Study: High blood sugar is linked with PAH adverse outcomes
Link between hyperglycemia and severity, long-term outcomes explored
Indicators of high blood sugar levels, particularly stress hyperglycemia ratio (SHR), may predict clinical worsening in people with idiopathic pulmonary arterial hypertension, a study in China indicates.
Clinical worsening was defined as the first occurrence of lung transplant, being rehospitalized due to heart failure, or death from any cause.
“The association appeared to be partially mediated through the pathway of pulmonary vascular remodeling, indicating that SHR may serve as a valuable indicator for providing additional risk information,” the researchers wrote. Vascular remodeling refers to structural alterations in blood vessels.
The study, “Is pulmonary vascular remodeling an intermediate link between hyperglycemia and adverse outcomes in patients with idiopathic pulmonary arterial hypertension? Insights from a multi-center cohort study,” was published in Cardiovascular Diabetology.
PAH is caused by a narrowing of the pulmonary arteries, the blood vessels that transport blood through the lungs, resulting in high blood pressure and the heart working harder to pump blood to the body. When there is no identifiable cause, it’s called idiopathic PAH (IPAH).
Studies have linked IPAH with high blood sugar, called hyperglycemia, an abnormal lipid (fat) profile, and diabetes. Insulin resistance, when the body doesn’t respond properly to the hormone, which is essential for regulating blood sugar levels, and diabetes have also been associated with higher PAH severity and poor prognosis.
Hyperglycemia, long-term outcomes
Researchers in China retrospectively studied 625 people diagnosed with IPAH to explore the association between hyperglycemia with disease severity and long-term outcomes. The patients had a median age of 32 and most (77.8%) were women. More than 13% had diabetes.
Over a mean of 3.8 years, 406 patients had no clinical worsening, while the disease worsened for 219. Two patients had a lung transplant, 137 were re-hospitalized due to heart failure, and 80 died.
Those who had clinical worsening showed worse World Health Organization functional classification (WHO-FC), a measure of how severe symptoms are. They also had higher rates of diabetes (18.3% vs. 11.3%) and greater limitations in physical activity in the six-meter walk test (409 vs. 432 m), which measures the distance a person can walk in six minutes. The patients with worsening disease also had significantly higher levels of NT-proBNP, a marker of heart damage, blood sugar levels at admission (4.85 vs. 5.58 mmol/L), and SHR.
They also had higher rates of structural alterations in the heart and higher pulmonary vascular resistance, a measure of blood vessel resistance to blood flow. Their levels of HDL cholesterol, known as “good cholesterol,” were lower.
Hyperglycemia indices correlated with established markers of IPAH severity, such as the WHO-FC, six-meter walk distance, and NT-proBNP. Also, SHR and blood sugar levels at admission were independent predictors of clinical worsening.
The risk of clinical worsening increased by 32.8% per each 0.1 unit increase in SHR and by 31.7% per each unit increase in blood sugar levels at admission. A survival analysis showed only SHR was significantly associated with an increased risk of all-cause mortality, a 23% increase per 0.1-unit increment.
A further analysis indicated the associations of SHR and blood sugar levels at admission with disease worsening were partially mediated by pulmonary vascular resistance. Finally, the addition of SHR to the European Society of Cardiology risk score significantly improved the identification of patients at risk for clinical worsening.
“SHR is a dependable and expedient indicator for predicting disease severity and long-term adverse outcomes in patients with iPAH, which is crucial for determining risk stratification and management of these patients,” the researchers wrote.
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