Losartan Repurposing: New Study Links Brown Fat Activation to Reduced Disease Risk

Key points

• Researchers at Rockefeller University and Memorial Sloan Kettering Cancer Center analyzed PET/CT scans from 101,243 patients to link BAT presence with reduced disease prevalence.
• The study found that patients with BAT had 58% lower odds of type 2 diabetes and 47% lower odds of chronic ischemic heart disease.
• Losartan, an angiotensin receptor blocker, was identified as a potential activator of BAT through a mechanism distinct from its blood pressure-lowering effects.
• Mice treated with losartan showed increased energy expenditure and oxygen consumption without significant weight loss, indicating enhanced metabolic activity.
• The findings suggest that BAT activity is associated with better glycemic control, lipid profiles, and lower rates of anxiety and depression.

Background

This study builds on 2021 research by the same team, which first linked BAT presence to reduced cardiometabolic disease risk in a smaller cohort of 50,000 patients. The current study expands this analysis to over 100,000 patients and introduces AI-driven quantification of BAT activity across six anatomical regions. It also explores the connection between BAT and psychiatric health, a novel finding not present in earlier work.

How outlets are covering it

News-Medical and NIH emphasize the potential for drug repurposing, highlighting losartan's safety profile and the distinct molecular pathways involved in BAT activation. The Nature abstract provides detailed statistical evidence, including odds ratios for various diseases, and notes that higher BAT activity in the axillary region is most strongly linked to cardiometabolic health. UA.News offers a critical perspective, noting that the retrospective nature of the study does not prove causation and that losartan's effects on human BAT have not yet been tested in clinical trials. All sources agree on the significance of the findings but differ in their emphasis on clinical applicability versus observational correlation.

Why it matters

This research opens new avenues for treating metabolic and psychiatric disorders by repurposing existing medications. If losartan can safely activate BAT in humans, it could offer a dual-benefit treatment for patients with high blood pressure and metabolic issues. The findings also underscore the importance of BAT in overall health, potentially leading to new therapeutic targets and diagnostic tools.

What to watch

Future research will focus on clinical trials to test losartan's effects on human BAT, explore the genetics of individuals with high BAT levels, and investigate other medications associated with BAT activity. Researchers also plan to study potential downsides, such as higher rates of osteoporosis and skin diseases in BAT-positive individuals.