Change in skeletal muscle mass is associated with lipid profiles in female rheumatoid arthritis patients -TOMORROW study

Association between atherogenic dyslipidemia and muscle quality defined by myosteatosis

Background

Myosteatosis, ectopic fat accumulation in skeletal muscle, is a crucial component of sarcopenia, linked to various cardiometabolic diseases. This study aimed to analyze the association between dyslipidemia and myosteatosis using abdominal computed tomography (CT) in a large population.

Methods

This study included 11,823 patients not taking lipid-lowering medications with abdominal CT taken between 2012 and 2013. Total abdominal muscle area (TAMA), measured at the L3 level, was segmented into skeletal muscle area (SMA) and intramuscular adipose tissue. SMA was further classified into normal attenuation muscle area (NAMA: good quality muscle) and low attenuation muscle area (poor quality muscle). NAMA divided by TAMA (NAMA/TAMA) represents good quality muscle. Atherosclerotic dyslipidemia was defined as high-density lipoprotein cholesterol (HDL-C) less than 40 mg/dL in men and 50 mg/dL in women, low-density lipoprotein cholesterol (LDL-C) greater than 160 mg/dL, triglycerides (TG) greater than 150 mg/dL, small dense LDL-C (sdLDL-C) greater than 50.0 mg/dL, or apolipoprotein B/A1 (apoB/A1) greater than 0.08.

Results

The adjusted odds ratios (ORs) of dyslipidemia according to the HDL-C and sdLDL definitions were greater in both sexes in the lower quartiles (Q1~3) of NAMA/TAMA compared with Q4. As per other definitions, the ORs were significantly increased in only women for LDL-C and only men for TG and ApoB/A1. In men, all lipid parameters were significantly associated with NAMA/TAMA, while TG and ApoB/A1 did not show significant association in women.

Conclusion

Myosteatosis measured in abdominal CT was significantly associated with a higher risk of dyslipidemia. Myosteatosis may be an important risk factor for dyslipidemia and ensuing cardiometabolic diseases.

Impact of disease burden or inflammation on nutritional assessment by the GLIM criteria in female patients with rheumatoid arthritis

BACKGROUND & AIMS

In 2018, the Global Leadership Initiative on Malnutrition (GLIM) released a global standard for evaluating malnutrition. The etiologies of malnutrition in the GLIM criteria includes disease burden/inflammation, but how this view affects nutritional assessment remains unclear. This study aimed to investigate the impact of disease burden/inflammation on the proportion of malnourished patients defined by GLIM criteria, and how differences in methods for determining disease burden/inflammation in GLIM criteria affect existing nutritional indices among patients with rheumatoid arthritis (RA). We also investigated factors associated with malnutrition in RA patients.

METHODS

Data from 135 female RA patients (66.8 ± 12.6 years) were cross-sectionally analyzed. Among the etiologies of malnutrition, disease burden/inflammation was defined as: (1) moderate or higher disease activity score (disease activity score composite of the 28-joint score and erythrocyte sedimentation rate [DAS28-ESR] ≥ 3.2) [DAS-malnutrition (MN)]; (2) elevated C-reactive protein (CRP) ≥0.5 mg/dL (CRP-MN); and (3) presence of RA (RA-MN). In each of the three conditions, nutritional indicators between well-nourished and malnourished groups were compared by analysis of covariance. Factors associated with malnutrition were analyzed with logistic regression analysis.

RESULTS

The frequencies of malnutrition as defined by DAS-MN, CRP-MN, and RA-MN were 39%, 30%, and 71%, respectively. When malnutrition was defined by the DAS-MN and/or the CRP-MN, grip strength and serum ceruloplasmin, iron, and zinc levels showed significant differences between the well-nourished and malnourished groups (p < 0.05). The use of targeted synthetic or biological disease-modifying antirheumatic drugs (ts-/b-DMARD) (OR = 0.29; 95% CI 0.11-0.82), grip strength (OR = 0.83; 95% CI 0.75-0.91), subjective reduction in walking speed (OR = 5.24; 1.85-14.86) were significantly associated with malnutrition as determined by DAS-MN.

CONCLUSION

Differences in disease burden/inflammation affect nutritional assessments. The number of malnourished patients with RA was negatively associated with the use of ts-/b-DMARDs and high physical function in women.

Muscle mass loss is associated with physical dysfunction in patients with early rheumatoid arthritis

Background

Muscle mass loss is common in long-standing rheumatoid arthritis (RA). The aim was to explore the prevalence and effects of RA disease characteristics in patients with early RA.

Methods

This cross-sectional study was carried out based on a Chinese RA cohort and control subjects. The body composition (BC) was assessed using bioelectric impedance analysis. Myopenia was defined by an appendicular skeletal muscle mass index of ≤ 7.0 kg/m2 in men and ≤ 5.7 kg/m2 in women. Physical dysfunction was defined as a health assessment questionnaire disability index > 1. Propensity score matching was performed to balance age and gender differences among patients with early RA (disease duration ≤ 12 months) and established RA, and controls (with 1:3:3 matching).

Results

In total, 2017 controls and 1,008 patients with RA were recruited for this study. Among the patients with RA, there were 190 (18.8%) patients with early RA, with a median disease duration of 7 (4, 11) months. The matched patients with early RA (n = 160) showed a higher prevalence of myopenia than the matched controls (41.3 vs. 15.8%, P < 0.0167), but no difference was found in the matched patients with established RA (41.3 vs. 50.4%, P > 0.0167). Compared with the patients with established RA, the patients with early RA exhibited higher disease activity scores [disease activity score in 28 joints with four variables including C-reactive protein (DAS28-CRP): median 4.76 vs. 3.93, P < 0.001] and a higher prevalence of physical dysfunction (26.3 vs. 19.4%, P = 0.035). In the patients with early RA, patients with myopenia showed a higher prevalence of physical dysfunction than those without myopenia (41.3 vs. 15.5%, P < 0.001), among which walking and common daily activities were the most involved subdimensions. Multivariate logistic regression analysis showed that DAS28-CRP was positively associated with myopenia [adjusted odds ratio (AOR) 1.558, 95% CI (1.138-2.132)], and myopenia [AOR 2.983, 95% CI (1.192-7.465)] was independently associated with physical dysfunction in the patients with early RA.

Conclusion

Our data indicate the importance of early detection of muscle involvement in the early stage of RA and imply the significance of early aggressive control of disease activity for the prevention of myopenia and physical dysfunction in patients with early RA. Our study provides a new perspective on RA management.

Lipid Metabolism Profiles in Rheumatic Diseases

Rheumatic diseases are a group of chronic autoimmune disorders that involve multiple organs or systems and have high mortality. The mechanisms of these diseases are still ill-defined, and targeted therapeutic strategies are still challenging for physicians. Recent research indicates that cell metabolism plays important roles in the pathogenesis of rheumatic diseases. In this review, we mainly focus on lipid metabolism profiles (dyslipidaemia, fatty acid metabolism) and mechanisms in rheumatic diseases and discuss potential clinical applications based on lipid metabolism profiles.