GPT and cystic fibrosis: After longitudinal analysis of a population of 7,769 individuals included in the Doetinchem Cohort Study, Rietman et al. (2019) found that none of the following parameters were predictive of CF: high-density lipoprotein (HDL) cholesterol, triglycerides, alanine aminotransferase (ALT), gamma-glutamyltransferase (GGT), C-reactive protein (CRP), albumin, uric acid, cystatin C or creatinine.