The purpose of the Nebido® publications portal (NPP) is to present testosterone related research, in an easily searchable and navigable interface, to health professionals who search for scientific information on hypogonadism, testosterone replacement therapy and testosterone related health issues.
Even though it has not been directly proven that testosterone-induced elevations in hematocrit may increase risk of venous thromboembolism, since it is mechanistically plausible, regular monitoring of hematocrit during testosterone therapy is important. In clinical practice it is of interest to know which testosterone preparations cause the largest and smallest elevations in hematocrit.
Testosterone cypionate or enanthate (short-acting injectable) causes the largest elevations in hematocrit.
Testosterone undecanoate (long-acting injectable) causes the smallest elevations in hematocrit.
In clinical practice, erythrocytosis commonly translates to a hemoglobin level higher than 18.5g/dL or an hematocrit level higher than 52% in men, although the exact cut-off varies between guidelines. The European Association of Urology (EAU) recommends 54% as the upper safe hematocrit threshold. It should be noted that Isolated hematocrit elevations can be the result of insufficient fluid intake on a hot day or dehydration following vigorous exercise. Only repeated measures of hematocrit above 54% should be followed by concomitant administration of aspirin, therapeutic phlebotomy and/or discontinuation of testosterone treatment until hematocrit declines below 54%. After normalization of hematocrit level testosterone treatment may be continued with a reduced dosage
The risk of erythrocytosis is lowest with long-acting testosterone undecanoate injections, followed by transderma gel. Short-acting testosterone injections (testosterone enanthate and cypionate) pose the greatest risk of erythrocytosis.
Polycythemia and erythrocytosis are used interchangeably to refer to an abnormal increase of hemoglobin and/or hematocrit levels; in men, hemoglobin level higher than 18.5g/dL or hematocrit level higher than 52%, although this definition varies. Increased hematocrit is associated with increased blood viscosity, decreased venous return, and increased platelet adhesiveness. While this theoretically may increase risk of thromboembolic, studies that directly assess TTh induced erythrocytosis and CV risk are not available.
This study shows that T therapy produced significant improvements in LUTS as assessed subjectively by I-PSS and objectively by the significant reduction in post-void bladder volume. Improvements in I-PSS and post-void bladder volume were progressive and sustained during the entire followup of approximately 8 years. Further analysis of I-PSS showed a clear difference between the treated and untreated groups.
Long-term T therapy in men with T deficiency was well tolerated with excellent adherence, suggesting a high level of patient satisfaction. Progressive sustained improvement in urinary and sexual function was recorded in men who received long-term T therapy, contributing to overall improvement in QoL. In untreated hypogonadal controls voiding and erectile function deteriorated with continued followup. These findings suggest that T therapy results in long-term improvements in urinary and sexual function as well as QoL.
This study suggests that a drop in testosterone levels at a younger age, a larger variation in testosterone and a testosterone drop of larger magnitude are associated with an increased lifetime risk of prostate cancer.
With longitudinal data and improved methodology, this study provides valuable insights regarding the etiological role of testosterone in prostate cancer development and perhaps the importance of customized testosterone therapy for prostate cancer prevention.
This meta-analysis, shows that testosterone treatment improves cholesterol and triglyceride levels, which could help prevent development atherosclerosis or reduce the atherosclerotic burden. Considering that atherosclerosis is the major cause of the development of CVD, preventing or reducing atherosclerosis could contribute to decrease the incidence of CVD.
In this large population-based follow-up study of men aged 30 or older, we observed that higher mortality rates were seen among those who had the most pronounced decline in TS levels. This association was independent of age, baseline hormone levels and lifestyle factors.
This study confirms that men with TD are at increased risk for all-cause mortality, with the additional observation that the co-occurrence of TD with abdominal obesity further increases this mortality risk.
One of the important health benefits of TTh is the improvement in metabolic and glycemic control. TTh in men with TD showed improved metabolic profiles with increased insulin sensitivity, lower blood glucose levels, and lower HbA1c levels. Data of meta-analyses show that TTh lowers HbA1c in placebo-controlled and uncontrolled trials and improves blood glucose and insulin sensitivity (as measured by HOMA-IR index).
In addition, data from long-term observational studies and meta-analyses demonstrate a positive effect of TTh on LBM and FM with parallel decreases in BMI, WC, and body weight and improvement in body composition, as well as attenuation of components of the metabolic syndrome.
Endocrinol Diabetes Metab Case Rep. 2017 Sep 4;2017
Hypogonadism occurs frequently in men with T2DM.
In case of pronounced abdominal fat deposition and T2DM, the male patient should be evaluated for testosterone deficiency.
Untreated hypogonadism can complicate the successful treatment of patients with T2DM.
Under testosterone therapy, critical laboratory values are facilitated to return back to normal ranges and even complete remission of diabetes can be achieved.
For this hypogonadal, obese diabetic patient, all classical cardiovascular disease risk factors such as blood pressure, lipid pattern, glycemic control and obesity were improved under testosterone therapy and for the most part even resolved. The patient’s type 2 diabetes had resolved after 10 years of treatment with testosterone undecanoate. Importantly, achievement of such benefits require long-term treatment. Previous analyses of 6 year data did not show remission of diabetes. This underscores the importance of long-term and potentially lifelong treatment with testosterone for achievement and maintenance of the full spectrum of benefits with testosterone therapy.