1006-P: Progression to Type 2 Diabetes Despite a Baseline Fasting Plasma Glucose ≤ 80 mg/dl in a Population-Based Cohort

Fasting plasma glucose (FPG) concentration is a major predictor of a person’s risk of developing diabetes mellitus (DM). However, we sought to examine characteristics of individuals who develop DM despite a baseline FPG of ≤ 80mg/dL. The Rochester Epidemiology Project (REP) links the medical records of virtually all persons who have resided in Olmsted County, MN, USA between 1966 and present. Electronic laboratory data are available from 2005. Using REP, we identified individuals with ≥ 2 FPG tests from 2005-17, after excluding people who met criteria for DM on/before their first FPG. Those who developed DM (FPG > 125mg/dL) were assigned an event date as the date of their first diagnostic value. Subjects who did not develop DM were censored at their last FPG value on/before Dec 31, 2017. The entire cohort consisted of 44,815 individuals, of whom 3689 (8.2%) developed DM. Although higher baseline FPG was strongly related to development of DM, 2315 had a baseline FPG of ≤ 80mg/dL with 130 (5.6%) developing DM. Within this subset, those who progressed were older at baseline (40 ± 11 vs. 36 ± 12 years, p<0.02) and were more likely to be male (38 vs. 22%, p<0.001). Those who progressed had no difference between BMI at baseline and time of diagnosis (28 ± 8 vs. 29 ± 8 kg/m2, p=0.07). Medical record review suggested that individuals who progressed had high medical complexity. Specifically, 28 (22%) were repeatedly exposed to high dose glucocorticoids during follow up, including 10 (8%) who received a solid organ transplant. Fifteen (12%) had a substance abuse disorder. Nineteen (15%) were treated with insulin at one year following diagnosis, four of whom were diagnosed with type 1 DM. Twenty nine (22%) had a first degree relative with DM. Additional longitudinal follow up revealed that 20 (15%) were deceased at a median time of 2.5 years following the DM diagnosis. While progression to DM in the context of a baseline FPG of ≤ 80mg/dL is uncommon, it typically occurs in the setting of significant medical comorbidity. Disclosure A. M. Egan: None. C. Wood-wentz: None. K. R. Bailey: None. A. Vella: Research Support; Self; Novo Nordisk. Funding National Institutes of Health (DK78646, DK116231, DK126206, K12HD065987)