Effectiveness of continuous glucose monitoring on glycaemic control in Type 1 Diabetes Mellitus: A systematic review and meta-analysis

Abstract

Background: The goal for Type 1 diabetes mellitus (T1DM) population is to maintain a near-normal glucose level. Self-monitoring blood glucose (SMBG) is a conventional finger-prick test which measures one’s blood glucose whereas continuous glucose monitoring (CGM) measures one’s interstitial glucose level every few minutes. However, insufficient studies were done to include the latest CGM technologies on glycaemic control amongst T1DM population. Objective: To assess the effectiveness of CGM as compared to SMBG for glycaemic control in T1DM population. Methods: Cochrane Library, PubMed, Embase, CINAHL, Scopus, trial registries and grey literature were searched from 9 June 2011 till 22 December 2020 for randomised controlled trials comparing CGM intervention against SMBG control among T1DM population on HbA1c, severe hypoglycaemia (SH) and diabetic ketoacidosis (DKA) outcomes. Data were extracted with standardised data extraction form. Risk of bias was appraised with Cochrane Risk of bias tool. Meta-analysis was performed using RevMan software. Heterogeneity was evaluated using Chi² and I² statistics. Overall effects and certainty of evidence were evaluated using Z-statistic and GRADE. Results: 22 studies involving 2,188 T1DM individuals were identified. Most studies had low-risk bias. Meta-analysis of 21 studies revealed CGM significantly decreased HbA1c level compared to SMBG (Z=3.5, P=0.0005) with larger effects experienced in higher baseline HbA1c (>8%) individuals (Z=6.67, P<0.00001). However, CGM had no influence on SH (P=0.06) and DKA (P=0.88). Certainty of evidence was moderate. Conclusion: CGM is superior to SMBG in improving glycaemic control among T1DM population especially poor glycaemic controlled individuals. Results must be interpreted with discretion due to substantial heterogeneity. Implication: T1DM individuals are encouraged to use CGM. With possible integration with telemedicine, CGM may provide an effective diabetes management approach in the community. Future research can evaluate CGM effectiveness across different age groups and insulin regimens.