Depression, anxiety, and other negative emotions have been associated with an increased risk for coronary heart disease (CHD). Although the association is strong, the relationship may be mediated by the presence of other risk factors, such as the metabolic syndrome or sympathetic nervous system activity. Todaro and associates examined the relationship between negative emotions and CHD after controlling for metabolic syndrome components and stress hormones (i.e., epinephrine and norepinephrine).
The Normative Aging Study, a long-term cohort study, followed 2,280 initially healthy men for at least 32 years with regular examinations. Men who had completed the Minnesota Multiphasic Personality Inventory, had a full physiologic assessment, and initially were not taking any cardiac or diabetes medications were included. The final study sample of 498 men underwent a complete medical examination, including urine testing for epinephrine and norepinephrine, fasting serum glucose testing, insulin and lipid testing, post-prandial glucose testing, anthropomorphic evaluation, and assessment of health behaviors using a standard questionnaire.
The mean age of participants was 60 years. Forty-five men (11 percent) had at least one episode of CHD during the three-year follow-up; there were 24 diagnoses of myocardial infarction, 23 of angina pectoris, and 12 of ischemic heart disease. After adjusting for factors such as components of the metabolic syndrome (i.e., visceral obesity, insulin resistance, hyperglycemia, dyslipidemia, and hypertension) and the presence of stress hormones, negative emotions were found to predict CHD incidents significantly.
High-density lipoprotein concentrations also were associated with CHD incidence. Further analysis revealed that the development of CHD was positively associated with increasing degrees of negative emotions. Contrary to results of earlier studies, when the types of negative emotions were further evaluated, depressed mood was only marginally associated with CHD, while social anxiousness and cognitive distortion significantly predicted CHD incidence.
The authors conclude that negative emotions are associated with increased CHD incidence among otherwise healthy men even when results are controlled for the presence of components of the metabolic syndrome or markers of sympathetic nervous system activity. Further studies are needed to clarify specific components of depression and their relationship with CHD risk.