Heart rate variability in adolescents and adults with type 1 diabetes

Large fibre, small fibre and autonomic neuropathy in adolescents with type 1 diabetes: A systematic review

AIMS

To estimate the prevalence of neuropathy in adolescents with type 1 diabetes.

METHODS

Systematic collection of published studies exploring the prevalence of large fibre neuropathy (LFN), small fibre neuropathy (SFN), and autonomic neuropathy in adolescents with type 1 diabetes. Following prospective registration (Prospero CRD42020206093), PubMed, EMBASE, and Cochrane Library were searched for studies from 2000 to 2020. PICO framework was used in the selection process (Population: adolescents aged 10-19 years with type 1 diabetes; Intervention: diagnostic methods for neuropathy; Comparison: reference data; Outcome: data on prevalence or comparison). Data were extracted concerning study quality based on available data and established methods for determining and diagnosing various neuropathy types.

RESULTS

From 2,017 initial citations, 27 studies (7589 participants) fulfilled eligibility criteria. The study population (47% males) had a diabetes duration between 4.0 and 10.6 years, and HbA1c level between 7.3 and 10.8%, 56-95 mmol/mol. The prevalence of LFN, based on nerve conduction studies, was 10-57%. Based on other tests for neuropathy, the prevalence of LFN and SFN was 12-62%, and that of cardiac autonomic neuropathy was 12-75%.

CONCLUSION

The described prevalence of neuropathy in adolescents with type 1 diabetes varied, which can be methodological due to different screening methods and classifications of neuropathy.

Cardiovascular Autonomic Neuropathy and Early Atherosclerosis in Adolescent Type 1 Diabetic Patient

AIM:

To evaluate cardiovascular autonomic neuropathy (CAN) in type 1 Diabetics and to detect its relation to coronary artery calcification.

PATIENTS AND METHODS:

It is a cross sectional study included 62 diabetics and 30 controls. Clinical, laboratory assessment and 24 Hr holter were done for all patients and controls and coronary artery calcium (CAC) scoring by multisclice CT was done for all patients only. T-test, Mann Whitney U test, and stepwise multiple regression were used for statistical analyses.

RESULTS:

CAC score was positive in 8.1 % of patients. Heart rate variability (HRV) was significantly lower in diabetics. All parameters of HRV were insignificantly lower in diabetics with positive CAC score. Patients with microalbuminuria had a significantly lower HRV. HRV had a significant correlation with age of patients, duration of disease, HbA1, and Qtc in diabetics.

CONCLUSION:

Percentage of arrhythmia and early atherosclerosis is high in adolescent type 1 diabetic patients. CAN is associated with early atherosclerosis. Cardiac autonomic neuropathy is associated with older age, longer duration, and poor glycemic control and microalbuminuria.

Cardiac Affection in Type 1 Diabetic Patients in Relation to Omentin

AIM:

To evaluate cardiac affection in type 1 diabetes in relation to Omentin.

PATIENTS AND METHODS:

Sixty two diabetics and 30 volunteer of the same age and sex were included as a control group. Blood sample was taken for assessment of omentin and oxidized low density lipoprotein (OxLDL), glycosylated hemoglobin (HbA1) and lipid profile. Urine sample was taken for assessment of albumin/creatinine ratio. 24 hour holter was also done. T-test, simple correlation followed by stepwise multiple regression analysis was used for analysis of data.

RESULTS:

Parameters of 24 hour holter were significantly lower in diabetics. Omentin was significantly lower, while OxLDL were significantly higher than controls. RMSSD, ST deviation and OxLDL were the parameters related to omentin by stepwise multiple regression analysis in diabetics.

CONCLUSION:

Diabetic patients had a cardiac autonomic neuropathy. A significant reduction of omentin and elevation OxLDL imply that they influence glucose metabolism in type 1 diabetes. Omentin had a significant relation to 24 hr holter which may reflect its role in cardiac affection. Omentin and OxLDL had a role in renal affection.

