Impact of Lockdown Measures on Glucose Control in Type 1 Diabetes

New information from a meta-analysis of observational studies is offering clinicians insight into the impact of lockdown and stay-at-home measures during the COVID-19 pandemic on glycemic control among patients with type 1 diabetes.

Using data from 17 studies with a population of more than 3000 patients with type 1 diabetes, investigators were able to provide a comprehensive overview of the impact on multiple glycemic control indexes, such as time in range, mean blood glucose, estimated HbA1c, and more.

“Our meta-analysis of aggregate data shows that well-controlled people with type 1 diabetes on both MDI and CSII with continuous or flash glucose monitoring did not experience a deterioration in glucose control throughout the COVID-19 lockdown, showing a modest, though statistically significant improvement in many glucose control parameters,” wrote investigators.

In the early stages of the COVID-19 pandemic, lockdown and stay-at-home measures were put in place across multiple regions of the world in hopes of slowing the spread of the SARS-CoV-2 outbreak. In the time that has passed, the impact of missed appointments, deferred care, and time spent at home has been the focus of innumerable studies and research efforts. The current study was designed as a meta-analysis of observational studies in patients with type 1 diabetes examining glucose metrics measured by glucose monitoring systems to explore how these may have been influenced by lockdown measures.

To do so, investigators conducted a systematic literature search for English language articles published in the Medline, Scopus, and Web of Science databases from inception through February 28, 2021. Using diabetes, lockdown, and glucose as key search terms, 221 records were identified for possible inclusion. After exclusion of duplicates and application of other inclusion criteria, 17 articles were selected for inclusion in the final analysis.

The primary outcome of interest in the investigators’ analysis was time in range. Other measures of interest included time above range, time below range, mean blood glucose and its variability, estimated HbA1c or glucose management indicator.

Of the 17 studies included, all had a retrospective observational design. Additionally, 7 were conducted in Italy, 6 in Spain, 2 in the United Kingdom, 1 in Greece, and 1 in France. The sample size of studies ranged from 33-1378, with a total of 3441 participants.

The only outcome measure available in all studies was time in range. When assessing Time in range, results incited time in range increased among patients in 16 of the 17 studies. Overall, time in range increased by 3.05% (95% CI, 1.67 to 4.43%; P <.0001) during lockdown, with high heterogeneity (I2=92%). When assessing time above range, results indicated the time above 180 mg/dL and 250 mg/dL declined by 3.39% (95% CI, -5.14 to -1.63) and 1.96% (95% CI, -2.51 to -1.42), respectively (P <.0001 for both).

For time below range, results indicated time below 70 mg/dL and 54 mg/dL remained unchanged during lockdown periods. Further analysis indicated mean blood glucose had decreased by 5.40 mg/dL (95% CI, -7.29 to -3.51; P <.0001) along with a reduction in variability. When assessing pooled estimated HbA1c and glucose management indicator, results indicated a decrease of 0.18% (95% CI, -0.24 to -0.11; P <.0001) and investigators pointed out a similar reduction was observed when considering glucose management indicator alone (0.15% [95 CI%, -0.23 to -0.07]; P <.0001).

“This meta-analysis including data from 17 observational studies and a total of 3,441 subjects provides evidence that glucose control modestly though significantly improved during the COVID-19 lockdown period in adults with type 1 diabetes on multiple daily insulin injections or continuous subcutaneous insulin infusion using continuous or flash glucose monitoring systems,” wrote investigators.

This study, “Glycaemic control during the lockdown for COVID-19 in adults with type 1 diabetes: A meta-analysis of observational studies,” was published in Diabetes Research and Clinical Practice.