Retrospective Analysis of Point-of-Care and Laboratory-Based Hemoglobin A1cTesting

Trends in Time in Range-Related Publications and Clinical Trials: A Bibliometric Review

Objective

The goal of this article was to describe trends in publications (including conference abstracts) and clinical trials that report on glycemic time in range (TIR).

Data sources

Reviewed databases included but were not limited to MEDLINE and Embase. Clinical trial registries were also sourced.

Study selection

All studies reporting TIR published between 2010 and 2021 were included. Clinical trials reporting TIR that started in or after 2010 were also included. Non-English publications, abstracts, and clinical trials were excluded. Book chapters, nonhuman studies, and studies not reporting TIR were excluded.

Data extraction

Manuscript/abstract category, publication year, study region, interventional versus observational role of continuous glucose monitoring (CGM), and clinical trial start and completion dates were captured. Glycemic outcomes reported in publications or trials, including TIR as a primary outcome, A1C, time below range (TBR), and time above range (TAR), were also captured.

Results

A total of 373 clinical trials, 531 publications, and 620 abstracts were included in the review. The number of trials, publications, and abstracts reporting TIR significantly increased, particularly between 2018 and 2021, during which time the number of clinical trials, publications, and conference abstracts reporting TIR increased by 6-fold, 12-fold, and 4.5-fold, respectively. About 35-44% of studies reported TIR as a primary outcome. Approximately 54% of clinical trials, 47% of publications, and 47% of conference abstracts reported the role of CGM to be observational. TBR was reported more often than TAR.

Conclusion

The marked increase in the number of trials, publications, and abstracts reporting TIR highlights the increasing significance and acceptance of TIR as an outcome measure in diabetes management.

Applications and pitfalls of hemoglobin A1C and alternative methods of glycemic monitoring

INTRODUCTION

Intensive glycemic control minimizes the risks of microvascular complications in diabetes. A1C is a convenient estimate of mean blood glucose, but is not the only marker available. The practical use and limitations of alternative markers and continuous glucose monitors are the focus of this review.

METHODS

PubMed and the Cochrane Library were searched for studies concerning applications or limitations of A1C, fructosamine, glycated albumin, 1,5-anhydroglucitol, skin autofluorescence, and continuous glucose monitoring. Papers reporting on strengths, limitations, or comparisons of these methods were reviewed for inclusion.

RESULTS

A1C reflects three months of glycemic control and is not an ideal marker in all patient populations. Fructosamine and glycated albumin reflect mean blood glucose over three weeks. 1,5-Anhydroglucitol can measure hyperglycemic excursions in days to weeks. Continuous glucose monitors provide immediate feedback for timely intervention to reduce glycemic excursions and can assess glycemic variability. Current barriers to continuous glucose monitor use include inexperience, cost, discomfort, and medication interference.

CONCLUSIONS

Many promising alternative glycemic markers exist. The main limitations for all alternative methods of glycemic monitoring are a lack of standardization for clinically useful cut-offs or guidelines, and a lack of long-term data on their association with complications, particularly in varied patient populations.