OBJECTIVES: The increasing obesity epidemic is driving the rising prevalence of type 2 diabetes (T2D), and most patients with T2D are overweight or have obesity. The objective of this literature review was to identify and present recent published country-specific (China, France, Germany, Italy, Japan, Spain, UK, USA) glycemic control data reported by body mass index (BMI) in patients with T2D.

METHODS: A literature search of electronic databases (MEDLINE, EMBASE) and recent congress abstracts was undertaken to identify real-world studies (2015-January 2020) reporting data on glycemic control (HbA1c) and BMI. Key aims included exploring the relationship between BMI and glycemic control and reporting average HbA1c by BMI.

RESULTS: Of 6696 de-duplicated references, 17 remained after initial abstract and full-text review. Most studies were from China (n=10), followed by Japan (n=3), the USA (n=2), Spain (n=1), and the UK (n=1). No studies were identified in the other countries. Eight of the thirteen studies that looked at proportions of patients achieving glycemic targets (generally HbA1c <7%), reported that the percentage of patients achieving control significantly declined as BMI increased; one study reported a clear trend but no statistical analysis; two studies reported glycemic control rates for those with obesity to be significantly worse than for one other group (overweight or normal weight); and two studies reported no significant difference in glycemic control rates as BMI increased. Four of six evaluable studies that reported average levels of HbA1c showed these were greater in patients with higher BMI.

CONCLUSIONS: Overall, studies have shown that the proportion of patients failing to achieve glycemic control increases with overweight and obesity. There is also evidence to suggest that HbA1c levels are greater in patients with higher BMI. These results indicate that management of overweight and obesity is important to consider in patients with T2D across geographies.