Testosterone is key to men’s sexual and reproductive development. Now, new findings published in the journal Scientific Reports suggest that low levels of the hormone are strongly associated with the development of more than one chronic illness among adult males, reports Medical News Today.

For the study, researchers examined data on 2,161 men ages 20 and older from the National Health and Nutrition Examination Survey to determine the relationship between total testosterone deficiency and chronic diseases.

Scientists calculated the prevalence of nine chronic conditions, which included arthritis, clinical depression, high cholesterol, stroke and type 2 diabetes. Afterward, researchers examined the differences between young men (20 to 39.9 years), middle-aged men (40 to 59.9 years) and older men (60 years and older)—with and without testosterone deficiency—who suffered from two or more of these conditions.

All participants with low total testosterone—especially younger and older men—were more likely to have two or more chronic diseases compared with those with normal levels of the hormone.

Researchers also noted a significant “dose-response relationship,” meaning that testosterone levels corresponded with factors such as muscle mass and sexual function.

Men, therefore, should be concerned about decreasing levels of the hormone, even if they haven’t lost enough testosterone to have been clinically diagnosed as deficient (total testosterone less than 300 nanograms per deciliter), explained Mark D. Peterson, PhD, an assistant professor of physical medicine and rehabilitation at the University of Michigan in Ann Arbor and lead author of the study.

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