Toxic stress, inflammation and symptomatology of chronic complications in diabetes

Diabetes affects at least 382 million people worldwide and the incidence is expected to reach 592 million by 2035. The incidence of diabetes in youth is skyrocketing as evidenced by a 21% increase in type 1 diabetes and a 30.5% increase in type 2 diabetes in the United States between 2001 and 2009. The effects of toxic stress, the culmination of biological and environmental interactions, on the development of diabetes complications is gaining attention. Stress impacts the hypothalamus-pituitary-adrenal axis and contributes to inflammation, a key biological contributor to the pathogenesis of diabetes and its associated complications. This review provides an overview of common diabetic complications such as neuropathy, cognitive decline, depression, nephropathy and cardiovascular disease. The review also provides a discussion of the role of inflammation and stress in the development and progression of chronic complications of diabetes, associated symptomatology and importance of early identification of symptoms of depression, fatigue, exercise intolerance and pain.

An evaluation of heart rate variability and its modifying factors in children with type 1 diabetes

OBJECTIVE

To evaluate heart rate variability by Holter monitoring in type 1 diabetic children compared with a healthy control group and determine the factors modifying heart rate variability.

METHODS

This was designed as a prospective study comparing 28 patients, diagnosed with type 1 diabetes and under follow-up, with 27 healthy control group subjects.

RESULTS

The patients were aged 9.9 ± 4.2 years in the diabetic group, including 13 (46.5%) girls and 15 (53.5%) boys. The healthy control group comprised 20 (74%) girls and seven boys (26%) with an average age of 8.6 ± 3.7 years. The search for factors modifying heart rate variability yielded the following correlations: for the time-dependent variables, negative between age and both average and maximal heart rate (r = -0.263 and -0.460, respectively), negative between haemoglobin A1c and percentage of differences between adjacent RR intervals >50 ms, positive between diabetes duration and square root of the mean of the sum of squares of differences between adjacent NN intervals. The average heart rate and percentage of differences between adjacent RR intervals >50 ms was significantly higher in the girls than the boys in all groups. With regard to the frequency-dependent factors affecting heart rate variability, correlations were found between haemoglobin A1c level and both total power and very low frequency (r = -0.751 and -0.644) and between very low frequency and diabetes duration.

CONCLUSION

A reduction in heart rate variability parameters was observed in type 1 diabetes mellitus patients who had a long disease duration or were poorly controlled, as compared with healthy controls.

Heart rate variability reflects the natural history of physiological development in healthy children and is not associated with quality of life

Background

Quality of life (QoL), being the sum expression of diverse influencing factors, is not easy to determine. A clinically relevant option would be to identify and measure quality of life on the basis of physiological parameters which correlate plausibly and statistically with psychometrically measured QoL. Analysis of heart rate variability (HRV) offers readily measurable physiological parameters which could be of use here. A correlation of HRV with both course of disease and QoL has been reported in patients with chronic illness. Various psychometric instruments have been developed for use in paediatric oncology. The aim of this study was to obtain data on HRV and QoL and their correlations, initially in healthy children.

Methods

Holter ECG and quality of life were examined in 160 children and adolescents (72 male) aged between 8 and 18 years. QoL was determined with the established questionnaire PEDQoL. Standard parameters of HRV from the frequency domain were calculated and correlated with QoL domains using Spearman (nonparametric) correlation analysis.

Results

Minor but significant associations were revealed only with regard to the PEDQoL domain “autonomy” on the one hand and heart rate and HRV (e.g. MRR, MRRn, MRRd, HRV_ULF, SDNN) parameters which evidently reflect distinct physiological functions on the other.

Conclusions

In healthy children and adolescents we have a first indication that there is a correlation between parameters of HRV and QoL. However, to a greater extent, HRV reflects associated physiological processes of the autonomic nervous system. A higher correlation is more likely to be found in chronically ill children.

Neurologic complications of pancreas and small bowel transplantation

In the past decade, substantial improvements in patient and graft survival for pancreas and small bowel transplants have been achieved. Despite this progress, many patients still develop neurologic complications in the course of their illness. Small bowel transplants produce more neurologic complications because of the complex metabolic environment in which the procedure is performed and because of the intense immune suppression necessitated by the greater immunogenicity of the intestinal mucosa. Pancreas transplants stabilize and/or improve the signs and symptoms of diabetic neuropathy over time. Because transplantation of the pancreas is often coupled with a kidney transplant and small intestine with liver, neurologic complications in these patients sometimes reflect problems involving the organ partner or both organs. The spectrum of neurologic complications for pancreas and small bowel transplant recipients is similar to other organ transplants but their frequency varies depending on the type of transplant performed.

