The association between higher serum ferritin level and lower bone mineral density is prominent in women ≥45 years of age (KNHANES 2008-2010).

SUMMARY: Data gathered from a nationally representative cohort demonstrate that higher serum ferritin levels are significantly associated with lower bone mass at various skeletal sites and the increased prevalence of osteoporosis and fractures, especially in women ≥45 years of age.

INTRODUCTION: Despite extensive in vitro and in vivo studies showing the detrimental effects of iron on bone metabolism, the clinical studies relating to osteoporosis-related phenotypes have not been evaluated extensively. In the present study, we investigated and compared the association between serum ferritin and bone mineral density (BMD), depending on the stratified age groups in both genders.

METHODS: This is a population-based, cross-sectional study from the Korea National Health and Nutrition Examination Surveys, including 14,017 Koreans (6,817 men and 7,200 women) aged 10-80 years. BMD was measured using dual X-ray absorptiometry, and osteoporosis was diagnosed by the World Health Organization definition.

RESULTS: Initially, we divided the subjects into three age groups, based on the patterns of age-related BMD changes in this national cohort (i.e., ≤24, 25-44, and ≥45 years old). Serum ferritin concentrations were inversely associated with BMD values at all measured sites after adjustment for confounders, only in women ≥45 years of age (P = 0.041 to <0.001). Furthermore, when we divided these women into serum ferritin quartiles, the odds for prevalent osteoporosis and fractures were 1.55-fold (95 % CI = 1.09-2.23) and 1.52-fold (95 % CI = 1.02-2.27) higher, respectively, in subjects in the highest quartile compared with those in the lowest quartile.

CONCLUSIONS: These results provide the first clinical evidence that the associations between serum ferritin level and bone parameters could be the most prominent in women ≥45 years of age.