Almost 20,000 Victorian athletes who use steroids are at risk of contracting hepatitis or HIV, a study has warned. The research, based on interviews with 134 Melbourne steroid users, found 29per cent had shared needles, injected drugs from a shared container or re-used syringes, exposing themselves to serious health risks. Researchers also were alarmed at the number of athletes, particularly body-builders, injecting insulin as an aid to muscle growth. Non-diabetic insulin users were at risk of developing acute hypoglycaemia, lapsing into a coma or eventually inducing diabetes.