By Mike Clark, Clinic Director of NBH Lifetime Health
Low testosterone levels for men can mean high health risks. After decades of research and hype surrounding female menopause and hormone replacement therapy, men have recently started receiving some attention about their own age-related hormonal decline, known as andropause.
At NBH Lifetime Health, our Austin hormone clinic, we have been treating men of all ages for testosterone deficiencies for more than ten years. A simple lab test for free and total testosterone will determine if the male is deficient in this primary male hormone. We also test the estradiol level to determine if testosterone is converting to estradiol. Another important test is DHEA. This hormone is often called the body’s repair hormone and master hormone.
For males in the 40’s and above, we offer tests for the major heart factors including cholesterol, homocysteine, fibrinogen, and CRP. Testosterone is of course a major heart factor in that low levels are associated with heart disease. We have found that most men over 40 have less than optimal levels of free testosterone. More and more, we are finding the younger males can also have these difficulties.
Declining testosterone levels
Declining testosterone levels can lead to the development of numerous symptoms such as a decrease in virility, libido and sexual activity, general sense of well-being, as well as fatigue, depression and sleep disturbances. In addition to problems such as sexual dysfunction or general malaise, low testosterone also translates into decreased muscle mass and strength, as well as a decrease in bone mass and an increase in abdominal fat. Studies show that the latter two pay a role in degenerative diseases such as osteoporosis, cardiovascular disease and diabetes. Moreover, depleted testosterone levels are being linked to the incidence of various lipid disorders and heart disease.
Less bone, more fat
While osteoporosis hasn’t always been considered a disease that afflicts males, the rising incidence of bone mass degeneration among aging men points a finger to some age-related cause. As androgen receptors are expressed in osteoblasts (bone-forming cells) researchers now believe that androgens have some direct effect on bone formation and resorption.
Declining Testosterone, Fat Mass and Heart Risk
A growing body of research now suggests that an age-related increase in fat mass, or obesity, can be attributed to a fall in free testosterone and growth hormone levels. Moreover, studies report a connection between abdominal obesity and increased cardiovascular mortality and Type II diabetes mellitus. Recent findings from the University Hospital in Ghent, Belgium illustrate that age is related to a drop in free testosterone levels and free insulin-like growth factor-1, while contributing to an increase in body mass index and fat mass.
One recent study consisting of 372 males aged >20-85, revealed that body mass index and age were independent factors in determining testosterone levels. These decreased by about one quarter when researchers compared the young controls to men in the elderly group, while free testosterone levels fell by almost half with age. Likewise, fat-free mass decreased by 18.9%. In a subgroup of 57 men aged 70-80 years, the lower that testosterone levels dropped, the higher the percentage of body and abdominal fat, as well as plasma insulin levels.
Low Testosterone and Increased Risk of Diabetes and Adipose Fat.
Other findings indicate that low testosterone levels predisposed men to adipose fat which, in turn, seemed to raise their risk of diabetes mellitus. Researchers at the University of Washington’s Department of Medicine set out to examine the effects of age-related decreasing serum testosterone levels on intra-abdominal fat in a group of 110 second-generation healthy Japanese-American men. Measurements were taken first to establish baseline levels of glucose, body mass index, visceral adiposity, subcutaneous fat, fasting insulin and C-peptide levels, and overall testosterone levels (which were within the normal range relative to the men’s age).
When the researchers performed follow-up measurements 7.5 years later, their results indicated that intra-abdominal fat had increased by an average of 8.0 centimeters squared. More importantly, though, they found that the change in intra-abdominal fat correlated to baseline total testosterone levels, but they were not significantly related to other measurements such as body mass index, total fat or subcutaneous fat. The study authors concluded that, in their sample, “lower baseline total testosterone independently predicts an increase in intra-abdominal fat. This would suggest that by predisposing to an increase in visceral adiposity, low levels of testosterone may increase the risk of type II diabetes mellitus.”
Low testosterone Levels, Excess Abdominal Fat and Heart Disease
Similarly, another study that analyzed some of the health effects of excess abdominal fat, also referred to as android obesity, reported that individuals exhibiting upper body excess fat distribution tend to have lower levels of plasma testosterone and growth hormone levels, suggesting what the authors describe as “complex hormonal abnormalities”.
Abdominal obesity lends itself to an apple-shaped figure and has been related to a heightened risk of conditions such as cancer, diabetes and heart disease. These researchers believe that, “Visceral fat tissue, through its portal drainage, could be an important source for free fatty acids that may exert complex metabolic effects: involvement in hepatic lipogenesis, increase in hepatic neoglucogenic flux, reduction in insulin metabolic clearance and involvement in peripheral insulin resistance through a competition mechanism described by Randle.”
They conclude that abdominal obesity may be related to diabetes by means of an enhanced fatty acid made available from fat tissues (visceral and subcutaneous) in individuals who are genetically predisposed to type II diabetes. Research has also pointed to the possibility of a link between abdominal obesity and hypercorticism, or elevated cortisol levels. A reason for this, suggest scientists, might be that excess cortisol opposes testosterone and growth hormone production, both of which are regulators of body fat. Moreover, low testosterone levels also seem to encourage cortisol levels to rise and elicit their many aging effects, including immune dysfunction, brain cell injury, arterial wall damage and other assaults.
Hypogonadism (low testosterone) and Heart Trouble
Low testosterone levels have also been implicated in playing a role in the development of chronic diseases such as atherosclerosis and cardiovascular heart disease. One study found that, in assessing a group of men and postmenopausal women over 50 years of age for levels of various hormones as they might relate to health conditions, plasma estradiol levels were highest in hypertensive men and testosterone levels were lowest in men with coronary heart disease. The researchers conclude that perhaps, “Decreased testosterone and/or increased estradiol may have an adverse effect on lipid profile in elderly men.”
Another study conducted among a male population likewise reported that low testosterone may be a risk factor for coronary heart disease, which may relate to lipoprotein metabolism by endogenous testosterone. Results showed that mean plasma testosterone levels among patients with coronary heart disease were significantly—about 40%—lower than in healthy subjects. Moreover, there was a negative association between plasma testosterone levels and plasma triglyceride levels and lipoprotein (a), which translated into higher blood lipid levels relative to lower testosterone levels. Contrarily, a positive association between plasma testosterone levels and high-density lipoprotein cholesterol and high-density lipoprotein 3 cholesterol meant that higher testosterone levels equaled higher “good” cholesterol levels.
The Natural Aging Factor
It is well documented in research that sex hormones such as testosterone are vital components in the sexual development of pubescent males, as well as contributing to the increase of their muscle and bone mass as they transform from boys into men. Meanwhile, dwindling testosterone levels as a result of metabolic aging trigger the opposite kind of effects, including the loss of body hair and progression of male pattern baldness, loss of muscle and bone mass, and increased fat.
Low testosterone levels aren’t just the prospect of a small segment of the male population but rather, they tend to affect the male population as a whole. Natural aging causes a gradual decline in male hormones, so that by age 70, men have less than a quarter of their optimal testosterone levels. Some figures reveal that free testosterone levels start to fall at the age of 25. While men with normal testosterone levels sometimes exhibit some of the symptoms, which may very well stem from other causes besides hypogonadism, the fact that androgen therapy usually alleviates these symptoms suggests a hormonal deficiency as the root cause of such deterioration in health.