Oral Presentation 49th Nutrition Society of Australia Annual Scientific Meeting 2025

Understanding the Role of Prostaglandins and Leukotrienes in the Pathogenesis of Obesity Related Asthma (129972)

Jarred M Kwanten 1 , Lisa G Wood 2 3 , Evan J Williams 2 3 , Lily M Williams 2 3 , Sarah R Valkenborghs 3 4 , John W Upham 5 , Robin Callister 3 , Natasha Weaver 6 , Christopher L Grainge 7 , Rebecca F McLoughlin 8 , Sophie Anderson 9 10 , Amrisha Mani 3 , Hayley A Scott 2 3
  1. Nutrition and Dietetics, School of Health Sciences, , The University of Newcastle, Callaghan, NSW, Australia
  2. Immune Health Research Program, Hunter Medical Research Institute, New Lambton Heights , NSW, Australia
  3. School of Biomedical Sciences and Pharmacy, The University of Newcastle, Callaghan, NSW, Australia
  4. Active Living Research Program, Hunter Medical Research Institute, New Lambton Heights , NSW, Australia
  5. Lung and Allergy Research Centre, Diamantina Institute, Brisbane, QLD, Australia
  6. School of Medicine and Public Health, The University of Newcastle, Callaghan, NSW, Australia
  7. Department of Respiratory and Sleep Medicine, John Hunter Hospital, Newcastle, NSW, Australia
  8. The University of Newcastle, Callaghan, NSW, Australia
  9. School of Environmental and Life Sciences, The University of Newcastle, Callaghan, NSW, Australia
  10. School of Nursing and Midwifery, The University of Newcastle, Callaghan, NSW, Australia

Obesity is a common comorbidity of asthma and is associated with more severe disease, which is more difficult to treat and does not respond well to existing asthma therapies. (1, 2) People living with obesity are more likely to consume a high-fat diet, which contains a large amount of saturated and omega-6 fatty acids. (3, 4) A high consumption of omega-6 fatty acids leads to an increased production of eicosanoids, such as prostaglandin E2 (PGE2) and leukotriene B4 (LTB4), which have pro-inflammatory effects. (4, 5) This study aims to determine whether prostaglandins and leukotrienes are differentially expressed in adults with asthma and obesity compared to those with asthma but without obesity, and to investigate whether this difference is correlated with systemic inflammation and asthma severity as measured by lung function. Participants were adults with stable physician-diagnosed asthma aged 18-55 years, with (n = 34) and without (n = 67) obesity. Obesity was defined as a body mass index (BMI) ≥30kg/m2. Plasma PGE2 and LTB4 concentrations were measured using high-sensitivity ELISA (Thermo Fisher Scientific and Cayman Chemical). Compared to participants without obesity, those with obesity had significantly lower mean (SD) %predicted forced vital capacity [FVC%; 95.7(11.6) vs 89.4 (11.3), p = 0.013] and higher median (IQR) systemic inflammation as measured by plasma interleukin (IL)-6 [1.02 (0.79, 1.26) vs 1.72 (1.45, 2.23) pg/mL, p < 0.001]. Although median (IQR) PGE₂ and LTB₄ concentrations did not significantly differ between participants without versus with obesity [PGE₂: 1404 (1017, 1810) vs 1472 (1209, 1942) pg/mL, p = 0.517; LTB₄: 68.4 (50.8, 84.1) vs 79.8 (63.2, 85.2) pg/mL, p = 0.058], LTB₄ was positively correlated with plasma IL-6 (rs = 0.433, p < 0.001) and sputum macrophage count (rs = 0.290, p = 0.007), while PGE₂ was inversely correlated with sputum IL-6 (rs = –0.213, p = 0.047). These findings suggest that obesity in asthma is characterised by increased systemic inflammation and reduced lung function, while PGE₂ and LTB₄ may differentially associate with systemic and airway inflammatory markers. Future studies should explore whether dietary manipulation of omega-6 and omega-3 fatty acid concentrations modulates eicosanoid concentrations and airway and systemic inflammation in people with asthma.

 

  1. Australian Institute of Health and Welfare (2024) Overweight and Obesity. Canberra: AIHW.
  2. Thomas D, Harvey ES, McDonald VM et al. (2021) J Allergy Clin Immunol Pract 9, 2715–2724.e5.
  3. Monteiro CA, Cannon G, Moubarac JC et al. (2018) Public Health Nutr 21, 5–17.
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  5. Cebulla D, van Geffen C, Kolahian S (2023) Pharmacol Ther 241, 108313.