Dr. Martinelli[/caption]
MedicalResearch.com Interview with:
Ida Martinelli MD, PhD
A Bianchi Bonomi Hemophilia and Thrombosis Center
Fondazione IRCCS Ca' Granda Ospedale Maggiore Policlinico
Milan, Italy
Medical Research: What is the background for this study? What are the main findings?
Dr. Martinelli: Hormonal therapies are associated with an increased risk of venous thromboembolism. Patients with acute deep-vein thrombosis or pulmonary embolism require anticoagulation, but women of childbearing potential require also an adequate contraception, as oral anticoagulants cross the placenta potentially leading to embryopathy or fetal bleeding. This study was aimed to evaluate the safety of hormonal therapies together with anticoagulant therapies in terms of recurrent venous thrombosis and uterine bleeding. We demonstrated for the first time that women who take oral anticoagulants can safely use hormonal therapies, as their risk of recurrent venous thromboembolism or uterine bleeding is not increased.
Dr. Trinh[/caption]
MedicalResearch.com Interview with:
Quoc-Dien Trinh MD
Assistant Professor, Harvard Medical School
Brigham and Williams Hospital
Medical Research: What is the background for this study? What are the main findings?
Dr. Trinh: Among elderly Medicare beneficiaries with metastatic prostate cancer, surgical castration is associated with lower risks of any fractures, peripheral arterial disease, and cardiac-related complications compared to medical castration using GnRH agonists.
Dr. Shinkai[/caption]
MedicalResearch.com Interview with:
Kanade Shinkai, MD PhD
Associate Professor of Clinical Dermatology
Director, Residency Program
Endowed Chair in Dermatology Medical Student Education
UCSF Department of Dermatology
San Francisco, CA 94115
Medical Research: What is the background for this study? What are the main findings?
Dr. Shinkai: Polycystic Ovary Syndrome (PCOS) is a common endocrine disorder in the United States that has important skin manifestations including acne, hair loss, hirsutism, and acanthosis nigricans. We performed a retrospective cross-sectional study of women referred to a multidisciplinary PCOS clinic at UCSF to determine whether skin findings and systemic associations differ between women who meet diagnostic criteria for PCOS versus those suspected of having PCOS but do not meet diagnostic criteria. We found that women with PCOS commonly have skin findings, however, present across a broad spectrum of cutaneous manifestations.
Comparing the skin findings in women who meet diagnostic criteria for PCOS with women who are suspected of having PCOS suggests that it can be very difficult to distinguish a patient with PCOS based on skin findings alone. Hirsutism and acanthosis nigricans are the most helpful findings to suggest PCOS and require a comprehensive skin examination to diagnose; acne and androgenic alopecia are common findings but do not differentiate. The finding of hirsutism and acanthosis were associated with important systemic abnormalities including elevated free testosterone levels, insulin resistance, obesity, and dyslipidemia. This is the first study to perform systematic comprehensive skin exams on women with PCOS and link the skin findings to key systemic associations that have significant implications for the treatment and prognosis of women with the disease.
Dr. Erik Alexander[/caption]
MedicalResearch.com Interview with:
Dr. Erik K. Alexander, MD FACP
Chief, Thyroid Section, Division of Endocrinology
Brigham & Women's Hospital
Associate Professor of Medicine, Harvard Medical School
Medical Research: What is the background for this study? What are the main findings?
Dr. Alexander: Thyroid nodular disease has become an increasingly common medical illness, with prevalence reported to range between 26-67% in the adult. Though advancing age is known to influence the formation of thyroid nodules, their precise relationship remains unclear. Furthermore, it is uncertain whether age influences the risk that any thyroid nodule may prove cancerous. Thus we conducted a study to determine the impact of patient age on nodule formation, the number of thyroid nodules, and risk of thyroid malignancy.
Medical Research: What are the main findings?
