Changes in body composition and metabolic profile during interleukin 6 inhibition in rheumatoid arthritis

Background The link between body mass index (BMI) and disease characteristics in rheumatoid arthritis (RA) remains controversial. Body composition (BC) has been more frequently recommended to be used instead of BMI for more accurate assessment. Our study aimed to investigate the characteristics of BC in RA patients and their associations with disease characteristics. Methods Body composition was assessed in consecutive Chinese RA patients and control subjects by bioelectric impedance analysis. Overfat was defined by body fat percentage (BF%) as ≥25% for men and ≥35% for women. Myopenia was defined by appendicular skeletal muscle mass index (ASMI) ≤7.0 kg/m 2 in men and ≤5.7 kg/m 2 in women. BMI and clinical data including disease activity, function, and radiographic assessment were collected. Active disease was defined by disease activity score in 28 joints with four variables including C‐reactive protein (DAS28‐CRP) ≥2.6. Functional limitation was defined as Stanford health assessment questionnaire disability index (HAQ‐DI) >1. Radiographic joint damage (RJD) was defined as the Sharp/van der Heijde modified sharp score (mTSS) >10. Results There were 457 RA patients (mean age 49.5 ± 13.1 years old with 82.7% women) and 1860 control subjects (mean age 34.3 ± 9.9 years old with 51.2% women) recruited. Comparisons of BMI and BC between RA patients and control subjects in age and gender stratification showed that lower BMI with 17.7% underweight and lower ASMI with 45.1% myopenia are the main characteristics in RA patients. Compared with those without myopenia, RA patients with myopenia had significantly higher DAS28‐CRP (median 3.5 vs. 3.0), higher HAQ‐DI (median 0.38 vs. 0.13) with higher rate of functional limitation (24.8% vs. 7.6%), and higher mTSS (median 22.3 vs. 9.0) with more RJD (71.8% vs. 45.8%) (all P < 0.001). Multivariate logistic regression analysis showed myopenia were positively associated with functional limitation (OR = 2.546, 95% CI: 1.043–6.217) and RJD (OR = 2.660, 95% CI: 1.443–4.904). All RA patients were divided into four BC subgroups according to overfat and myopenia. Those with both overfat and myopenia had the worst disease characteristics. After adjustment for confounding factors, significant additive interactions were observed between overfat and myopenia in active disease (AP = 0.528, 95% CI: 0.086–0.971), functional limitation (AP = 0.647, 95% CI: 0.356–0.937), and RJD (AP = 0.514, 95% CI: 0.139–0.890). Conclusions Myopenia is very common in RA patients that is associated with functional limitation and joint damage in RA. Further research on the underlying mechanism and the effect of skeletal muscle mass improvement in RA management are worth exploring in the future.

Section: Discussionmentioning

confidence: 99%

Section: Discussionmentioning

confidence: 99%

Myopenia is associated with joint damage in rheumatoid arthritis: a cross‐sectional study

Lin

Liang

et al. 2019

“…Sarcopenia associates with various clinical complications in aging and cachexia‐associated chronic diseases; therefore, sensitive and reproducible measures of muscle mass are required to assess the evolution of muscle loss and to follow outcomes of therapeutic interventions directed at attenuation of tissue loss in order to improve outcome of patients. Considering availability of diagnostic CT scans in the majority of cachexia‐associated disease such as cancer and cirrhosis, as well as high accuracy and time efficacy of different software programmers for body composition measurements, finding an appropriate indicator of muscle mass, i.e.…”

Section: Discussionmentioning

confidence: 99%

Poor performance of psoas muscle index for identification of patients with higher waitlist mortality risk in cirrhosis

