Body Fat Patterns Linked to Psoriasis and PsA Risk

New UK Biobank Research Reveals Surprising Muscle Fat Connection

New research using UK Biobank data is shedding light on how fat distribution, particularly within organs and muscle, may play a significant role in psoriasis and psoriatic arthritis (PsA).

Visceral and Organ Fat Predict Disease Presence

Findings presented at the GRAPPA 2025 Annual Meeting and Trainee Symposium suggest distinct body composition profiles in individuals with psoriatic diseases. Rheumatologist **Jean-Guillaume Letarouilly**, MD, PhD, from Lille University, analyzed data from over 35,000 individuals. His study indicated that patients with psoriasis exhibited lower muscle volume, increased liver fat, higher visceral fat, and greater fat infiltration within muscles compared to controls.

Individuals diagnosed with PsA also showed elevated liver fat and more muscle fat infiltration, along with increased overall abdominal fat, though not necessarily visceral fat. **Letarouilly** noted, “What we need to do now is determine in a longitudinal way whether these body composition changes appear before the disease itself and what role these different types of body fat play in the [pathologic] process.”

Body Composition Profiles Foretell Comorbidities

Further analysis by **Lyn Ferguson**, MBChB, PhD, of the University of Glasgow, explored the predictive power of these body composition measures for associated health conditions. Her research on UK Biobank participants found that individuals with psoriasis displayed more fat surrounding organs, in the liver, and within muscle tissue than matched controls.

Similarly, those with PsA had higher fat content in their liver and muscles. These altered fat distribution patterns were significantly associated with a greater likelihood of developing type 2 diabetes. “This could be in part related to the fat distribution pattern in psoriasis and PsA,” **Ferguson** stated.

The Critical Role of Muscle Quality

A particularly striking finding was the prevalence of “adverse muscle composition”—defined as low muscle volume or high muscle fat—in approximately half of individuals with psoriasis or PsA. This condition was linked to more than double the risk of coronary heart disease and triple the risk of type 2 diabetes compared to normal muscle composition.

Even more surprisingly, poor muscle quality was associated with over double the risk of developing new-onset psoriasis. “Having more fat stored in the muscle and lower muscle volume appears to be associated with greater risk of developing psoriasis,” **Ferguson** commented. This suggests a potential, yet unconfirmed, link between muscle fat and inflammation or pre-existing metabolic dysregulation.

Implications for Weight Loss Therapies

Both researchers highlighted the implications of these findings in the context of emerging weight-loss treatments like GLP-1 receptor agonists. “It’s really important that people stay physically active to maintain muscle quality, especially if you’re losing a lot of weight” due to these medications, **Ferguson** advised.

The concern is that significant weight loss could include muscle mass, particularly in those already predisposed to adverse muscle composition. **Letarouilly** echoed this sentiment, noting reports of sarcopenic obesity (muscle loss with fat gain) after stopping GLP-1 drugs. “That’s why it is important to advise people to do more exercise,” he said, drawing parallels to post-bariatric surgery monitoring.