Dr. Alexander: Our study is a prospective cohort analysis of consecutive adults who presented for evaluation of nodular disease from 1995-2011 at Brigham and Women’s Hospital, Boston, MA. 6,391 patients underwent thyroid ultrasound and fine needle aspiration that resulted in 12,115 thyroid nodules ≥1 cm. Patients were stratified into six age groups and compared using sonographic, cytologic, and histologic endpoints.
We found that the prevalence of thyroid nodular disease increases with advancing age. The mean number of nodules at presentation increased from 1.5 in the youngest cohort (ages 20–30) to 2.2 in the oldest cohort (>70 years). In contrast, the risk for malignancy in a newly identified nodule declined with advancing age. Thyroid cancer incidence per patient was 22.9% in the youngest cohort, but 12.6% in the oldest cohort. Despite a lower likelihood of malignancy, identified cancers in older patients demonstrated a more aggressive cancer subtype. While nearly all malignancies in younger patients were well-differentiated, older patients were more likely to have higher risk papillary thyroid cancer variants, poorly differentiated cancer, or anaplastic carcinoma.
Dr. Kevin Nead[/caption]
MedicalResearch.com Interview with:
Kevin T. Nead, MD, MPhil
Dept. of Radiation Oncology
Perelman School of Medicine
University of Pennsylvania
MedicalResearch: What is the background for this study? What are the main findings?
Dr. Nead: There are a growing number of studies suggesting that the use of Androgen Deprivation Therapy (ADT) may be associated with cognitive changes and some of these changes overlap with characteristic features of Alzheimer’s disease. In addition, low testosterone levels have been associated with Alzheimer’s disease risk and ADT lowers testosterone levels. Despite these findings, we could not identify any studies examining the association between ADT and Alzheimer’s disease risk. We therefore felt this study could make an important contribution in guiding future research to fully understand the relative risks and benefits of ADT.
We examined electronic medical record data from Stanford University and Mt. Sinai hospitals to identify a cohort of 16,888 patients with prostate cancer. We found that men with prostate cancer who received Androgen Deprivation Therapy were more likely to develop Alzheimer’s disease than men who did not receive Androgen Deprivation Therapy. We also found that this risk increased with a longer duration of ADT. These results were consistent using multiple statistical approaches and separately at both Stanford and Mr. Sinai.
MedicalResearch.com Interview with:
Dr Emad Al-Dujaili
Reader in Biochemistry and Nutrition,
Queen Margaret University
Department of Health Science
Queen Margaret University
Medical Research: What is the background for this study? What are the main findings?
Dr. Al-Dujaili: Recent studies have implicated vitamin D deficiency as a risk factor for Cardiovascular disease and its deficiency is a potential biological predictor of increased rates of CVD. We have done 2 earlier studies investigating the effects of Vitamin D intake on Blood pressure and the stress hormone level cortisol and found that people taking the supplement of Vitamin D had reduced systolic and diastolic blood pressure compared to those who took the placebo. Vitamin D deficiency has also been associated with hypertension, obesity, diabetes mellitus and oxidative stress and reduced exercise performance. For instance, the Framingham offspring study proved that low levels of vitamin D are independently related to Cardiovascular disease incidence. In this placebo-controlled study, We have observed that people given 50ug of Vitamin D daily for 2 weeks showed a significantly reduced systolic and diastolic blood pressure, reduced urinary free cortisol (the hormone that produces stress and high blood pressure if its levels are high. Moreover, the distance cycled in 20 minutes significantly increased by 30% with slightly less efforts compared with that before Vitamin D supplement.
MedicalResearch.com Interview with:
Urszula T. Iwaniec, Ph.D.
Associate Professor
Skeletal Biology Laboratory
School of Biological and Population Health Sciences
Oregon State University
Corvallis, OR 97331
Medical Research: What is the background for this study? What are the main findings?
