Objective The objective of this study was to explore whether circulating testosterone (T) concentration is associated with the occurrence and risk for acute coronary syndromes (ACS).

Method This case–control study included male patients with acute myocardial infarction (AMI) (n=174) or unstable angina pectoris (UAP) (n=90) and healthy controls (n=238). Patients gave serum samples during the acute (n=264) and recovery (n=132) phases after a median of 10.5 months after the incident event. Secondary events (ACS or cardiovascular death) were registered during the following 6 years.

Results During the acute phase, AMI and UAP patients had similar significantly reduced concentrations of serum testosterone in comparison to controls. Testosterone associated inversely with weight, the degree of inflammation (i.e. C-reactive protein concentration) and signs of a chronic infection. In a multiadjusted Cox regression, when compared to testosterone concentrations considered high-normal (14.91–34.0 nmol/l), low-normal testosterone (9.26–14.90 nmol/l) in the acute phase predicted better prognosis for cardiovascular death rate with a hazard ratio (HR) of 0.17 (0.04–0.68, P=0.012). The increased testosterone concentrations after the recovery period did not associate with future cardiovascular disease events.

Conclusion Low-normal testosterone levels in the acute phase of ACS predicted better survival. The observation may indicate better adaptation to stress in survivors and warrants further study.