Diabetes mellitus in idiopathic pulmonary fibrosis: a systematic review and meta-analysis

Some contradictory results about the relationship between diabetes mellitus (DM) and idiopathic pulmonary fibrosis (IPF) have been reported. This systematic review aims to estimate the relationship between IPF and DM from the perspective of evidence-based medicine and evaluate the value of DM for the etiology of IPF. Studies published prior to February 2016 in PubMed, Embase, The Cochrane Library and the relevant professional association website were reviewed for relevant studies. Summary odds ratio (OR) and 95% confidence intervals (CI) were performed to evaluate the relationship between DM and the risk of IPF. The sources of heterogeneity and the effect of potential confounding were explored using sensitivity analysis and subgroup analysis. The possible publication bias was evaluated by Begg's test and Egger's test. The search yielded 17 studies for estimating the prevalence of DM in IPF patients, which 9 studies suitable for meta-analysis. The prevalence of DM in IPF patients was 13.9%, 23.67%, 25.23% in Europe, Asia and North America, respectively. DM was significantly associated with IPF and increased the risk of IPF (OR, 1.696; 95% CI, 1.34 to 2.14). Significant publication bias was not found. DM is prevalent in IPF patients. The prevalence of diabetes in IPF patients was higher than the ordinary population. DM constitutes a risk factor for IPF, there was an increase in the odds for developing IPF among diabetics. DM has significant etiologic value for IPF and is expected to be one of the causes of IPF.