Poor muscle health in Individuals with obesity increases risk of early death, study finds

A pivotal study presented at the European Congress on Obesity (ECO) in Venice, Italy, from 12-15 May, 2024, has unveiled a stark correlation between suboptimal muscle health and an increased risk of premature death among individuals with obesity.

The research, carried out by a Swedish team on a UK cohort, established that individuals with compromised muscle composition were three times more likely to die during the study period compared to those with healthier muscle conditions. Dr. Jennifer Linge of AMRA Medical in Linköping, Sweden, spearheaded the research and shared compelling insights. “By examining muscle composition, we can predict which individuals with obesity are most at risk of early death in the forthcoming years,” Dr. Linge explained, highlighting the potential of muscle analysis as a predictive tool for mortality.

In recent years, weight loss has become a central strategy in managing chronic conditions such as type 2 diabetes and cardiovascular diseases. With pharmaceutical advancements, patients are now achieving significant weight reductions, previously possible only through surgical interventions. However, this brings to light concerns about possible detrimental effects on muscle health, including severe muscle mass loss and reduced mobility.

Dr. Linge elaborated on the complexities of muscle health in individuals with obesity, “Although individuals with obesity typically have more muscle mass, their muscles tend to be comparatively weaker. They also exhibit lower muscle quality, as well as reduced mobility and function.” She emphasised the importance of thorough muscle composition assessments, which consider both muscle quantity and quality, in evaluating the safety of rapid weight loss treatments, particularly for more vulnerable patients, such as those with sarcopenic obesity or advanced age.

The study also highlighted a critical gap in research concerning muscle health among populations with obesity, despite existing evidence from MRI studies that link poor muscle health with reduced functional performance, increased illness, and higher mortality rates in individuals with non-alcoholic fatty liver disease (NAFLD) and the general populace.

To address this, Dr. Linge and her colleagues utilised the AMRA Researcher software to analyse MRI scans from 56,109 participants in the UK Biobank study. They measured muscle volume and muscle fat, establishing a personalised muscle volume z-score to benchmark each individual’s muscle volume against the norm for their sex and body size.

From the extensive dataset, 9,840 participants—half of whom were men, with an average age of 64.4 years and a mean BMI of 33.5 kg/m²—were identified as having obesity and had comprehensive data on muscle composition. Of these, 2,001 (20.3%) exhibited adverse muscle composition. Over an average follow-up of 3.9 years, 174 participants died, predominantly from ischemic and hypertensive diseases.

The study findings indicated that neither low muscle volume z-score nor high muscle fat alone significantly influenced mortality risk. However, adverse muscle composition—characterised by both low muscle volume and high muscle fat—was strongly associated with a tripled risk of death during the follow-up period. This association persisted even when adjustments were made for factors like strength (hand grip), other diseases (cancer, type 2 diabetes, and coronary heart disease), and lifestyle factors (smoking, alcohol consumption, and physical activity), revealing a 70% increased risk of early death.

Sex, age, type 2 diabetes, and smoking were also noted as factors increasing the risk of premature death.

Dr. Linge concluded, “These results underscore the paramount importance of maintaining muscle health in people with obesity. It is crucial to determine whether drugs that achieve significant or rapid weight loss are inadvertently causing excessive muscle loss or worsening muscle quality, to ensure safer treatment approaches for obesity, particularly for those at greater risk.” This call to action not only emphasises the significance of maintaining muscle health but also the necessity of careful evaluation of treatment strategies for obesity.