Obesity and low muscle mass increases risk of death from major traumas

Obesity can increase a patient’s risk of losing skeletal muscle mass, leading to a condition known as sarcopenic obesity. A study by Penn State College of Medicine researchers shows that patients with this condition have decreased resiliency to traumatic injuries and an increased likelihood of dying from major traumas.

Dr. John S. Oh, Dr. Scott Armen and Anna  Ssentongo from the Department of Surgery at Penn State Health Milton S. Hershey Medical Center discovered that secondary assessment of computed tomography (CT) scans can help to classify trauma patients with sarcopenic obesity who are at increased risk of dying.

Using data from the Milton S. Hershey Medical Center’s trauma registry, the investigators identified 883 adults who had CT scans upon admission to the hospital from January 2012 through March 2018. The majority of patients were male (70%) and the bulk of the patients suffered from blunt trauma (95%). Among those studied, more than half (51%) had a severe injury.

The study revealed that obese patients may also have low muscle mass or sarcopenia. Through analyzing the CT scans, the researchers identified patients with sarcopenic obesity by calculating the visceral fat to skeletal muscle ratio. According to their findings, 38% of patients had sarcopenic obesity. The researchers noted that this condition was difficult to detect in obese patients until they underwent a CT scan.

According to the researchers, patients with sarcopenic obesity had a decreased resilience to traumatic injury and an increased risk of death during their admission to the hospital. Sarcopenic obesity predicted mortality better than obesity or sarcopenia alone, suggesting that the presence of both had a synergistic effect.

“We are beginning to realize that sarcopenia, in addition to obesity, increases a critically ill, trauma patient’s risk of dying,” said Oh. “Further research needs to be done to identify the biologic mechanisms involved, but these findings likely identify patients with frailty.  This means that these patients may have decreased physiologic resiliency to stress.”

The investigators also noted that patients with sarcopenic obesity were also more likely to have pre-existing health conditions with the most common being high blood pressure (38%), followed by coronary artery disease (15%) and chronic obstructive pulmonary disease (14%).

The analysis of the data from the study showed that patients who are both overweight and have low muscle mass may be at an increased risk of death after sustaining an injury that places them in an intensive care unit. According to the researchers, the study could not identify the exact cause, but it seems to be partly due to the high blood sugar observed in these types of patients after injury.

“This study highlights why some obese patients tend to have a worse prognosis compared to others,” said Ssentongo, a researcher and recent graduate from Penn State Public Health Sciences’ Doctor of Public Health program. “Conducting secondary analysis of CT scans could allow trauma doctors to quickly and efficiently identify patients with an increased risk of mortality. Future studies should be aimed at risk-reduction in patients with sarcopenic obesity.”

Paddy Ssentongo of Penn State Center for Neural Engineering; Laura Keeney from Penn State College of Medicine; Thomas Dykes from Texas Tech University Health Sciences Center; and David Soybel from Dartmouth Geisel School of Medicine contributed to this research.

The researchers declare no conflicts of interest or specific funding for this research.

Read the full study in The American Journal of Surgery.

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