Low-dose tibolone (1.25 mg/d) does not affect muscle strength in older women.
OBJECTIVE
More than 50% of all fractures occur in people without osteoporosis. Hormone therapy increases bone density, improves postural balance, and reduces fracture risk in postmenopausal women. It is unclear whether tibolone, a synthetic steroid hormone drug, can improve muscle strength. Thus, the aim of this study was to study the effects of low-dose tibolone therapy on muscle strength in older women.


METHODS
Eighty healthy women (69 completed the study) 60 years or older were recruited through advertising in the local media. They were randomly allocated to receive either tibolone 1.25 mg/day or placebo for 6 months. The stand-up test was used to assess leg muscle strength and balance. Handgrip and leg muscle strength were measured using JAMAR and modified Cybex dynamometers.


RESULTS
Baseline characteristics, including serum estradiol values and muscle strength, were similar in the two groups. Compliance with the therapy regimen was very high, averaging more than 97% in both groups. After 6 months, mean values for handgrip strength, knee extensor strength, and average time to perform 10 stands were improved numerically in both groups compared with values during baseline. However, there were no significant differences in these parameters within or between groups, and differences remained nonsignificant after adjustment for age, serum estradiol, and baseline value.


CONCLUSIONS
Short-term treatment with low-dose tibolone (1.25 mg/d) seems not to affect muscle strength in older women.
Ribom
Eva L
EL
Department of Surgical Sciences, Orthopedic Unit, Uppsala University, Sweden. eva.ribom@surgsci.uu.se
Svensson
Peter
P
van Os
Steve
S
Larsson
Marita
M
Naessen
Tord
T
D000368:Aged; D004958:Estradiol / Q000097:blood; D020847:Estrogen Receptor Modulators / Q000008:administration & dosage* / Q000009:adverse effects; D005260:Female; D018737:Hand Strength / Q000502:physiology; D006801:Humans; D007866:Leg / Q000502:physiology; D008875:Middle Aged; D053580:Muscle Strength / Q000187:drug effects*; D018482:Muscle, Skeletal / Q000187:drug effects; D009652:Norpregnenes / Q000008:administration & dosage* / Q000009:adverse effects; D004856:Postural Balance / Q000187:drug effects
D020847:Estrogen Receptor Modulators; D009652:Norpregnenes; D004958:Estradiol; C027385:tibolone