12395 Continuous Glucose Monitoring In Pseudohypoparathyroidism Type 1a

Abstract Disclosure: J. Tamaroff: None. A.E. Lee: None. A.H. Shoemaker: None. Background: Pseudohypoparathyroidism type 1A (PHP1A), due to heterozygous mutations in GNAS, is a rare disorder that leads to multi-hormone resistance, cognitive impairment, and early-onset obesity. Individuals with PHP1A have dysglycemia on oral glucose tolerance tests and increased rates of type 2 diabetes (T2DM). Individuals with rare diseases, like PHP1A, may travel significant distances for specialized clinical or research care. Wearable technology may alleviate barriers and provide useful information for clinical care or for use as potential biomarkers. The objective of this study is to evaluate glycemia in individuals with PHP1A and feasibility of utilizing continuous glucose monitors (CGMs) in this population. Methods: Observational study of individuals with PHP1A (3R01DK118407-03S1). CGMs (Dexcom Pro, Dexcom Inc, San Diego, CA) were placed on participants’ abdomens, typically by a family member, over secure-video call with study staff. CGMs collected data every 5 minutes for up to 10 days. Results: Seven participants (all female) with PHP1A without a diagnosis of diabetes had available data. Median age was 17 years (IQR: 14, 19; range: 8-23). Body mass index (BMI) categories (by percent of the 95th percentile for those under 18 years and BMI for adults) spanned from overweight to class 3 obesity. In terms of feasibility, 1 individual had to replace a CGM sensor due to an upcoming MRI and 1 individual had a “sensor failure” of unclear etiology. Both were able to place new CGMs. Individuals participated across 5 states in the United States. Median length of wear was 9.8 days (IQR 8.6, 9.9). Participants had a median average glucose of 104mg/dL (IQR 102, 111) and COV of 16% (15, 21). Percent of glucose > 140mg/dL was 5.0% (IQR: 1.8, 10.9; range:1.2-19.4%). One individual had 3.2% of glucose values ≥ 200mg/dL despite a normal hemoglobin A1c (HbA1c) level (5.5%). This level of hyperglycemia is qualitatively higher than published CGM data in healthy individuals. One study found individuals (6-24 years of age) had median percent of glucose values over 140mg/dL ranging from 1.2 to 2.4% with IQR values ranging from 0.3 to 4.4%, based on age categories.1Conclusions: In females with PHP1A, with overweight or obesity, CGM placement at home is a feasible way to collect real-world data. Participants with rare diseases often must travel for clinical and research care and CGMs may provide insight into glycemia without requiring an in-person visit. This “real-world” data mirrors research data reporting glycemia with normal HbA1c levels. The rate of hyperglycemia is higher than expected in some individuals with PHP1A though more data is needed. Ongoing studies will evaluate matched control participants and assess drivers of glycemia including inactivity and decreased sleep duration, as measured by actigraphy. References: 1. Shah VN et al. J Clin Endocrinol Metab. 2019 PMID: 31127824 Presentation: 6/3/2024