Liraglutide improves FVC in type 2 diabetes patients: LIRALUNG Study

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.