Chronic kidney disease, hypertension, diabetes, and obesity in the adult population of Morocco: how to avoid “over”- and “under”-diagnosis of CKD

The prevalence of hypertension, diabetes, obesity, and chronic kidney disease (CKD) in an adult Arabic-Berber population was investigated according to 2012 KDIGO guidelines. A stratified, randomized, representative sample of 10,524 participants was obtained. Weight, height, blood pressure, proteinuria (dipstick), plasma creatinine, estimated glomerular filtration rate, and fasting glycemia were measured. Abnormal results were controlled within 2 weeks; eGFR was retested at 3, 6, and 12 months. The population adjusted prevalences were 16.7% hypertension, 23.2% obesity, 13.8% glycemia, 1.6% for eGFR under 60 ml/min/1.73 m2 and confirmed proteinuria 1.9% and hematuria 3.4%. Adjusted prevalence of CKD was 5.1%; distribution over KDIGO stages: CKD1: 17.8%; CKD2: 17.2%; CKD3: 52.5% (3A: 40.2%; 3B: 12.3%); CKD4: 4.4%; CKD5: 7.2%. An eGFR distribution within the sex and age categories was constructed using the third percentile as threshold for decreased eGFR. A single threshold (under 60 ml/min/1.73 m2) eGFR classifying CKD3-5 leads to “overdiagnosis” of CKD3A in the elderly, overt “underdiagnosis” in younger individuals with eGFR over 60 ml/min/1.73 m2, below the third percentile, and no proteinuria. By using the KDIGO guidelines in a correct way, “kidney damage” (confirmed proteinuria, hematuria) and the demonstration of chronicity of decreased eGFR <60 ml/min/1.73 m2, combined with the third percentile as a cutoff for the normality of eGFR for age and sex, overcome false positives and negatives, substantially decrease CKD3A prevalence, and greatly increase the accuracy of identifying CKD.