Abstract
Introduction: The high fat, low carbohydrate ketogenic diet has become increasingly popular in recent years for weight loss and glycemic control in patients with type 2 diabetes. Although prior studies have suggested this diet can improve glycemic control and decrease glucose variability, the impact of a ketogenic diet on rates of hypoglycemia in patients with hypoglycemia unawareness is not well described. Case Description: Our patient is a 37 year-old woman with Type 1 diabetes for 13 years complicated by hypoglycemia unawareness with HbA1c of 7.7%. Her insulin treatment regimen included insulin glargine 22 units daily, insulin aspart using a 1:15 carbohydrate ratio for prandial insulin dosing with a correction factor of 90. She had 5 episodes of severe hypoglycemia within the previous 3 months. The patient decided to resume a ketogenic diet given her previous improvement in glycemic control. Ketosis was confirmed using urine ketone strips performed by the patient. After 2 weeks on the ketogenic diet, a professional blinded continuous glucose monitor (CGM) was used for 4 weeks to monitor glycemic control.
CGM data for weeks 1 and 2 showed overall stability of time in target glucose range [TIR, 60% and 69%, respectively], with a slight increase in time spent below range [TBR, 13% and 17%, respectively]. During week 3, the patient experienced a significant decline in TIR to 31%, and associated increase in hypoglycemia (TBR, 13% to 28%). In addition, glycemic variability increased during this time [CV (coefficient of variation), 40.6% during week 1 to 58.1% during week 3]. Patient did not experience symptoms concerning for DKA, and continued to have asymptomatic hypoglycemia despite reductions in her insulin doses during week 3. Following these dose adjustments, CGM data during week 4 were similar to week 1 (TIR 65%, TBR 10%, CV 35%). Patient stopped following the ketogenic diet after 6 weeks due to social factors.
Conclusion: A ketogenic diet was associated with increased frequency of hypoglycemic events. In a patient with Type 1 diabetes and hypoglycemia unawareness, use of ketogenic diet may further increase the risk of severe hypoglycemia.
The Impact of Severe Hypoglycemia and Impaired Awareness of Hypoglycemia on Relatives of Patients With Type 1 Diabetes
