Background and objectives: Type D personality, characterized by two stable traits (social inhibition and negative affectivity), is associated with adverse cardiovascular events. A possible mediating factor for this association could be hypertension. Previous research has shown that individuals with Type D personality were associated with an increased risk of hypertension. However, the association of negative affectivity and social inhibition on blood pressure in normotensive individuals has not yet been reported. Therefore, the aim of this study was to investigate whether negative affectivity and social inhibition were associated with systolic and diastolic blood pressure in normotensive middle-aged and older Taiwanese adults.
Materials and methods: A cross-sectional study design was used. Individuals attending general health examination at a regional hospital in southern Taiwan who were 40 to 75 years old were recruited. Patients with self-reported hypertension or currently receiving antihypertensive medication were excluded. Negative affectivity and social inhibition were assessed with the 14-item Type D Scale-Taiwanese version. Multiple linear regression analyses were conducted to determine the association of Z-score transformed negative affectivity and social inhibition on blood pressure.
Results: A total of 92 patients with a mean age of 51.5 years were included in the study, and 15 (16.3%) were defined as having a Type D personality. The Z-score transformed negative affectivity score (p = 0.035, effect size = 0.18) and Z-score transformed social inhibition score (p = 0.054, effect size = 0.17) were significantly associated with a higher systolic blood pressure. In addition, the Z-score transformed negative affectivity score (p = 0.036, effect size = 0.28) and Z-score transformed social inhibition score (p = 0.154, effect size = 0.24) were significantly associated with a higher diastolic blood pressure.
Conclusions: Negative affectivity of the Type D personality was significantly associated with higher systolic and diastolic blood pressure, with a medium effect size, in apparently healthy middle-aged and older adults. Assessment of negative affectivity may be clinically useful in identifying individuals at risk of hypertension.
Keywords: Type D personality; blood pressure; hypertension; negative affectivity; social inhibition.