To validate results from the primary study, gluteal and abdominal adipose tissue samples from 40 additional subjects (20 male, 20 female) were collected from the Oxford Biobank. Among the females 5 subjects were metabolic syndrome cases (3 IDF), and 15 were controls. Among the males 7 subjects were metabolic syndrome cases (3 IDF), and 13 were controls. A logistic regression model for case-control status, estimated on relevant clinical phenotypes (body mass index, blood high-density lipoprotein level, blood triglyceride level, blood fasting glucose level, waist circumference, diastolic blood pressure, systolic blood pressure) in the primary data set, was used to predict which of the available subjects in the Oxford Biobank that were most similar to the cases and controls in the primary study, with the aim of establishing a relevant and as similar as possible, replication study. Validation cohort metabolic syndrome subjects consisted of a set of cases fulfilling the formal IDF criteria, as well as a set of cases that were predicted as cases through the logistic regression model. As the main focus of this study is on tissue related effects, the subjects in the replication study are to be considered as relatively well matched to the primary study subjects.
