A new article published in The Journal of Clinical Endocrinology and Metabolism found that patients with idiopathic pulmonary fibrosis (IPF) are at a 1.54-fold increased risk of having diabetes mellitus (DM) compared to the general population (odds ratio (OR): 1.54; 95% CI, 1.3-1.84; P <.001).
On the other hand, when investigating studies in patients with and without DM, the analysis found a slight decrease in the risk of IPF for patients with DM. This separate finding was not statistically significant (OR: 8.89; 95% CI, 0.64-1.25; P =.497), possibly because only 2 relevant studies were found with DM and non-DM groups from which to do analyses. These 2 studies also had different study populations, numbers of patients, and time periods. By comparison, the analyses of IPF and non-IPF groups for risk of DM included 16 studies.
The authors stated, “Due to the limited number of studies investigating the prevalence of IPF in patients with diabetes, we cannot draw a complete and valid conclusion about whether there is an association between diabetes and IPF. Therefore, future large, prospective cohort studies should focus on this aspect to further investigate their association.”
Subgroup analysis of the studies comparing IPF and non-IPF patient rates of DM found that patients aged less than 65 years had a higher prevalence of DM than those aged 65 or more years. The authors stated that this might be “due to the significant increase of the DM patients in hospitals, and the fact that IPF patients have more frequent and thorough medical work-up than the general population.”
A total of 18 studies were included in the article containing a total of 26,312,009 participants. Among the 16 studies included in the IPF and non-IPF group comparisons, a total of 25,180 IPF patients and 73,434 controls were included.
There was a significant amount of heterogeneity between the studies included in this analysis (I2 =90.7%; P <.001) so the authors performed sensitivity analysis by removing each study individually from the meta-analysis. No individual study substantially affected the results when removed. Heterogeneity was much smaller between the 2 studies that included DM and non-DM groups (I2 =50.3%; P =.156), but sensitivity analysis could not be performed since there were only 2 studies.
Li C, Xiao Y, Hu J, et al. Associations between diabetes and idiopathic pulmonary fibrosis: a study-level pooled analysis of 26 million people. J Clin Endocrinol Metab. Published online July 24, 2021. doi:10.1210/clinem/dgab553