Post-bariatric hypoglycemia (PBH) is an increasingly recognized complication of bariatric surgery, with prevalence of up to 36% after gastric bypass. Hypoglycemia typically follows postprandial glycemic spikes. Continuous glucose monitors (CGM) can alert patients to high or low sensor glucose (SG), allowing treatment and prevention of severe hypoglycemia. The aim of this study (NCT03353415) was to determine whether CGM, currently indicated only for diabetes, could reduce hypoglycemia in PBH. In an open label, nonrandomized, pre-post design, sensor glucose data were collected using Dexcom CGM in two sequential phases: (1) masked (no access to SG or alarms); and (2) unmasked (access to SG and alarms for low or rapidly declining SG). Data were available for paired analysis for 22 individuals with PBH (mean±SD age 51.1±13.0 yrs, 20F/2M, BMI 30.6±6.2 kg/m2, 82% with level 3 hypoglycemia and 100% with neuroglycopenia). Participants with PBH spent a lower percentage of time in hypoglycemia with unmasked vs masked CGM (<60 mg/dL, median [MAD]: 0.7 [0.8] vs 1.4 [1.7]%, p=0.03; <70 mg/dL: 2.9 [2.5] vs 4.7 [4.8]%, p=0.04), with similar trends overnight. Likewise, there was more time between 70-180 mg/dL (94.8 [3.9] vs 90.8 [5.2]%, p=0.004), and lower glycemic variability (mean amplitude of glycemic excursion: 74.0 [17.7] vs 79.6 [17.8] mg/dL, p=0.04) during unmasked wear. During the day (6:00 AM-11:59 PM), participants spent more time in normoglycemia with unmasked CGM (94.2 [4.8] vs 90.9 [6.2]%, p=0.005), largely due to reduced hyperglycemia (>180 mg/dL: 1.9 [2.2] vs 3.9 [3.6]%, p=0.02). Availability of real-time CGM data and alarms is associated with reductions in low SG, elevated SG, and glycemic variability. This suggests CGM helps patients detect hyperglycemic peaks and imminent hypoglycemia, allowing dietary modification and self-treatment to reduce hypoglycemia. CGM may thus improve safety in PBH, particularly for patients with hypoglycemia unawareness.


C.J.Cummings: None. A.Jiang: None. A.L.Sheehan: None. R.Ferraz-bannitz: None. A.Puleio: None. D.C.Simonson: Stock/Shareholder; Phase V Technologies, Inc., GI Windows. J.Dreyfuss: None. M.Patti: Consultant; MBX Biosciences, AstraZeneca, Hanmi Pharm. Co., Ltd., Other Relationship; Fractyl Health, Inc.


Diabetes Research Center (P30DK036836)

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