For the study, 545 men who used androgenic anabolic steroids were matched with 5,450 controls. In addition, 644 men who were sanctioned because they refused to submit to a doping test and 6440 controls were included as a replication cohort.

Over an average follow-up of 7.4 years, there were seven (1.3 percent) deaths among users of androgenic anabolic steroids and 23 (0.4 percent) among participants in the control group, translating to a three-times higher risk of death associated with androgenic anabolic steroids. The median annual number of hospital contacts was 0.81 in the androgenic anabolic steroid users and 0.36 in the controls. Acne, gynaecomastia, and erectile dysfunction affected more than 10 percent of the androgenic anabolic steroid users, and the prevalence of these disorders was significantly higher than in the control group. Similar results were seen in the replication cohort.

"This study has shown that anabolic steroids are associated with a range of side effects that can be directly attributed to their pharmacological activities," said lead author Dr. Henrik Horwitz, of the University of Copenhagen, in Denmark.