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

Abstract

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.

Keywords: Insulin resistance; Time in range; β-Cell function.

Figure 1

Plasma glucose and insulin responses during the 100 g standard steamed bread meal test. (a) Plasma glucose (mmol/L) and (b) serum insulin values (mIU/L) among the four groups divided according to TIR quartiles (Q1–Q4). Data are shown in the box. Q1 (TIR ≤ 52%), Q2 (57–67%), Q3 (71–81%), and Q4 (≥86%).

Figure 2

Independent factors influencing the achievement of the target TIR (TIR > 70%). Multinomial logistic regression analysis models were applied to investigate the associations of target TIR with insulin sensitivity and β‐cell function. Model 1 was adjusted for sex, age, BMI, blood pressure, diabetes duration, lipid profile. Model 2 includes all variables in model 1 plus HbA1c. INS, insulin; GAUC, glucose area under the curve; IAUC, insulin area under the curve.