A man over 60 who has low blood testosterone levels may have a higher risk of bone fractures, compared to men with normal testosterone levels for their age, according to an article published in Archives of Internal Medicine (JAMA/Archives), January 14th issue.
Approximately one third of all osteoporotic fractures caused by porous bones happen in men, explain the authors. A man who has already had an osteoporotic fracture has three to four times the risk of another fracture compared to a woman of the same age who has already had a fracture. “Preventing the first such fracture may have major public health implications. Thus, understanding the determinants of fracture risk in men may reduce the burden of disease through facilitating better prevention strategies.”
Christian Meier, M.D., of the University of Sydney, Concord, New South Wales, Australia, and team looked at 609 men between January 1989 and December 2005 – their average age was 72.6. At the beginning of the study they recorded each man’s bone mineral density as well as several lifestyle factors. They measured serum testosterone and estradiol (an estrogen) levels, during follow-up they also measured the occurrence of low-trauma fracture. A low-trauma fracture is one associated with a fall from standing height or less.
113 men had low-trauma fractures during the follow-up. The risk of fracture was substantially higher among those whose testosterone levels were low. “Twenty-five men experienced multiple incident fractures. A total of 149 incident fractures were reported, including 55 vertebral, 27 hip, 28 rib, six wrist and 16 upper and 17 lower extremity fractures,” the researchers wrote.
According to the authors “After adjustment for sex hormone-binding globulin (a blood protein), serum testosterone and serum estradiol levels were associated with overall fracture risk. After further adjustment for major risk factors of fractures (age, weight or bone mineral density, fracture history, smoking status, calcium intake and sex hormone-binding globulin), lower testosterone was still associated with increased risk of fracture, particularly with hip and non-vertebral fractures.”
Even though lower levels of estradiol and testosterone were linked to higher fracture risk among men over 60, the effect of testosterone was the only one found to be independent of other risk factors.
“While testosterone may affect fracture risk via skeletal and non-skeletal mechanisms, the present findings suggest that measurement of serum testosterone provides additional clinical information for the assessment of fracture risk in elderly men,” the researchers concluded.
“Endogenous Sex Hormones and Incident Fracture Risk in Older Men – The Dubbo Osteoporosis Epidemiology Study”
Christian Meier, MD; Tuan V. Nguyen, PhD; David J. Handelsman, MBBS, PhD, FRACP; Christian Schindler, PhD; Mark M. Kushnir, PhD; Alan L. Rockwood, PhD; A. Wayne Meikle, MD; Jacqueline R. Center, MBBS, FRACP, PhD; John A. Eisman, MBBS, PhD, FRACP; Markus J. Seibel, MD, PhD, FRACP
Arch Intern Med. 2008;168(1):47-54.
Written by – Christian Nordqvist