medwireNews: Levels of the adipocytokines adiponectin, leptin, and fibroblast growth factor (FGF)-21 are significantly associated with both low lean mass and excess adiposity in people with rheumatoid arthritis (RA), US study findings indicate.
Joshua Baker (University of Pennsylvania, Philadelphia) and colleagues therefore suggest that laboratory screening for these biomarkers “could help identify patients with altered body composition who may be at greater risk of adverse outcomes.”
They analyzed whole-body dual-energy X-ray absorptiometry data and calculated fat mass index (FMI), as a marker of adiposity, and adiposity adjusted appendicular lean mass index (ALMIFMI), as a marker of lean mass, for 424 individuals from three US-based RA cohorts.
The researchers report in Arthritis Care & Research that, after adjustment for potential confounders, low lean mass (ALMIFMI Z-Score ≤–1) was significantly associated with higher levels of adiponectin, while the presence of obesity (FMI ≥13 for women and ≥9 for men) was significantly associated with lower adiponectin levels.
In addition, lower levels of lean mass and higher levels of fat mass were each associated with higher leptin and FGF-21 levels.
When the researchers added adiponectin and leptin levels to regression models that included age, sex, race, BMI, and study cohort, the accuracy for prediction of lean mass increased significantly from 66% to 75%.
For predicting obesity, there was a small but significant increased accuracy from 97.2% to 97.8% with the inclusion of adiponectin and leptin.
Baker and team note that the limited improvement in the prediction of obesity may be due to the “high prevalence of obesity” among the study participants. They suggest that future studies could investigate “whether adipokines might add to prediction of excess adiposity in particular subgroups such as those with BMI 25-30 kg/m2.”
The researchers comment: “Since a major limitation to addressing adverse changes in body composition in patients with RA is their accurate identification and characterization, these findings help to support the potential use of circulating biomarkers to identify patients with lean mass deficits that might benefit from appropriate intervention.”
They also indicate “that a strong relationship between adipokines and body composition in an at-risk population may help to explain previously defined relationships between adipokines and adverse long-term outcomes such as fracture and mortality among older adults and with radiographic damage progression in patients with RA.”
medwireNews is an independent medical news service provided by Springer Healthcare Ltd. © 2021 Springer Healthcare Ltd, part of the Springer Nature Group