Diabetes and age at onset of diabetes were obtained from reports made at five home visits at age 36, 43, 53, 60-64 and 68-70, and from the response to a postal questionnaire at 31 years which indicated that the cohort member had an onset of physician diagnosed diabetes. Type 1, Type 2 and gestational diabetes cases were distinguished based on age at diagnosis, medication history and the reasons documented.

The metabolic syndrome at age 53 years and its components were defined using cut points recommended by ATPIII8 (2001). The ATPIII8 definition was modified to include glycated haemoglobin (HbA1c) instead of fasting plasma glucose, data for which were unavailable. Details of the cut points used are available on request.

The derived diabetes variables have been updated to take account of the most recent data collections.