Genetic association of telomere length, obesity and tobacoo smoking with idiopathic pulmonary fibrosis risk

Background Due to the inadequacy of published evidence, association of telomere length (TL), obesity and tobacco smoking with idiopathic pulmonary fibrosis (IPF) remains unclear. The aim of the study was to explore whether these exposures genetically affected the risk of the disease. Methods Genetic variants from genome-wide association studies for TL, body mass index (BMI), body fat percentage (BFP) and tobacco smoking (including maternal smoking) were used as instrumental variables. Inverse-variance weighted were mainly adopted to determine the genetic association of these exposures with IPF. All analyses were conducted by R-software (version 3.6.1). Results Firstly, longer TL was associated with the decreased risk of IPF (OR = 0.475 per SD increase in TL, 95%CI = 0.336 similar to 0.670, P<0.001). Secondly, higher levels of BMI and BFP were related to the increased risk of the disease (OR = 1.425 per SD increase in BMI level, 95%CI = 1.114 similar to 1.823, P = 0.005; OR = 1.702 per SD increase in BFP level, 95%CI = 1.202 similar to 2.409, P = 0.003). Thirdly, maternal smoking was implicated in the increased risk of the disease (OR = 13.183 per SD increase in the prevalence of maternal smoking, 95%CI = 1.820 similar to 95.484, P = 0.011). Conclusion TL should be a genetic risk factor for IPF. Obesity and exposure to tobacco smoking as a fetus might also contribute to the development of this fibrotic diseases. These findings should be verified by future studies.