Limitations of estimating glomerular filtration rate from serum creatinine in the general population.

OBJECTIVE: To compare estimated glomerular filtration rate (GFR) in the general population on the basis of equations derived from different subsets of the general population. PARTICIPANTS AND METHODS: Adults (ages _45 years) were randomly selected from 1997 to 2000 from the Olmsted County, Minnesota, population and had their serum creatinine levels measured. The GFR was estimated using previously reported equations derived from a sample of patients with chronic kidney disease (CKD), a sample of healthy persons, and the combined samples. Serum creatinine was measured with the same assay used to derive these equations.
RESULTS: Of 4203 subjects, 2042 (47% participation rate) were enrolled and studied. Serum samples from 1982 subjects were used to measure creatinine levels. The prevalence of a reduced estimated GFR (<60 mL/min per 1.73 m2) was 12% (95% confidence interval [CI], 10%-13%) based on an equation derived with all CKD patients, and this finding was similar to prior reports. However, the prevalence of a reduced estimated GFR was 5.7% (95% CI, 4.8%-6.8%) based on an equation derived with both CKD patients and healthy persons and 0.2% (95% CI, 0.1%-0.5%) based on an equation derived with all healthy persons. Women had a higher risk of reduced estimated GFR according to an equation derived with all CKD patients, but men had a higher risk with an equation derived with both CKD patients and healthy persons.