Comparative assessment of outcomes and adverse effects using two different intramuscular testosterone therapy regimens: 100 mg IM weekly or 200 mg IM biweekly.

This study aimed to compare the change in levels of several laboratory values and the development of adverse events using two commonly used intramuscular testosterone therapy regimens. Men were included if they were 18 years or older and received one of the following testosterone therapy regimens: 100 mg intramuscular once weekly or 200 mg intramuscular once every other week. Primary outcomes were relative changes in total testosterone, free testosterone, estradiol, prostate-specific antigen, and hematocrit at 6 months after initiation of testosterone therapy. Secondary outcomes were any significant rises in estradiol, hematocrit, prostate-specific antigen, and any other treatment-related adverse events requiring cessation of testosterone therapy. A total of 263 men were enrolled. In a subanalysis of men who had a baseline hematocrit below 54% before intramuscular testosterone therapy initiation, we found the following: men who received 100 mg weekly injections were significantly less likely to have hematocrit levels rising above 54% (1/102 (1%) vs. 4/51 (8%); p = 0.023). No significant differences were recorded in the increase in total testosterone, free testosterone, prostate-specific antigen, and estradiol levels between both groups. A higher average serum testosterone over the dosing interval seen with the 200 mg regimen appears to be associated with a higher risk of erythrocytosis.

Brain injury caused by HIV protease inhibitors: role of lipodystrophy and insulin resistance.

HIV-associated neurocognitive disorders (HAND) remain prevalent even with widespread use of combination antiretroviral therapy (ART), suggesting a potential role for co-morbidities in neurologic decline. Indeed, it is well established that ART drugs, particularly HIV protease inhibitors, can induce hyperlipidemia, lipodystrophy, and insulin resistance; all of which are associated with neurologic impairment. This study was designed to determine how metabolic dysfunction might contribute to cognitive impairment and to reveal specific metabolic co-morbidities that could be targeted to preserve brain function. Adult male C57BL/6 mice were thus treated with clinically relevant doses of lopinavir/ritonavir for 4 weeks, and subjected to thorough metabolic, neurobehavioral, and biochemical analyses. Data show that lopinavir/ritonavir resulted in manifestations of lipodystrophy, insulin resistance, and hyperlipidemia. Evaluation of neurologic function revealed cognitive impairment and increased learned helplessness, but not motor impairment following treatment with lopinavir/ritonavir. Further analyses revealed a significant linear relationship between cognitive performance and specific markers of lipodystrophy and insulin resistance. Finally, analysis of brain injury indicated that lopinavir/ritonavir treatment resulted in cerebrovascular injury associated with decreased synaptic markers and increased inflammation, and that the cerebral cortex was more vulnerable than the cerebellum or hippocampus. Collectively, these data reveal an intimate link between metabolic co-morbidities and cognitive impairment, and suggest that remediation of selective aspects of metabolic syndrome could potentially reduce the prevalence or severity HIV-associated neurocognitive disorders.