Endocrine Abstracts

Background: People on dialysis have an increased risk of developing diabetes mellitus. An oral glucose tolerance test (OGTT) is the most reliable method to identify dysglycemia, but it is cumbersome. We examined the effectiveness of the glucose challenge tests (GCT) in identifying people with dysglycemia who need further investigation with OGTT.

Methods: This single-center prospective cohort study included adults on dialysis at the University Hospital of Antwerp. Exclusion criteria were chronic infections, a history of diabetes and receiving glucose-lowering agents. The protocol involved a 50g-GCT followed by a 75g-OGTT 8-10 days later. Additionally, each participant was required to wear a blinded continuous glucose monitoring (CGM) sensor (DEXCOM® G6) during these ten days.

Results: Out of the 123 individuals screened, 50 met the eligibility criteria for the study. The primary reason for exclusion was a history of diabetes mellitus ( n = 56). Additionally, 27 individuals declined to participate, with 15 citing the extended duration of the OGTT. Ultimately, 23 individuals took part in the study, of whom 13 had dysglycemia, defined as a 2-hour glucose level after OGTT of ≥140 mg/dl. Individuals with dysglycemia exhibited higher BMI (26.2±3.9 vs 22.8±3.3 kg/m², P = 0.039), a longer dialysis vintage (4.5±2.9 vs 1.6±1.4 years, P = 0.009), and fewer listings for transplantation (8 of 13 vs 0 of 10, P = 0.005). In terms of CGM data, individuals with dysglycemia showed a lower time in range (95±3% vs 98±3%, P = 0.020) and a higher coefficient of variation (24% [IQR 20-29%] vs 16% [IQR 14-18%], P < 0.001). The participants with dysglycemia had a lower insulinogenic index (4.3±2.1 vs 7.0±3.6, P = 0.04) and similar HOMA-IR compared to those without dysglycemia. Interestingly, dysglycemia was more prevalent in individuals undergoing hemodialysis compared to peritoneal dialysis (12/14 vs 1/9, P < 0.001). Fasting glycemia levels were within the normal range and similar in both dialysis groups (85±6 vs 85±13 mg/dl, P = 0.855). CGM data showed a significantly lower coefficient of variation in peritoneal dialysis (23.6% vs 15.7%, P = 0.002). Importantly, the GCT had a sensitivity of 84% and specificity of 70% for detecting dysglycemia. Using a two-step approach, up to 40% of OGTTs could be avoided. Additionally, only 15% of individuals with dysglycemia would be missed.

Conclusion: Using a two-step approach of GCT and OGTT, up to 40% of OGTTs can be omitted, facilitating screening procedures for diabetes mellitus in people undergoing dialysis. This practical approach, should be further studied in order to help healthcare providers to identify and manage dysglycemia efficiently in this population.