Capturing the real‐world benefit of residual β‐cell function during clinically important time‐periods in established Type 1 diabetes

Abstract

Aims Many individuals with type 1 diabetes retain residual β‐cell function, with increased endogenous insulin secretion associated with reduced hyperglycaemia, hypoglycaemia and glycaemic variability. However, it is unknown when these improvements occur during the day. Dysglycaemia is common in overnight and postprandial periods and associated with diabetes complications. Therefore, this study aimed to determine the influence of residual β‐cell function upon nocturnal and postprandial glycaemic control in established type 1 diabetes. Methods Under free‐living conditions, 66 participants wore a blinded continuous glucose monitor (CGM), kept a food diary, and completed a stimulated urine C‐peptide creatinine (UCPCR) test. Nocturnal, and postprandial CGM outcomes (participant means and discrete event analysis) were compared between UCPCR groups: undetectable (Cpepund), low (Cpeplow: 0.001–0.19 nmol/mmol) and high (Cpephigh: ≥0.2 nmol/mmol). Results Greater β‐cell function was associated with incremental improvements in glycaemia. Cpephigh spent significantly greater time in normoglycaemia than Cpepund overnight (76 ± 20% vs. 58 ± 20%, p = 0.005) and 0–300 mins postprandially (68 ± 22% vs. 51 ± 22%, p = 0.045), while also having reducing nocturnal variability (SD 1.12 ± 0.41 vs. 1.52 ± 0.43 mmol/L, p = 0.010). Analysis of individual events, controlling for diabetes duration, BMI, basal insulin, use of a continuous or flash glucose monitor and (for postprandial) meal type, carbohydrate and bolus insulin intake, replicated the group findings, additionally demonstrating Cpepund had increased hyperglycaemia versus Cpeplow overnight and increased postprandial hypoglycaemic events compared with Cpephigh. For all participants, breakfast had a significantly higher incremental area under the curve than lunch and dinner. Conclusions Residual β‐cell function is associated with improved nocturnal and postprandial glycaemic control. These data may be of clinical importance for identifying specific periods and individuals where further glycaemic management strategies would be beneficial.

Association of Smartphone-Based Activity Tracking and Nocturnal Hypoglycemia in People With Type 1 Diabetes

“…We excluded those with a post-prandial c-peptide of more than 0.6 mcg/L as residual c-peptide is known to reduce the risk of hypoglycemia and possibly attenuate the effect of activity on NH. 24 We excluded those using continuous glucose monitoring, those with an estimated glomerular filtration rate <30 ml/min/m 2 , and those unable to carry a smartphone during their predominant form of PA (e.g., swimming, contact sports). People using an insulin pump without CGM were eligible to participate.…”

Application of urine C-peptide creatinine ratio in type 2 diabetic patients with different levels of renal function

“…Previous studies have shown that UCPCR can be used to determine hepatocyte nuclear factor 1alpha (HNF1α) and HNF4α for distinguishing between maturity-onset diabetes of the young (MODY) and other types of diabetes ( 8 , 9 ). Recent studies have shown that UCPCR can also be used to evaluate the function of islet β-cells in patients with T1DM and T2DM ( 10 , 11 ). However, no study has been carried out to assess the application of UCPCR for the evaluation of islet β-cell function in patients with T2DM till now, especially in T2DM patients with differences in renal function.…”