37-year-old Hispanic female with diagnosis of T1DM at age 18, uncontrolled on MDI with complications of mild non-proliferative diabetic retinopathy and CKD V presented giving additional history of a son just diagnosed with MODY 3. Multiple other family members were reported as having diabetes- diagnosed as both type 1 and type 2. Patient’s GAD 65 antibodies previously checked were negative. A sulfonylurea challenge test was performed. Baseline labs obtained included insulin 18.7 u(IU)/dL, C-peptide 1.9 ng/dL, glucose of 98 ml/dL. Patient was then advised to hold her morning insulin doses. One and a half hours after receiving glipizide and ingesting a meal, insulin level was 18.7 u(IU)/dL, C-peptide 10.3 ng/dL, glucose 141 ml/dL. MODY 3 was strongly suspected and decision made to transition from insulin to sulfonylurea. Given her advanced renal disease, there was significant concern with the potential of hypoglycemia despite cautious initiation of low dose glipizide. A continuous glucose monitoring system- the Freestyle Libre- was procured to allow for the close monitoring of glucose trends, to both guide ability to reduce insulin doses, as well as to judge sulfonylurea dosing in the setting of significant renal disease. The patient was able to decrease insulin doses and transition to sulfonylurea without hypoglycemia. MODY 3 is a form of monogoneic diabetes, and is a rare form of diabetes that should be suspected in patients diagnosed with diabetes mellitus in their early years along with a strong family history and negative GAD65 antibodies. Although not traditionally described in Hispanic populations, MODY3 has been reported in various minority populations. Continuous glucose monitoring should be considered in MODY 3, to aid in the safety of transitioning patients from multiple dose insulin regimens to sulfonylurea therapy, especially in the setting of severe renal disease.


O. Najera: None. B.E. Wisse: None. D. Trence: Stock/Shareholder; Self; Medtronic, Sanofi-Aventis.

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