To study the prevalence and incidence of elevated liver enzymes and their relationship with body weight, metabolic factors and other diseases in Turner syndrome (TS). Five-year follow-up. Women with TS (n = 218, mean age 33 +/- 13, range 16-71 years) from outpatient clinics at university hospitals in Sweden. Fasting blood samples for aspartate (AST) and alanine aminotransferase (ALT), bilirubin, alkaline phosphatase (ALP), gamma-glutamyl transferase (GT), viral hepatitis serology and hepatic auto-antibodies, vitamin B12, blood glucose, lipids and hormones. Seventy-nine subjects (36%) had one or more liver enzyme levels higher than the reference level, the most prevalent being GT. Karyotype 45,X was present in 51% of all TS women and in 48% of those with elevated liver enzymes. Body weight, body mass index (BMI), total cholesterol, triglycerides, and apolipoproteins A and B at start were higher in TS women with elevated liver enzymes than in TS women with normal levels. At 5 years, AST, ALT and GT were increased and another 23% of patients had developed elevated liver enzymes, that is, 59% in total (36% + 23%), while in 6%, the elevated liver enzymes had been normalized and all 6% also had lowered cholesterol levels. Multivariate analysis showed that GT was correlated with total cholesterol; P = 0.0032 at start and P = 0.0005 at 5 years, independently of other factors. Liver biopsy in six TS women showed one cholangitis, one hepatitis C, two steatosis and two normal biopsies. Withdrawal of oestrogen substitution did not influence the liver enzymes. Pathological liver enzymes were common in TS women, with a prevalence of 36% at 33 years of age, an annual incidence over 5 years of 3.4%. There was no relation to karyotype, alcohol, viral hepatitis, E(2) or autoimmunity, but a connection with total serum cholesterol.