OBJECTIVES

Epidemiology information on microvascular complications associated with type 2 diabetes mellitus (T2DM) is scant in China. This study aims to estimate the overall prevalence of diabetic retinopathy (DR), diabetic nephropathy (DN) and diabetic foot (DF) in Chinese patients with T2DM, and to identify any associated risk factors.

METHODS

A systematic literature search was conducted in both Chinese and English databases over the past 5 years (January 2014 - August 2019). Information on prevalence rate of microvascular complications, publication year, age, gender, HbA_1c, BMI, duration of T2DM, study region and treatment setting (hospital or community) was extracted. A meta-analysis was conducted using R 3.4.3 following normal transformations given the skewed raw data. Due to high heterogeneity, a random effect model was selected. A meta-regression analysis was performed to investigate the risk factors.

RESULTS

A total of 2,682 studies were retrieved. After screening, 171 studies were included in the meta-analysis, representing a total of 807,313 patients with T2DM in China. Of which, 86 studies in DR (138,344 patients), 61 in DN (550,518 patients) and 24 in DF (118,451 patients). Results of the meta-analysis showed that the prevalence of DR was 26.19% (95% CI: 23.02%-29.50%), DN 27.09% (95% CI: 23.55%-30.79%), and DF 7.41% (95% CI: 5.48%-10.03%), respectively. Duration of T2DM was identified as the only risk factor which was significantly associated with the prevalence of all three microvascular complications (p<0.05), indicating that patients with a longer history of T2DM may experience a higher chance of developing microvascular complications.

CONCLUSIONS

The prevalence of microvascular complications in patients with T2DM is high in China, which subsequently exerts a huge burden on the healthcare system. Early diagnosis and treatment of T2DM may prevent or delay the onset of microvascular complications. Future studies are warranted to explore the underlying causes of T2DM and to develop innovative antidiabetic drugs.