Circadian change of cardiac autonomic function in correlation with intra-esophageal pH

Inflammation and Dry Eye-like Symptoms as Concomitant Manifestations of Laryngo-Pharyngeal Reflux

PURPOSE

Laryngo-pharyngeal reflux (LPR) is a common worldwide disease. LPR symptoms may involve distant organs and tissues including the ocular surface with manifestations of a Dry Eye-like disease. We evaluated the concomitant involvement of the ocular surface in patients with LPR. We also defined the clinical signs and the roles of chemical and neuro-inflammatory mediators in the tears of LPR patients.

METHODS

Seventy-seven patients with LPR (mean age 65.8 ± 16.8 SD) and 25 healthy controls (mean age 56.5 ± 16.3 SD) were recruited from the otorhinolaryngology unit. Each subject was evaluated for the presence of concomitant ocular surface disease through clinical examination, including the measurement of tear break-up time (TBUT) and the Ocular Surface Disease Index (OSDI) questionnaire. Tears and conjunctival imprints were collected. The presence of pepsin in tears was detected by ELISA. HLA-DR in conjunctival imprints were imaged by immunofluorescence microscopy. RT-PCR quantified conjunctival mRNA transcripts of HLA-DR, IL-8, MUC5AC, NADPH, VIP, and NPY.

RESULTS

Patients with LPR had significantly increased OSDI and reduced TBUT scores compared to control subjects (p < 0.05 each). Pepsin was detected in 51% of patient tears while it was not measurable in the controls (p < 0.01). Immunoreactivity for HLA-DR in the conjunctival impressions was greater than for the controls with an increased mRNA expression (p < 0.05). mRNA transcripts for IL-8, NADPH, and VIP were significantly increased in LPR patients (p < 0.05 each), but neither MUC5AC nor NPY were different from controls.

CONCLUSIONS

LPR can adversely affect the ocular surface, leading to moderate signs and symptoms of dry eye. This study provides evidence that the presence of pepsin, HLA-DR immunoreactivity, and increased mRNA expression of neuro-inflammatory markers in the tears and conjunctival imprints of LPR patients suggests a potential link between LPR inflammation and ocular surface disease.

Roles of Heart Rate Variability in Assessing Autonomic Nervous System in Functional Gastrointestinal Disorders: A Systematic Review

Functional gastrointestinal disorders (FGID) and gastroesophageal reflux (GERD) disease affect a large global population and incur substantial health care costs. Impairment in gut-brain communication is one of the main causes of these disorders. The central nervous system (CNS) provides its inputs to the enteric nervous system (ENS) by modulating the autonomic nervous system (ANS) to control the gastrointestinal functions. Therefore, GERD and FGID's might be associated with autonomic dysfunction, which can be identified via heart rate variability (HRV). FGIDs may be treated by restoring the autonomic dysfunction via neuromodulation. This article reviews the roles of HRV in the assessment of autonomic function and dysfunction in (i) gastroesophageal reflux (GERD), and the following FGIDs: (ii) functional dyspepsia (FD) and gastroparesis, (iii) irritable bowel syndrome (IBS) and (iv) constipation. The roles of HRV in the assessment of autonomic responses to various interventions were also reviewed. We used PUBMED, Web of Science, Elsevier/Science direct and Scopus to search the eligible studies for each disorder, which also included the keyword 'heart rate variability'. The retrieved studies were screened and filtered to identify the most suitable studies using HRV parameters to associate the autonomic function with any of the above disorders. Studies involving both human and animal models were included. Based on analyses of HRV, GERD as well as the FGIDs were found to be associated with decreased parasympathetic activity and increased sympathetic nervous system activity with the autonomic balance shifted towards the sympathetic nervous system. In addition, the HRV methods were also reported to be able to assess the autonomic responses to various interventions (mostly neuromodulation), typically the enhancement of parasympathetic activity. In summary, GERD and FGIDs are associated with impaired autonomic dysfunction, mainly due to suppressed vagal and overactive sympathetic tone, which can be assessed noninvasively using HRV.

