Objective
The main aim of this study is to investigate whether acupuncture could be an effective complementary treatment for reducing the risk of macrovascular complications in diabetic patients currently taking antidiabetic medications using a nationwide population-based database.

Methods
We conducted a retrospective cohort study to assess the efficacy of acupuncture on cardiovascular complications in diabetic patients using data from patients between 40 and 79 years of age, newly diagnosed with diabetes between 2003 and 2006, found in the National Health Insurance Service-National Sample Cohort (NHIS-NSC) in Korea. From the data, we identified 21,232 diabetic patients who were taking antidiabetic medication between 2003 and 2006. The selected patients were divided into two groups—those who received acupuncture at least three times and those who received no acupuncture (non-acupuncture) in the year following their diagnosis of diabetes. After 1:1 propensity score matching (PSM), each group had 3350 patients, and the observation ceased at the occurrence of a major adverse cardiovascular event (MACE), which was defined as either myocardial infarction, stroke, or death due to cardiovascular cause.

Results
After PSM, the acupuncture group had a lower incidence of MACE (hazard ratio [HR]: 0.87; 95% confidence interval [CI]: 0.81–0.94; P = 0.0003) and all-cause mortality (HR: 0.77; 95% CI: 0.70–0.84; P < 0.0001) than the non-acupuncture group; the HRs for stroke-related mortality (HR: 0.75; 95% CI: 0.56–1.00; P = 0.0485), ischemic heart disease mortality (HR: 0.53; 95% CI: 0.34–0.84; P = 0.006) and circulatory system disease mortality (HR: 0.67; 95% CI: 0.55–0.82; P < 0.0001) were lower in the acupuncture group than in the non-acupuncture group in the secondary analysis.

Conclusion
Our results indicate that diabetic patients receiving acupuncture treatment might have a lower risk of MACE, all-cause mortality and cardiovascular mortality. This population-based retrospective study suggests beneficial effects of acupuncture in preventing macrovascular complications associated with diabetes. These findings call for further prospective cohort or experimental studies on acupuncture treatment for cardiovascular complications of diabetes.

Key words: Acupuncture, Diabetes, Major adverse cardiovascular event, Myocardial infarction, Stroke, Macrovascular complication