Dr. Iwaniec: Excessive weight gain in adults is associated with a variety of negative health outcomes. Unfortunately, dieting, exercise, and pharmacological interventions have had limited long-term success in weight control and can result in detrimental side effects, including accelerating age-related bone loss. Leptin, a hormone produced by fat cells plays an essential role in weight regulation. Delivery of leptin directly into the hypothalamus by gene therapy normalizes body weight. We investigated the efficacy of using hypothalamic leptin gene therapy as an alternative method for reducing weight in skeletally-mature female rats and determined the impact of leptin-induced weight loss on bone. Our findings show that hypothalamic leptin gene therapy reduced body weight with minimal effects on bone mass or microarchitecture.
MedicalResearch.com Interview with:
Rodrigo R. Munhoz, MD
Hospital Sírio Libanês
São Paulo, Brazil
Medical Research: What is the background for this study? What are the main findings?
Dr. Munhoz: Chemotherapy-induced early menopause and its impact on quality of life is clinically relevant issue that often arises during the treatment with curative intent of premenopausal patients with early breast cancer. The use of neo-/adjuvant chemotherapy is associated with risks of ovarian dysfunction, permanent or transient amenorrhea, infertility and symptoms of menopause with a premature onset. In addition to osteoporosis, loss of libido, increased cardiovascular risk and atrophic vaginitis, early ovarian dysfunction may adversely impact quality of life and result in significant psychosocial burden.
Currently available guidelines addressing fertility preservation in young women undergoing treatment for early breast cancer recommend that patients at reproductive ages should be advised about the potential risks of fertility impairment and additional effects of adjuvant chemotherapy and that preservation techniques should be carefully considered. However, “evidence regarding the effectiveness of ovarian suppression” is quoted as “insufficient” and the use GnRH agonists as “experimental” .
The current meta-analysis includes a large number of patients and also the results of recently presented clinical trials, and suggest that the use of GnRH agonists is associated a higher rate of recovery of regular menses in patients with breast cancer undergoing chemotherapy.These results summarize the findings of different clinical trials and has immediate clinical implications - this was not clear in the literature, since negative results had been reported across different clinical trials.
MedicalResearch.com Interview with:
Anthony V. D'Amico, MD, PhD
Chief, Division of Genitourinary Radiation Oncology
Professor of Radiation Oncology, Harvard Medical School
Medical Research: What is the background for this study? What are the main findings?
Dr. D'Amico: Controversy exists as to whether androgen deprivation therapy (ADT) used to treat prostate cancer can cause fatal cardiac events.
We found that in men with moderate to severe comorbidity based most often on a history of a heart attack that the use of 6 months of androgen deprivation therapy to treat non metastatic but clinically significant prostate cancer was associated with both an increased risk of a fatal heart attack and shortened survival.
MedicalResearch.com Interview with:
Richard S. Legro, MD
Vice Chair of Research and Professor of Obstetrics and Gynecology and Public Health Sciences Penn State College of Medicine
Medical Research: What is the background for this study? What are the main findings?
Dr. Legro: Weight loss is recommended for obese women with PCOS, but there are no randomized studies to show that it improves fertility outcomes.
Both Lifestyle modification and oral contraceptives are also recommended for chronic treatment of women with PCOS so that this study has relevance to all obese women with PCOS.
We designed this study to prospectively examine the effects of these common treatments on reproductive, metabolic and quality of life parameters, as well as on fertility in women seeking pregnancy.
The main findings are summarized in the abstract and conclusion to the study. I would repeat those here. I would highlight that quality of life improved in all treatment groups, but the group that had both oral contraceptives and lifestyle modification had a significant improvement in their physical well-being compared to the oral contraceptive group.
MedicalResearch.com Interview with:
Abdulmaged M. Traish, MBA, Ph.D.
Professor of Biochemistry
Professor of Urology
Boston University School of Medicine
Boston, MA 02118
Medical Research: What is the background for this study?
