title: Red cell distribution width and risk of peripheral artery disease: analysis of National Health and Nutrition Examination Survey 1999-2004.
abstract: Red cell distribution width (RDW) is an independent predictor of the 10-year estimated risk of coronary heart disease (CHD) events. However, RDW's association with peripheral artery disease (PAD) - a CHD risk equivalent - has not been evaluated to date. In this cross-sectional study, we examined 6950 participants of the National Health and Nutrition Examination Survey, 1999-2004. PAD was defined as an ankle-brachial index below 0.9 (n = 618). RDW was divided into quartiles (Q) (Q1: ≤ 12.2; Q2: 12.3-12.5; Q3: 12.6-13.0; Q4: ≥ 13.1) and PAD risk was compared across these quartiles using adjusted multivariate logistic regression. A graded increase in prevalent PAD with increasing RDW quartiles was observed (4.2% in Q1 vs 13.9% in Q4; test of trend p < 0.001). Risk of PAD was significantly higher (odds ratio (OR) 1.19, 95% confidence interval (CI): 1.06-1.34; p = 0.003) after adjusting for age, sex, race, body mass index, hypertension, hyperlipidemia, diabetes, smoking, estimated glomerular filtration rate, C-reactive protein, hemoglobin, mean corpuscular volume, and nutritional factors (folate, iron and vitamin B(12)) deficiencies with each unit (0.1) increase in RDW. Upon receiver-operating characteristics analysis, the predictive accuracy of the American College of Cardiology / American Heart Association (ACC/AHA)-defined PAD screening criteria (for a high-risk population) was 0.657 at best, but improved significantly (0.727) after addition of RDW (p < 0.0001). In conclusion, higher levels of RDW are independently associated with a higher risk of PAD and can significantly improve the risk prediction beyond that estimated by ACC/AHA-defined PAD screening criteria.
authors.affiliation: Division of Cardiology, Department of Internal Medicine, Detroit Medical Center/Wayne State University, Detroit, MI 48201, USA.
authors.forename: Sandip K
authors.initials: SK
authors.lastname: Zalawadiya
authors.forename: Vikas
authors.initials: V
authors.lastname: Veeranna
authors.forename: Sidakpal S
authors.initials: SS
authors.lastname: Panaich
authors.forename: Luis
authors.initials: L
authors.lastname: Afonso
mesh_terms: D000328:Adult; D000368:Aged; D055109:Ankle Brachial Index / Q000379:methods; D019540:Area Under Curve; D003430:Cross-Sectional Studies; D003625:Data Collection; D004909:Erythrocyte Indices; D004912:Erythrocytes / Q000473:pathology*; D005260:Female; D006801:Humans; D016015:Logistic Models; D008297:Male; D008875:Middle Aged; D009749:Nutrition Surveys; D058729:Peripheral Arterial Disease / Q000097:blood / Q000175:diagnosis* / Q000453:epidemiology; D011237:Predictive Value of Tests; D012372:ROC Curve; D012307:Risk Factors; D014481:United States / Q000453:epidemiology