Sarcopenic Obesity Associated with Lower Survival After Liver Transplants

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Sarcopenic obesity (a combination of low muscle mass and obesity) is common in patients before liver transplantation and is linked to a higher risk of death after the procedure, according to research published in Frontiers in Nutrition. Identifying and managing sarcopenic obesity for those awaiting liver transplants may improve survival outcomes.

Pre-liver transplantation individuals often develop sarcopenia due to conditions such as chronic disease wasting, eating disorders and anticancer treatments, as well as other factors including obesity, advanced age and limitations on physical activity. Obesity is connected to diabetes, hypertension, nonalcoholic fatty liver disease and abnormal lipid metabolism, and has been linked to an increased risk of surgical and anesthesia complications.

“Sarcopenic obesity, which may lead to a higher risk of adverse outcomes than either muscle loss or obesity alone, is receiving increasing attention in the field of liver transplantation,” wrote a team of investigators from Guang'anmen Hospital, China Academy of Chinese Medical Sciences, in Beijing, China.

Investigators conducted a database search to identify studies that assessed the relationship between sarcopenic obesity and posttransplant survival among patients undergoing liver transplantation. Their primary focus was all-cause mortality at any time during follow-up.

Subgroup analysis compared results for different definitions of sarcopenic obesity: skeletal muscle index (SMI) + body mass index (BMI) versus SMI + visceral fat area (VFA).

Nine cohort studies, comprising 2,416 patients, were included in the review. All studies were rated as moderate to high quality. The mean prevalence of sarcopenic obesity in pretransplant patients was as high as 34%. These patients had a significantly higher overall mortality than patients without sarcopenic obesity at the longest follow-up available, with similar results observed when comparing patients with or without the condition at one, three and five years of follow-up.

Subgroup analysis based on the definition type of sarcopenic obesity further confirmed these results. Interestingly, the results contradicted the obesity paradox, which states that although obesity is associated with a variety of comorbidities, it may have a protective effect against mortality.

Ultimately, sarcopenic obesity was linked to a more than 130% increase in mortality among this patient population.

Investigators noted these results are aligned with recent meta-analyses conducted in cirrhotic patients, emergency laparotomy and gastrointestinal oncology, emphasizing the potential for adverse clinical outcomes in patients with sarcopenic obesity.

Investigators noted the retrospective study design as a limitation of the study, which may have impacted the meta-analysis due to potential biases within the included studies. Additionally, they were unable to consider all of the factors that may have influences on mortality, such as severity of sarcopenic obesity, disease duration, any treatments used to combat obesity, diet type and the use of supplements. Lastly, the studies differed on definitions of obesity, protocols and the thresholds for SMI.

Given these findings, interventions designed to improve muscle function are crucial. These methods include physical activity, such as aerobic endurance and resistance training; nutritional strategies, including low-calorie, low-fat and low-carbohydrate diets and protein supplements; and pharmacological treatments, such as ammonia-lowering therapies. Current guidelines from the European Society for Clinical Nutrition and Metabolism suggest a combination of nutritional therapy, protein supplements and physical activity.