Dr. Traish: This study was undertaken to evaluate the data in the contemporary literature on the use of finasteride and dutasteride for treatment of ( benign prostatic hypertrophy) BPH and androgenetic alopecia (AGA). These drugs were proven effective in management of patients withy BPH andandrogenetic alopecia; however, these drugs inhibit a family of enzymes widely distributed in many tissues and organs and therefore may have undesirable effects. Most importantly, few studies have been undertaken to evaluate the effects of these drugs on the central nervous system. The adverse impact of these drugs on sexual function and well-being in a subset of patients raised the questions that we do not know much about the safety of such drugs.
Medical Research: What are the main findings?
Dr. Traish: The main findings of this study is that these agents, while useful in treatment of BPH and androgenetic alopecia, exert undesirable side effects on sexual function and well-being. More importantly, limited data is available on the impact of these agents on the central nervous system.
MedicalResearch.com Interview with:
Quan-Yang Duh MD
Chief, Section of Endocrine Surgery
UCSF Medical Center
Medical Research: What is the background for this study? What are the main findings?
Dr. Quan-Yang Duh: At UCSF we have a monthly Adrenal Conference (involving surgeons, endocrinologists and radiologists) to discuss patients we are consulted for adrenal tumors. About 30% of these are for incidentally discovered adrenal tumors (versus those found because of specific indications such as clinical suspicion or genetic screening). Of these 15-20% has bilateral adrenal tumors.
The evaluation of unilateral incidentaloma has been very well studied and many national guidelines have been published with specific management recommendations. So during our monthly adrenal conference, we have a routine "script" for evaluation and recommendations (rule out metastasis by looking for primary cancer elsewhere, rule out pheochromocytoma and Cushing, resect secreting tumors or large tumors, and if no operation recommended repeat scan in 6 months, etc.). This “script” has worked very well for patients with unilateral incidentaloma.
However, we were less certain when we made recommendations about bilateral incidentalomas because there was very little literature or guidelines written about it. We had some gut feelings, but we were not sure that we were recommending the right things. We needed more data. That was the main reason for the study.
What we found in our study was that although the possible subclinical diseases were the same – hypercortisolism and pheochromocytoma, the probabilities were different. The patients with bilateral incidentalomas were more likely to have subclinical Cushing’s and less likely to have pheochromocytomas than those with unilateral incidentalomas.
MedicalResearch.com Interview with:
Darius A. Paduch, MD, PhD
Associate Professor of Urology and Reproductive Medicine
Director Sexual Health and Medicine
Research Director of Male Infertility Fellowship
Co-Director Male Infertility Genetics Laboratory
Weill Cornell Medical College
Dept of Urology
New York, NY 10065
Medical Research: What is the background for this study? What are the main findings?
Dr. Paduch: Ejaculatory dysfunction, inability to ejaculate or delayed ejaculation affects 10-8% of men. Inability to ejaculate either intravaginally or at all is independent of erectile function.
Men with normal erection may take very long time to ejaculate (>30 min) or not able to ejaculate at all. The men in our study had either normal erections or minimal erectile dysfunction.
Men of all ages have spontaneous erections but don't ejaculate just from erection, it is progression of arousal and activation of spinal cord motor generator for ejaculation which is necessary for ejaculation.
One of important factors in our ability to ejaculate is testosterone (T), testosterone allows for normal function of CNS centers for ejaculation, it is a modulator and is necessary; preadolescent boys don't ejaculate because their spinal cord centers for ejaculations are not mature – process dependent on testosterone. However testosterone is just one of many neurotransmitters and hormones needed of normal ejaculation.
Actually our study showed that in men who achieved normal levels of testostosterone the ejaculatory function have improved. As this was first double blinded and randomized clinical trial we had to report our results based on radomization to testosterone treatment or placebo. Unfortunately only 70-80% of men treated with topical testosterone preparation will achieve normal testosterone level , we simply didn’t reach statistical significance based on randomization and considering relatively low number of patients in each group. But in men who achieved normal testosterone levels the difference was statistically significant.