Heart rate variability predicts ESRD and CKD-related hospitalization

Autonomic imbalance, a feature of both diabetes and hypertension, may contribute to adverse cardiovascular outcomes. In animal models, sympathetic nerve activity contributes to renal damage but the extent to which autonomic dysfunction precedes the development of CKD and ESRD in humans is unknown. We measured resting heart rate and heart rate variability in 13,241 adults (45- to 64-years old) followed for a median of 16 years in the Atherosclerosis Risk in Communities (ARIC) Study. We examined heart rate parameters by quartiles, defining those in the lowest quartile (by time and frequency domain measures separately) as the risk group of interest. We identified 199 cases of incident ESRD and 541 patients with CKD-related hospitalizations; higher resting heart rate and lower heart rate variability associated with both outcomes. The fully adjusted hazard ratios for ESRD were 1.98 (95% confidence interval [CI] 1.45 to 2.70) among those in the highest heart rate quartile and 1.56 (95% CI 1.14 to 2.14) for high-frequency power. Other time and frequency domain measures were similarly and significantly associated with ESRD and CKD-related hospitalizations. These results suggest that autonomic dysfunction may be an important risk factor for ESRD and CKD-related hospitalizations and call for further studies to define the mechanisms that underlie these associations.

Microalbuminuria and heart rate variability in adolescents with diabetes

INTRODUCTION

Limited clinical and research data are available on early renal and cardiovascular complications in youth with diabetes. The possible associations of elevated microalbuminuria to creatinine (MC) ratios with heart rate variability (HRV) were explored in adolescents with type 1 (T1DM) or type 2 (T2DM) diabetes.

METHODS

A descriptive study was conducted with 41 adolescents with diabetes (n = 31 T1DM vs. n = 10 T2DM). Twenty-four hour Holter recordings for determining HRV, urine spot checks for MC ratio, and the most recent measures of glycosylated hemoglobin (A1c) were obtained.

RESULTS

HRV was significantly lower in the T2DM group, while body mass index percentile, triglycerides, and diastolic blood pressure were significantly higher. For the T1DM group, clinical case examples provided evidence of elevated MC ratios (>30 mirog/mg) occurring in two female subjects who also had decreased HRV measures.

DISCUSSION

Although HRV was not significantly associated with MC ratios for the sample, individual clinical findings can be a warning sign for some adolescents with diabetes. Current recommendations for screening of early renal complications and associated treatment are provided.

Impaired cardiac autonomic function in women with prior gestational diabetes mellitus

BACKGROUND

Cardiac autonomic neuropathy is a common dysfunction in manifest diabetes mellitus and is associated with duration of diabetes and/or an inadequate glycaemic control. Heart rate variability (HRV) reflects autonomic heart function. The aim of the present study was to investigate whether in women with prior gestational diabetes (GD; pre-type 2 diabetes) alterations of cardiac autonomic function can be observed after delivery in relation to insulin sensitivity and glycaemic control.

MATERIALS AND METHODS

Forty-eight healthy women with prior GD were consecutively admitted to the study. HRV was analysed by both time, as well as frequency, domain methods using 24-h Holter monitoring. In addition, 20 women with normal glucose tolerance during and after pregnancy were investigated as control subjects. All women underwent a frequently sampled intravenous glucose tolerance test (FSIGT) for measurement of insulin sensitivity.

RESULTS

Time domain analysis (standard deviation of normal RR intervals; SDNN) showed a reduced HRV in 25 out of the 48 (52%) women with prior GD. Frequency domain analysis revealed that in these 25 subjects both low and high frequency components of power spectral density (reflecting mainly sympathetic respectively parasympathetic activity) were reduced, indicating that sympathetic as well as parasympathetic functional impairment may be assumed. However, a relative predominance of the sympathetic over parasympathetic cardiac function was observed. The impairment of cardiac autonomic function (reduced SDNN) was correlated with HbA1c values and the 2-h blood glucose concentration (oral glucose tolerance test) but not with insulin sensitivity.

CONCLUSION

The present results demonstrate that in 52% of the women examined who had prior GD, an impairment of cardiac sympathetic as well as parasympathetic function was present, which related to glycaemic control, but not to insulin sensitivity. This infers that functional autonomic changes could be an early prognostic indicator in pre-type 2 diabetes.

