High-density Lipoprotein (HDL) Cholesterol in Women Taking Tibolone

Effects of Tibolone and PPARα-agonist on HDL Metabolism in Postmenopausal Women

Tibolone (Livial) has been shown in previous studies to lower HDL cholesterol by up to 40%.

This study aims to study the effects of fenofibrate on HDL and subfractions in women taking tibolone.

Tibolone decreases plasma concentrations of HDL cholesterol and HDL-apoA1 and pre-beta HDL, consistent with a pro-atherogenic effect. The mechanism of tibolone on HDL cholesterol has been suggested to result from an acceleration of the catabolism of HDL by stimulation of hepatic lipase with no effect on cellular cholesterol efflux.

PPAR-a agonists, in particular fenofibrate, improve HDL metabolism by increasing the expression and hepatic secretion of HDL apoAI and apoAII.

We hypothesise that fenofibrate will rectify the perturbations on HDL metabolism wrought by tibolone.

Inclusion Criteria:

• Post-menopausal women
• More than 6 months of amenorrhoea
• Raised FSH and low oestradiol level
• If hysterectomised, raised FSH and low oestradiol level

Exclusion Criteria:

• Diabetes
• Renal failure
• Proteinuria
• High alcohol intake
• Regular endurance exercise
• Active weight loss of dieting
• Smokers
• Agents known to influence lipid metabolism
• Major systemic illness
• Intolerance to tibolone and fenofibrate
• Cholelithiasis
• CK and ALT > 2ULN
• Bleeding disorders
• Peptic ulcer disease.