Antioxidant effect of short-term hormonal treatment in postmenopausal women.

OBJECTIVES: Recent studies have shown that estrogens alone or in association with progestins can exert an antioxidant effect on Low-Density Lipoprotein (LDL) and lipids of platelet membranes. It has been demonstrated that the oxidative modification of LDLs also involving the formation of lipid peroxides, exerts several biological effects that may contribute to the onset and progression of cardiovascular diseases. Therefore, the aim of our study was to evaluate the effect of short-term treatment with oral estrogens alone and estrogens plus progestin on endogenous and copper-induced serum levels of lipid peroxides in postmenopausal women. METHODS: Thirty-nine postmenopausal women were randomly divided into three groups: group I was treated with oral conjugated equine estrogens (CEE) for 21 days; group II received oral CEE for 21 days and, after 14 days of this treatment, 5 mg/day of medrogestone was added for 7 days; group III did not receive any therapy (controls). Endogenous and copper-induced serum levels of lipid peroxides were determined before and after 21 days of treatment in the two treated groups and in the control group. RESULTS: The serum endogenous levels of lipid peroxides in postmenopausal women did not change after short-term treatment with hormone replacement therapy. Moreover, copper-induced serum levels of lipid peroxides significantly decreased after therapy in both groups I and II. CONCLUSIONS: Our data show that hormone replacement therapy (HRT) inhibits lipid peroxidation and may play a role in preventing cardiovascular diseases.

Hypolactasia and metabolic changes in post-menopausal women.

OBJECTIVES: The aims of the study were to evaluate the prevalence of hypolactasia in a group of post-menopausal women in Southern Italy, and to relate hypolactasia to possible changes occurring in biochemical indicators of carbohydrate and fat metabolism as well as in biochemical markers of bone metabolism. METHODS: Fifty post-menopausal women entered the study. Lactose malabsorbers were identified by breath hydrogen test. The kinetics of D-xylose was evaluated by a graphic-mathematical analysis after oral administration of a solution of 10 g of D-xylose in water. Serum glucose, insulin, C-peptide, cholesterol and triglycerides were assayed by commercial kits. The evaluation of dietary habits and physical activities was performed by a questionnaire. The assessment of bone turnover was obtained by measuring osteocalcin, serum alkaline phosphatase, calcium, phosphorus, and urinary hydroxyproline and urinary calcium expressed as a ratio or urinary creatinine. RESULTS: Twenty-six of 50 women showed hypolactasia. Significant differences were found in serum levels of insulin, glucose, and triglycerides, which were lower in malabsorbers than lactose absorbers, and in HDL-cholesterol levels which were higher in the first group than in the second. As regards bone turnover, dietary habits or lactose intake, there were no significant differences between the two groups. CONCLUSIONS: The significant differences found in serum levels of glucose, triglycerides, and HDL-cholesterol between lactose absorbers and malabsorbers may be imputable to the low or absent lactase activity which does not allow the whole amount of lactose in the small bowel of malabsorbers to be metabolized. Moreover, changes in lactose absorbing capacity of intestinal mucosa did not modify the intake of milk or its by-products in malabsorbers as demonstrated by the analysis of food.

alpha-Tocopherol and beta-carotene serum levels in post-menopausal women treated with transdermal estradiol and oral medroxyprogesterone acetate.

Estrogens exert a protective effect against atherosclerosis. It is well known that hormone replacement therapy (HRT) can effectively decrease LDL-cholesterol and increase HDL-cholesterol and Apo-Al serum levels. Some recent studies have suggested that estrogens alone or in association with progestins may exert an antioxidant effect on lipids. Besides sex steroids, also vitamins exert an antioxidant effect on LDL and may preserve the endogenous antioxidants of LDL. The aim of our study was to evaluate whether HRT can improve alpha-tocopherol and beta-carotene serum levels in post-menopausal women. Fifteen postmenopausal women with climacteric symptoms were treated with 50 micrograms/24 h estradiol transdermally applied twice a week for 21 days. A daily dose of 10 mg oral medroxyprogesterone acetate was added for 12 days in each treatment cycle. This therapy lasted 6 months. A significant reduction was found in total cholesterol and LDL-cholesterol after treatment. Besides, our study has shown that alpha-toc/LDL and beta-car/LDL ratios significatively increased after treatment, while alpha-tocopherol and beta-carotene serum levels did not change significantly after therapy. These preliminary findings suggest that HRT can preserve the content of alpha-tocopherol and beta-carotene in LDL particles and keep the LDL in a reduced antioxidant state.