Following initial diagnosis of type 1 diabetes mellitus, there may be a ‘honeymoon period’ characterised by transient improvement of beta cell function and thereby increased endogenous insulin production. As a result, there is a significant decrease in exogenous insulin requirements whilst metabolic control is maintained. Case reports have described the absence of diabetic ketoacidosis at presentation as a predictive factor for this period.

We report a case of a 17 year old gentleman in the ‘honeymoon phase’ of type 1 diabetes mellitus.

He initially presented to the Emergency Department with a one month history of polydipsia, polyuria and weight loss of approximately 7kg. He was haemodynamically stable and examination was otherwise unremarkable. Formal blood glucose level was 19.9 mmol/L with elevated ketones of 4.8. Interestingly he was not acidotic with a pH of 7.37 and bicarbonate of 26 mmol/L.

Initial insulin level was on the lower end of the reference range at 10 pmol/L and c-peptide was low at 145 pmol/L. Insulin antibodies, GAD antibodies and Islet cell IA2 antibodies were all negative. He was managed with a basal bolus insulin regime and discharged home on levemir 6 units BD and novorapid 1 unit per 25g carbohydrate TDS pre-meal. Initially he recorded blood glucose levels ranging from 8 – 14 on this regime. However, within 3 months of his diagnosis he decreased and even omitted his novorapid at times as he developed recurrent episodes of symptomatic hypoglycaemia. He is an active teenager playing rugby and kayaking with associated stress related to sitting his HSC exams this year.

Repeat pathology 6 months following diagnosis showed a HbA1C of 7.2%, elevated insulin level of 815 pmol/L and an elevated c-peptide level of 450 pmol/L.

In summary, we present a case of a 17 year old high school student with type 1 diabetes mellitus with negative antibodies in a ‘honeymoon phase’ characterised by elevated c-peptide levels and decreased exogenous insulin requirements.