) (3.9 +/- 0.4 vs 3.8 +/- 0.4; p < 0.001), and lower C-reactive protein (CRP) (mg/dl) (12.3 +/- 19.7 vs 16.1 +/- 25.15; p < 0.001). Hypertensive patients received less time of dialysis (233 +/- 25 vs 237 +/- 25 minutes/session; p < 0.001 and 703 +/- 85 vs 718 +/- 88 minutes/week; p < 0.001) and lower dialysis dose (urea reduction ratio (URR), Kt/V Daugirdas 2.a gen) (70.7 +/- 7.8 vs 72.0 +/- 7.8; p < 0.001; 1.33 +/- 0.28 vs 1.37 +/- 0.29; p < 0.001). A significative correlation existed between hypertension and the use of low-flux membranes. Interdialytic weight gain (kg) was higher in hypertensive patients (2.1 +/- 0.9 vs 2.0 +/- 0.9; p = 0.002). In a multiple logistic regression analysis the independent risk factors defining hypertension in hemodialysis patients were: age (OR = 0.98; CI = 0.976-0.988, p < 0.001), time on dialysis (OR = 0.99; CI = 0.997-0.999; p = 0.006), creatinine (OR = 1.07; CI = 1.024-1.116; p 0.002). CRP (OR = 0.99; CI = 0.989-0.998; p = 0.003). Albumin (OR = 1.36; CI = 1.106-1.668; p = 0.004). Interdialytic weight gain (OR = 1.11; CI = 1.000-1.224; p = 0.049), duration of the session (OR = 0.99; CI = 0.986-0.993; p < 0.001), low-flux membranes (OR = 0.74; CI = 0.618-0.883; p = 0.001), diabetes (OR = 1.81; CI = 1.435-2.274; p < 0.001) and coronary hear disease (OR = 1.52; CI = 1.218-1.900; p < 0.001). There was a relationship between hypertension severity and age (p < 0.001), interdialytic weight gain (p < 0.001) and albumin (p < 0.001).

1) Hypertension prevalence in hemodiaysis patients in Andalucia was 53.8%. 2) Hypertensive patients: are younger; have shorter time on dialysis; receive shorter hemodialysis sessions; show excessive interdialytic weight gain. 3) Coronary heart disease and diabetes are risk factors for hypertension. 4) There are a relationship between hypertension severity and age, interdialytic weight gain and serum albumin. 5) An effective hypertension therapeutic strategy in hemodialysis patients must include: increase time of hemodialysis, strict control of dry weight and prevention and treatment of others cardiovascular risk factors.