New US research has found that a lower level of testosterone could have a negative effect on a man’s risk of developing chronic disease.
Previous research has already linked low levels of testosterone to sexual health and muscle mass. However, the new study, carried out by researchers from Michigan Medicine at the University of Michigan, set out to look at whether there was also an association between testosterone, age and chronic disease.
“If we look at data for men from a population level, it has become evident over time that chronic disease is on the rise in older males,” explained lead author of the study Mark Peterson. “But we’re also finding that a consequence of being obese and physically inactive is that men are seeing declines in testosterone even at younger ages.”
For the study Peterson and the team looked at data from the National Health and Nutrition Examination Survey, for 2,161 men, 20 or over, who gave complete information on demographics, such as age, ethnicity and household income, chronic disease diagnoses, blood samples to measure total testosterone, grip strength, and lab results for cardiometabolic disease risk factors.
The researchers also looked at rates of nine chronic conditions among participants, including Type 2 diabetes, arthritis, cardiovascular disease, stroke, pulmonary disease, high triglycerides, hypercholesterolemia, hypertension and clinical depression.
They then studied the prevalence of multimorbidity — which is when two or more chronic conditions are present — among young, middle-aged and older age groups, both with and without testosterone deficiency.
The results showed that a low level of total testosterone was associated with multimorbidity in all age groups, when compared to men with a normal level. However, it was more prevalent among young (20-39.9) and older men (over 60) with testosterone deficiency.
The researchers also found strong evidence of a dose-response relationship, with the youngest group of men with a low testosterone level showing a higher risk of a multimorbidity than the oldest men with a low level, “Which means that men should be concerned about declining total testosterone, even if it has not reached a level to warrant a clinical diagnosis (<300 ng/dL [10.4 nmol/L])," says Peterson. Co-author Aleksandr Belakovskiy noted that although the association between testosterone and multimorbidity was robust, it does not prove causation and more research is needed. However, the team hope the findings will raise public awareness, with Peterson commenting that, "A lot of men may not be aware of the risk factors for testosterone deficiency because of their current lifestyle. And more importantly, that declining levels could be contributing to a silent decline in overall health and increased risk for chronic disease." The results were published in Scientific Reports.