Spain: Liraglutide may increase forced vital capacity (FVC) in type 2 diabetes patients, finds a recent study. This effect was shown to be linked to a significant decrease in circulating serum levels of surfactant protein (SP-D) that may be beneficial for alveolar-capillary function in these patients. The study was published in the journal Diabetes on November 04, 2021.
Previous cross-sectional studies have shown decreased indices of forced expiration and lung volume and diffusion capacity in patients with type 2 diabetes versus age-matched healthy populations. This may be attributable to changes in lung elasticity and decreased muscle strength, which can be mediated by insulin resistance, advanced glycation end-products accumulation, and a proinflammatory state. Damage to the alveolar-capillary barrier causes a leak of the surfactant proteins A and D (SP-A and SP-D) from the alveolar space into the bloodstream and are useful systemic biomarkers for assessing lung injury. Also, experimental studies have shown that glucagon-like peptide 1 (GLP-1) improves lung fibrosis, thus causing a decrease in n serum SP-D levels.
Against the above background, Albert Lecube, Instituto de Salud Carlos III, Madrid, Spain, and colleagues aimed to test the impact of liraglutide, a GLP-1 receptor agonist (GLP-1RA), on pulmonary function and circulating levels of SP-D in type 2 diabetes patients in LIRALUNG Study.
LIRALUNG is a double-blind, randomized, crossover, placebo-controlled clinical trial consisting of 76 patients with a baseline forced expiratory volume in 1 s <90% of that predicted. Liraglutide administration was done for 7 weeks (2 weeks of titration plus 5 weeks at 1.8 mg daily). The short duration was intentional to minimize weight loss as a potential confounding factor. Serum SP-D levels were used as a biomarker of alveolar-capillary barrier integrity.
Following were the study's key findings:
Liraglutide exerted a positive impact on forced vital capacity (FVC) in comparison with placebo (ΔFVC 5.2% of predicted).
No differences in the other pulmonary variables were observed.
Participants under liraglutide treatment also experienced a decrease in serum SP-D.
The absolute change in FVC correlated with final serum SP-D in participants receiving liraglutide (r = −0.313).
Stepwise multivariate regression analysis showed that final serum SP-D independently predicted changes in FVC.
"Our results of the LIRALUNG study showed that short-term administration of liraglutide produces a significant increase of FVC," the authors wrote in conclusion. "There is a need for long-term studies with more patients to confirm our initial results and for understanding the underlying mechanisms."
Reference:
Carolina López-Cano, Andreea Ciudin, Enric Sánchez, Francisco J. Tinahones, Ferran Barbé, Mireia Dalmases, Marta García-Ramírez, Alfonso Soto, Anna Michela Gaeta, Silvia Pellitero, Raquel Martí, Cristina Hernández, Rafael Simó, Albert Lecube; Liraglutide Improves Forced Vital Capacity in Individuals With Type 2 Diabetes: Data From the Randomized Crossover LIRALUNG Study. Diabetes 1 February 2022; 71 (2): 315–320. https://doi.org/10.2337/db21-0688