Fasting for Laboratory Tests Poses a High Risk of Hypoglycemia in Patients with Diabetes: A Pilot Prevalence Study in Clinical Practice

Objective: Fasting for lipid profiles is a deeply-rooted tradition that is being revisited. In patients with diabetes, such fasting poses a risk of hypoglycemia, as observed in recent studies and case reports. This iatrogenic, overlooked, form of hypoglycemia has been referred to as Fasting-Evoked En-route Hypoglycemia in Diabetes (FEEHD). The objective of the study is to determine the prevalence of FEEHD in clinical practice. Methods: A two-page survey was administered to adults with diabetes on anti-diabetic medication(s). Patients were asked if they recalled having experienced hypoglycemia while fasting for laboratory tests (FEEHD) during the preceding 12 months. Results: Of 168 patients enrolled, 166 completed the survey, with a mean age of 55.3 (SD: 15.4) years. Seventy-nine (47.6%) were females. Of these 166 patients, 119 (71 %) had type 2 diabetes. Forty-five patients (27.1%) reported having experienced one or more FEEHD events. Notably, only 31.1% of the patients who experienced a FEEHD event informed their provider of the event, and only 40% of FEEHD events reportedly resulted in any subsequent provider-made medication change(s) to prevent future events. Conclusions: This is the first study of FEEHD prevalence in clinical practice, the results of which serve to increase awareness amongst clinicians about the occurrence of FEEHD. We believe that FEEHD appears to be overlooked by clinicians. The prevalence of FEEHD in clinical practice is strikingly high (27.1%). More concerning is the significant underreporting of FEEHD events by patients to their clinicians (31%). We hope this study will trigger further investigation to confirm these preliminary findings and modify practice guidelines.