Sex steroids and the cardiovascular system

Antiatherogenic properties of acetone extract of Alpinia zerumbet seeds

Oxidation of low-density lipoprotein (LDL) is the principal risk factor for the development of atherosclerosis. In this study, we used several methods to investigate the ability of the acetone extract from rhizomes, stems, leaves, flowers, pericarps and seeds of Alpinia zerumbet to inhibit atherosclerosis in vitro. The seed extract had the strongest activity against tyrosinase, pancreatic lipase (PL), 15-lipoxygenase (15-LO) and LDL oxidation activities (IC₅₀ = 2.30 ± 0.02, 5.00 ± 0.07, 1.29 ± 0.07 and 15.40 ± 0.86 µg/mL, respectively), amongst all different parts. It also had similar effects to the positive controls. Most of the extracts showed partial agonistic properties towards estrogenic activity. Cholest-4-ene-3,6-dione, a steroid present only in the seed extract seems to be the compound responsible for these activities. The results showed that cholest-4-ene-3,6-dione had similar ability to curcumin and quercetin against PL and LDL oxidation (IC₅₀ = 19.50 ± 1.17 and 16.12 ± 1.43 µg/mL, respectively). Furthermore, cholest-4-ene-3,6-dione (IC₅₀ = 34.21 ± 1.31 µg/mL) had higher inhibition against 15-LO than quercetin (IC₅₀ = 54.79 ± 1.12 µg/mL).

The HDL2/HDL3 ratio in menopause

OBJECTIVES

The influence of the menopause on the HDL2/HDL3 ratio was assessed in association with hypertriglyceridemia.

METHODS

Fasting blood samples were collected from 607 patients. Commercially available enzymatic methods were used for determination of TG, and total HDL-C. HDL2 and HDL3 were measured by ultracentrifugation.

RESULTS

The HDL2/HDL3 ratio had a strong negative correlation with TG (r=-0.272, P<0.0001 and r=-0.314, P<0.0001) in both pre- and postmenopausal women. No significant differences were observed in HDL2, HDL3, and HDL2/HDL3 ratio between pre- and postmenopausal women without hypertriglyceridemia. Postmenopausal women had a significantly higher HDL2/HDL3 ratio than premenopausal women with hypertriglyceridemia.

CONCLUSIONS

These results indicate that menopausal status not only increases plasma LDL-cholesterol and triglyceride levels, but also increases the HDL2/HDL3 ratio when associated with elevation of plasma triglyceride levels. These changes may increase the risk for CHD due to enlargement of the lipid pool.

Associated response in bone and lipids during hormone replacement therapy

OBJECTIVE

In postmenopausal women, we investigated if the response in bone mineral density (BMD) was associated with the response in the atherogenic lipid profile during hormone replacement therapy.

METHODS

We performed an exploratory, post-hoc analysis of data from a prospective double-blind placebo-controlled trial. Healthy postmenopausal women were randomised into five groups, each receiving different combinations of 17 beta-estradiol and gestodene or placebo. A total of 133 women completed the study. The study period was 3 years. The response in bone mass was expressed as the percentage change in BMD from baseline calculated by linear regression from semi-annual measurements. The change in lipid profile was evaluated as the average of three mid-cycle and end-cycle values in percentage from baseline in order to account for cyclic changes during sequential hormone therapy.

RESULTS

A significant correlation between the increase in BMD of the spine and hip and forearm with the decrease in serum low density lipoprotein (LDL) and cholesterol was found. Additionally, the decrease in atherogenic lipids correlated significantly with the response in biochemical bone markers for resorption and formation.

CONCLUSION

In conclusion, our study shows that it is the same women who have a favourable response in BMD as in the lipid-profile during hormone replacement therapy (HRT). The association is most likely driven by a common response in FSH to exogenous estradiol therapy. This indicates that common denominators for the response to HRT exist. Further studies are needed to explore and identify such predictors.