(RxWiki News) About 1.5 million people around the world are currently on hemodialysis — an artificial blood filtering treatment for kidney failure. This treatment is known to impact patients' physical function, but they may have more control than they realize.
A recent study found that hemodialysis patients with more muscle mass had better physical function and scored better on mental and physical health questionnaires compared to hemodialysis patients with low muscle mass.
The researchers suggested that physical activity that builds muscle mass may be associated with better overall health and quality of life for hemodialysis patients.
"Discuss an appropriate physical activity regimen with your doctor."
The lead author of this study was Srinivasan Beddhu, MD, from the Veterans Affairs Salt Lake City Healthcare System and the Department of Medicine at the University of Utah School of Medicine — both in Salt Lake City, Utah.
The study included 105 patients who had been on maintenance hemodialysis for at least three months at the University of Utah and Vanderbilt Medical Center outpatient dialysis units between January 2008 and June 2012.
All of the participants were 18 years old and older. Fifty-six percent of the participants were male and 21 percent were African American.
The researchers obtained demographic data, past medical history, lifetime smoking status, alcohol consumption and medication history, and measured body mass index (BMI; height to weight ratio), waist size, the mid-thigh muscle area and the intra-abdominal (belly) fat area at the beginning of the study.
The participants also did the six-minute walk test, which measures how far a person can walk in six minutes, and took physical and mental health questionnaires at the beginning of the study, at six months and at 12 months.
The findings showed that the patients with a higher BMI, waist size and intra-abdominal fat measurement at the beginning of the study scored poorly on the six-minute walk test at all assessment times.
The patients with greater measurements of mid-thigh muscle — an indication of high muscle mass — were able to walk longer distances during the six-minute walk test compared to the patients with low muscle mass.
Increases in mid-thigh muscle mass were associated with higher mental and physical health scores at the beginning of the study after adjusting for BMI. However, the associations between muscle mass and high health scores were significantly weaker at six months and 12 months.
According to the researchers, higher levels of muscle mass were associated with better physical function and thus a better quality of life for hemodialysis patients.
"Because this study shows that higher muscle mass is associated with better physical function and quality of life in dialysis patients, interventions such as increased physical activity that decrease fat mass and increase muscle mass are likely to improve physical function, quality of life, and survival in dialysis patients," Dr. Beddhu said in a press statement. "Such interventions need to be tested in clinical trials."
This study was limited because not all of the participants did the six-minute walk test, and those who did not do it were more likely to be obese and have higher levels of fat and lower levels of muscle. Also, many hemodialysis patients have co-occurring conditions that could affect their level of physical function and quality of life.
This study was published on April 24 in the Clinical Journal of the American Society of Nephrology.
The National Kidney Foundation, the University of Utah Study Design and Biostatistics Center, the Public Health Services and the National Center for Research Resources provided funding for this research.