Self-peerceived chronic stress and self-rated health as mediating markers for the association with cardiovascular disease risk: The Malmö Preventive Project

Abstract: Cardiovascular (CVD) is one of the most common causes of mortality. Apart from known causal risk factors such as smoking, obesity, dyslipidaemia and hypertension, chronic psychological stress has been suggested as a possible independent risk marker, also because the CVD burden follows a social gradient. Another self-reported variable is self-rated health (SRH) which in many studies has ben shown to predict morbidity and mortality in otherwise healthy subjects. Aims This study aimed to investigate a possibly interaction effect of self-perceived chronic stress and SRH on CVD risk. We also wanted to investigate if social class modified this effect. Subjects and methods Data were analyzed from a population based cohort study consisting of 10,868 men and 2741 women from Malmö, southern Sweden, with a mean followed up time for 27 years. Subjects were screened at baseline for traditional biochemical and physical risk factors for CVD and filled a self-administered questionnaire containing ratings of psychological and lifestyle related factors. Subjects were then followed in both national and regional registries for first CVD event. The influence of self-perceived chronic stress and SRH were analyzed in a Cox regression model with stepwise adjustment for other risk factors. Interaction effects between stress/SRH were also tested. Results In all, 3252 men and 320 women suffered a CVD event during follow-up. In the total co- hort (n=13,609) the hazard ratio for CVD was 1.28 (95% CI; 1.06-1.55) among subjects reporting both chronic stress and poor SRH compared to the reference group (no stress, optimal SRH). Men who reported poor SRH with or without stress had a HR of 1.53 (CI 1.24-1.87) and 1.21 (1.03-1.41) respectively after full adjustments for other risk factors. There were no associations among women. No significant interaction effect between stress/SRH was found in either sex. Conclusion Self-perceived chronic stress and poor self-rated health are both independent, long- term cardiovascular risk markers in middle-aged men, but not in women. The biological mediators of this increased risk pattern have still not been well characterized.