Testosterone, which is taken to build muscle mass in older men, carries a risk of heart disease in those with impaired mobility, a study has found. The study by scientists from Massachusetts, published in the New England Journal of Medicine, lasted only six months, because the patients receiving the hormone developed skin, heart and breathing problems that were absent in the control group. Testosterone was applied to the shoulders and arms of the patients in the form of a gel. According to the medical team led by Dr. Shelander Bassin of Boston University Medicine, the study raises many questions about the safety of testosterone therapy in older men. Testosterone is a male sex hormone, the secretion of which in the body decreases with age. Taking dietary supplements containing testosterone in young men leads to the accumulation of muscle mass and reduces the feeling of lack of strength. The current study includes men over 65 years old who have problems with their movement – they have difficulty walking and climbing ten steps. The study involved 209 volunteers with an average age of 74 who suffered from obesity, diabetes, high blood pressure and high cholesterol. When applying the gel with testosterone, elderly people improved their mobility. By the end of the study, however, 23 of them began to suffer from weakness, chest pain and heart attacks, and one died of a heart attack. Testosterone retains salt and water in the body, which may be a factor in the development of heart problems, scientists suggest. The research team itself was surprised by the result. The number of subjects included in the study was too small to make generalizations, especially since the patients suffered from various diseases in which testosterone treatment can produce this side effect. Doctors note that there is still a risk of heart problems with testosterone therapy and advise that the patient’s condition be monitored for three months after the end of treatment, and that the patient be informed of side effects and given the opportunity to choose. . The American National Institute on Aging, which commissioned and funded the study, points out that the volunteers took two to three times higher doses than recommended in medical practice.