Association of kidney function with serum lipoprotein(a) level: the third National Health and Nutrition Examination Survey (1991-1994)

Background: Elevated lipoprotein(a) (Lp[a]) levels have been observed in patients on dialysis therapy. However, few studies explored the relationship between kidney function and Lp(a) levels in patients with mild to moderate chronic kidney disease. Methods: We examined the association of estimated glomerular filtration rate (GFR) with Lp(a) level in 7,675 participants in the second phase of the Third National Health and Nutrition Examination Survey. Results: There was no association between Lp(a) level and estimated GFR in the overall sample (geometric mean, 10.4 mg/dL [95% confidence interval (CI), 9.2 to 11.8] in the group with a GFR of 90 to 149 mL/min/1.73 m 2 versus 9.3 mg/dL [95% CI, 7.9 to 11.0] in the group with a GFR of 60 to 89 mL/min/1.73 m 2 versus 12.1 mg/dL [95% CI, 9.0 to 15.9] in the group with a GFR of 15 to 59 mL/min/1.73 m 2 ; P = 0.77 for linear trend) or non-Hispanic whites (geometric mean, 8.9 mg/dL [95% CI, 7.8 to 10.2] versus 8.5 mg/dL [95% CI, 7.1 to 10.2] versus 10.9 mg/dL [95% CI, 8.1 to 14.7]; P = 0.54 for linear trend). However, non-Hispanic blacks (geometric mean, 30.4 mg/dL [95% CI, 28.0 to 33.0] versus 35.2 mg/dL [95% CI, 31.4 to 39.4] versus 40.2 mg/dL [95% CI, 27.7 to 58.2]; P = 0.01 for linear trend) and Mexican Americans (geometric mean, 6.2 mg/dL [95% CI, 5.3 to 7.2] versus 7.4 mg/dL [95% CI, 6.4 to 8.5] versus 11.0 mg/dL [95% CI, 5.7 to 20.3]; P = 0.04 for linear trend) showed modestly, but significantly, greater Lp(a) levels with lower GFRs. In a weighed quantile regression model adjusted for age, sex, and race, a lower GFR was associated with greater 95th percentile serum Lp(a) values in the overall sample and non-Hispanic whites and with greater median Lp(a) levels in Mexican Americans. Conclusion: In a cross-section of the US population, a low GFR is associated with only moderately greater Lp(a) levels, and this association may differ by race-ethnicity. Am J Kidney Dis 40:899-908. © 2002 by the National Kidney Foundation, Inc.