-Hepatocyte nuclear factor-1a (HNF-1a) maturity onset diabetes of the young (MODY) is the commonest cause of monogenic diabetes but is frequently misdiagnosed as type 1 diabetes. The availability of genetic testing in MODY has improved diagnosis. Sulphonylurea sensitivity in HNF-1a patients means that those on insulin from diagnosis can transfer to sulphonylureas and may improve glycaemic control. To gain insight into the implications for patients of stopping insulin, in-depth interviews were conducted with eight HNF-1a patients transferred to sulphonylureas after a median of 20 years on insulin. Thematic content analysis highlighted four key themes: fear, anxiety and excitement regarding stopping insulin, particularly among those who had been on insulin for many years or had never omitted insulin in the past improved lifestyle and self image accompanied by feelings of relief and 'increased normality' reflections on their time on insulin, including feelings of annoyance, particularly when the need for insulin treatment had been questioned at diagnosis difficulty 'letting go' of insulin treatmentsome patients found it hard to believe that they no longer required injections as this conflicted with messages previously received from healthcare professionals.Transferring from insulin to sulphonylureas had a positive impact on lifestyle but support was needed for patients to adjust, many having grown up with the belief they would be on insulin for life.KEY WORDS: genetic testing, hepatocyte nuclear factor-1a (HNF-1a), maturity onset diabetes of the young (MODY), sulphonylurea sensitivity
BackgroundMaturity onset diabetes of the young (MODY) is an unusual genetic type of diabetes affecting 20,000 people in the UK. It is characterised by a young age of onset, autosomal dominant inheritance and noninsulin dependent diabetes. 1 However, MODY is often misdiagnosed as type 1 diabetes as it presents in young, slim adults with marked hyperglycaemia 2 and the significance of the family history is not appreciated. 3 Mutations in hepatocyte nuclear factor-1a (HNF-1a) account for 65% of UK MODY 4 and these patients are particularly sensitive to the hypoglycaemic effects of sulphonylureas (Table 1). 5 Isolated cases of patients with HNF-1a MODY transferring from insulin to sulphonylureas have previously been reported. 2,7 We have recently shown no deterioration in glycaemic control in eight patients with HNF-1a MODY following transfer from long-term insulin to sulphonylureas. 8 The aim of the study was to assess the emotional impact of stopping insulin in these patients, many of whom had previously been considered to have type 1 diabetes.
MethodsEight patients with mutations in HNF-1a who had been treated with insulin from diagnosis were transferred to a sulphonylurea. They were aged 17-48 years (median 34 years), diagnosed between the ages of 8 and 17 years (median 14 years), and had been on insulin for 4-35 years (median 20 years).