Gastroesophageal reflux disease is associated with abnormal ventricular repolarization indices

BACKGROUND/AIMS

Gastroesophageal Reflux Disease (GERD) is a clinical entity affecting the upper gastrointestinal tract. The pathophysiology of GERD has been associated with autonomic nervous system disorders. Autonomic nervous system disturbances in GERD patients have been shown to lead to fatal ventricular arrhythmias (VAs) that result in electrical and ventricular repolarization anomalies. The maximum to terminal electrocardiographic T wave (Tpe) has been associated with repolarization of transmural dispersion. In addition, a higher Tpe interval (TpeI) and Tpe/QT ratio correspond with VAs. The goal of this report was to assess ventricular repolarization, by TpeI and Tpe/QT ratio, in GERD patients.

MATERIALS AND METHODS

The study was comprised of 46 GERD subjects and 43 healthy volunteers. TpeI, cTpe, and Tpe/Q ratios were determined from electrocardiograms and associations of the groups were compared.

RESULTS

The clinical characteristics were similar between the two groups. TpeI, corrected Tpe (cTpe) interval, and Tpe/QT ratio were higher in subjects with GERD in comparison to the control group (P<0.001, P=0.018, and P<0.001, respectively).

CONCLUSION

TpeI and Tpe/QT ratio were higher in GERD patients. Patients with GERD may have an increased risk for VAs.

Mathematical modeling and simulation in animal health. Part III: Using nonlinear mixed-effects to characterize and quantify variability in drug pharmacokinetics

A common feature of human and veterinary pharmacokinetics is the importance of identifying and quantifying the key determinants of between-patient variability in drug disposition and effects. Some of these attributes are already well known to the field of human pharmacology such as bodyweight, age, or sex, while others are more specific to veterinary medicine, such as species, breed, and social behavior. Identification of these attributes has the potential to allow a better and more tailored use of therapeutic drugs both in companion and food-producing animals. Nonlinear mixed effects (NLME) have been purposely designed to characterize the sources of variability in drug disposition and response. The NLME approach can be used to explore the impact of population-associated variables on the relationship between drug administration, systemic exposure, and the levels of drug residues in tissues. The latter, while different from the method used by the US Food and Drug Administration for setting official withdrawal times (WT) can also be beneficial for estimating WT of approved animal drug products when used in an extralabel manner. Finally, NLME can also prove useful to optimize dosing schedules, or to analyze sparse data collected in situations where intensive blood collection is technically challenging, as in small animal species presenting limited blood volume such as poultry and fish.

Gastroesophageal reflux is not associated with short-term variability of parasympathetic activity in children

PURPOSE

A lower parasympathetic activity was described in patients with the gastroesophageal reflux disease. We aimed to determine whether gastroesophageal reflux (GER) episodes are associated with a short-term parasympathetic tone variability in children.

METHODS

In order to address this question we performed simultaneous 24-h esophageal multichannel intraluminal impedance-pH and electrocardiographic monitoring in 16 children (age range 6-18 years), including 8 with asthma and 2 with gastroesophageal reflux disease. After describing duration, height, and acidity of 483 GER episodes we also measured parasympathetic-related heart rate variability parameters in 4 time periods: preceding, containing, following GER, and in-between GERs (control). High frequency (HF) power and root-mean square differences of successive R-R intervals (r-MSSD) were assessed in 2.5-min and 1-min periods, respectively.

RESULTS

We did not identify the searched short-term parasympathetic tone changes.

CONCLUSIONS

In conclusion, GER episodes and their characteristics were not associated with short-term variability of parasympathetic activity in children.

Cardiac autonomic dysfunction in patients with gastroesophageal reflux disease

AIM: To investigate autonomic nervous function in patients with a diagnosis of gastroesophageal reflux disease (GERD).

