Daily Heart Rate Variability Indices in Subjects with and Without Metabolic Syndrome Before and After the Elimination of the Influence of Day-time Physical Activity

Abstract

Background and Objectives: The available research shows conflicting data on the heart rate variability (HRV) in metabolic syndrome (MetS) subjects. The discrepancy suggests a methodical shortcoming: due to the influence of physical activity, the standard measuring of HRV at rest is not comparable with HRV assessment based on 24 h Holter monitoring, which is preferred because of its comprehensiveness. To obtain a more reliable measure and to clarify to what extent HRV is altered in MetS, we assessed a 24 h HRV before and after the elimination of the influence of physical activity. Materials and Methods: We investigated 69 metabolic syndrome (MetS) and 37 control subjects, aged 50–55. In all subjects, 24 h monitoring of electrocardiogram, blood pressure, and actigraphy profiles were conducted. To eliminate the influence of day-time physical activity on RR intervals (RRI), a linear polynomial autoregressive model with exogenous terms (ARX) was used. Standard spectral RRI analysis was performed. Results: Subjects with MetS had blunted HRV; the diurnal SDNN index was reliably lower in the MetS group than in control subjects. The elimination of the influence of physical activity did not reveal a significant HRV change in long-term indices (SDNN, SDANN, and SD2), whilst adjacent RRI values (RMSSD, pNN50, and SD1) and SDNN index significantly increased (p < 0.001). An increase in the latter indices highlighted the HRV difference between the MetS and control groups; a significant (p < 0.001) decrease of all short-term HRV variables was found in the MetS group (p < 0.01), and low-frequency spectral components were less pronounced in the MetS group. Conclusion: The application of a polynomial autoregressive model in 24 h HRV assessment allowed for the exclusion of the influence of physical activity and revealed that MetS is associated with blunted HRV, which reflects mitigated parasympathetic tone.

Heart Rate Variability, Deceleration Capacity of Heart Rate, and Death: A Veteran Twins Study

“…During sleep, gross physical activity and postural effects are minimized, as are other potential influences such as meals, fluid intake, and psychosocial exposures. 53 On the other hand, nighttime HRV could be confounded by sleep quality or sleep disorders, which may have an impact on the magnitude of the association between HRV and death. Furthermore, the daytime may have more stressful exposures that can uncover underlying vulnerabilities through HRV, while the nighttime is a more controlled period from an autonomic system standpoint, without as much autonomic stimulation except for sleep disturbance.…”

A Novel Adaptive Noise Elimination Algorithm in Long RR Interval Sequences for Heart Rate Variability Analysis

“…The remaining 34 subjects were the same age without MetS and had BP was less than 130/85 mmHg. All subjects were recruited from the ongoing Lithuanian High Cardiovascular Risk (LitHiR) primary prevention program as a part of an ongoing project that analyses metabolic syndrome patients [ 39 ]. In addition, daily activities according to the data from the subjects’ diary are presented in Appendix A .…”

Differences in Long-Term Heart Rate Variability between Subjects with and without Metabolic Syndrome: A Systematic Review and Meta-Analysis

“…No study was published before the year 2000, 5 were published between 2006 and 2010, and 8 between 2013 and 2020. The population studied was from: (a) North America (n = 3), all of them from United States [21][22][23]; (b) Europe (n = 7), where two of them were from Poland [24,25] and one from France [26], Serbia [27], Germany [28], Turkey [29] and Lithuania [30]; and (c) Asia (n = 3), retrieving one from Japan [31], Taiwan [11] and Korea [32]. [33].…”