We analysed Oral Glucose Tolerance Tests sampled every 30 mins and defined stages of CF Insulin Deficiency (CFID) as early glucose abnormalities, CFID1 (BGmax >=8.2 and <11.1mmol/L) and CFID2 (BGmax >=11.1 and BG120min <11.1), progressing to diabetes without fasting hyperglycaemia (CFID3), and finally to diabetes with fasting hyperglycaemia (CFID4). Currently insulin treatment is standard only for CFID3 and 4, but we have data showing that the earlier stages (CFID1 and 2) are also associated with declining weight and lung function.