Função autonômica cardíaca em indivíduos com diabetes mellitus tipo 2 um ano ou mais após o diagnóstico de COVID- 19

Abstract

Diabetes mellitus (DM) can favor the development of autonomic changes, such as cardiac autonomic neuropathy, especially in patients with inadequate glycemic control. Like DM, COVID-19 infection can cause an elevation in plasma glucose and is associated with longterm cardiac autonomic dysfunctions, as well as reduced functional capacity. There is still a lack of information about the combined action of DM and COVID-19 on cardiac autonomic function, as well as on the long-term functional capacity of individuals with diabetes affected by COVID-19. Therefore, a cross-sectional case-control study was conducted including individuals with type 2 diabetes, with a history of COVID-19 (DM2COV group) and without (DM2 group) one year or more ago, to compare cardiac autonomic function in static and stress conditions, as well as functional capacity between the two groups. Cardiac autonomic function was assessed through measures of heart rate variability (HRV) at rest and during post-exercise recovery, heart rate (HR) at the 1st (REC1) and 2nd minute (REC2) of incremental post-exercise recovery, and five cardiovascular autonomic reflex tests. Functional capacity was assessed based on the distance covered in the Incremental Shuttle Walking Test (ISWT). Categorical data are presented as absolute and relative frequency, and numerical data as mean ± standard deviation. The comparison of categorical variables between the two groups was performed using the chi-square test, and the t-test for independent samples, or the Mann-Whitney test, and two-way ANOVA for numerical variables. A significance level of 5% was adopted for the statistical tests. Thirty-six individuals of both sexes participated in the study, 18 in the DM2COV group and 18 in the DM2 group (60.6 ± 10.8 vs. 57.4 ± 10.0 years, P = 0.378; 61% vs. 50% men, P = 0.738). There was no significant difference between the groups regarding the measures of HRV at rest, in recovery after exercise, and functional capacity. REC1 was significantly lower in the DM2COV group compared to the DM2 group (20.1 ± 10.9 bpm vs. 28.6 ± 11.5 bpm; P=0.037). The DM2COV group exhibited reduced blood pressure response to the sustained handgrip test (10.1 ± 4.9 mmHg vs. 17.0 ± 9.8 mmHg; P=0.015) compared to the DM2 group. The findings of this study revealed that COVID-19 infection promotes autonomic impairment even one year after its occurrence in individuals with DM2. Additionally, it was observed that the assessment of cardiac autonomic function under stress conditions was more effective in identifying these impairments.