Conventional wisdom says that a low protein intake is essential for patients with kidney disease. However, scientists from Osaka Metropolitan University explained that this may not always be the case with their recent study on the relationship between protein intake and skeletal muscle mass in kidney transplant recipients. Their findings were published in Clinical Nutrition.
Chronic kidney disease patients are known to have caused sarcopenia due to chronic inflammation, hyper-catabolism, low nutrient intake, and decreased physical activity associated with impaired kidney function. The restoration of kidney function due to successful kidney transplantation is able to correct or improve many of those physiological and metabolic abnormalities. As a result, kidney transplant recipients increase skeletal muscle mass after kidney transplantation. Because excessive protein intake worsens kidney function, it is common for patients with chronic kidney disease, including kidney transplant recipients, to limit protein intake to protect the kidneys. On the other hand, it has been suggested that severe protein restriction may exacerbate sarcopenia and adversely affect prognosis.
Since nutrition and exercise therapy are recommended for improving sarcopenia, protein intake is suspected to be related to the recovery of skeletal muscle mass after kidney transplantation. However, few studies have examined the relationship between skeletal muscle mass and protein intake in kidney transplant recipients.
In response to this gap, the research group led by Dr. Akihiro Kosoko, Dr. Tomoaki Iwai and Professor Junji Uchida in the Department of Urology at Osaka Metropolitan University School of Medicine investigated the relationship between changes in skeletal muscle mass – measured. By analysis of bioelectrical impedance – and protein quantity, which was estimated from urine collected from 64 kidney transplant recipients 12 months after kidney transplantation. The results showed that changes in skeletal muscle mass during this period were positively related to protein intake, and that insufficient protein intake resulted in decreased muscle mass.
Dr. Iwai and Dr. Kosoko commented, “To improve the life expectancy of kidney transplant recipients, further research is needed to clarify optimal protein intake to prevent deterioration of renal function or sarcopenia. It is hoped that dietary guidance, including protein intake, will improve average Life expectancy and outlook.