Testosterone should not be used to treat any conditions, including ejaculatory dysfunction, in absence of low testosterone level.
EjD is very common but it bares significant embarrassment stigma, it is difficult for the couple to bear fact that male partner can’t ejaculate, it also creates issues within couple and question about attraction and fidelity.
We have previously showed that treatment with tadalafil improves ejaculatory and orgasmic dysfunction and these data has been published.
This study was focused on effect of testosterone, but its main significance was it’s design: we developed new tools to assess ejaculatory function and learned a lot about when patients or their partners start to be bothered by EjD. If time to ejaclate takes > 30 min
We are now looking into novel and available pharmacotherapy modulating dopaminergic and canabioid signaling and reward mechanisms. I am also very excited about our potential work in direct spinal cord motor generator nano stimulator, this could be very useful for men with spinal cord injuries and diabetic patients. We paved the road for others and I am sure new treatments are just a matter of time.
MedicalResearch.com Interview with: Dr. Hannah Arem Ph.D. M.H.S. Postdoctoral Fellow Nutritional Epidemiology Branch Division Cancer Epidemiology and Genetics National Cancer Institute MedicalResearch: What is the background for this study? Dr. Arem: In the United States, men are more likely to develop colorectal cancer (CRC) than women. In large prospective studies, researchers observed that women who reported...
MedicalResearch.com Interview with:
Michael S. Irwig MD
Division of Endocrinology Medical Faculty Associates
George Washington University
Medical Research: What is the background for this study? What are the main findings?
Response: Many factors are associated with lower testosterone levels and many men who have their testosterone levels checked have non-specific depressive symptoms. The main finding is a remarkably high rate of depression and depressive symptoms (56%) in men who are referred for borderline testosterone levels. Other significant findings include a prevalence of overweight and obesity higher than the general population.
MedicalResearch.com Interview with:
Aileen Gariepy, MD, MPH
Assistant Professor Section of Family Planning
Department of Obstetrics, Gynecology, and Reproductive Sciences
Yale School of Medicine
New Haven, CT
Medical Research: What is the background for this study? What are the main findings?
Dr. Gariepy: Women who have just given birth are often highly motivated to prevent a rapid, repeat pregnancy. For women who desire the contraceptive implant, a highly effective reversible form of contraception that is placed in the arm and can last for 3 years, new research shows that it is more cost-effective to place the implant while women are still in the hospital after giving birth, compared to delaying insertion to the postpartum visit 6-8 weeks later which is currently the most common practice.
When the costs associated with the implant insertion and the costs of unintended pregnancy are compared in women who receive immediate contraceptive implant insertion (while still in the hospital after giving birth) to women who are asked to come back in 6-8 weeks for the implant insertion (delayed insertion), immediate insertion is expected to save $1,263 per patient. Based on these estimates, for every 1,000 women using postpartum implant, immediate placement is expected to avert 191 unintended pregnancies and save $1,263,000 compared with delayed insertion in the first year. Cost savings would continue to increase for the second and third year after insertion.
In fact, over half of U.S. pregnancies are unintended. Maternal and infant care costs for unintended pregnancies amount to $11.1 billion annually for public insurance programs alone. The immediate postpartum period (after delivery but before discharge home) provides an ideal opportunity for initiating contraceptives as patients are motivated and timing is convenient.
However, the majority of insurance company policies do not provide coverage for insertion of the contraceptive implant when the new mother is still in the hospital. This lack of reimbursement is the most significant barrier to providing this highly effective contraceptive method for women who have just delivered a baby. Surprisingly, the reason most insurance companies do not offer reimbursement for immediate insertion is due to an outdated insurance protocol, “the global obstetric fee” which precludes separate reimbursement of individual procedures (like inserting the implant).
