Greater pericardial adipose tissue (PAT) and abdominal visceral adipose tissue (VAT) has been linked to interstitial lung abnormalities, increased high attenuation areas (HAAs), and decreased forced vital capacity (FVC), according to results of an analysis published in the journal CHEST.
Researchers sought to explore whether adipose tissue is involved in the pathogenesis of interstitial lung disease (ILD) by using data from the ongoing Multi-Ethnic Study of Atherosclerosis (MESA). The MESA study is a large, diverse, multicenter, prospective cohort analysis conducted among community-dwelling adults. A total of 6814 adults between 45 and 84 years of age with no clinically evident cardiovascular disease were enrolled in the MESA study between 2000 and 2002, with 6 follow-up examinations.
The primary exposure was PAT volume, which was calculated by cardiac computed tomography (CT) scans. The secondary exposures included VAT and subcutaneous adipose tissue (SAT) cross-sectional areas. They evaluated the association of CT measures of PAT, abdominal VAT, and abdominal SAT with HAAs and interstitial lung abnormalities. Secondary assessments included the association of adipose depot size with FVC, as well as with biomarkers of inflammation and obesity.
Every doubling in PAT volume was associated with a 63.4-unit significantly higher HAA (95% CI, 55.5-71.3; P <.001). Further, every doubling in abdominal VAT area was linked to a 41.5-unit significantly higher HAA (95% CI, 28.3-54.7; P <.001). In contrast, abdominal SAT area was not significantly associated with HAA in base models (9.3 units; 95% CI, -9.4 to 28.1; P =.33) but was significantly associated with HAA in fully adjusted models (56.1 units; 95% CI, 38.8-73.5; P <.001).
Interstitial lung abnormalities were detected in 12% of the participants after exclusion of those with scans that were indeterminate for interstitial lung abnormalities. Individuals with and without interstitial lung abnormalities had a mean body mass index (BMI) of 28.1±4.8 vs 28.1±5.1, respectively. When fully adjusted models were used, every doubling in PAT volume was linked to 20% increased odds of interstitial lung abnormalities (odds ratio [OR], 1.2; 95% CI, 0.98-1.5; P =.07). In a similar fashion, every doubling in VAT area was associated with increased odds for interstitial lung abnormalities, which was not statistically significant in fully adjusted models (OR, 1.3; 95% CI, 0.9-1.8; P =.21).
Every doubling in PAT volume was linked to a 5.5% lower percent predicted FVC in fully adjusted models (95% CI, -6.8 to -4.3; P <.001). Greater abdominal VAT area and greater abdominal SAT area were both also associated with significantly lower FVC in unadjusted and fully adjusted models (P <.001 for both). Overall, interleukin-6 (IL-6) and leptin accounted for 17% and 18%, respectively, of the link between visceral adipose tissue and HAA.
A major limitation of the current study is the fact that interstitial lung abnormalities were measured at examination 5, whereas adipose tissue and lung function measures were obtained from earlier examinations. The researchers concluded that adipose tissue may represent a modifiable risk factor for ILD. Additional investigation is warranted to explore the potential roles of IL-6, monocyte chemoattractant protein-1 (MCP-1), and leptin in lung injury and fibrosis.
Disclosure: Several study authors declared affiliations with the pharmaceutical industry. Please see the original reference for a full list of authors’ disclosures.
Anderson MR, Kim JS, Allison M, et al. Adiposity and interstitial lung abnormalities in community dwelling adults: the MESA cohort study. CHEST. Published online April 15, 2021. doi:10.1016/j.chest.2021.03.058