ABSTRACT
Multiscale entropy (MSE) analysis provides information about complexity on various time scales. The aim of this study was to test whether MSE is able to detect autonomic dysregulation in young patients with diabetes mellitus (DM). We analyzed heart rate (HR) oscillations, systolic (SBP) and diastolic blood pressure (DBP) signals in 14 patients with DM type 1 and 14 age- and sex-matched healthy controls. SampEn values (scales 1-10) and linear measures were computed. HR: among the linear measures of heart rate variability significant differences between groups were only found for RMSSD (p = 0.043). MSE was significantly reduced on scales 2 and 3 in DM (p = 0.023 and 0.010, respectively). SBP and DBP: no significant differences were detected with linear measures. In contrast, MSE analysis revealed significantly lower SampEn values in DM on scale 3 (p = 0.039 for SBP; p = 0.015 for DBP). No significant correlations were found between MSE and linear measures. In conclusion, MSE analysis of HR, SBP and DBP oscillations is able to detect subtle abnormalities in cardiovascular control in young patients with DM and is independent of standard linear measures.
Subject(s)
Blood Pressure , Diabetes Mellitus, Type 1/physiopathology , Entropy , Heart Rate , Adult , Female , Humans , MaleABSTRACT
We aimed to test whether the evaluation of the cardio-respiratory interaction using the analysis of heart rate and blood pressure variabilities and respiratory maneuvers can reveal cardiovagal dysfunction in obese adolescents 12-18 years old. The spectral power in high frequency band of the heart rate variability (HRV) reflecting respiratory sinus arrhythmia was used as an index of the cardiac vagal control, and the spectral power in high frequency band of the blood pressure variability (BPV) as an indicator of mechanical effects of respiration. The deep breathing test and Valsalva maneuver were applied. The obese group had a reduction in spectral power in high frequency band of the HRV. Differences in high frequency band spectral power of the BPV between the obese and control groups were not found. The finding of lower respiratory sinus arrhythmia, indicating a cardiovagal dysfunction in obese adolescents, can provide important diagnostic information about early subclinical autonomic dysfunction in obesity.
Subject(s)
Autonomic Nervous System Diseases/physiopathology , Hemodynamics/physiology , Obesity/physiopathology , Respiratory Mechanics/physiology , Adolescent , Anthropometry , Arrhythmia, Sinus/physiopathology , Autonomic Nervous System Diseases/etiology , Blood Pressure/physiology , Body Mass Index , Child , Data Interpretation, Statistical , Electrocardiography , Female , Heart Rate/physiology , Humans , Male , Obesity/complications , Respiratory Function Tests , Valsalva Maneuver/physiologyABSTRACT
The aim of this study was to obtain information about parameters of heart rate variability (HRV) in three frequency bands (high frequency - HF, low frequency - LF and very low frequency - VLF), the sensitivity of cardiovascular tests, and subjective feelings depending on autonomic nervous system balance in a group of young patients with diabetes mellitus type 1 (IDDM). Sixty-four subjects were examined: 32 patients with diabetes with a mean age of 16.1 +/- 0.7 years and a mean duration of IDDM of 6.3 +/- 0.8 years, and 32 healthy controls matched for age, sex and BMI. Shorter R-R intervals and abnormal values reflecting HRV were found in the diabetic group. In particular, parameters of total power, and HF and LF bands were reduced. The ratio VLF/HF power revealed predominance of sympathetic tone in the diabetic subjects. Although relative power VLF was increased in the supine position, the reactive rise of the VLF band activity in orthostasis was lower in the IDDM group. Using cardiovascular tests (deep breathing, Valsalva, orthostasis), significant differences in reactions were found only in the deep breathing test. Evaluation of sympathetic:parasympathetic:indifferent subjective feelings by questionnaire did not reveal any differences between the diabetic and healthy groups.
Subject(s)
Autonomic Nervous System Diseases/physiopathology , Diabetes Mellitus, Type 1/physiopathology , Heart Rate/physiology , Heart/physiopathology , Adolescent , Adult , Autonomic Nervous System Diseases/diagnosis , Child, Preschool , Female , Humans , Hypotension, Orthostatic/physiopathology , Infant , Male , Parasympathetic Nervous System/physiopathology , Posture/physiology , Respiratory Mechanics/physiology , Supine Position/physiology , Sympathetic Nervous System/physiopathology , Valsalva Maneuver/physiologyABSTRACT
In 27 children (14 juvenile hypertonics and 13 healthy control children, with the mean age 14.7 +/- 0.4 y. or 15.2 +/- 0.5 y., respectively, P greater than 0.05) the changes of heart rate (HR), its variability (HRV) during deep inspiration and subsequent expiration, Valsalva's maneuver, doubled breathing frequency and the deepening of breathing were studied. The resting supine mean HR was significantly higher (P less than 0.001) in hypertonics than in controls. Deep inspiration was in both groups accompanied with the HR increase. However, the percentage increase in hypertonics was significantly lower than in normals (P less than 0.02). With subsequent expiration, the HR fell in both groups. There was no significant difference between the percentage decreases in both groups (P greater than 0.05). During the Valsalva's maneuver, in the first phase the tachycardic response occurred, which was in hypertonics significantly less pronounced. After the recovery of breathing a bradycardic reaction occurred which was equal in both groups (P greater than 0.05). Both, in juvenile hypertonics and in controls the doubled frequency of breathing increased the mean HR and decreased the HRV. During the deepened breathing there was an increase in mean HR in both groups, and only in the controls there was an increase in HRV. Heart rate variability in hypertonics was lower than in the controls under all the conditions.
