Impact of diabetes mellitus on mortality in pulmonary hypertension: A systematic review and meta-analysis

Background: Pulmonary hypertension (PH) is a progressive disease characterized by endothelial dysfunction and vascular remodeling and is a leading cause of mortality worldwide. Although it is independently associated with multiple comorbidities, the impact of diabetes mellitus (DM) on mortality in patients with PH remains uncertain. To address this issue, we conducted a systematic review and meta-analysis to investigate the effect of DM on survival in patients with pulmonary hypertension.

Aim: To investigate the impact of diabetes mellitus on mortality in pulmonary hypertension patients.

Methods: We conducted a comprehensive search of four major electronic bibliographic databases like PubMed, Google Scholar, Scopus, and Embase, and identified 106 relevant studies, out of 1561 articles, published since the year 2000 for full-text review. Fourteen retrospective and prospective cohort studies that compared survival between patients with DM and those without DM in the context of PH were deemed eligible for inclusion in our meta-analysis. The study was registered on PROSPERO with the identifier CRD42023390232.

Results: A total of 116455 patients with PH were included in the meta-analysis, of whom 41228 suffered from DM and 75227 did not. The results of our meta-analysis indicate an elevated mortality rate among PH patients with diabetes mellitus in comparison to those without DM [odds ratio (OR) = 1.40, 95%CI: 1.15-1.70, P = 0.0006]. The meta-regression analysis unveiled a statistically significant negative association between mean age and effect size (coefficient = -0.036, P value = 0.018). Conversely, a statistically significant positive association was detected between female proportion and effect size (coefficient = 0.000, P value < 0.001).

Conclusion: Our meta-analysis, which included approximately 116500 PH patients, revealed that the presence of diabetes mellitus was associated with increased odds of mortality when compared to non-diabetic patients. The meta-regression analysis indicates that studies with older participants and lower proportions of females tend to exhibit smaller effect sizes. Clinically, these findings underscore the importance of incorporating diabetes status into the risk stratification of patients with PH with more aggressive monitoring and early intervention to improve prognosis potentially.