'Low testosterone levels may up chronic diseases in men'

Low levels of testosterone hormone may increase the risk of chronic diseases such as diabetes and hypertension, even among men 40 years of age and younger, a study has found.

The research published in the journal Scientific Reports analysed the relationship among testosterone, age and chronic diseases.

"Previous research in the field has shown that total testosterone deficiency in men increases with age, and studies have shown that testosterone deficiency is also associated with obesity-related chronic diseases," said Mark Peterson from Michigan Medicine - University of Michigan in the US.

"But it has not been previously understood what the optimal levels of total testosterone should be in men at varying ages, and to what effect those varying levels of the hormone have on disease risk across the life span," said Peterson.

Using data from the US National Health and Nutrition Examination Survey, the research team examined the extent to which hypogonadism is prevalent among men of all ages.

Hypogonadism is a reduction or absence of hormone secretion or other physiological activity of the gonads (testes or ovaries).

Of the 2,399 men in the survey who were at least 20 years old, 2,161 had complete information on demographics (age, ethnicity and household income), chronic disease diagnoses, blood samples obtained for total testosterone, grip strength and lab results for cardiometabolic disease risk factors.

Peterson and team then examined prevalence of nine chronic conditions, including type 2 diabetes, arthritis, cardiovascular disease, stroke, pulmonary disease, high triglycerides, hypercholesterolemia, hypertension and clinical depression.

The researchers studied the prevalence of multimorbidity, or when two or more of the chronic conditions were present, among three age groups (young, middle-aged and older men) with and without testosterone deficiency.

They found that low total testosterone was associated with multimorbidity in all age groups - but it was more prevalent among young and older men with testosterone deficiency.

"We also found a large dose-response relationship between the age-specific low total testosterone and moderate total testosterone levels and multimorbidity, even after adjusting for obesity and muscle strength capacity," Peterson said.

"Which means that men should be concerned about declining total testosterone, even if it has not reached a level to warrant a clinical diagnosis," he said.