Time in range assessed by capillary blood glucose in relation to insulin sensitivity and β‐cell function in patients with type 2 diabetes mellitus: A cross‐sectional study in China

AIMS: This study investigated the association of capillary blood glucose (CBG)‐assessed time in range (TIR) (3.9–10.0 mmol/L) with insulin sensitivity and islet β‐cell function. MATERIALS AND METHODS: We recruited 455 patients with type 2 diabetes mellitus. Seven‐point glucose‐profile data (pre‐ and 120 min post‐main meals, bedtime) were collected over three consecutive days. Plasma glucose and serum insulin concentrations were measured at 0, 60, and 120 min after a 100 g standard steamed bread meal test. The homeostasis model assessment of insulin resistance (HOMA‐IR) and Matsuda index were computed to evaluate insulin resistance. The HOMA of β‐cell function (HOMA‐β) and the area under the curve between insulin and blood glucose (IAUC(0−120)/GAUC(0−120)) were used to estimate β‐cell function. RESULTS: TIR was positively correlated with the 60 and 120 min insulin values, IAUC(0−120), the Matsuda index, HOMA‐β, and IAUC(0−120)/GAUC(0−120) (r (s): 0.154, 0.129, 0.137, 0.194, 0.341, and 0.334, respectively; P < 0.05) but inversely correlated with HOMA‐IR (r (s): –0.239, P < 0.001). After adjusting for confounders, multinomial multiple logistic regression analysis revealed that the odds ratios (ORs) of achieving the target time in range (>70%) increased by 12% (95% confidence interval [CI]: 3–21%), 7% (95% CI: 1–14%), 10% (95% CI: 5–16%), and 45% (95% CI: 25–68%) for each 10 mIU/L increase in the 60 and 120 min insulin values, 10 unit increase in HOMA‐β, and unit increase in IAUC(0−120)/GAUC(0−120), respectively (P < 0.05). Nevertheless, the OR decreased by 10% (95% CI: 1–18%) for each unit increase in HOMA‐IR (P < 0.05). CONCLUSIONS: Insulin resistance and islet β‐cell function are related to capillary blood glucose‐assessed TIR.