Endocrinology It is generally assumed that iron stores increase during menopausal transition (Kim et al. 2012). However, no longitudinal studies have been conducted to ascertain this. Some women undergoing menopause experience increased insulin resistance and other cardiovascular conditions, which are not attributable to changes in adiposity or sex hormones. Iron is known to be a strong pro-oxidant, which catalyzes reactions tending to raise oxidative stress. This, in turn, is a risk factor for insulin resistance. Increased measures of iron during menopause may then contribute to insulin resistance at this period (Kim et al.).

In response, the Study of Women's Health across the Nation or SWAN was designed and conducted to determine and investigate biologic and sociologic changes during and after menopause (Kim et al. 2012). The researchers measured several iron markers at pre-menopause and post-menopause to find out if 1) iron measures increase from pre-menopause to post-menopause longitudinally; 2) there are an increase in insulin resistance and glucose level from pre-menopause to post-menopause longitudinally; and 3) pre-menopausal measures of iron and changes in these measures during and after menopause are in any way connected with changes in insulin resistance and glucose levels, in addition to other factors associated with insulin resistance. These include changes in adiposity, inflammation, and sex hormone-binding globulin (Kim et al.).

Participants and Methods

Participants to this multi-site longitudinal cohort study were 70 community-based female respondents aged 42-52 (Kim et al. 2012). They had intact uterus with at least one ovary and did not take estrogen or similar medications, which could have affect ovarian function. They all had at least menstrual period in the three months preceding...

They were enrolled in one of the 7 identified clinic sites, one in Detroit. This report emanated from the Michigan SWAN site and approved by the University of Michigan Institutional Review Board. The inclusion criteria for the choice of respondents were natural menopause as differentiated from that resulting from hysterectomy or oophorectomy and the last known menstrual period. They were selected according to estimated differences in ferritin derived from observations in cross-section studies between pre-menopausal and post-menopausal women (Kim et al.).
Post-menopausal women were those who ceased to menstruate for 12 months or more (Kim et al. 2012). Those on estrogen or progestin therapy at the pre-menopausal or post-menopausal visit or reported diabetes from any examination were excluded. Changes in insulin resistance and glucose levels could be affected by subsequent medications and behavioral changes. They were chosen at random, had similar age, came from same race or ethnicity, and were of anthropometric size as compared with those of Michigan SWAN without diabetes and who had entered natural menopause (Kim et al.).

Discussion and Conclusion

Discussion

Tests found that ferritin increased and sTfR:ferritin decreased from pre-menopause to post-menopause (Kim et al. 2012). This occurrence was consistent with an increase in iron stores. Insulin resistance and glucose levels likewise increase during the transition. The largest changes in iron stores also had the strongest link between iron and changes in HOMA-IR. Their measures of iron were lower during pre-menopause and highly increased over the menopausal transition (Kim et al.).

To the best of the authors' knowledge, this is the only longitudinal study on such changes and the only investigation ever…