Serum creatinine levels in the US population: third National Health and Nutrition Examination Survey.
Level 4 - case-series / case-control
Cross-sectional survey of a representative population sample (NHANES III)
PubMed 9856515 · doi:10.1016/s0272-6386(98)70074-5
What was done
Analyzed serum creatinine levels across subgroups defined by sex, age, and ethnicity (non-Hispanic white, non-Hispanic black, and Mexican-American) in 18,723 participants aged 12 years and older from the Third National Health and Nutrition Examination Survey (NHANES III), conducted between 1988 and 1994 as a representative sample of the US noninstitutionalized population.
What was found
Mean serum creatinine was 0.96 mg/dL for women and 1.16 mg/dL for men. Across ethnic groups, mean levels were highest in non-Hispanic blacks (women: 1.01 mg/dL; men: 1.25 mg/dL), intermediate in non-Hispanic whites (women: 0.97 mg/dL; men: 1.16 mg/dL), and lowest in Mexican-Americans (women: 0.86 mg/dL; men: 1.07 mg/dL). Mean levels increased with age in both sexes and all ethnic groups (total US ranges: 0.88 to 1.10 mg/dL in women; 1.00 to 1.29 mg/dL in men), with the highest mean observed in non-Hispanic black men aged 60 and older. Values >= 1.5 mg/dL were present in 9.74% of men and 1.78% of women, corresponding to an estimated 10.9 million US individuals with levels >= 1.5 mg/dL, 3.0 million >= 1.7 mg/dL, and 0.8 million >= 2.0 mg/dL.
Why it matters
This study provides national reference distributions for serum creatinine and demonstrates that demographic variables (age, sex, and ethnicity) markedly shift baseline levels, indicating that a single universal cutpoint to define elevated creatinine is clinically misleading.
Limits
Glomerular filtration rate (GFR) and lean body mass were not directly measured, making it impossible to determine how much of the demographic variation reflects physiological differences in muscle mass versus underlying renal disease.
Cited by
- supports Serum creatinine levels are known to increase over time with aging.