In a 2017 study, researchers examined the effect of testosterone therapy on levels of hemoglobin in older men with low testosterone and unexplained anemia. It was found that testosterone increases hemoglobin levels in older men with unexplained anemia as well as men with anemia with a known cause and non-anemic men, and testosterone therapy was associated with reductions in the proportion of anemic patients.
In roughly a third of cases of anemia – a deficiency of red blood cells or of the iron-containing, oxygen-carrying protein found within them, hemoglobin – in older adults, a cause cannot be identified. As anemia tends to be more common in older men than in older women, it is believed that testosterone – levels of which decline with age – may be a factor. Studies have demonstrated that testosterone supplementation increases hemoglobin levels in otherwise healthy older men with low levels of testosterone, and associations between low testosterone and unexplained anemia in men have been drawn. However, further research is required to determine the effect of testosterone treatment in men with unexplained anemia.
In a 2017 study published in JAMA Internal Medicine, researchers investigated the effect of testosterone supplementation on levels of hemoglobin in older men with low levels of testosterone and unexplained anemia. Men aged 65 and older, with a low risk of prostate cancer, blood testosterone levels below 275 ng/dL, and hemoglobin levels between 10.0 and 12.7 g/dL were recruited for the study. Based on blood tests and medical history, participants were classified as non-anemic, anemic with a known cause, or anemic with an unknown cause. Participants were assigned to receive testosterone gel or a placebo for 1 year, beginning at 5 g/day and adjusted after months 1, 2, 3, 6, and 9 to mimic testosterone levels in young men. Whole blood samples were taken at the beginning of the trial and at months 3, 6, 9, and 12. Walking ability, assessed based on a 6-minute walk test, and questionnaire-based assessments of overall health, walking, sexual desire, energy, fatigue, and memory were conducted every three months. Efficacy was determined based on a change in hemoglobin levels of at least 1.0 g/dL. Though participants were not otherwise treated for anemia, 7 patients with unexplained anemia and 8 with explainable anemia were taking iron at the beginning of the study and 6 and 8, respectively, by the end.
In total, 126 anemic men– 64 with anemia of a known origin and 62 with unexplained anemia – and 657 non-anemic men fit the study criteria, of which 90.5% completed the study. Testosterone therapy was associated with increases in hemoglobin levels of 1.0 g/dL or greater in 39% more unexplained anemia patients, 33% more explained anemia patients, and in 34% more non-anemic patients than in condition-matched placebo patients. After 12 months, 58% of testosterone-treated men, compared to 22.2% of placebo-treated men, who had unexplained anemia at the beginning of the study were no longer anemic. Similarly, 60% of testosterone-treated men, compared to 14.8% of placebo-treated men, with explainable anemia, were no longer anemic by the end of the study. Testosterone therapy did not significantly impact hemoglobin levels or anemia status between patients who were anemic versus patients who were non-anemic at the beginning of the study. It was also found that in anemic patients for every improvement of 8.3 meters in the 6-minute walk test, hemoglobin levels increased 1.0 g/dL and fatigue – measured on a 13-point scale – improved by 1 point. Increases in hemoglobin levels of at least 1.0 g/dL were associated with improved general health and energy. Hemoglobin levels of 17.5 g/dL or more were observed in 6 non-anemic participants, of which 4 had testosterone levels 800 ng/dL or above and abnormally high numbers of red blood cells.
Overall, the study’s findings suggest testosterone increases hemoglobin levels in older men with unexplained anemia. Moreover, testosterone treatment for 1 year was associated with increased hemoglobin in all participants and with reductions in explained and unexplained anemia. Together these findings suggest testosterone therapy increases the production of red blood cells in men aged 65 and older who are low in testosterone. Testosterone therapy may, therefore, serve as a viable treatment option for unexplained anemia in some older men, especially those displaying symptoms of low testosterone production. As there were a few cases of abnormally high hemoglobin levels and red blood cell numbers in testosterone-treated non-anemic men, monitoring hemoglobin levels during testosterone therapy may be a beneficial practice. In the study, increased hemoglobin levels were associated with modest improvements in the walking ability and vitality of anemic men, and with improvements in self-reported overall health and energy in all participants, though further research with objective measures will be required to confirm these health benefits of testosterone therapy in older anemic men.
Written By: Raishard Haynes, MBS