Prognostic significance of insulin resistance in pulmonary hypertension

Aims: The relationship between insulin resistance (IR) and glucose intolerance with pulmonary hypertension (PH) has been suggested in recent investigations. In the present study, we aimed to show the prevalence of IR and its correlation with haemodynamic variables as well as its prognostic significance in this group of patients.

Methods and results: Among 100 new and returning patients with PH, scheduled for right heart catheterization (RHC), 59 non-diabetic patients were enrolled. The homeostasis model assessment of insulin resistance (HOMA-IR) was used to assess IR. The study population were followed up for a median (interquartile range) of 48 (23-48) months for all-cause mortalities. Most of the study population [mean (standard deviation) age of 45.9 (17.3)] were classified as class I of PH classification (47.5%). Overall, 27% of our study population had IR considering the Iranian cut points of HOMA-IR. The prevalence of IR in non-diabetic, non-metabolic syndrome patients with precapillary PH (PAH) was 34.2%, which was higher than the prevalence of IR in non-diabetic, non-metabolic syndrome Iranian population (24.1%). There was no difference between IR and insulin sensitive (IS) groups regarding demographic and clinical findings, 6 min walk test, and laboratory and haemodynamic data in univariable and multivariable analyses. The mortality rate in the follow-up period was 44.1%. The survival of patient with IR was slightly lower than IS patients; however, IR was not an independent predictor of death.

Conclusions: The glucose metabolism is dysregulated in patients with PH, and IR may increase the risk of adverse events among these patients.