Heterogenous changes in neuropeptide Y, norepinephrine and epinephrine concentrations in the hearts of diabetic rats

The changes in concentrations of neuropeptide Y (NPY), norepinephrine and epinephrine were investigated in the rat hearts 1, 2, 4, 6, 9 and 12 months after administration of streptozotocin (STZ; 65 mg/kg i.v.). About 30% of diabetic animals displayed symptoms of partial spontaneous recovery, i.e. decreasing blood glucose levels and increasing insulin concentrations in the plasma and pancreas. NPY concentrations in the atria of diabetic rats did not differ from those in age-matched control rats 1, 2, 4, 6 months in the right atria and even 9 months after STZ in the left atria. However, uncompensated diabetes led to a significant decrease in NPY levels 9 and 12 months after STZ administration in the right and left atria, respectively. In the ventricles, NPY concentrations were significantly decreased 6 months after the onset of diabetes. Interestingly, partial spontaneous recovery of diabetes was associated with increased NPY levels in the atria. Myocardial norepinephrine concentrations increased 1 month after STZ and then declined reaching approximately 60% of the respective control values 12 months after the onset of the disease. Partial spontaneous recovery of diabetes had no effect on norepinephrine concentrations. Myocardial epinephrine concentrations did not differ from those found in controls till month 9 of the disease and they became significantly lower at month 12. Partial recovery of diabetes resulted in epinephrine concentrations not differing from the control values at month 12 of diabetes. Regarding to preferential localization of norepinephrine in the sympathetic postganglionic fibers and that of NPY also in intrinsic ganglion neurons, intrinsic neuronal circuits seem to be less susceptible to STZ-induced damage than extrinsic nerves and they might be able to recover after amelioration of diabetes.

Cardiovascular endurance and heart rate variability in adolescents with type 1 or type 2 diabetes

BACKGROUND

Incidence rates of both type 1 and type 2 diabetes mellitus (DM) are increasing in youth and may eventually contribute to premature heart disease in early adulthood. This investigation explored the influence of type of diabetes, gender, body mass index (BMI), metabolic control (HbA1c), exercise beliefs and physical activity on cardiovascular endurance (CE), and heart rate variability (HRV). Differences in exercise beliefs, physical activity, HRV, and CE in youth with type 1 versus type 2 DM were determined.

METHODS

Adolescents with type 1 DM (n = 105) or with type 2 DM (n = 27) completed the Exercise Belief Instrument and the Physical Activity Recall. Twenty-four HRV measures were obtained via Holter monitoring and analyzed using SpaceLabs Vision Premier software system. The McMaster cycle test was used to measure CE (V0(2peak)).

RESULTS

Regardless of the type of DM, females and those with higher BMI, poorer metabolic control, and lower amounts of physical activity tended to have lower levels of CE. Exercise beliefs consistently predicted both frequency and time domain HRV measures. Measures of exercise beliefs, self-reported physical activity, CE (V0(2peak)), and HRV were significantly lower in adolescents with type 2 DM in comparison to those with type 1 DM.

CONCLUSIONS AND RECOMMENDATIONS

Early findings of poor physical fitness, lower HRV, fewer positive beliefs about exercise, and less active lifestyles highlight the importance of developing culturally sensitive interventions for assisting youth to make lifelong changes in their physical activity routines. Females, those with poorer metabolic control, and minority youth with type 2 DM may be particularly vulnerable to later cardiovascular disease.

A disturbance of the gastric myoelectric activity in post-operative patients with biliary atresia

BACKGROUND

Abnormalities in gastrointestinal motility have been reported in adult patients with advanced liver disease. However, there have so far been no reports on the gastric myoelectric activity in post-operative patients with biliary atresia (BA).

AIM

The purpose of this study was to evaluate the gastric myoelectric activity in post-operative patients with BA in relation to liver fibrosis.

PATIENTS AND METHODS

Twenty-one post-operative patients with BA, consisting of 6 boys and 15 girls with a mean age of 8.0 years and 6 healthy children (control group) were included in the study. The gastric myoelectric activity was measured by electrogastrography (EGG). The patients with BA were divided into two groups according to the serum hyaluronic acid (HA) level as a marker of liver fibrosis: the fibrotic group (FG, n=11), HA>50 ng/ml and the non-fibrotic group (NF, n=10), HA <==50 ng/ml. All recorded data were spectrally analyzed and any parameters related to changes in the dominant peak frequency (DPF) and its power were investigated. Furthermore, the gastrointestinal symptom scores (GSS) were calculated in patients with dyspeptic symptoms according to the degree of advanced liver fibrosis.

