Healthy Testosterone Levels Reduce Risk of Fractures in Aging Men

Testosterone is a critical component of bone strength in both men and women. Women are significantly more likely to experience complications from osteoporosis as a result of inherently lower testosterone levels. New research illuminates the risk of bone fractures resulting from circulating testosterone abnormalities, and it's more complicated than you might think.

A new study shows that fracture risk is not only associated with low testosterone but high testosterone as well. The relationship between fracture risk and testosterone levels is U-shaped, which goes against the commonly accepted wisdom of many.

Aging Men at Increased Risk of Fractures

Bone health is of incredible importance to aging men. Hip fractures in older men significantly increase mortality risk. According to one study, men with hip fractures have a 37.1% mortality rate, compared with a 9.9% rate in a similar, age-adjusted population. Learning how to reduce the risk of hip fractures is of critical importance to efforts to improve the long-term health and well-being of aging men.

Testosterone and Fracture Risk

This research was released in a recent edition of respected The Journal of Clinical Endocrinology & Metabolism. The leader of the study was endocrinologist Bu Bang Yeap.

All of the participants were Australian males. While estradiol levels can also affect fracture risk (notably in women), this study shows that plasma testosterone levels are more accurate at determining fracture risk in older males.

Yeap and his fellow researchers utilized data from 3,307 men from Perth, Australia. The data was collected from a larger survey known as the "Health in Men Study." The average age of the men selected was 77 years old. Each man had a baseline blood sample taken, which was rigorously analyzed between the years of 2001 and 2004.

Variables of concern to this research were plasma testosterone, estrogen, and dihydrotestosterone, along with luteinizing hormone and sex hormone-binding globulin.

Researchers combined this data with information from the West Australian Data Linkage System to assess which participants in the "Health in Men Study" experienced fractures later in their lives.

Advanced statistical modeling was used to relate the relative levels of each variable mentioned above to the risk of fracture. This data was modeled with respect to frailty status, comorbidity, and age to increase the accuracy of the results.

Incidence of Fracture Based on Testosterone Levels

Yeap and associates determined that, among these 3,307 men, fractures were experienced at a rate of 1.1% per year over an average of 10.6 years. The incidence of hip fractures was lower, around 0.5% per year, over the same time frame.

They found a particularly notable correlation between testosterone levels and fracture risk. Men with average levels of testosterone experienced the fewest fractures of any kind after taking into account frailty and age. The risk of fracture was similar for patients with low testosterone vs. high testosterone.

SHBG Levels and Fracture Risk

Also notable in this study was the fact that SHBG levels were also associated with fracture risk. Free testosterone is critical to the influence of the hormone on human physiology.

Sex hormone-binding globulin binds to testosterone, preventing it from performing its necessary duties. High levels of SHBG increase fracture risk because testosterone is less able to promote bone strength.

No notable change in risk of fracture was associated with luteinizing hormone, estradiol, or dihydrotestosterone.

While further research is certainly needed, this study clearly portrays the importance of maintaining healthy testosterone levels to safeguard skeletal health.

It also shows that accurate treatment is critical because too much testosterone may also have a detrimental effect. For men with low-T, testosterone therapy leads to favorable outcomes concerning frailty and bone health.

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