Iron status and inflammation in women of reproductive age: A population-based biomarker survey and clinical study

Abstract

Background: Women of reproductive age (WRA) are at increased risk for anemia and iron deficiency. However, there is limited population-level data in India, which could help inform evidence-based recommendations and policy.

Aims: To conduct a population-based biomarker survey of anemia, iron deficiency, and inflammation in WRA in Southern India.

Methods: Participants were WRA (15-40 y) who were not pregnant or lactating. Blood samples (n = 979) were collected and analyzed for hemoglobin (Hb), serum ferritin (SF), soluble transferrin receptor (sTfR), C-reactive protein (CRP), and alpha-1 acid glycoprotein (AGP). Anemia and severe anemia were defined as Hb < 12.0 and < 8.0 g/dL. Serum ferritin was adjusted for inflammation using BRINDA methods. Iron deficiency was defined as SF <15.0 μg/L, iron insufficiency was defined as SF < 20.0 and < 25.0 μg/L, and iron deficiency anemia was defined as Hb < 12.0 g/dL and SF < 15.0 μg/L. Inflammation was defined as CRP > 5.0 mg/L or AGP > 1.0 g/L. Restricted cubic spline regression models were also used to determine if alternative SF thresholds should be used t to classify iron deficiency.

Results: A total of 41.5% of WRA had anemia, and 3.0% had severe anemia. Findings from spline analyses suggested a SF cut-off of < 15.0 μg/L, consistent with conventional cut-offs for iron deficiency. 46.3% of WRA had SF < 15.0 μg/L (BRINDA-adjusted: 61.5%), 55.0% had SF < 20.0 μg/L (72.7%), 61.8% had SF < 25.0 μg/L (81.0%), and 30.0% had IDA (34.5%). 17.3% of WRA had CRP > 5.0 mg/L and 22.2% had AGP > 1.0 g/L. The prevalence of ID (rural vs. urban: 49.1% vs. 34.9%; p = 0.0004), iron insufficiency (57.8% vs. 43.8%; p = 0.0005), and IDA (31.8% vs. 22.4%; p = 0.01) were significantly higher in rural areas, although CRP levels were lower and there were no differences in elevated CRP or AGP.

Conclusions: The burden of anemia and iron deficiency in this population was substantial, and increased after adjusting for inflammation, suggesting potential to benefit from screening and interventions.

Registration number: NCT04048330.

Keywords: Anemia; India; Inflammation; Iron status; Periconceptional; Woman of reproductive age.

Conflict of interest statement

Declaration of competing interest The authors have no conflicts of interest to disclose related to this manuscript. SM is an unpaid board member and holds equity in a startup commercializing point-of-care diagnostic technology partially developed in his research laboratory at Cornell University. Findings and conclusions in this report are those of the authors and do not necessarily represent the official positions of the Centers for Disease Control and Prevention, the DRDC, Eunice Kennedy Shriver National Institute of Child Health and Human Development (NICHD), National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK), or the National Institutes of Health.

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