RESULTS

The results showed that 1) the postprandial DPF in the FG tended to be higher than that in the NFG ( p=0.051), 2) the postprandial variability index of the DPF in the FG and NFG were significantly higher than those in the controls ( p<0.05), and 3) the preprandial percentage of normal waves (PNW) in the FG tended to be lower than that in the controls ( p=0.089). The postprandial PNWs in the FG and NFG were significantly lower than those in the controls ( p<0.05). Especially, the postprandial PNW in the FG was significantly lower than that in the NFG ( p<0.05). 4) The power ratio in the FG and NFG were significantly lower than those in the controls ( p<0.05), and 5) the GSSs in the FG were significantly higher than those in the NFG ( p<0.05).

CONCLUSIONS

The gastric myoelectric activity appeared to be disturbed in BA patients associated with portal hypertension and neurohormonal changes due to liver fibrosis.

Cardiovascular autonomic function in healthy adolescents

OBJECTIVE

The purpose of this study was to determine effects of age, sex, race, body mass index, and Tanner's stage on short-term evoked cardiovascular autonomic tests (ie, Valsalva ratio and change in heart rate with deep breathing) and 24-hour heart rate variability (HRV) in a sample of healthy adolescents, as well as to identify normative indices of both short-term evoked and 24-hour HRV in this age group.

DESIGN

A descriptive, correlational design was used.

SETTING

Study took place in a university hospital in a health science center located in the mid-South.

SUBJECTS

Participants included 75 healthy adolescents: mean age was 15.0 +/- 1.6 years, 14 were African American, 61 were white, 49 were girls, and 26 were boys.

OUTCOME MEASURES

Study measures included the Valsalva ratio, change in heart rate with deep breathing, and 24-hour HRV with power spectral analysis with Holter monitoring.

RESULTS

Major significant findings included lower values of 24-hour HRV measures for girls and African American adolescents (P <.05). Indices for normal ranges of both the short-term evoked and 24-hour HRV measures were computed with 95% confidence intervals.

CONCLUSIONS

Few published studies address cardiac autonomic function, including 24-hour HRV, in adolescents. Most studies reporting actual normative control values of HRV for youth typically have not addressed sex or racial differences. Our study included the largest number of adolescents to date in the reported literature and demonstrated the importance of considering sex and race variation in interpreting test results. The availability of state-of-the-art technology for obtaining HRV data allows for the early identification of subclinical cardiac autonomic changes in youth who have predispositions for cardiac complications, such as those with diabetes, congenital heart disease, or obesity.

Prevalence of autonomic dysfunction in cirrhotic and noncirrhotic portal hypertension

OBJECTIVE

Autonomic dysfunction is common in patients with cirrhosis of the liver, but more so in patients with decompensated state, and is associated with increased mortality. We evaluated the presence and extent of autonomic dysfunction in patients with extrahepatic portal venous obstruction (EHPVO) and noncirrhotic portal fibrosis (NCPF), diseases with relatively preserved liver functions.

METHODS

Heart rate variability in response to standing, deep breathing, and Valsalva maneuver and blood pressure response to sustained handgrip and standing were studied in 18 patients with EHPVO (13 mol/L, 5 F, mean age 15.2 +/- 6 yr), 12 patients with NCPF (5 mol/L, 7 F, mean age 26.4 +/- 8 yr), 15 patients with cirrhosis (7 mol/L, 8 F, mean age 12.6 +/- 6 yr), and 17 healthy controls (11 mol/L, 6 F, mean age 18.6 +/- 3 yr). Time-domain parameters of heart rate variability on 24-h ambulatory monitoring were assessed in all the patients.

RESULTS

Autonomic dysfunction was observed in 67% of EHPVO, 25% of NCPF, and 80% of cirrhotic subjects but none of the healthy controls (p < 0.05). Four of five time-domain heart rate variability indices showed significant abnormalities in patients with EHPVO (p < 0.05) and cirrhosis (p < 0.05), when compared with patients with NCPF and healthy controls.

CONCLUSIONS

Autonomic dysfunction is frequently encountered in patients with EHPVO and cirrhosis, and the presence of autonomic dysfunction in patients with noncirrhotic portal hypertension suggests a primary role of portal hypertension per se in the dysfunction.