Background and objectives: Epidemiological data on the incidence and prevalence of cardiovascular disease in chronic renal failure are scant The objective of the present study is to assess the relationship between renal function, measured by the estimated glomerular filtration rate, and the presence of early or established cardiovascular disease, in a population of hypertensives from primary care.
Patients and methods: Cross-sectional, multicentre study carried out in primary care centres all over Spain. Hypertensive subjects, older than 55 years, were included. In all of them a structured interview including cardiovascular risk factors or disease was performed. Blood pressure was measured following a standard procedure, and serum biochemistry and an electrocardiogram were obtained. Renal function was estimated using the abbreviated MDRD (Modification of Diet in Renal Disease Study Group) equation. For each glomerular filtration rate stratum the odds ratio and 95% confidence interval (CI) of left ventricular hypertrophy or cardiovascular disease were calculated, adjusted by confounding variables.
Results: A total of 13 687 patients (mean age 68.1 years, women 55.4%, diabetics 30.6%, body mass index 28.6 kg/m2) were included. Of these, 26.4% had established cardiovascular diseases and 20.3% electrocardiographic left ventricular hypertrophy. The average serum creatinine was 1.01 mg/dl, creatinine clearance 70.0 ml/min, and glomerular filtration rate 74.0 ml/min per 1.73 m2. Thirty-three patients (0.24%) had glomerular filtration rate < 5 ml/min per 1.73 m2; 89 (0.65%) from 15 to 29; 3745 (27.36%) from 30 to 59; 7798 (56.97%) from 60 to 89; and 2019 (14.75%) higher than 89 ml/min per 1.73 m2. In a multiple regression analysis, after adjusting by age, sex, body mass index, diabetes, systolic and diastolic blood pressure, and smoking, a lower glomerular filtration rate was associated with a higher prevalence of left ventricular hypertrophy. Likewise, a reduction in the glomerular filtration rate was also associated with a higher prevalence of cardiovascular disease.
Conclusions: In hypertensive patients from primary care, the prevalence of cardiovascular disease is inversely proportional to the level of renal function. Estimated glomerular filtration is easy to determine and complements evaluation of the hypertensive patient.