HbA1c in pulmonary arterial hypertension: a marker of prognostic relevance?

Abstract

BACKGROUND:

Patients with pulmonary arterial hypertension (PAH) exhibit impaired glucose metabolism and increased insulin resistance. The clinical consequences of these metabolic changes are not known.

METHODS:

We assessed HbA1c levels in 115 patients newly diagnosed with PAH (79 females and 36 males; mean age 49.2 years; idiopathic n = 67, collagen vascular disease n = 16, congenital heart defect n = 19, pulmonary veno-occlusive disease n = 8, portopulmonary n = 5). No patients had diabetes or were receiving anti-diabetic medication or systemic steroids. After initiation of pulmonary vasoactive treatment, patients remained in long-term follow-up.

RESULTS:

Initially, patients were in an advanced stage of disease (mean pulmonary arterial pressure 53 ± 18 mm Hg, cardiac index 2.3 ± 0.8 liters/min/m2) with a 6-minute-walk distance of 337 ± 123 meters, and in NYHA Functional Class 3.0 ± 0.7. The HbA1c was 5.73 ± 0.75%. A moderate but statistically significant positive correlation was observed between HbA1c levels and BNP (r(p) = 0.41, p = 0.014), but no correlation was found with hemodynamics or 6-minute-walk distance. The 5-year survival rate for the entire group was 68%. Kaplan-Meier analysis and multivariate Cox proportional hazard models correcting for demographic and clinical covariates revealed that patients with HbA1c < 5.7% had a significantly better 5-year survival compared with those having higher initial values (85.1% vs. 55.9%; log rank p = 0.002). HbA1c was a predictor of all-cause mortality with a hazard ratio of 2.23 (95% CI 1.06 to 4.70; p = 0.034) per 1-unit increase of HbA1c.

CONCLUSIONS:

In patients with pulmonary arterial hypertension, the HbA1c level at time of diagnosis is an independent predictor of long-term prognosis.

• Authors: Michael J Belly, Henning Tiede, Rory E Morty, Richard Schulz, Robert Voswinckel, Christian Tanislav, Horst Olschewski, Hossein A Ghofrani, Werner Seeger, Frank Reichenberger
• Journal: The Journal of heart and lung transplantation : the official publication of the International Society for Heart Transplantation (J Heart Lung Transplant) Vol. 31 Issue 10 Pg. 1109-14 (Oct 2012) ISSN: 1557-3117 [Electronic] United States
• PMID: 22975101 (Publication Type: Journal Article)
• Copyright: Copyright © 2012 International Society for Heart and Lung Transplantation. Published by Elsevier Inc. All rights reserved.

Chemical References

• Biomarkers
• Glycated Hemoglobin A

Topics

• Adult
• Aged
• Biomarkers (blood)
• Familial Primary Pulmonary Hypertension
• Female
• Follow-Up Studies
• Glycated Hemoglobin (metabolism)
• Humans
• Hypertension, Pulmonary (blood, diagnosis, mortality)
• Kaplan-Meier Estimate
• Longitudinal Studies
• Male
• Middle Aged
• Prognosis
• Proportional Hazards Models
• Survival Rate