The medical community remains deeply polarized over the management of low testosterone in the context of obesity, a dilemma that will take center stage at ENDO 2026 in Chicago. On Sunday, June 14, two of the world’s foremost experts in andrology will engage in a high-stakes debate titled "Low Testosterone in Obesity: Should We Treat or Not?" to address a clinical question that has grown increasingly complex alongside the global obesity epidemic. The session, moderated by Endocrine Society Past-President Stephen Hammes, MD, PhD, aims to reconcile divergent interpretations of pathophysiology, diagnostic nomenclature, and the long-term efficacy of testosterone replacement therapy (TRT).
As obesity rates continue to climb—with the Centers for Disease Control and Prevention (CDC) reporting that over 40% of American adults now live with the condition—the prevalence of low testosterone readings in men has surged. However, whether these readings represent a true pathological deficiency or a secondary symptom of metabolic dysfunction remains a point of intense scholarly friction. The upcoming debate follows a series of formal disagreements published in the Journal of Clinical Endocrinology & Metabolism (JCEM) in late 2025, suggesting that the live exchange will be both intellectually rigorous and professionally pointed.
Chronology of a Growing Scholarly Dispute
The confrontation at ENDO 2026 is the culmination of a year-long dialogue that began in the literature. In the fall of 2025, Franck Mauvais-Jarvis, MD, PhD, a professor of medicine at Tulane University, and David Handelsman, MBBS, PhD, FRACP, of the University of Sydney, published a series of papers in JCEM. This sequence included a primary "Approach to the Patient" paper, followed by a Letter to the Editor and a subsequent author response.
These publications established the battle lines. Dr. Mauvais-Jarvis advocates for a more proactive approach to treating what he terms "testosterone deficiency" (TD), viewing it as a critical predictor of chronic disease. Conversely, Dr. Handelsman argues that the phenomenon is often "pseudohypogonadism," a transient state that does not justify hormonal intervention. This paper trail has set the stage for the Chicago meeting, where the two experts will attempt to defend their positions before an audience of thousands of endocrinologists seeking a clearer standard of care.
Pathophysiological Divergence: Defining the Condition
At the heart of the debate is a fundamental disagreement over what is actually happening in the male body when obesity and low testosterone coexist. Dr. Handelsman employs the term "pseudohypogonadism" to describe the hormonal profile typical of simple obesity. He asserts that the low testosterone levels observed in these patients are proportionate to a reduction in serum sex hormone-binding globulin (SHBG), a protein that carries testosterone through the blood.
In Handelsman’s view, because the hypothalamic-pituitary-testis (HPT) axis remains functional—evidenced by normal levels of luteinizing hormone (LH) and follicle-stimulating hormone (FSH)—the patient is "eugonadal." In this framework, the low testosterone reading is a biomarker of obesity rather than a failure of the testes. He warns that treating this state with exogenous testosterone ignores the underlying disease of obesity and risks creating "iatrogenic androgen dependence," where the body stops its own natural production due to the presence of external hormones.
Dr. Mauvais-Jarvis, however, rejects the concept of pseudohypogonadism, calling it a theory with "no scientific foundation." He prefers the term "functional testosterone deficiency." He argues that while some forms of TD are theoretically reversible through weight loss, in clinical practice, they rarely are. Over 95% of patients presenting today fall into this "functional" category, and for Mauvais-Jarvis, the distinction between organic and functional deficiency is less important than the patient’s current symptomatic state and overall health risks.
Supporting Data: Prescribing Trends and Metabolic Risks
The debate is fueled by staggering statistics regarding testosterone use over the last two decades. Dr. Handelsman points to data showing that testosterone prescribing has increased 100-fold in recent years, often without new clinical indications or evidence of long-term safety. He suggests that this "overprescribing" is driven by a diagnostic failure: clinicians measuring total serum testosterone in isolation without accounting for the suppressive effects of obesity on SHBG.