The main reason that immediate insertion results in cost savings is because more women will get the implant compared to a strategy of delayed insertion. Women can get pregnant again within 4 weeks of delivering a baby. Starting contraception as soon as possible after giving birth is important because most women will resume sexual activity before their postpartum office visit and therefore will be at risk of pregnancy. And approximately 35% of women do not return for a postpartum visit.
Even for women who want another pregnancy soon, the implant has benefits. When women conceive and deliver a baby within 2 years of last giving birth, there is a significantly higher risk of poor maternal and neonatal outcomes, including preterm birth, low birth weight, and even early neonatal and maternal death. Birth spacing is better for moms and babies.
MedicalResearch.com Interview with:
Dr.Carey Gleason Ph.D
School of Medicine and Public Health, University of Wisconsin
Geriatric Research, Education and Clinical Center
William S. Middleton Memorial Veterans Hospital
Wisconsin Alzheimer's Disease Research Center, Madison, Wisconsin
Dr. Gleason: In this response I refer to hormone therapy (HT), which was formally called hormone "replacement" therapy. In particular, we examined menopausal HT, i.e., the use of HT during the menopausal transition to address menopausal symptoms.
Medical Research: What is the background for this study? What are the main findings?
Dr. Gleason: The WHI Memory Study (WHIMS) suggested that HT was associated with cognitive harm for women age 65 and older. In contrast, we found that the cognitive performance of women randomized to receive menopausal hormone therapy did not differ from that of women randomized to receive the placebo. On a measure of mood states, women treated with conjugated equine estrogens showed improvements compared to those on placebo.
MedicalResearch.com Interview with:
Kevin Yarasheski, PhD
Assistant Director, Biomedical Mass Spectrometry Research Facility
Professor of Medicine, Cell Biology & Physiology, Physical Therapy
Washington University School of Medicine
Medical Research: What is the background for this study?
Dr. Yarasheski: People living with HIV and taking combination antiretroviral therapy (cART) have successfully reduced the amount of HIV virus in their blood and have partially reconstituted their immune system (CD4+ T-cell count >250 cells/µL). Despite this, many still experience residual immune cell activation and inflammation that is believed to increase HIV morbidity (non-AIDS conditions e.g., CVD, T2DM, obesity, liver fat, bone loss, dementia) and mortality. Scientists are seeking safe and effective interventions for residual immune cell activation and inflammation, that have the potential to reduce non-AIDS complications that threaten quality and quantity of life among HIV infected adults.
We have been testing the safety and efficacy of sitagliptin in people living with HIV; a dipeptidyl peptidase 4 inhibitor that is FDA approved for treating T2DM, and appears to have favorable anti-inflammatory and immune modulatory properties that might specifically benefit people living with HIV and experiencing cardiometabolic complications associated with residual immune cell activation and inflammation.
Medical Research: What are the main findings?
Dr. Yarasheski: In a randomized, double-blinded, placebo controlled 8-wk trial, we found that sitagliptin had beneficial anti-inflammatory, immune regulatory, hematopoietic progenitor cell mobilizing, and glucose lowering effects in cART-treated virally suppressed HIV adults with impaired glucose tolerance. Sitagliptin improved glucose tolerance (a risk factor for CVD), reduced circulating and adipose-specific inflammatory markers (risk factors for obesity, T2DM, liver fat accumulation, and CVD), and increased the number of blood stem cells that can repair damage and inflammation in the vascular walls.
MedicalResearch.com Interview with:
Ranjith Ramasamy MD
Assistant Professor of Urology
University of Miami
Medical Research: What is the background for this study?
Dr. Ramasamy: The association between testosterone supplementation therapy (TST) and thrombotic risk in elderly men remains controversial. We evaluated the prevalence of thrombotic events and all-cause mortality in men older than 65 years with hypogonadism treated with testosterone therapy. We compared men treated with testosterone to an age and comorbidity matched cohort of hypogonadal men not treated with testosterone supplementation therapy.
Medical Research: What are the main findings?
