Soy-tibolone combination - effect on lipids in postmenopausal monkeys and women.
OBJECTIVE
To determine whether co-administration of soy during tibolone treatment would prevent tibolone-induced dyslipoproteinemia in postmenopausal monkeys and women.


METHODS
Surgically postmenopausal cynomolgus monkeys (n = 18) were assigned randomly to one of four dietary regimens in a Latin Square crossover design, such that all animals received all diets for 14 weeks with a 4-week washout period: (1) casein/lactalbumin (CL); (2) tibolone (Tib, 1.25 mg/day women's equivalent); (3) soy (138 mg isoflavones/day women's equivalent); (4) Soy + Tib. Postmenopausal women on tibolone treatment were randomized to receive soy powder (52 g of soy protein containing 112 mg isoflavones) or placebo (containing 52 g of milk protein) daily in a crossover trial for 8 weeks with a 4-week washout period.


RESULTS
Monkeys given Tib alone had approximately 14% increase in plasma LDL + VLDL-C; whereas those given soy combined with tibolone had significant ( approximately 22%) reductions. Tib treated monkeys had reductions in plasma HDL-C of about 48% vs. no reductions in Soy + Tib. In postmenopausal women using tibolone, soy reduced plasma LDL-C concentrations by approximately 10% from baseline without a change in HDL-C.


CONCLUSIONS
Co-administration of soy during tibolone treatment improved the lipoprotein profile in both monkeys and women; however, the effects were more robust in monkeys.
Appt
Susan E
SE
Wake Forest University School of Medicine, Winston-Salem, NC 27157-1040, USA. sappt@wfubmc.edu
Törmälä
Riina
R
Franke
Adrian A
AA
Mikkola
Tomi S
TS
Tikkanen
Matti J
MJ
Ylikorkala
Olavi
O
Clarkson
Thomas B
TB
D000818:Animals; D018592:Cross-Over Studies; D019587:Dietary Supplements; D004359:Drug Therapy, Combination; D020847:Estrogen Receptor Modulators / Q000009:adverse effects*; D005260:Female; D006801:Humans; D006951:Hyperlipoproteinemias / Q000139:chemically induced / Q000517:prevention & control*; D007529:Isoflavones / Q000627:therapeutic use*; D008252:Macaca fascicularis; D008875:Middle Aged; D009652:Norpregnenes / Q000009:adverse effects*; D017698:Postmenopause
D020847:Estrogen Receptor Modulators; D007529:Isoflavones; D009652:Norpregnenes; C065753:isoflavanone; C027385:tibolone