Impact of surgical menopause on lipid and bone metabolism

OBJECTIVE: To clarify the effects of ovariectomy on lipid and bone metabolism. METHODS: This study was a prospective study with a longitudinal design within 1 year after surgery. Sixty-two premenopausal women were recruited and divided into two groups: group M (preservation of ovary, n=27) and group BSO (bilateral ovariectomy, n=35). Serum lipid levels, urinary N-telopeptide of type I collagen (NTx) and bone mineral density (BMD) were measured. We also examined the number of postoperative episodes requiring pharmacological intervention. RESULTS: There was a significant elevation in the level of low density lipoprotein cholesterol in group BSO from 6 to 12 months compared with the baseline level; the level did not change in group M. The NTx level significantly increased from 6 to 12 months, and the BMD was significantly decreased by as much as 6.7% at 12 months in group BSO; these variables did not change in group M. The effect of lipid and bone metabolism in group BSO was observed when the ages of the two groups were matched. Carbohydrate metabolism and arterial stiffness, measured by pulse wave velocity, did not change throughout the study period in either group. No subjects in group M required medication expect for two patients whose ovarian function was diminished by postoperative radiation and by natural menopause. Eleven women received medication in group BSO: nine for climacteric disorders using hormone therapy (25.7%), and two for dyslipidemia using statins (5.7%). CONCLUSIONS: Bilateral ovariectomy seems to cause dyslipidemia and serious loss of bone mineral density within only 1 year, and patients who lose ovarian function may require careful medical care.