{
  "abstract": "Introduction Interstitial lung disease (ILD) is the leading cause of death in systemic sclerosis (SSc). Little is known about the association between body composition and lung function in SSc. Thoracic computed tomography (CT) scans are routinely obtained in SSc patients to screen for ILD. Accessory respiratory muscles and fat measurements can be calculated from these CT scans. Our aim was to examine the association between thoracic body composition and pulmonary function in SSc patients.Material and Methods SSc patients who met 2013 ACR/EULAR classification criteria were recruited longitudinally from two academic medical centers. We performed a cross-sectional analysis using baseline thoracic CTs and pulmonary function tests. The following were measured using ImageJ: Pectoralis muscle (PM), erector spinae (ES) muscle, visceral fat (VF), and subcutaneous fat (SF) area and density. PM area to SF area ratio (MFR) was calculated. To evaluate the relationship between body composition measurements (exposures) and the % predicted forced vital capacity (ppFVC) (outcome), we performed unadjusted and multivariable-adjusted linear regression analyses. The multivariable regression model was adjusted for age, sex, height, weight, disease duration, smoking status, SSc subtype, and Scl-70 positivity.Results One hundred-four CT scans from SSc patients were analyzed. The median (interquartile range [IQR]) age was 55.0 (44.0, 62.0) years. The mean (standard deviation (SD]) BMI was 27.6 (7.0) kg/m 2. The majority were female (79.8%) and white (76.9%). The median (IQR) disease duration was 1.5 (1.0, 3.1) years from first non-Raynaud symptom. There were no differences in muscle or fat area and density between diffuse and limited subtypes. In unadjusted analyses, the following body composition measures were inversely associated with ppfvc: pm area (β coefficient = -0.48, 95% confidence interval [ci] -0.92 to -0.005), sf density (β coefficient -0.58, 95% ci -0.98 to -0.18), and mfr (β coefficient = -7.08, 95% ci -13.31 to -0.84) (table 1). In a multivariable-adjusted model, the following measures were significantly associated with ppFVC: ES area (β coefficient = 0.56, 95% CI 0.072 to 1.04), SF density (β coefficient = -0.79, 95% CI -1.19 to -0.38), and MFR (β coefficient = -8.20, 95% CI -15.63 to -0.70).Conclusions High SF density, low ES area, and high MFR may be risk factors for diminished ppFVC. However, it remains unknown whether thoracic muscle and fat area and density can predict ppFVC over time. Longitudinal studies are needed to determine whether thoracic body composition can predict outcomes in SSc-ILD.Abstract P.125 Table 1Association between body composition parameters and %predicted forced vital capacity",
  "authors": [
    {
      "affiliations": [
        "Columbia University Irving Medical Center, New York, USA"
      ],
      "name": "Aradhna Agarwal"
    },
    {
      "affiliations": [
        "Columbia University Irving Medical Center, New York, USA"
      ],
      "name": "Niki Pradhan"
    },
    {
      "affiliations": [
        "University of Michigan, Ann Arbor, USA"
      ],
      "name": "James St Clair"
    },
    {
      "affiliations": [
        "University of Michigan, Ann Arbor, USA"
      ],
      "name": "Dinesh Khanna"
    },
    {
      "affiliations": [
        "Columbia University Irving Medical Center, New York, USA"
      ],
      "name": "Elana Bernstein"
    }
  ],
  "title": "P.125 Association between thoracic muscle and fat area and density and pulmonary function in systemic sclerosis",
  "uid": "6b4e5a9a-091b-55f7-8339-373ca4777222"
}