The decline in hormone production that typically begins around the age of 40 manifests very differently in men and women. In women, the decrease in estrogen and progesterone occurs abruptly and rapidly (within about a year), with symptoms such as hot flashes and the end of menstruation. In men, testosterone production decreases gradually, by about 1% to 2% per year.

Studies conducted in the United States show that a significant portion of the male population over the age of 60 has testosterone levels below the lower limits found in adults aged 20 to 30.

Commonly referred to as andropause—by analogy to menopause—the decline in testosterone production due to aging is medically known as late-onset male hypogonadism. Because it progresses slowly, often over decades, it may cause few or even no specific symptoms. The most common symptoms include loss of muscle strength, decreased libido, sexual and erectile dysfunction, increased body fat, osteoporosis, mood changes, and depression.

It is also associated with metabolic syndrome, a condition that forces the pancreas to produce more insulin and increases the risk of diabetes and cardiovascular diseases. “Since it occurs during a phase of life marked by changes—such as a slowdown in professional activity, children becoming independent, and reduced sexual interest in one’s partner—it can be difficult for the patient to recognize whether the symptoms are related to hormonal changes or external factors,” says Dr. Limírio Leal da Fonseca Filho, a urologist at Einstein.

Diagnosis

Medical evaluation is essential to determine whether the symptoms are indeed caused by late-onset hypogonadism. Hormonal assessment through laboratory tests is recommended when the patient presents at least three of the classic symptoms for a significant period—preferably six months, although there is no consensus in the medical literature on this timeframe. “In addition to total and free testosterone, levels of luteinizing hormone, prolactin, and SHBG protein are measured, which together provide an accurate indicator of hormonal function,” says Dr. José Roberto Colombo Junior, a urologist at Einstein.

Measuring only total testosterone is not recommended for diagnosing hypogonadism, as testosterone production can vary significantly throughout the day. “Depending on the time of collection, the result may be misleading,” comments Dr. Filho.

Reduced hormone levels may also be a symptom of more serious conditions, such as certain types of tumors. Therefore, when hormonal evaluation indicates low production, it is necessary to rule out these possibilities with additional tests before confirming a diagnosis of late-onset hypogonadism.

In the vast majority of cases, test results show that the symptoms are due to causes other than decreased testosterone production. “Studies conducted in the United States followed about 3,000 men aged 40 to 80 who exhibited classic symptoms of late-onset hypogonadism. After testing, it was found that in only 3% of cases were the symptoms actually due to low testosterone levels,” highlights Dr. Colombo Junior.

Hormone Replacement Therapy

Testosterone replacement is the first-line treatment for managing this condition. There is currently a wide variety of formulations available, administered either orally or via injection. Most patients respond quickly and positively to treatment, especially with regard to alleviating symptoms related to sexuality and depression. In cases involving osteoporosis, metabolic syndrome, and/or cardiovascular diseases, hormone replacement should be combined with specific therapeutic approaches for each condition.

As with women, male hormone replacement therapy can bring adverse effects, such as sleep apnea, an increased risk of developing prostate cancer, and, more rarely, breast cancer. Therefore, the cost-benefit of this therapy must be evaluated based on each patient’s individual characteristics.

There is no way to predict whether a man will develop late-onset hypogonadism. Many may go through old age without a significant drop in testosterone production or any related symptoms. On the other hand, ignoring some of its manifestations by assuming they are simply natural signs of aging can worsen the problem and increase the risk of more serious conditions.

By the Einstein Board