METHODS: The investigation was performed on 29 patients (14 men), aged 18-80 years (51.14 ± 18.34), who were referred to our Neurocardiology Laboratory at the Clinical and Hospital Center “Bezanijska Kosa” with a diagnosis of GERD. One hundred sixteen healthy volunteers matched in age and sex with the examinees served as the control group. The study protocol included the evaluation of autonomic function and hemodynamic status, short-term heart rate variability (HRV) analysis, 24 h ambulatory ECG monitoring with long-term HRV analysis and 24 h ambulatory blood pressure monitoring.

RESULTS: Pathologic results of cardiovascular reflex test were more common among patients with reflux compared to the control group. Severe autonomic dysfunction was detected in 44.4% of patients and in 7.9% of controls (P < 0.001). Parameters of short-term analysis of RR variability, which are the indicators of vagal activity, had lower values in patients with GERD than in the control group. Long-term HRV analysis of time-domain parameters indicated lower values in patients with reflux disease when compared to the control group. Power spectral analysis of long-term HRV revealed lower low- and high-frequency values. Detailed 24 h ambulatory blood pressure analysis showed significantly higher values of systolic blood pressure and pulse pressure in the reflux group than in the control group.

CONCLUSION: Patients with GERD have distortion of sympathetic and parasympathetic components of the autonomic nervous system, but impaired parasympathetic function appears more congruent to GERD.

Chronopharmacokinetics of drugs in toxicological aspects: A short review for pharmacy practitioners

A rough 24-hour cycle driven endogenously in biochemical, physiological or behavioral processes is called circadian rhythm. Chronobiology is the study of biological temporal rhythms. For decades, we know that the biological rhythm and the drug metabolism are also affected from daylight and chronopharmacology became recognized by scientists in the early 1970s. Its lateral branch chronocopharmacokinetics is the study of rhythmic, predictable-in-time differences in the pharmacokinetics of drugs. Chronopharmacokinetic studies are performed at every step of the biotransformation i.e., absorption, distribution, metabolism and excretion. Feeding schedules, sex and phenotype must be taken into consideration while applying pharmacotherapy to increase the efficiency and to decrease side effects. The impact of drugs on circadian rhythm should be not neglected. On the other hand, new special drug delivery systems can be used to synchronize drug concentrations according to circadian rhythms. “Chronopharmaceuticals” can identify the proper dosing time and this amelioration will lead to improved progress and diffusion of pharmacotherapy. Chronopharmaceuticals coupled with nanotechnology could be the future of drug delivery systems, and lead to safer and more efficient disease therapy in the future. In this review, we will discuss the pharmacokinetic effects of circadian rhythm and its toxicological outcomes. Besides, we will try to give some practical points for clinical pharmacist/pharmacy practitioners, concerning chronopharmacokinetics.

[Heart rate variability during sleep in children with multiple disabilities]

OBJECTIVES

To study heart rate variability during sleep in children with multiple disabilities in order to observe the behavior of the autonomic nervous system.

METHODS

The R-R interval variability of 4 to 12 years old children was recorded with a heart rate monitor during one night. Children with multiple disabilities (G1) and healthy children (G2) were compared in time, frequency, and non-linear domains.

RESULTS

Temporal (P<0.01), frequency (P<0.05), and non-linear (P<0.01) variables in the G1 were lower than in the G2 group.

DISCUSSION

The time and frequency analysis confirmed the predominance of the sympathetic nervous system during sleep in G1 children. Reduced non-linear variables can explain sleep with less informations (correlation dimension: 2.203 ± 1.239 versus 3.842 ± 0.378; P<0.001), less complex cycles of sleep (approximate entropy: 1.153 ± 0.200 versus 1.365 ± 0.099; P<0.01), and a reduced correlation in short-term variability (SD1: 42.37 ± 19.0 (ms) versus 73.44 ± 25.3; P<0.01). The fractal structure of the recordings was not affected (P>0.05). The diseases encountered are probably the reason for these findings, but the variety of disorders and medications of the children with multiple disabilities needs to be studied with a larger and more varied sample.

