Prevalence and Associations of Anemia of CKD: Kidney Early Evaluation Program (KEEP) and National Health and Nutrition Examination Survey (NHANES) 1999-2004

Received 21 November 2007; accepted 28 December 2007.

Background

Early identification of anemia of chronic kidney disease may be important for the development of preventive strategies. We compared anemia prevalence and characteristics in the National Kidney Foundation Kidney Early Evaluation Program (KEEP) and National Health and Nutrition Examination Survey (NHANES) 1999-2004 populations.

Methods

Clinical, demographic, and laboratory data were collected from August 2000 to December 31, 2006, from participants in KEEP, a community-based health-screening program targeting individuals 18 years and older with diabetes, hypertension, or family history of kidney disease, diabetes, or hypertension. Anemia was defined as hemoglobin level less than 13.5 g/dL for men and less than 12.0 g/dL for women (Kidney Disease Outcomes Quality Initiative [KDOQI] 2006) or less than 13.0 g/dL for men and less than 12.0 g/dL for women (World Health Organization [WHO]).

Results

In KEEP (n = 70,069), 68.3% of participants, and in NHANES (n = 17,061), 52% of participants, were women. African Americans represented 33.9% of the KEEP and 11.2% of the NHANES cohorts, and Hispanics comprised 12.4% of KEEP and 13.2% of NHANES. Using the KDOQI classification, anemia was present in 13.9% and 6.3% of KEEP and NHANES participants, whereas using the WHO classification, anemia was present in 11.8% and 5.3%, respectively. In adjusted analysis of KEEP data, KDOQI-defined anemia was significantly more likely in men (odds ratio [OR], 1.30; 95% confidence interval [CI], 1.23 to 1.37); this pattern was reversed when using WHO-defined anemia (OR, 0.68; 95% CI, 0.64 to 0.72). Adjusted odds of anemia were greater for African American than white KEEP participants (OR, 2.98; 95% CI, 2.80 to 3.16; OR, 3.00; 95% CI, 2.81 to 3.20 for KDOQI- and WHO-defined anemia, respectively).

Conclusion

Anemia was twice as common in the targeted KEEP chronic kidney disease screening program cohort than in the NHANES sample population. African Americans had a 3-fold increased likelihood of anemia compared with whites. Targeted screening can identify anemia in a high-risk population.

Index Words: Anemia, chronic kidney disease, diabetes, race, sex

1 Division of Endocrinology, SUNY-Downstate and Kings County Hospital Centers, Brooklyn, NY

2 Chronic Disease Research Group, Minneapolis Medical Research Foundation, Minneapolis, MN

3 University of Missouri-Columbia School of Medicine, Columbia, MO

4 National Kidney Foundation, New York, NY

5 Department of Medicine, Division of Nephrology, Mount Sinai School of Medicine, New York, NY

6 Hypertensive Diseases Unit, Section of Endocrinology, Diabetes and Metabolism, University of Chicago, Pritzker School of Medicine, Chicago, IL

7 Department of Medicine, Divisions of Cardiology, Nutrition and Preventive Medicine, William Beaumont Hospital, Royal Oak, MI

8 Charles R. Drew University of Medicine and Science, Los Angeles, CA

9 David Geffen School of Medicine, University of California, Los Angeles, CA.

Address correspondence to Samy I. McFarlane, MD, MPH, Department of Medicine, Box 50, State University of New York, Health Science Center at Brooklyn, Kings County Hospital Center, 450 Clarkson Ave, Brooklyn, NY 11203.

A list of the members of the Kidney Early Evaluation Program Investigators appears at the end of this article.

PII: S0272-6386(08)00007-3

doi:10.1053/j.ajkd.2007.12.019

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