From the opposing perspective, Dr. Mauvais-Jarvis highlights the systemic risks of leaving low testosterone untreated. He cites research indicating that testosterone levels are perhaps the single best marker of a man’s overall health status. According to his analysis, testosterone deficiency is a potent predictor of:
- Metabolic syndrome and visceral obesity.
- Type 2 diabetes and cardiovascular disease.
- Osteoporosis and anemia.
- Cognitive decline and depression.
- Increased overall mortality.
Furthermore, he emphasizes the socioeconomic and personal impact, noting that TD is a known contributor to professional loss of productivity and marital dysfunction. To Mauvais-Jarvis, testosterone is not just about sexual health; it is a public health priority.
The Role of GLP-1 Receptor Agonists in 2026
The emergence of highly effective weight-loss medications, specifically glucagon-like peptide 1 (GLP-1) receptor agonists like tirzepatide and semaglutide, has added a new layer of complexity to the discussion. If obesity is the driver of low testosterone, logic suggests that significant weight loss via these drugs should resolve the issue.
However, Dr. Mauvais-Jarvis expresses skepticism regarding the sufficiency of GLP-1 RAs for this specific population. He notes that these drugs typically result in a body weight reduction of approximately 10% to 15%, which he argues may not be enough to fully reverse symptomatic testosterone deficiency in many obese men. Furthermore, he raises a significant clinical concern: GLP-1 RAs are associated with a loss of lean muscle mass. If a patient stops the medication, fat mass often rebounds while lean mass does not, potentially worsening the patient’s metabolic profile. He argues that combining testosterone therapy with lifestyle changes may be the only way to preserve lean mass and achieve true hormonal recovery.
Dr. Handelsman’s position remains rooted in the idea that if weight loss is the goal, the focus should remain on weight-loss therapies and lifestyle modifications rather than hormonal supplementation, which carries "undefined safety risks" regarding prostate health and cardiovascular stability.
Moderating the "Spirit of Chicago"
Stephen Hammes, MD, PhD, who will moderate the session, acknowledges that the lack of a clear consensus makes this debate essential. As the Louis S. Wolk Distinguished Professor of Medicine at the University of Rochester, Hammes has spent decades observing the evolution of endocrine guidelines.
"Ask five endocrinologists and you will get 10 answers," Hammes observed, reflecting on the current state of clinical practice. He notes that while the evidence for long-term benefits of treating obesity-related low testosterone is relatively low, the evidence for definitive harm is also sparse. This "grey area" leaves clinicians in a difficult position when facing symptomatic patients.
Hammes expects the personalities of the debaters to play a significant role in the session’s impact. He describes both Handelsman and Mauvais-Jarvis as possessing "larger-than-life personalities" and deep expertise, ensuring that the debate will be more than just an academic exercise—it will be a "spirited exchange" intended to challenge the audience’s existing biases.
Broader Impact and Clinical Implications
The outcome of this debate has significant implications for how healthcare systems manage male health. If the "don’t treat" camp prevails, the focus of care will shift almost entirely toward aggressive weight management and lifestyle intervention, potentially reducing the pharmaceutical costs and side-effect risks associated with long-term TRT.
If the "treat" argument gains traction, it could lead to a more integrated model of care where testosterone is viewed as a standard component of metabolic rehabilitation. This could potentially improve quality of life for millions of men suffering from the symptoms of low T—such as fatigue, low libido, and depressed mood—while potentially mitigating the long-term risks of chronic diseases like diabetes.
For the clinicians attending ENDO 2026, the session represents a search for a roadmap. In the absence of a "gold standard" of care, physicians are currently forced to mitigate uncertainties on a case-by-case basis. The Chicago debate aims to provide the evidentiary framework necessary to move toward a more standardized, data-driven approach to one of the most common presentations in modern endocrinology.
As the meeting approaches, the medical community remains watchful. Whether the solution lies in the syringe or the scale—or perhaps a combination of both—remains the defining question for the future of men’s health in an era of epidemic obesity.
