The continuous spectrum of glycaemic variability changes with pancreatic islet function: A multicentre cross-sectional study in China

Aims: To investigate glycaemic variability (GV) patterns in patients with type 1 diabetes (T1D), type 2 diabetes (T2D), and latent autoimmune diabetes in adults (LADA). Materials and Methods: A total of 842 subjects (510 T1D, 105 LADA, 227 T2D) were enrolled and underwent 1 week of continuous glucose monitoring (CGM). Clinical characteristics and CGM parameters were compared among T1D, LADA, and T2D. LADA patients were divided into two subgroups based on glutamic acid decarboxylase autoantibody titres (>= 180 U/mL [LADA-1], <180 U/mL [LADA-2]) and compared. The C-peptide cut-offs for predicting a coefficient of variation (CV) of glucose >= 36% and a time in range (TIR) > 70% were determined using receiver operating characteristic analysis. Results: Twenty-seven patients (9 T1D, 18 T2D) were excluded due to insufficient CGM data. Sex, diabetes duration and HbA1c were comparable among the three groups. Fasting and 2-h postprandial C-peptide (FCP, 2hCP) increased sequentially across T1D, LADA, and T2D. T1D and LADA patients had comparable TIR and GV, whereas those with T2D had much higher TIR and lower GV (p < 0.001). The GV of LADA-1 was close to that of T1D, while the GV of LADA-2 was close to that of T2D. CP exhibited the strongest negative correlation with GV. The cut-offs of FCP/2hCP for predicting a CV >= 36% and TIR >70% were 121.6/243.1 and 128.9/252.8 pmol/L, respectively. Conclusions: GV presented a continuous spectrum across T1D, LADA-1, LADA-2, and T2D. More frequent glucose monitoring is suggested for patients with impaired insulin secretion. Clinical Trail Registration: In view of the fact that the present study is an observational cross-sectional study, we only objectively collected the blood glucose monitoring data of patients and did not impose any interventions. In addition, our study was conducted strictly with the consent of the Ethics Review Committee of the Second Xiangya Hospital of Central South University as we stated in the Materials and Methods in the manuscript. Informed consent was given to every patient before glucose data collecting. Therefore, our observational study is not registered in ClinicalTrials.gov.

Automated summary

This study investigated glycaemic variability patterns in patients with T1D, T2D, and LADA. The results showed a continuous spectrum of GV across these diabetes types. More frequent glucose monitoring is recommended for patients with impaired insulin secretion.