[Prospective CKD screening of high-risk patients in general practice]

Chronic kidney disease (CKD) is frequently underdiagnosed. In particular, the determination of albumin excretion in urine (urine albumin-creatinine ratio, UACR) is rarely performed despite existing indications.

Patients without a previous diagnosis of chronic kidney disease (CKD) were prospectively screened for CKD in general practice as part of routine check-ups, such as the Check-Up 35. Inclusion criteria were age between 40 and 70 years and the presence of at least one of the following risk factors: manifest cardiovascular disease, a positive family history of kidney disease, obesity with a BMI > 35 kg/m², diabetes mellitus, arterial hypertension, heart failure, or the use of potentially nephrotoxic medications. Serum creatinine (calculated to determine eGFR), urinalysis using test strips, and UACR in spot urine were measured.

The mean eGFR of the patients was 82.2 ± 16.4 ml/min/1.73 m², and the mean UACR was 47.0 ± 98.7 mg/g. A presumptive diagnosis of CKD was made in 83 of the 233 screened patients (35.6%). A UACR of ≥ 30 mg/g was detected in 68 (29.2%) of the patients. An eGFR < 60 ml/min/1.73 m² was found in 24 (10.3%) patients. Of the 170 (73.0%) patients with negative protein detection in the urine dipstick test, 35 patients (20.6%) had a UACR ≥ 30 mg/g.

Screening patients without a previous CKD diagnosis but with at least one of the aforementioned risk factors resulted in a suspected CKD diagnosis in more than one-third of the patients (35.6%). Risk-adjusted screening of these patients in general practice is feasible and leads to a high rate of new CKD diagnoses with significant implications for treatment allocation and improved prognosis for CKD patients. Urine dipstick tests are only of limited use for CKD diagnosis.