Poor Iron Status is Not Associated with Overweight or Overfat in Non-obese Pre-menopausal Women

Background: Associations between obesity and poor iron status have been described in children and adults. Proposed mechanisms for this association implicate a physiologic etiology, suggesting body fat accretion may progressively degrade iron status. However, the relationship between iron status and body composition in non-obese adults remains unclear.

Objective: In this study we examined the relationship between body composition, inflammation, and iron status in healthy, non-obese, pre-menopausal females.

Methods: Iron status was assessed using red cell distribution width, transferrin saturation, serum ferritin, and soluble transferrin receptor (sTfR). Tumor-necrosis factor-alpha provided a marker of inflammation, and body fat percentage (BF) was calculated from mean skinfold thickness measurements at 3 sites.

Results: In this cohort (n = 207), the prevalence of iron deficiency was similar (p > 0.05) between normal and overweight (BMI 25.0-30.0 kg/m(2)), and normal and overfat (BF >or=30.0%) volunteers. There were no differences in individual iron status indicators, including sTfR, between overweight or overfat volunteers as compared to normal weight and normal fat peers. Logistic regression analyses indicated that overfat volunteers had a lower (p < 0.05) risk of iron deficiency, whereas overweight individuals demonstrated no change in relative risk as compared to peers.

Conclusion: These findings suggest that, in non-obese adults, decrements in iron status are not associated with increasing adiposity.