Prevalence of impaired awareness of hypoglycaemia in people with diabetes mellitus: A systematic review and meta‐analysis from 21 countries and regions

Abstract Aims Impaired awareness of hypoglycaemia (IAH) is a complication of glucose‐lowering therapies for diabetes. The purpose of this review was to estimate the pooled prevalence of IAH and unawareness of hypoglycaemia (UAH). Methods We searched the major databases from inception to 8 August 2022 and included all cross‐sectional and cohort studies reporting IAH prevalence in people with diabetes. A random‐effects model was used to pool effect values. Subgroup analysis and meta‐regression were used to identify study‐level characteristics affecting prevalence. Results Sixty‐two studies from 21 countries published between 2000 and 2022 were included, with 39,180 participants (type 1 diabetes: 19,304 vs. Type 2 diabetes: 14,650). The pooled prevalence was 23.2% (95% CI: 18.4%–29.3%) via the Clarke questionnaire, 26.2% (95% CI: 22.9%–29.9%) via the Gold score, and 58.5% (95% CI: 53.0%–64.6%) via the Pedersen‐Bjergaard method, all from studies classified as presenting a moderate and low risk of bias. The prevalence of IAH was generally higher in people with type 1 diabetes than in those with type 2 diabetes and lowest in Europe. Meta‐regression results show that the duration of diabetes was a factor influencing the prevalence of IAH. The prevalence of UAH by the Pedersen‐Bjergaard method was 17.6 (95% CI: 14.9%–20.3%). Conclusions IAH is a prevalent risk event among people with type 1 and type 2 diabetes, showing clinical heterogeneity and regional variability. UAH, an adverse progression of IAH, is also a serious burden. More primary research on the prevalence of IAH is needed in areas with a high diabetes burden.