A population-based survey of Chronic REnal Disease In Turkey--the CREDIT study

Abstract

Background: Chronic kidney disease (CKD) is a growing health problem worldwide that leads to end-stage kidney failure and cardiovascular complications. We aimed to determine the prevalence of CKD in Turkey, and to evaluate relationships between CKD and cardiovascular risk factors in a population-based survey.

Methods: Medical data were collected through home visits and interviews. Serum creatinine, blood glucose, total cholesterol, triglycerides, HDL, LDL and uric acid were determined from 12-h fasting blood samples, and spot urine tests were performed for subjects who gave consent to laboratory evaluation.

Results: A total of 10 872 participants were included in the study. The final analysis was performed on 10 748 subjects (mean age 40.5 ± 16.3 years; 55.7% women) and excluded 124 pregnant women. A low glomerular filtration rate (GFR) (< 60 mL/min/1.73 m(2)) was present in 5.2% of the subjects who were evaluated for GFR, while microalbuminuria and macroalbuminuria were observed in 10.2% and 2% of the subjects, respectively. The presence of CKD was assessed in subjects who gave consent for urinary albumin excretion measurement (n = 8765). The overall prevalence of CKD was 15.7%; it was higher in women than men (18.4% vs. 12.8%, P < 0.001) and increased with increasing age of the subjects. The prevalence of hypertension (32.7% in the general population), diabetes (12.7%), dyslipidaemia (76.3%), obesity (20.1%) and metabolic syndrome (31.3%) was significantly higher in subjects with CKD than subjects without CKD (P < 0.001 for all).

Conclusions: The prevalence of CKD in Turkey is 15.7%. Cardiovascular risk factors were significantly more prevalent in CKD patients.

Fig. 1

Percentage of subjects according to glomerular filtration rate with respect to gender and age groups. There was a significant relation between the stage of glomerular filtration rate and age group (P < 0.001).

Fig. 2

Percentage of subjects with microalbuminuria (30–299 mg/g creatinine) or macroalbuminuria (> 300 mg/g creatinine) with respect to gender and age group.

Fig. 3

Percentage of subjects with chronic renal disease according to the stages of the disease with respect to gender and age group.

Fig. 4

Glomerular filtration rate (A), and microalbuminuria [as microalbuminuria (30–299 mg/g creatinine) or macroalbuminuria (> 300 mg/g creatinine)] (B) in subjects with and without concomitant hypertension, diabetes mellitus, dyslipidaemia, obesity or metabolic syndrome.