Estimated glucose disposal rate predicts mortality in adults with type 1 diabetes

Aims This study aimed to investigate the association between insulin resistance as determined by the estimated glucose disposal rate (eGDR), and survival in adults with type 1 diabetes (T1D) in Sweden. Material and Methods Using the Swedish National Diabetes Register, indviduals with T1D were included from January 1, 2005 to December 31, 2012. Outcomes were retrieved from National healthcare registers. Hazard ratios (HRs) with 95% confidence intervals (CIs) were calculated for the associations between eGDR (mg/kg/min) categorized into <4, 4 to 5.99, 6 to 7.99, and ≥8 (reference) and outcomes. Relative survival methods were used to compare survival to a matched Swedish reference population. Results Among 17 050 included individuals with T1D, 10.5%, 20.2%, 20.5% and 48.9% had an eGDR of <4, 4 to 5.99, 6 to 7.99, and ≥8, respectively. Individuals with an eGDR <8 were older and had more comorbidities. During a median follow‐up of 7.1 years, there were 946 (6%) deaths; 264 (15%), 367 (11%), 195 (6%) and 120 (1%) deaths occurred in individuals with an eGDR of <4, 4 to 5.99, 6 to 7.99 and ≥8, respectively. After adjustment for a wealth of different covariates including diabetes duration, age, sex and renal function, individuals with an eGDR <4, 4 to 5.99, and 6 to 7.99 had an increased risk of death compared to those with an eGDR ≥8 (adjusted HRs, 95% CIs, P values: 2.78, 2.04 to 3.77, <.001; 1.92, 1.49 to 2.46, <.001; 1.73, 1.34 to 2.21, <.001). Survival in individuals with an eGDR ≥8 was equal to a matched general population. Conclusions There is a strong association between eGDR and all‐cause mortality, as well as cardiovascular mortality, in individuals with T1D. Our findings may guide preventive measures by improving risk assessment in individuals with T1D.