CONCLUSION

Sympathetic predominance during sleep in children with multiple disabilities is associated with a decrease in adaptive abilities of these children's autonomic nervous system.

Gastroesophageal reflux disease and sleep disorders: evidence for a causal link and therapeutic implications

Gastroesophageal reflux disease (GERD) and sleep disturbances are both common health problems. There is a significant association between disturbed sleep and GERD, and this may be bidirectional. Sleep disorders may induce gastrointestinal (GI) disturbances, while GI symptoms also may provoke or worsen sleep derangements. Reflux of gastric acid is a less frequent event during sleep, however, acid clearance mechanisms (including swallowing, salivation and primary esophageal motility) are impaired during sleep resulting in prolongation of acid contact time. Nighttime reflux can lead to sleep disturbance and sleep disturbance may further aggravate GERD by prolonged acid contact time and heightened sensory perception. This may facilitate the occurrence of complicated GERD and decreased quality of life. However, the interplay between sleep problems and GERD is complex, and there are still relatively limited data on this issue. Further investigation of sleep-related GERD may identify common pathophysiological themes and new therapeutic targets.

Gastroesophageal reflux disease and sleep quality in a Chinese population

BACKGROUND/PURPOSE

Although evidence suggests that gastroesophageal reflux disease (GERD) may interrupt sleep, the effects of symptomatic and endoscopically diagnosed GERD remain elusive because the patient population is heterogeneous. Accordingly, we designed a cross-sectional study to assess their association.

METHODS

Consecutive participants in a routine health examination were enrolled. Definition and severity of erosive esophagitis were assessed using the Los Angeles classification system. Demographic data, reflux symptoms, sleep quality and duration, exercise amount, alcohol consumption, and smoking habits were recorded. Factors affecting sleep quality and sleep duration were revealed by a polytomous logistic regression analysis.

RESULTS

A total of 3663 participants were recruited. Subjects with reflux symptoms, female gender, higher body mass index, and regular use of hypnotics had poorer sleep quality. Exercise was associated with better sleep quality. Either symptomatically or endoscopically, GERD did not disturb sleep duration. Among the 3158 asymptomatic patients, those with erosive esophagitis were more likely to have poor sleep quality. The risk increased with the severity of erosive changes (p = 0.03).

CONCLUSION

The present study highlights the adverse effect of gastroesophageal reflux on sleep, even in the absence of reflux symptoms. This finding has therapeutic implications in patients with silent erosive disease, and future trials are warranted.

Developments in pathogenesis and diagnosis of gastroesophageal reflux disease

PURPOSE OF REVIEW

Although gastroesophageal reflux is a common disorder, diagnosis is still imprecise. Moreover, its pathogenesis is incompletely understood. This review summarizes recent progress in diagnosis and our understanding of the pathogenesis of gastroesophageal reflux disease.

RECENT FINDINGS

Recent studies have focused on the pattern of reflux in the distal esophagus, just above the esophago-gastric junction, challenging its importance on the genesis of reflux symptoms. New techniques, such as impedance, could improve the diagnostic yield, especially in patients with nonacid reflux. Esophageal sensitivity and motility, transient lower esophageal sphincter relaxations, and hiatus hernia are important pathogenic mechanisms of reflux disease. Studies showed that obesity plays a role in the pathogenesis of reflux symptoms; a disruption of the esophago-gastric junction (leading to hiatus hernia) could allow reflux to occur. The association between reflux (particularly nonacid) and extraesophageal manifestations of gastroesophageal reflux disease has been further evaluated.

SUMMARY

Improvement of diagnostic techniques and better understanding of the pathogenesis of reflux may lead to new or better therapeutic modalities. Our understanding of some of the risk factors for reflux has been increased. Extra-esophageal manifestations and their association with gastroesophageal reflux are still a very controversial and promising area of research.