Vascular function ‘not impaired’ in young BD patients
MedWire News: US researchers have found no evidence for impaired vascular function among relatively young patients with bipolar disorder (BD).
The findings, published in the Journal of Psychosomatic Research, suggest that the previously reported increased risk for cardiovascular disease among BD patients occurs later in the course of illness, or may be a result of behavioural factors, such as smoking.
"Cardiovascular risk factors and vascular disease are more prevalent and may manifest earlier in BD than the general population," explain Jess Fiedorowicz (University of Iowa, Iowa City) and team.
"Perhaps as a consequence, individuals with BD face nearly twice the adjusted risk for cardiovascular mortality," they add.
As endothelial dysfunction precedes cardiovascular disease, the team investigated vascular function among a relatively young group of 27 BD patients (mean age 32.1 years) and 27 age-, gender-, and smoking-matched mentally healthy individuals (controls). The BD patients had experienced their first mood episode at a mean age of 20.0 years.
All of the participants were assessed for flow-mediated dilation (FMD), nitroglycerin-mediated dilation (NMD), pulse wave velocity (PWV), aortic augmentation pressure (AAP), and systolic aortic pressure (SAP). They were also assessed for weight, lipid levels, and insulin resistance.
The researchers found that there were no significant differences between the BD patients and controls regarding FMD (8.4 vs 7.6%), NMD (15.2 vs 12.5%), PWV (7.2 vs 7.2 m/s), AAP (3.4 vs 4.0mmHg), or SAP (103 vs 104 mmHg).
There were also no significant differences between the groups regarding body mass index, high- or low-density lipoprotein cholesterol levels, or triglyceride levels.
However, BD patients had greater insulin resistance than controls, at homeostatic model for the assessment of insulin resistance values of 2.6 versus 1.3.
Fiedorowicz and colleagues conclude: "The lack of an association between BD and vasculopathy in our young sample supports the hypothesis that the development of vascular disease in people with BD may depend on disease course over time, symptom burden, medication exposure, or behavioral mediators."
They add: "Insulin resistance may represent an early risk factor."
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By Mark Cowen