HealthDay News — For individuals with type 1 diabetes, type A personality is associated with lower all-cause mortality during 22 years of follow-up, researchers have found.
Every one-point increase on the Bortner Rating Scale for type A behavior was associated with a 1% decrease in all-cause mortality, Trevor J. Orchard, MD, of the University of Pittsburgh, and colleagues reported in Diabetes Care.
This correlation remained significant after adjusting for sex, age, education level, duration of diabetes, smoking status, BMI and physical activity. However, depression seemed to diminish risk-reducing effects of type A personality on mortality.
Furthermore, higher Bortner scores were not associated with higher prevalence of coronary artery disease or associated mortality, as it has been in previous studies.
The researchers analyzed data from 506 patients with type 1 diabetes who participated in the Pittsburgh Epidemiology of Diabetes Complications study to examine whether type A behavior predicts all-cause mortality and incident coronary artery disease during a 22 year follow-up period.
Patients completed the Bortner Rating Scale and Beck Depression Inventory (BDI), a self-reported 21-item assessment of depressive symptoms, at baseline. Higher scores are associated with increased depression. A score of 0 to 9 indicates minimal depression, and a score of 30 to 63 represents severe depression.
CAD was defined as myocardial infarction, coronary artery stenosis ≥50% or a history of revascularization, ischemia on an electrocardiogram, physician-diagnosed angina or CAD death. A total of 128 deaths (25.3%) occurred during follow-up.
There was a significant inverse correlation between Bortner scores and all-cause mortality in univariate analysis (P=0.01), which persisted after adjustment for multiple confounders (P=0.03).
The correlation was attenuated after adjustment for BDI scores (P=0.11). The protective effect was limited among those with lower BDI scores (lower three quartiles; P=0.07), but no effect was observed in those with higher BDI scores (P=0.97). A borderline association was observed for Bortner scores with incident CAD (P=0.09).
“Those with higher type A behavior have lower all-cause mortality in our type 1 diabetic population, an effect that interacts with depressive symptomatology such that it is only operative in those with low BDI scores,” the authors write. “Further research should focus on understanding this interaction.”