Psychosocial factors and heart rate variability in healthy women.
OBJECTIVE: This study was conducted to investigate associations between psychosocial risk factors, including social isolation, anger and depressive symptoms, and heart rate variability in healthy women. METHODS: The study group consisted of 300 healthy women (median age 57.5 years) who were representative of women living in the greater Stockholm area. For the measurement of social isolation, a condensed version of the Interpersonal Support Evaluation List was used and household size assessed. Anger was measured by the anger scales previously used in the Framingham study and depressive symptoms by a questionnaire derived from Pearlin. Health behaviors were measured by means of standard questionnaires. From 24-hour ambulatory electrocardiographic monitoring, both time and frequency domain measures were obtained: SDNN index (mean of the SDs of all normal to normal intervals for all 5-minute segments of the entire recording), VLF power (very low frequency power), LF power (low frequency power), HF power (high frequency power), and the LF/HF ratio (low frequency by high frequency ratio) were computed. RESULTS: Social isolation and inability to relieve anger by talking to others were associated with decreased heart rate variability. Depressive symptoms were related only to the LF/HF ratio. Adjusting for age, menopausal status, exercise and smoking habits, history of hypertension, and BMI did not substantially change the results. CONCLUSIONS: These findings suggest heart rate variability to be a mediating mechanism that could explain at least part of the reported associations between social isolation, suppressed anger, and health outcomes.