Effect of slow deep breathing on cardiovascular autonomic neuropathy in type 2 diabetes mellitus patients.

OBJECTIVE: This study aimed to investigate the effects of slow deep breathing (SDB) on heart rate variability (HRV) in patients with type 2 diabetes mellitus (T2DM) patients with cardiovascular autonomic neuropathy (CAN). METHODS: Sixty patients with CAN secondary to type T2DM were randomly assigned to SDB (n = 30) and control (n = 30) groups. All patients were treated with mecobalamin (0.5 mg; times daily). Patients in the SDB group underwent slow deep breathing training against a background of soothing music. Before treatment and 3 months after treatment, height, body weight, heart rate (HR), blood pressure (BP), HbA1c, LDL, TG, heart-rate-variability (HRV), and hart rate recovery (HRR) were measured 1 min after the 6-min walk test in the two groups. RESULTS: BMI, SBP, DBP, HbA1c, LDL, and TG levels were comparable between the two groups and remained unchanged after treatment in two groups (P > 0.05). In the SDB group, the standard deviation of N-N intervals (SDNN), the square root of the mean squared differences of successive RR (RMSSD), low-frequency power (LF), high-frequency power (HF), and LF/HF ratio changed significantly after treatment (P < 0.05), and these measurements remained statistically significant after adjusting for age (P < 0.05), but HR and the root mean square of the difference between adjacent R-R intervals (PNN50) remained unchanged (P > 0.05). In the control group, HR, SDNN, RMSSD, PNN50, LF, HF, and LF/HF ratio remained unchanged after treatment (P > 0.05). The SBP, SDNN, RMSSD, LF, HF, and LF/HF ratios were significantly different between the two groups after treatment.(P < 0.05), and these measurements remained statistically significant after adjusting for age (P < 0.05). In addition, the HRR1 levels were comparable between the two groups (P > 0.05). CONCLUSION: With soothing music as the background, sustained slow deep breathing training can improve heart rate variability in patients with type 2 diabetes mellitus and cardiac autonomic neuropathy, independent of age, providing a new approach for the treatment of cardiac autonomic neuropathy in type 2 diabetes. CLINICAL TRIAL NUMBER: The study was registered in the Chinese Clinical Trial Registry (ChiCTR2200063260).