A case of an elderly patient with insulin-dependent diabetes and dementia receiving one basal insulin plus one bolus insulin injections a day for 6 months

Multiple daily injections of insulin, referred to basal–bolus regimen, are generally essential in achieving glycemic control and preventing ketosis in insulin-dependent diabetes, such as type 1 diabetes (T1D). A 75-year-old man with T1D receiving basal–bolus insulin therapy exhibited symptoms of dementia after hospitalization due to pyelonephritis and failed to continue insulin self-injection. Given that his social and familial circumstances allowed insulin injection once a day during the morning, bolus insulin injections needed to be discontinued. Ketonuria was observed the day following discontinuation of bolus insulin. Although increasing the basal insulin dose (degludec) from 10 to 15 units improved ketonuria, his preprandial glucose levels increased to ≥ 500 mg/dL before lunch and ≥ 400 mg/dL before dinner. Hence, another bolus insulin injection was simultaneously added to the basal insulin dose before breakfast, which, subsequently, decreased his preprandial glucose levels to ≤ 220 mg/dL before lunch and ≤ 350 mg/dL before dinner. For half a year after discharge, ketonuria or hypoglycemia had not been detected. After 6 months, he was able to restart intensive insulin therapy with familial support. Hence, in cases where elderly patients with diabetes exhibit symptoms of dementia and can receive insulin injection once a day due to their social circumstances, short-term one basal plus one bolus insulin injections a day might be considered to prevent life-threatening diabetes complications among those who are insulin-dependent.