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

Abstract

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 Chinese Clinical Trial Registration (ChiCTR) website approved by WHO; http://www.chictr.org.cn/ ‐ ChiCTR2200065036

Preserved C-peptide is common and associated with higher time in range in Chinese type 1 diabetes

“…In addition, in a recent study recruiting participants from The Netherlands, Coco et al suggested that residual insulin secretion, as measured by urinary C-peptide to creatinine ratio, was associated with longer TIR, shorter TBR and TAR, and lower CV (23). Although a study conducted in Chinese patients with diabetes including T1D, type 2 diabetes, and latent autoimmune diabetes in adults showed a continuous spectrum of glycemic variability pattern (29), no large-scale study focusing on T1D population in Chinese has been reported. Our study provided a relatively large sample size covering the entire duration of T1D in Chinese and showed that residual b-cell function was associated with TIR after adjustment for potential confounders.…”

Residual β-Cell Function Is Associated With Longer Time in Range in Individuals With Type 1 Diabetes

“…Residual β-cell function has also been linked to a decrease in total daily insulin dose ( 16 , 18 ). Furthermore, some smaller studies that included highly selected patient populations have investigated the association between residual β-cell function and TIR ( 19–21 ), with one study demonstrating a correlation between fasted C-peptide and CGM-derived metrics ( 20 ). Our findings are in line with a group in the U.S. that found an association between residual β-cell function as estimated by mixed-meal test and CGM-derived metrics in a small and highly selected group of participants (21).…”

“…Our findings are in line with a group in the U.S. that found an association between residual β-cell function as estimated by mixed-meal test and CGM-derived metrics in a small and highly selected group of participants (21). In addition, in recently diagnosed T1D, an association between higher C-peptide levels and lower glucose CV was found ( 19 ). Our study provides a potentially more accurate estimate of residual β-cell function by using the postmeal UCPCR, which correlates well with gold-standard mixed-meal–stimulated C-peptide levels ( 22 ).…”

Individualized coefficient of variability cut-off values for reducing the risk of hypoglycemia in Chinese type 1 diabetes mellitus (T1DM) patients

“…The details of their clinical characteristics, biochemical indices, and CGM data were collected and had been described previously. [4] The study flow chart is shown in Supplementary Figure 1, http://links.lww.com/CM9/B600. The targets were set according to the international consensus guidelines on CGM: time in range (TIR, 3.9-10.0 mmol/L) ≥70%, time above range (TAR, >10.0 mmol/L) <25%, time below range (TBR, <3.9 mmol/L) <4%, and CV <36%; target HbA1c levels <7.0% for adults and <7.5% for minors are recommended.…”