Zinc metabolism in post-menopausal women receiving hormone replacement therapy

Hormone replacement therapy (HRT) provides relief to many women from the disturbing symptoms of the menopause, but some questions relating to this practice are unresolved while possible averse effects of long-term administration remain to be determined. As steroid hormones are known to influence zinc metabolism, a study of current HRT practice on zinc status has been conducted. Fourteen post-menopausal women treated with HRT had significantly lower concentrations of Zn in serum compared with 11 untreated controls and 13 pre-menopausal subjects (mean±SD; 14.1±3.52, 16.6±1.82 and 15.3±1.52 μmol/l, respectively). Impaired intestinal absorption was indicated by low urinary Zn in most of the HRT subjects (2.2-6.4 μmol/24 h) but 2 had elevated values, possibly due to contamination, and the mean excretion rate was,not significantly different from those of the other groups. Serum albumin concentrations of the HRT women were slightly lower than those of the other groups (43.57±2.03, 47.91±1.30 and 49.25±2.05 g/l; respectively) and could be reponsible for some of the reduction of serum Zn. However, these two parameters were not strongly correlated and the decrease in zinc could not be entirely attributed to the change in albumin concentrations. Dietary Zn intalce and other markers of zinc status were normal. This investigation demonstrated that long-term use of HRT produces a reduction in serum zinc concentration. This is partly due to changes in the circulating albumin levels but the treatment may also affect intestinal absorption. There was no evidence for severe zinc deficiency