Ebadi

Wang

Lai

et al. 2018

118

BackgroundSarcopenia, characterized by low muscle mass, associates with mortality in patients with cirrhosis. Skeletal muscle area in a single computed tomography image at the level of the third lumbar vertebrate (L3) is a valid representative of whole body muscle mass. Controversy remains regarding applicability of psoas muscle to identify patients at greater risk of mortality. We aimed to determine psoas muscle index (PMI) association with skeletal muscle index (SMI) and to evaluate the capacity of PMI to predict liver transplant waitlist mortality.MethodsWe evaluated listed adult patients with cirrhosis from 2012 to 2013 at four North American liver transplant centres. From L3 computed tomography images within 3 months of listing, we determined SMI and PMI expressed by cm2/m2. Low SMI was defined as SMI <39 cm2/m2 in women and <50 cm2/m2 in men as published by us earlier. Cut‐offs for PMI to predict mortality were established using a receiver‐operating characteristic analysis. Mortality predictors were determined using competing‐risk analysis with reported results as subdistribution hazard ratios (sHRs).ResultsOf 353 waitlist candidates, 68% were men, mean age 56 ± 9 years, and Model for End‐stage Liver Disease of 16 ± 8 points. Low SMI was present more frequently in men than women (51 vs. 36%, P = 0.02). Moderately strong correlation between SMI and PMI was observed (r > 0.7, P < 0.001). Low PMI (males < 5.1 cm2/m2; females < 4.3 cm2/m2) yielded poor and moderate concordance with low SMI in men and women, respectively (Kappa coefficient 0.31 and 0.63). SMI (39 ± 9 vs. 43 ± 7 cm2/m2; P = 0.009) and PMI (4.4 ± 1.3 vs. 5.2 ± 1.1 cm2/m2; P = 0.001) were lower in women who died and/or were delisted (compared with non‐deceased patients) whereas men who died and/or were delisted had only lower SMI (47 ± 7 vs. 51 ± 9 cm2/m2; P = 0.003), but not PMI compared with non‐deceased patients. In women, both SMI (sHR 0.94, P = 0.048) and PMI (sHR 0.58, P = 0.002) were predictors of mortality, while in men, SMI was significant (sHR 0.95, P = 0.001) and PMI showed a trend to be (sHR 0.85, P = 0.09) associated with mortality. Overall, 104 patients (29%) were misclassified between SMI and PMI categories. Using PMI cut‐offs, 66% and 28% of low SMI men and women, who have a higher risk of mortality, were incorrectly classified as low risk.ConclusionsSkeletal muscle index is a more complete and robust measurement than PMI, especially in men with cirrhosis. Low PMI identifies an incomplete subset of patients at increased risk of mortality indicated by low SMI. Given the poor performance of PMI, SMI should not be substituted by PMI.

“…As we have now demonstrated that CER, a well‐known biomarker for muscle mass, is also associated with muscle performance, CER could potentially be utilized as a modifiable factor to improve post‐transplant patient and graft survival. Although, CER is a non‐invasive, easily accessible, inexpensive, and direct measurement of total body muscle mass; it is often not included in the imaging technique armamentarium available and applied for evaluation of muscle mass in clinical intervention studies and observational studies . Each of the imaging techniques that can be applied in clinical intervention and observational studies has its drawbacks, with expenses and availability as most important drawbacks for magnetic resonance imaging and computed tomography, while DEXA and muscle ultrasonography share the major disadvantage of not being able to measure intramuscular adipose tissue .…”

Section: Discussionmentioning

confidence: 99%

Muscle mass determined from urinary creatinine excretion rate, and muscle performance in renal transplant recipients

Stam

Eisenga

Gomes-Neto

et al. 2019

Background Muscle mass, as determined from 24‐h urinary creatinine excretion rate (CER), is an independent predictor for mortality and graft failure in renal transplant recipients (RTR). It is currently unknown whether CER is comparable with healthy controls after transplantation and whether it reflects muscle performance besides muscle mass. We aimed to compare urinary CER and muscle performance between RTR and healthy controls and to investigate whether urinary CER is associated with muscle performance in RTR. Methods We included RTR, transplanted between 1975 and 2016 in the University Medical Center Groningen. Healthy controls were subjects screened for kidney donation. CER was calculated from a 24‐h urine collection. Muscle performance was assessed by handgrip strength, sit‐to‐stand test, and 2‐min walk test. Statistical analyses were performed using linear regression analyses. Results We included 184 RTR (mean age 56.9 ± 11.9 years, 54% male recipient) and 78 healthy controls (age 57.9 ± 9.9, 47% male recipient). RTR were at a median time of 4.0 (1.1–8.8) years after transplantation. Mean CER was lower in RTR compared to healthy controls (11.7 ± 4.0 vs. 13.1 ± 5.2 mmol/24 h; P = 0.04). Significantly poorer results in muscle performance were found in RTR compared to controls for the handgrip strength (30.5 [23.7–41.1] N vs. 38.3 [29.3–46.0] N, P < 0.001) and the 2‐min walk test (151.5 ± 49.2 m vs. 172.3 ± 12.2 m, P < 0.001) but not for the sit‐to‐stand (12.2 ± 3.3 m vs. 11.9 ± 2.8 m, P = 0.46). In RTR, CER was significantly associated with handgrip strength (std. β 0.33; P < 0.001), independent of adjustment for potential confounders. In RTR, CER was neither associated with the time used for the sit‐to‐stand test (std. β −0.09; P = 0.27) nor with the distance covered during the 2‐min walk test (std. β 0.07; P = 0.40). Conclusions Muscle mass as measured by CER in RTR is lower compared to controls. CER is positively associated with muscle performance in RTR. The results demonstrate that CER does not only reflect muscle mass but also muscle performance in this patient setting. Determination of CER could be an interesting addition to the imaging technique armamentarium available and applied for evaluation of muscle mass in clinical intervention studies and observational studies.