Dr. Ramasamy: No man who received testosterone supplementation therapy died, whereas 6 hypogonadal men who did not receive TST died (p=0.007). There were 4 thrombotic events (1 MI - myocardial infarction, 2 CVA/TIA - stroke, 1 PE - pulmonary embolism) in men who received testosterone supplementation therapy compared to 1 event (CVA/TIA) among men who did not receive TST (p = 0.8). All the events (except one death which took place at 6 months of follow–up) occurred 2 years or more after follow–up. Strengths of the study include long follow–up (>3 years), availability of serum testosterone levels before and after therapy and of a control group (hypogonadal men not treated with TST) for comparison. Limitations included retrospective study design, and a small sample size.
MedicalResearch.com Interview with:
Jim Dupree, MD, MPH
Assistant Professor
Department of Urology, Division of Andrology
University of Michigan
Medical Research: What is the background for this study? What are the main findings?
Dr. Dupree: There are increasing discussions in the United States about testosterone therapy and men with clinical hypogonadism (or low testosterone). Yet, to date, there have not been any nationally-representative studies of the prevalence of low testosterone in the United States. Using a validated national health examination program from the CDC, we found that the national prevalence of low testosterone (serum testosterone ≤ 300 ng/dL) in adult males in the US was 28.9%. Among other factors, men who were older, had a higher body mass index (BMI), or had a larger waist circumference were at risk for having lower testosterone levels.
MedicalResearch.com Interview with:
Bianca Jones Marlin, PhD
Froemke Laboratory
New York University Langone School of Medicine
Medical Research: What is the background for this study? What are the main findings?
Dr. Marlin: Oxytocin is a hormone that plays an important role in the expression of social and parental behaviors, but little is know about how it works in the brain to produce these behaviors. Virgin mice will usually ignore, and sometimes cannibalize newborn mouse pups. Our study has shown that oxytocin works in the auditory cortex of virgin mice to change both their neural responses, and eventually their behaviors, to mirror the maternal response.
MedicalResearch.com Interview with:
Mohamed Kabbaj, PHD
Professor of Biomedical Sciences & Neurosciences
College of Medicine
Florida State University
Medical Research: What is the background for this study? What are the main findings?
Dr. Kabbaj: While anxiety and depressive disorders a major public health concern worldwide, so too are the pervasive sex differences that exist within these pathologies. Fluctuations in the predominant female reproductive hormones, estradiol and progesterone, are thought to be a major contributor to the higher prevalence of anxiety and depression in women compared to men. However, many studies in humans and rodents alike have demonstrated that testosterone, the primary male sex hormone, also influences affective status and may yield protective benefits against the development of mood-related disturbances. Indeed, hypogonadal males with low testosterone levels experience increased rates of anxiety and depressive symptoms. In many of these cases, testosterone replacement alone or in addition to antidepressant medication have been shown to effectively improve mood. How this hormone acts in the brain to exert its beneficial effects, however, is much less clear. Interestingly, it is well-known that many of testosterone’s effects in the brain occur via its conversion to estrogen by the enzyme aromatase. What remained unclear was whether or not this conversion to estrogen was critical for testosterone’s protective anxiolytic and antidepressant effects—so Nicole Carrier and Samantha Saland from Dr. Kabbaj’s lab aimed to figure out just that.
To do this, Carrier and Saland targeted an area of the hippocampus in the brain involved in mood regulation where testosterone is known to act to carry out some of its anxiolytic and antidepressant effects in male rats. Here, they inhibited the enzyme responsible for the conversion of testosterone into estrogen and investigated performance in mood-related behaviors. In doing so, they discovered that testosterone’s anxiolytic- and antidepressant-like effects were lost unless this hormone was first converted into estrogen. Importantly, they also found that continuous testosterone and estrogen treatments had very similar effects on the expression of genes within this brain region that are highly implicated in the regulation of mood as well as antidepressant treatments.