Abdominal obesity and muscle loss increase the risk of death by 83% after age 50

A study by researchers at the Federal University of São Carlos (UFSCar) in Brazil, in partnership with University College London (UCL) in the United Kingdom, concluded that the combination of abdominal fat and muscle loss increases the risk of death by 83%, compared to people without these conditions.

This combination is so dangerous that it identifies an even greater problem: sarcopenic obesity. This condition is characterized by loss of muscle mass while gaining fat throughout the body. It is a difficult condition to diagnose, and it is related to loss of autonomy and a worsening quality of life in older adults. It is also known as frailty syndrome and is associated with an increased risk of falls and other comorbidities.

”In addition to assessing the risk of death associated with abdominal obesity and low muscle mass, we were able to prove that simple methods can be used to detect sarcopenic obesity. This is important because the lack of consensus on diagnostic criteria for this disease makes it difficult to detect and treat,” says Tiago da Silva Alexandre, a professor in the Department of Gerontology at UFSCar and one of the authors of the study supported by FAPESP. “Thus, our findings allow older adults to have greater access to early interventions, such as nutritional monitoring and physical exercise, ensuring an improvement in quality of life.”

The results, published in the journal Aging Clinical and Experimental Research, were obtained from 12 years of follow-up of 5,440 participants in the English Longitudinal Study of Ageing (ELSA) aged 50 years or older.

No need for costly diagnosis

Sarcopenic obesity is typically diagnosed using complex tests such as magnetic resonance imaging, computed tomography, electrical bioimpedance, or densitometry. These tests identify excess body fat and reduced muscle mass and function. However, despite their high accuracy, they are expensive and only available through a few health services. This makes diagnosing the disease a major challenge in clinical practice.

“By correlating data from ELSA study participants, we found that simple measures, such as measuring abdominal circumference and estimating lean mass [using a consolidated equation that considers clinical variables such as age, sex, weight, race, and height], showed for the first time that it’s possible to screen these individuals early,” Alexandre celebrates.

The relationship between muscle mass loss and abdominal obesity has an amplified effect on metabolism. “The study revealed that individuals with both conditions had an 83% higher risk of death compared to those who didn’t have them. We also found that the risk of death was reduced by 40% among those with low muscle mass and no abdominal obesity, a finding that reinforces the potential danger of the coexistence of the conditions. Interestingly, individuals with abdominal obesity but adequate muscle mass weren’t associated with an increased risk of death,” explains Valdete Regina Guandalini, a professor at the Federal University of Espírito Santo (UFES) and researcher in the Department of Gerontology at UFSCar. She is also the first author of the article.

She explains that excess fat intensifies inflammatory processes that trigger metabolic and catabolic changes, further aggravating muscle loss. “In addition to one condition interfering with the other, fat infiltrates the muscle and takes up its space. This systemic and progressive inflammation directly affects muscle tissue, compromising its metabolic, endocrine, immunological, and functional capabilities,” she says.

Since there is no consensus among researchers worldwide on the definition of sarcopenic obesity, the study used simpler measures to define abdominal obesity and muscle mass loss. Thus, to predict the risk of sarcopenic obesity, the researchers identified abdominal obesity as having an abdominal circumference greater than 102 centimeters for men and 88 centimeters for women. At the same time, low muscle mass was defined as a skeletal muscle mass index of less than 9.36 kg/m² for men and less than 6.73 kg/m² for women.

About São Paulo Research Foundation (FAPESP)
The São Paulo Research Foundation (FAPESP) is a public institution with the mission of supporting scientific research in all fields of knowledge by awarding scholarships, fellowships and grants to investigators linked with higher education and research institutions in the State of São Paulo, Brazil. FAPESP is aware that the very best research can only be done by working with the best researchers internationally. Therefore, it has established partnerships with funding agencies, higher education, private companies, and research organizations in other countries known for the quality of their research and has been encouraging scientists funded by its grants to further develop their international collaboration. You can learn more about FAPESP at www.fapesp.br/en and visit FAPESP news agency at www.agencia.fapesp.br/en to keep updated with the latest scientific breakthroughs FAPESP helps achieve through its many programs, awards and research centers. You may also subscribe to FAPESP news agency at http://agencia.fapesp.br/subscribe.