SHPT May Contribute to Protein-Energy Wasting in HD
Protein-energy wasting is characterized by undernutrition unrelieved by nutritional therapy and increased fat and protein catabolism.
High parathyroid hormone (PTH) levels may lead to protein-energy wasting (PEW) in hemodialysis (HD) patients, according to the authors of a new review article published in Therapeutic Apheresis and Dialysis.
Undernutrition contributes to PEW, but it is not the sole cause, Hirotaka Komaba, MD, and Masafumi Fukagawa, MD, of Tokai University School of Medicine in Japan, contend. In their cross-sectional study of 2221 HD patients, body mass index (BMI) increased along with patients' normalized protein catabolic rate (nPCR), a proxy for protein intake.
Several clinical studies associate PTH with increasing resting energy expenditure (REE), leading to fat and protein catabolism associated with PEW. A study by Lilian Cuppari, PhD, and colleagues (J Am Soc Nephrol 2004 Nov;15:2933-2939) found that patients with severe SHPT had significantly higher REE than those with mild to moderate or no SHPT, which improved in a subset who underwent parathyroidectomy. A study by Fong-Fu Chou, MD (Arch Surg 1999;134:1108–1111) found that parathyroidectomy improved muscle weakness associated with PEW in HD patients. In addition, various animal studies suggest that PTH-related protein, and likely PTH, mediates adipose tissue browning and wasting in a setting of renal failure.
In addition, the authors speculated that fibroblast growth factor 23 contributes to PEW by increasing inflammation in kidney failure patients.
“Protein-energy wasting is a serious problem associated with morbidity and mortality in ESRD patients,” Dr Komaba and Dr Fukagawa concluded. “Recent translational work has provided compelling evidence for a causal role for PTH in the pathogenesis of PEW. These results provide a biological explanation for the clinical association between SHPT and PEW in hemodialysis patients and may serve as an additional rationale for treating SHPT.”
Komaba H and Fukagawa M. Secondary hyperparathyroidism and protein-energy wasting in end-stage renal disease. Thera Apher Dial. 2018. doi: 10.1111/1744-9987.12683