High density lipoprotein is an inappropriate substrate for hepatic lipase in postmenopausal women

HDL and the menopause

PURPOSE OF REVIEW

To summarize recent provocative findings on conventional and novel metrics of HDL including HDL-C, HDL subclasses and HDL cholesterol efflux capacity as related to menopause.

RECENT FINDINGS

Pattern of menopause-related changes in HDL-C are not consistent, suggesting a complex relationship between HDL and menopause. Growing body of literature indicates that higher levels of HDL-C may not be consistently cardio-protective in midlife women, suggesting a potential change in other metrics of HDL that could not be captured by the static metric HDL-C. It is also possible that higher HDL-C at certain conditions could be a marker of HDL metabolism dysfunctionality. Significant alterations in other metrics of HDL have been reported after menopause and found to be related to estradiol.

SUMMARY

The impact of changes in novel metrics of HDL over the menopausal transition on cardiovascular disease (CVD) risk later in life is not clear in women. Much of our understanding of how the menopausal transition may impact HDL metrics comes from cross-sectional studies. Future longitudinal studies are needed to evaluate other metrics of HDL shown to better reflect the cardio-protective capacities of HDL, so that the complex association of menopause, HDL and CVD risk could be characterized.

Atorvastatin and hormone therapy influence expression of ABCA1, APOA1 and SCARB1 in mononuclear cells from hypercholesterolemic postmenopausal women

BACKGROUND

Reverse cholesterol transport (RCT) has been inversely related to atherosclerosis and cardiovascular risk. The influence of menopause in the RCT process is poorly understood and the effects of cholesterol-lowering interventions, including statins and hormone therapy (HT), on genes controlling the RCT in postmenopausal women are also unknown.

METHODS

The effects on serum lipids and expression profile of genes involved in RCT - APOA1, ABCA1, ABCG1, SCARB1 and LXRA - were evaluated by TaqMan(®) quantitative PCR in peripheral blood mononuclear cells (PBMC) from 87 postmenopausal hypercholesterolemic women treated with atorvastatin (AT, n=17), estrogen or estrogen plus progestin (HT, n=34) and estrogen or estrogen plus progestin associated with atorvastatin (HT+AT, n=36).

RESULTS

Atorvastatin and HT treatments reduced the mRNA levels of APOA1 and SCARB1, respectively, whereas ABCA1 expression was reduced after all treatments. Although the expression of LXRA, an important transcription factor controlling the expression of genes involved in RCT, was not modified after any treatment, it was correlated with ABCA1, APOA1 and SCARB1 RNAm values before and after treatments, however no correlation with ABCG1 was observed. In a linear regression analysis, HT was related to an increase in apoAI levels after treatment when compared to atorvastatin and, moreover, higher SCARB1 and ABCA1 basal expression were also associated with decreased apoAI levels after treatments.

CONCLUSION

ABCA1 mRNA levels are decreased by atorvastatin and HT, however these treatments have a differential effect on APOA1 and SCARB1 expression in PBMC from postmenopausal women. Basal ABCA1 and SCARB1 expression profile could be helpful markers in predicting the effect of atorvastatin and HT on RCT, according to the changes in apoAI levels in this sample population.