Prevalence and Risk Factors of Cardiovascular Autonomic Neuropathy in Individuals with Type 1 Diabetes Mellitus: A Systematic Review and Meta-Analysis

Background: Cardiac autonomic neuropathy (CAN) is a severe complication of type 1 diabetes mellitus (T1DM). This meta-analysis aimed to synthesize relevant literature on the prevalence of CAN and its risk factors in individuals with T1DM. Methods: We screened relevant literature from databases based on predefined search criteria until June 28, 2022. Data extraction and quality assessment were conducted independently by two reviewers. A meta-analysis was conducted to determine the prevalence of CAN and its risk factors in individuals with T1DM using a random-effects model. A subgroup analysis was conducted to assess variations in CAN prevalence based on diabetes duration, diagnostic criteria, study quality, study design, and geographic region of the participants. Results: A total of 21 studies provided information on the prevalence of CAN, while 18 studies explored the potential risk factors for CAN. The overall estimated prevalence of CAN in individuals with T1DM was 25.8% (95% confidence interval (95% CI): 0.208-0.307), with no significant differences observed among the five regions. Additionally, smoking, lipid abnormalities, hypertension, duration of diabetes, increased body mass index, elevated glycated haemoglobin concentrations, and presence of chronic complications of diabetes, such as diabetic retinopathy, diabetic neuropathy, and diabetic nephropathy, were associated with a higher prevalence of CAN in individuals with diabetes. Conclusions: CAN is prevalent in individuals with T1DM worldwide. Efforts should be made to improve early screening and intervention for CAN, as well as to implement strategies aimed at improving or controlling early risk factors associated with CAN.