Reconsidering the relation between serum homocysteine and red blood cell distribution width: a cross-sectional study of a large cohort

Purpose: In a recent small sample study, red blood cell distribution width (RDW) was suggested as a predictor of homocysteine levels. The current study was aimed to reexamine this association in a large scale sample.Methods: A retrospective cross-sectional study of healthy adults, conducted at Rabin Medical Center, during 2000-2014. Data were retrieved from the medical charts and a logistic regression controlling for interfering factors was carried out. Sensitivity analysis was implemented by exclusion of individuals with anaemia.Results: Five thousand, five hundred fifty-four healthy individuals were included. Mean serum homocysteine level was 10.10 (SD 2.72) mol/L. 34.4% of the study population had a homocysteine level higher than the upper limit of normal (10.8mol/L). Homocysteine showed no association with RDW (OR 1.00; 95% CI 0.97-1.03), but increased with age (OR 1.05; 95% CI 1.04-1.06) and decreased with a rise in haemoglobin (OR 0.77; 95% CI 0.71-0.83), and in the mean corpuscular volume (OR 0.86; 95% CI 0.85-0.88). Exclusion of individuals with anaemia did not reveal an association between homocysteine and RDW but found a somewhat smaller association between haemoglobin and RDW [OR 0.82; 95% CI 0.73-0.91].Conclusions: In our large scale sample we did not find an association between RDW and serum homocysteine.