Reflux hypersensitivity (RH) is one of the phenotypes of gastroesophageal reflux disease. The latest Rome IV defines RH as a condition with typical reflux symptoms and positive reflux-symptom association despite normal acid exposure. Subsequently, the Lyon consensus proposed detailed cutoff values for the criteria on the basis of experts’ consensus. Rome IV brought a clear-cut perspective into the pathophysiology of gastroesophageal reflux disease and the importance of esophageal hypersensitivity. This perspective can be supported by the fact that other functional gastrointestinal disorders such as irritable bowel syndrome and functional dyspepsia often overlap with RH. Although several possible pathophysiological mechanisms of esophageal hypersensitivity have been identified, there is still unmet medical needs in terms of treatment for this condition. This review summarizes the current knowledge regarding RH.

BACKGROUND: Aging is a process that increases oxidative stress. Increased oxidative stress leads to the development of atherosclerosis and mitochondrial dysfunction. Mitochondria contribute to energy production that might have a beneficial influence on maintaining muscle strength. Therefore, the height-related single nucleotide polymorphism (SNP) rs17081935, which is also reported to be associated with mitochondrial metabolism, might be associated with reduced muscle strength and this association might be affected by atherosclerosis status. To clarify those associations, a cross-sectional study of 1374 elderly Japanese individuals aged 60-89 years was conducted. METHODS: Logistic regression was used to clarify the association between rs17081935 and reduced handgrip strength. Since atherosclerosis might affect handgrip strength, participants were stratified by atherosclerosis status. Reduced handgrip strength was defined as being in the lowest quintile of handgrip strength (< 25.6 kg for men and < 16.1 kg for women). RESULTS: No significant associations were found between a minor allele of rs17081935 and reduced handgrip strength among elderly participants without atherosclerosis. A significant inverse association was observed among elderly participants with atherosclerosis. After adjusting for known cardiovascular risk factors and height, the adjusted odd ratio (OR) and 95% confidence interval (CI) for reduced handgrip strength and a minor allele of rs17081935 were 1.13 (0.86, 1.43) for elderly participants without atherosclerosis and 0.55 (0.36, 0.86) for those with atherosclerosis, respectively. CONCLUSION A minor allele of the height-related SNP rs17081935 was significantly inversely associated with reduced handgrip strength among older individuals with atherosclerosis, but not among those without atherosclerosis.
Aged ; Aged, 80 and over ; Atherosclerosis/epidemiology* ; Body Height ; Cross-Sectional Studies ; Female ; Hand Strength ; Humans ; Japan/epidemiology* ; Male ; Middle Aged ; Polymorphism, Single Nucleotide ; Prevalence

BACKGROUND: Human T-cell leukemia virus type 1 (HTLV-1) activates inflammatory cascades by activating the NF-κB pathway. The minor allele of single nucleotide polymorphism (SNP) in breast cancer suppressor BRCA1-associated protein (BRAP), which has a common etiology with HTLV-1 infection, has been reported to be positively associated with carotid atherosclerosis, but inversely associated with hypertension. Therefore, HTLV-1 infection may be inversely associated with hypertension by activating endothelial maintenance, including atherosclerosis. To clarify these associations, a cross-sectional study was conducted using 2989 Japanese individuals aged 60-99 years participating in a general health check-up. METHODS: Logistic regression models were used to clarify the association between HTLV-1 and hypertension. Platelet levels stratified analyses were also performed since platelet production, which plays a crucial role in endothelium maintenance, can be stimulated by activating the NF-κB pathway. RESULTS: HTLV-1 infection was found to be significantly inversely associated with hypertension, particularly in subjects with high platelet levels (≥ second tertiles of platelet levels); the fully adjusted odds ratios (ORs) and 95% confidence intervals (CIs) were 0.75 (0.62, 0.92) for total and 0.64 (0.50, 0.82) for high platelet levels, respectively. Further analysis of the non-hypertensive subjects demonstrated that HTLV-1 infection was significantly positively associated with atherosclerosis in subjects with the highest tertile of platelet levels (2.11 [1.15, 3.86]) but not in subjects with low platelet levels (first and second tertiles of platelet level) (0.89 [0.57, 1.39]). CONCLUSION Asymptomatic HTLV-1 infection is inversely associated with hypertension, possibly by activating endothelial maintenance, including atherosclerosis progression.
Aged ; Aged, 80 and over ; Carotid Artery Diseases/virology* ; Cross-Sectional Studies ; Female ; HTLV-I Infections/complications* ; Human T-lymphotropic virus 1/physiology* ; Humans ; Hypertension/virology* ; Japan/epidemiology* ; Male ; Middle Aged

