Association between time in range and cancer mortality among patients with type 2 diabetes: a prospective cohort study

BACKGROUND: Little was known about the association among time in range (TIR), time above range (TAR), time below range (TBR), and cancer mortality among patients with type 2 diabetes. We aimed to investigate the association among TIR, TAR, TBR, and the risk of cancer mortality among patients with type 2 diabetes. METHODS: A total of 6225 patients with type 2 diabetes were prospectively recruited in Shanghai, China. TIR was measured with continuous glucose monitoring at baseline and was defined as the average percentage of time in the target glucose range during a 24 h period. Cox proportion hazard regression analysis was used to determine the association between TIR and the risk of cancer mortality. RESULTS: During a mean follow-up of 7.10 years, we confirmed 237 death events related to cancer. The multivariable-adjusted hazard ratio (HR) for cancer mortality was 1.32 (95% confidence interval [CI]: 1.01–1.75) in patients with TIR ≤70% compared with those with TIR >70%. When TIR was considered as a continuous variable, the multivariable-adjusted HR for cancer mortality associated with each 10% decrease in TIR was 1.07 (95% CI: 1.02–1.14). In the site-specific analysis, a significant association between TIR as a continuous variable and the risk of hepatocellular cancer was found (HR: 1.24; 95% CI: 1.09–1.41). However, no relationship between hemoglobin A1c and cancer mortality was observed (HR: 1.04; 95% CI: 0.97–1.10). CONCLUSIONS: The present study found an inverse association of TIR with the risk of cancer mortality among patients with type 2 diabetes. New evidence of TIR was added into the clinical practice that TIR may be an optimal target of glycemic control among patients with type 2 diabetes.