Donation intensity and metabolic syndrome in active whole-blood donors

Background and Objectives Increased iron and metabolic syndrome (MetS) go hand in hand. Frequent blood donation depletes iron stores. This study investigates whether high-intensity blood donation is associated with lower MetS prevalence compared with low-intensity blood donation, and whether iron acts as an intermediary factor. Materials and Methods A random sample of 422 male and 211 female active whole-blood donors >= 45 years of age was included in a cross-sectional study. Lipids, glucose and iron parameters were measured after overnight fasting. MetS was defined according to the joint interim statement of the International Diabetes Federation Task Force on Epidemiology and Prevention. Three groups of donation intensity were created by sex-specific tertiles of donation frequency per year and duration of donor career. Results MetS was present in 22.9% of donors. Prevalence of MetS was 1.46 (95% confidence interval [CI]: 0.93-2.30) times higher in men with high donation intensity, whereas in women MetS prevalence was 2.14 (95% CI: 0.94-4.86) times higher in donors with high donation intensity compared with those with low donation intensity. In men, increased prevalence of MetS was mainly associated with higher ferritin, whereas high hepcidin predominantly affected MetS prevalence in women. Conclusion High-intensity blood donation is not associated with a decreased prevalence of MetS. In men and women, different iron parameters are associated with MetS prevalence. The temporal relationship between blood donation, iron and MetS, and gender differences herein need to be explored in future research.