Postmenopausal women are weaker, as measured by grip and pinch tests, than women who have not entered menopause, according to a study published in the American Journal of Epidemiology. However, the researchers found that physical activity protected women from losing strength as they progress through menopause.
Researchers at Rush University Medical Center and the University of Chicago Hospitals followed a racially mixed group of 563 Chicago-area women for five years. Strength tests determined how firmly they could grip and pinch. The results of these tests were assessed against the women's age, state of menopause, ethnicity, income and use of hormone replacement therapy.
Women who participated in the study were tested for grip strength with a handgrip dynamometer and a pinch gauge was used to measure strength over the course of the study. Statistical models were developed to assess whether menopausal status was associated with grip and pinch strength. Other variables, such as race and body mass index, were controlled for.
The authors of the study found that progression to postmenopausal status was associated with a significant decline in pinch strength and a marginally significant decline in grip strength for all women in the study. However, the relation between menopausal status and grip and pinch strength did not differ significantly by race. Overall, African-American women had greater grip and pinch strength than Caucasian women.
"Previous studies examining the relation between menopausal status and physical function have been inconsistent," said Dr. Martha Gulati, one of the principal investigators of the study from Rush University Medical Center.
"This is the first longitudinal study to document the effects of the natural menopausal transition on changes in physical function in a diverse group of women," said Lianne M. Kurina of the department of Health Studies at the University of Chicago.
Gulati said that is possible that reduced levels of estrogen or changes in other reproductive hormones are responsible for the decline in strength.
"The good news for women is that being physically active -- whether it is a formal exercise program or doing work around the house -- may help stave off a decline in strength brought on by going through menopause," Gulati said.
The authors theorized that physical activity may influence one's performance own on grip and pinch testing through a variety of metabolic and neurologic mechanisms.