Impact of arterial hypertension and type 2 diabetes on cardiac autonomic modulation in obese individuals with recommendation for bariatric surgery.

BACKGROUND AND AIM

Obese individuals with recommendation for bariatric surgery (BS) exhibit increased cardiovascular risk. The association of obesity with comorbidities, such as arterial hypertension (HTN) and type 2 diabetes mellitus (T2DM) can worsen cardiovascular dysfunction. This study aimed to investigate the effect of HTN on cardiac autonomic function and whether diabetes exacerbates HTN-related impairment of autonomic function in obese subjects.

METHODS

Samples (n=63) were allocated to three groups: Obese without HTN and T2DM (n=29), Obese with HTN (OHTN, n=17) and OHTN with T2DM (OHTN+T2DM, n=17), in which anthropometric measures, body composition, blood biochemical parameters, blood pressure (BP) and heart rate variability (HRV) were evaluated.

RESULTS

The age was higher in OHTN+T2DM and OHTN than in obese groups (<0.05). OHTN+T2DM individuals had increased neck circumference and compromised glycemic profile when compared to obese and OHTN groups (<0.05). Mean values for standard deviation of RR (SDRR), square root of the mean squared differences of successive RR interval (RMSSD) and number of pairs of successive normal-to-normal beat intervals that differed by 50 ms (pRR50) were significantly lower in OHTN+T2DM and OHTN groups when compared to patients with obesity alone (<0.05). The low frequency (LF), low frequency/high frequency (LF/HF) ratio were higher in the OHTN+T2DM and OHTN than subjects with obesity alone (<0.05). Nonlinear parameters SD2 and SD1 were also lower in the OHTN+T2DM when compared to the obese group (<0.05). However, the SD2/SD1 ratio was higher in the OHTN+T2DM and OHTN groups than the obese group.

CONCLUSION

T2DM and/or HTN impair the cardiac autonomic function in obese patients. However, the presence of T2DM did not exacerbate the hypertension-related impairment of autonomic function.