BACKGROUND: A positive association between handgrip strength and blood pressure has been reported. Since these factors are linked to the condition of the endothelium, the activity of endothelial repair might influence the association between handgrip strength and hypertension. METHODS: A cross-sectional study was conducted with 257 Japanese men aged 60-69 years who underwent an annual health checkup. As individuals with high level of circulating CD34-positive cells might show active endothelial repair, which plays an important role in vascular homeostasis, participants were stratified by circulating CD34-positive cell levels, using the median value of this population (0.96 cells/μL) as the cutoff. RESULTS: Independent of known cardiovascular risk factors, for participants with a high CD34-positive cell, handgrip strength is significantly positively associated with hypertension (odds ratio and 95% confidence interval of hypertension for 1 standard deviation increment of handgrip strength were 1.85 (1.19, 2.88) but not for participants with a low CD34-positive cell (0.91 (0.61, 1.37)). CONCLUSION The positive association between handgrip strength and hypertension is limited to high CD34-positive cells. This result may help clarify the role of vascular homeostasis in maintaining muscle strength.

Background/Aims: Belching is the act of expelling gas from the stomach or esophagus noisily through the oral cavity. Although it is a physiological phenomenon, belching may also be a symptom of upper gastrointestinal diseases such as reflux esophagitis and functional dyspepsia (FD). A detailed epidemiology of belching has not yet been reported. The aim of this study is to examine the prevalence and clinical characteristics of clinically significant belching (CSB) in adults. Methods: We analyzed 1998 subjects who visited the hospital for annual health checkups. Belching was evaluated by a simple question “Do you burp a lot?” and scored as 0 (never), 1 (occasionally), 2 (sometimes), 3 (often), or 4 (always). Subjects with CSB were defined ashaving scores ≥ 3. We also collected the clinical parameters, endoscopic findings, and data according to the Athens Insomnia Scale, Rome IV questionnaire, and Hospital Anxiety and Depression Scale (HADS). Results: Of the 1998 subjects, 121 (6.1%) had CSB. Subjects with CSB had FD more commonly than reflux esophagitis, but presence of heartburn was high (10.7% vs 3.1%). In addition, the HADS and Athens Insomnia Scale scores in subjects with CSB were significantly higher than those in subjects without CSB. Presence of heartburn (OR, 2.07; 95% CI, 1.05-4.09), presence of FD (OR, 2.12; 95% CI, 1.33-3.36), anxiety/depression (OR, 2.29; 95% CI 1.51-3.45), and sleep disturbances (OR, 1.73; 95% CI, 1.14-2.61) were significantly associated with CSB. Conclusion The detailed epidemiology of belching in the general adult population was clarified.

Background/Aims: Belching is the act of expelling gas from the stomach or esophagus noisily through the oral cavity. Although it is a physiological phenomenon, belching may also be a symptom of upper gastrointestinal diseases such as reflux esophagitis and functional dyspepsia (FD). A detailed epidemiology of belching has not yet been reported. The aim of this study is to examine the prevalence and clinical characteristics of clinically significant belching (CSB) in adults. Methods: We analyzed 1998 subjects who visited the hospital for annual health checkups. Belching was evaluated by a simple question “Do you burp a lot?” and scored as 0 (never), 1 (occasionally), 2 (sometimes), 3 (often), or 4 (always). Subjects with CSB were defined ashaving scores ≥ 3. We also collected the clinical parameters, endoscopic findings, and data according to the Athens Insomnia Scale, Rome IV questionnaire, and Hospital Anxiety and Depression Scale (HADS). Results: Of the 1998 subjects, 121 (6.1%) had CSB. Subjects with CSB had FD more commonly than reflux esophagitis, but presence of heartburn was high (10.7% vs 3.1%). In addition, the HADS and Athens Insomnia Scale scores in subjects with CSB were significantly higher than those in subjects without CSB. Presence of heartburn (OR, 2.07; 95% CI, 1.05-4.09), presence of FD (OR, 2.12; 95% CI, 1.33-3.36), anxiety/depression (OR, 2.29; 95% CI 1.51-3.45), and sleep disturbances (OR, 1.73; 95% CI, 1.14-2.61) were significantly associated with CSB. Conclusion The detailed epidemiology of belching in the general adult population was clarified.