Cachexia in rheumatoid arthritis is not explained by decreased growth hormone secretion

Abstract

Objective. Patients with rheumatoid arthritis (RA) lose body cell mass (BCM) by unknown mechanisms. Since the loss of BCM in normal aging individuals parallels the characteristic age-related decline in growth hormone (GH) secretion, this study was carried out to determine whether further decreased GH secretion plays a role in the pathogenesis of this loss of BCM in RA patients, termed "rheumatoid cachexia."Methods. GH secretory kinetics were determined by deconvolution analysis in 16 patients with RA and 17 healthy controls matched for age (mean ؎ SD 45.4 ؎ 13.2 years and 47.1 ؎ 14.6 years, respectively), sex, race, and body mass index. Blood samples were obtained every 20 minutes for 24 hours. Body composition was ascertained using total-body potassium (TBK) as a measure of BCM and dual x-ray absorptiometry to determine fat mass.Results. BCM was reduced in patients with RA compared with healthy controls (mean ؎ SD gm TBK 79.5 ؎ 9.5 versus 94.9 ؎ 11.9; P < 0.0005), but there was no difference in fat mass. GH kinetic parameters in patients with RA did not differ from those in controls.Conclusion. These findings suggest that GH kinetics are unaltered in RA patients compared with healthy subjects; thus, GH deficiency does not account for rheumatoid cachexia.

Body composition in patients with rheumatoid arthritis is not different than healthy subjects

“…Since the primary objective of the present study was to compare the body fat content between RA patients and controls, the sample size was estimated by using the results of a previous study that investigated cachexia in RA (26). Based on the findings of body fat % in RA (40.5±10.3) and controls (36.0±8.2) in the study mentioned above, the sample size was calculated as 23 for both samples.…”

Physical activity and body composition in patients with ankylosing spondylitis

“…Accelerated muscle loss is observed at a higher age (sarcopenia), and in chronic diseases such as cancer and chronic obstructive pulmonary disease, and is collectively referred to as cachexia (20). In patients with RA, several studies, although not all, have shown evidence for a decreased FFM compared to healthy controls (21)(22)(23)(24)(25). In patients with AS, evidence is limited.…”

Cachexia and adiposity in rheumatoid arthritis. Relevance for disease management and clinical outcomes

“…The consequence is chronic erosion of BCM resulting in a cachectic state. Rheumatoid cachexia is associated with low bioavailability of insulin-like growth factor [13] but, differently from sarcopenia of aging, does not depend on reduced testosterone or growth hormone production [14].…”