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Objective To identify the differences in cardiac autonomic control between older people with good and poor sleep quality. Material and Methods This is a cross-sectional study with 40 older people aged ≥ 60 years, registered at a community health center in Petrolina, Pernambuco, Brazil. The sleep quality was assessed with the Pittsburgh Sleep Quality Index (PSQI). To assess heart rate variability (HRV), the RR intervals (RRI) were recorded for 10 min with a validated smartphone app and a wireless transmitter Polar H7 positioned on the patient's chest. The HRV parameters were calculated with Kubios HRV, and the data were analyzed in SPSS. Subjects with good and poor sleep quality (PSQI >5) were compared with the Mann-Whitney U test. Results A total of 31 older people were included in the final analysis, with 18 (58.1%) of them having poor sleep quality. Older people with good sleep quality have similar cardiac autonomic control to those with poor sleep quality. The medians of time (mean RRI, pNN50, SDNN, and RMSSD) and frequency-domain HRV parameters (LFms², LFnu, HFms², HFnu, and LF/HF ratio) were statistically similar (p > .05) in older people with good and poor sleep quality. According to the effect size, the HRV indicators were slightly better among those with good sleep quality. Conclusion There were no statistical differences in cardiac autonomic control between older people with good and poor sleep quality. [ABSTRACT FROM AUTHOR]

Purpose: The incidence of cardiovascular events is higher in coronary artery disease patients with type 2 diabetes (CAD + T2D) than in CAD patients without T2D. There is increasing evidence that the recovery phase after exercise is a vulnerable phase for various cardiovascular events. We hypothesized that autonomic regulation differs in CAD patients with and without T2D during post-exercise condition., Methods: A symptom-limited maximal exercise test on a bicycle ergometer was performed for 68 CAD + T2D patients (age 61 ± 5 years, 78% males, ejection fraction (EF) 67 ± 8, 100% on β-blockade), and 64 CAD patients (age 62 ± 5 years, 80% males, EF 64 ± 8, 100% on β-blockade). Heart rate (HR) recovery after exercise was calculated as the slope of HR during the first 60 s after cessation of exercise (HRR(slope)). R-R intervals were measured before (5 min) and after exercise from 3 to 8 min, both in a supine position. R-R intervals were analyzed using time and frequency methods and a detrended fluctuation method (α(1))., Results: BMI was 30 ± 4 vs. 27 ± 3 kg m(2) (p < 0.001); maximal exercise capacity, 6.5 ± 1.7 vs. 7.7 ± 1.9 METs (p < 0.001); maximal HR, 128 ± 19 vs. 132 ± 18 bpm (p = ns); and HRR(slope), -0.53 ± 0.17 vs. -0.62 ± 0.15 beats/s (p = 0.004), for CAD patients with and without T2D, respectively. There was no differences between the groups in HRR(slope) after adjustment for METs, BMI, and medication (ANCOVA, p = 0.228 for T2D and, e.g., p = 0.030 for METs). CAD + T2D patients had a higher HR at rest than non-diabetic patients (57 ± 10 vs. 54 ± 6 bpm, p = 0.030), but no other differences were observed in HR dynamics at rest or in post-exercise condition., Conclusion: HR recovery is delayed in CAD + T2D patients, suggesting impairment of vagal activity and/or augmented sympathetic activity after exercise. Blunted HR recovery after exercise in diabetic patients compared with non-diabetic patients is more closely related to low exercise capacity and obesity than to T2D itself.