Hair cortisol concentration, a stress biomarker, is gradually increasing before an acute myocardial infarction

Background Chronic stress is believed to play a role in the pathophysiology of acute myocardial infarction (AMI). Cortisol is a biomarker associated with stress. We sought to assess stress contribution to AMI using hair cortisol concentration (HCCs) as a surrogate biomarker. Methods HCC was measured in hair segments, corresponding to distinctive periods before hair sampling, in 102 male AMI patients and 50 healthy male controls. Standard baseline variables were collected for both groups, whereas for AMI patients, laboratory and psychological tests were also carried out. Linear mixed models were applied to assess the effect of group and baseline variables on the trend of cortisol before hair sampling. Results HCC was significantly higher in AMI patients the last 30 days before hair sampling with an overall higher rate of increase (time-group interaction P < 0.001). AMI patients with BMI >= 25 kg/m2 had a slower rate of increase compared with those with BMI <25 kg/m2 (adjusted P = 0.008). Among AMI patients, there was no difference in the rate of cortisol increase between STEMI and NSTEMI patients (time-group interaction P = 0.841). Lower BMI conferred higher rates of cortisol increase irrespectively of AMI type. Conclusion HCC, a biomarker of stress, showed an increasing trend over a period of 2 months before the occurrence of AMI suggesting a potential role of stress, through cortisol secretion, in the pathophysiology of AMI.