Reexamination of hemoglobin adjustments to define anemia: altitude and smoking

• Type of Material: Article
• Authors: Andrea J. Sharma, Centers for Disease Control and Prevention; O. Addo, Emory University; Zuguo Mei, Centers for Disease Control and Prevention; Parminder Suchdev, Emory University
• Language: English
• Date: 2019-08-01
• Publisher: WILEY
• Publication Version: Author Accepted Manuscript (After Peer Review)
• Copyright Statement: © 2019 New York Academy of Sciences.
• Final Published Version (URL): http://dx.doi.org/10.1111/nyas.14167
• Title of Journal or Parent Work: ANNALS OF THE NEW YORK ACADEMY OF SCIENCES
• Volume: 1450
• Issue: 1
• Start Page: 190
• End Page: 203
• Keywords: BIOMARKERS REFLECTING INFLAMMATION; Science & Technology - Other Topics; CIGARETTE CONSUMPTION; altitude; Science & Technology; SOLUBLE TRANSFERRIN RECEPTOR; NUTRITIONAL DETERMINANTS; ADAPTATION; Multidisciplinary Sciences; hemoglobin; anemia; ERYTHROPOIESIS; smoking
• Research Categories: Health Sciences, Public Health

Abstract

The correct interpretation of hemoglobin (Hb) to identify anemia requires adjusting for altitude and smoking. Current adjustments were derived using data collected before 1985, from low-income preschool-aged children (PSC) in the United States and indigenous men in Peru for altitude, and from White women of reproductive age (WRA) in the United States for smoking. Given the oldness and limited representativeness of these data, we reexamined associations between Hb and altitude and/or smoking using 13 population-based surveys and 1 cohort study each conducted after 2000. All WHO regions except South-East Asia were represented. The dataset included 68,193 observations among PSC (6−59 months) and nonpregnant WRA (15−49 years) with data on Hb and altitude (−28 to 4000 m), and 19,826 observations among WRA with data on Hb and smoking (status or daily cigarette quantity). Generalized linear models were used to assess the robustness of associations under varying conditions, including controlling for inflammation-corrected iron and vitamin A deficiency. Our study confirms that Hb should be adjusted for altitude and/or smoking; these adjustments are additive. However, recommendations for Hb adjustment likely need updating. Notably, current recommendations may underadjust Hb for light smokers and for those residing at lower altitudes and overadjust Hb for those residing at higher altitudes.