Comparison between the profiles of patients defined by age-adapted and fixed threshold CKD criteria, a national-wide, cross-sectional study

Has the time come for age-adapted glomerular filtration rate criteria to define chronic kidney disease: how soon is now?

PURPOSE OF REVIEW

The conventional definition of chronic kidney disease (CKD) primarily relies on the identification of albuminuria or a decline in estimated glomerular filtration rate (eGFR). For many years, a straightforward eGFR threshold of <60 ml/min/1.73 m 2 has been widely adopted as the standard for defining CKD. Nonetheless, this criterion fails to consider the natural aging process of the kidney, and this oversight may affect the accurate diagnosis of kidney disease particularly at the extremes of age.

RECENT FINDINGS

The fixed eGFR threshold of <60 ml/min/1.73 m 2 for defining CKD misses crucial opportunities for risk prevention. Studies have revealed that the eGFR threshold at which the risks for adverse long-term health outcomes such as mortality, cardiovascular events, and kidney failure begin to rise varies substantially by age. Specifically, this threshold is lower for the elderly and higher for young adults. Consequently, this results in the over-diagnosis of kidney disease in the elderly and the under-diagnosis of kidney disease in young adults.

SUMMARY

To address these limitations of the current CKD definition, we discuss a number of proposed age-adapted eGFR criteria and weigh their pros and cons against the current, simple, and universally accepted approach.

Age- and Gender-Specific Diagnostic Value of the Albumin-to-Creatinine Ratio for the Early Screening of Chronic Kidney Disease Among Middle-Aged and Elderly Males in Southeast China

Objective

To evaluate the potential diagnostic value of the albumin-to-creatinine ratio (ACR) in screening for early kidney injury in a physically examined population from Southeast China.

Methods

A total of 13,250 candidates were selected. Urinary ACR values <30, 30-300, and >300 mg/g were utilized as positive cut-off points to denote normal proteinuria, microalbuminuria, and macroalbuminuria, respectively.

Results

Age, systolic blood pressure, diastolic blood pressure, body mass index, waistline, fasting blood glucose, glycated hemoglobin, triglycerides, and high-density lipoprotein cholesterol were significantly different among the three groups. eGFR was negatively correlated with the levels of sCr, BUN, and UA in the microalbuminuria and macroalbuminuria groups. Furthermore, there was a significant difference in CKD stage between the normal and abnormal urine ACR groups. Meanwhile, for the 20-40 years patients, the eGFR, sCr and BUN showed no significant difference between microalbuminuria group compared with the normal proteinuria group; in contrast, for the 41-60 years and >61 years patients, eGFR, sCr, BUN and UA were all markedly increase in microalbuminuria and macroalbuminuria group in comparison with the normal proteinuria group. Finally, for the 41-60 males, only eGFR significantly decreased in microalbuminuria group compared with the normal proteinuria group, while for the 41-60 females, only UA showed no significant difference between microalbuminuria group and normal proteinuria group. On the other hand, for the >61 males, eGFR, sCr and BUN all significantly changed between microalbuminuria group and normal proteinuria group, while for the >61 females, eGFR, sCr and BUN all showed no significant difference between microalbuminuria group and normal proteinuria group, as well as microalbuminuria group and macroalbuminuria group.

Conclusion

We proposed using the urinary ACR for the screening of physically examined patients, especially among the elderly males. This approach would assist in the early diagnosis and treatment of renal damage.