Weight Gain After HIV Therapy Initiation: Pathophysiology and Implications

Rapid advances in the potency, safety, and availability of modern HIV antiretroviral therapy (ART) have yielded a near-normal life expectancy for most people living with HIV (PLWH). Ironically, considering the history of HIV/AIDS (initially called "slim disease" because of associated weight loss), the latest dilemma faced by many people starting HIV therapy is weight gain and obesity, particularly Black people, women, and those who commenced treatment with advanced immunodeficiency. We review the pathophysiology and implications of weight gain among PLWH on ART and discuss why this phenomenon was recognized only recently, despite the availability of effective therapy for nearly 30 years. We comprehensively explore the theories of the causes, from initial speculation that weight gain was simply a return to health for people recovering from wasting to comparative effects of newer regimens vs prior toxic agents, to direct effects of agents on mitochondrial function. We then discuss the implications of weight gain on modern ART, particularly concomitant effects on lipids, glucose metabolism, and inflammatory markers. Finally, we discuss intervention options for PLWH and obesity, from the limitations of switching ART regimens or specific agents within regimens, weight-gain mitigation strategies, and potential hope in access to emerging antiobesity agents, which are yet to be evaluated in this population.