Repeat testing is essential when estimating chronic kidney disease prevalence and associated cardiovascular risk

Area of Science:

• Nephrology
• Cardiology
• Epidemiology

Background:

• Chronic kidney disease (CKD) diagnosis and cardiovascular risk assessment in CKD patients may be inaccurate using single kidney function tests.
• Single tests can overestimate CKD prevalence and misrepresent cardiovascular risk in the affected population.

Purpose of the Study:

• To evaluate the impact of repeat testing at three months on the estimated prevalence of CKD.
• To determine how repeat testing affects the estimated 10-year cardiovascular risk in the CKD population.

Main Methods:

• Prospective study involving repeat blood and urine sample analysis for CKD indicators at a three-month interval.
• Calculation of estimated 10-year cardiovascular risk using Framingham study criteria for participants with initial and confirmed CKD diagnoses.
• Preliminary and validation cohorts screened 512 and 528 volunteers, respectively, with repeat testing for those initially flagged for CKD.

Main Results:

• A single abnormal CKD test had a low positive predictive value (0.5 preliminary, 0.39 validation) for repeat abnormalities.
• Confirmed CKD cases (repeat testing) showed significantly higher 10-year cardiovascular risk (16.5% preliminary, 18.1% validation) compared to the general population.
• Individuals with a solitary abnormal CKD test did not exhibit elevated cardiovascular risk.

Conclusions:

• Repeat testing after three months is crucial for accurately diagnosing CKD.
• This approach reduces estimated CKD prevalence and identifies individuals with true CKD and elevated cardiovascular risk.
• Confirms that a single abnormal kidney function test can lead to misleading conclusions about CKD prevalence and cardiovascular risk.