Jun Tayama

Effect of a corticotropin releasing hormone receptor antagonist on colonic sensory and motor function in patients with irritable bowel syndrome

Background and aims: Corticotropin releasing hormone (CRH) is a major mediator of the stress response in the brain-gut axis. Irritable bowel syndrome (IBS) is presumed to be a disorder of the brain-gut link associated with an exaggerated response to stress. We hypothesised that peripheral administration of α-helical CRH (αhCRH), a non-selective CRH receptor antagonist, would improve gastrointestinal motility, visceral perception, and negative mood in response to gut stimulation in IBS patients. Methods: Ten normal healthy subjects and 10 IBS patients, diagnosed according to the Rome II criteria, were studied. The tone of the descending colon and intraluminal pressure of the sigmoid colon were measured at baseline, during rectal electrical stimulation (ES), and at recovery after administration of saline. Visceral perception after colonic distension or rectal ES was evaluated as threshold values on an ordinate scale. The same measurements were repeated after administration of αhCRH (10 μg/kg). Results: ES induced significantly higher motility indices of the colon in IBS patients compared with controls. This response was significantly suppressed in IBS patients but not in controls after administration of αhCRH. Administration of αhCRH induced a significant increase in the barostat bag volume of controls but not in that of IBS patients. αhCRH significantly reduced the ordinate scale of abdominal pain and anxiety evoked by ES in IBS patients. Plasma adrenocorticotropic hormone and serum cortisol levels were generally not suppressed by αhCRH. Conclusion: Peripheral administration of αhCRH improves gastrointestinal motility, visceral perception, and negative mood in response to gut stimulation, without affecting the hypothalamo-pituitary-adrenal axis in IBS patients.

Higher Brachial-Ankle Pulse Wave Velocity Is Associated with More Advanced Carotid Atherosclerosis in End-Stage Renal Disease

Brachial-ankle pulse wave velocity is a new measure of arterial stiffness. We examined whether higher brachial-ankle pulse wave velocity is associated with more advanced carotid atherosclerosis and left ventricular hypertrophy in patients with end-stage renal disease, and whether this effect would be mediated by the influence of wave reflection on central arterial pressure. In 68 patients with end stage renal disease, we examined blood pressures, brachial-ankle pulse wave velocity and the augmentation index of the left common carotid artery, a measure of the impact of wave reflection on the systolic peak in central arteries. The degree of carotid atherosclerosis was quantified by a plaque score and maximum intimal-medial thickness. Echocardiography was used to determine the left ventricular mass index. In simple regression analysis, brachial-ankle pulse wave velocity was correlated with both plaque score and maximum intimal-medial thickness (r=0.420, p<0.001 and r=0.452, p<0.0005, respectively) but not with left ventricular mass index. Multiple regression analysis was performed with the plaque score or maximum intimal-medial thickness as the dependent variable and brachial-ankle pulse wave velocity and known clinical risk factors as the independent variables. The brachial-ankle pulse wave velocity was an independent risk factor for both plaque score (β=0.006, p=0.004) and maximum intimal-medial thickness (β=0.008, p=0.04). Independent risk factors for left ventricular mass index were left ventricular diastolic dimension (β=3.509, p=0.000007) and augmentation index (β=0.580, p=0.04). The brachial-ankle pulse wave velocity was unrelated to augmentation index in patients with end stage renal disease. In conclusion, higher brachial-ankle pulse wave velocity was found to be a risk factor for carotid atherosclerosis in patients with end-stage renal disease; this effect was independent of the influence of wave reflection on central arterial pressure. The brachial-ankle pulse wave velocity was unrelated to left ventricular structure.

Higher plasma homocysteine concentration is associated with more advanced systemic arterial stiffness and greater blood pressure response to stress in hypertensive patients.

Hyperhomocysteinemia has been reported to be associated with both vascular structure alteration and increased cardiovascular risk. This study examined whether hyperhomocysteinemia causes increased systemic arterial stiffness, thereby enhancing blood pressure response to stress in hypertensive patients. In 50 treated hypertensive patients, we studied brachial-ankle pulse wave velocity (PWV), a new measure for arterial stiffness, blood pressure response to stress, and blood pressure recovery after stress. Autonomic nervous activities were examined by spectral analysis of blood pressure and RR interval variabilities. Total plasma homocysteine and neurohumoral parameters were determined from fasting blood. Brachial-ankle PWV correlated with age (r=0.64, p<0.001), plasma homocysteine concentration (r=0.35, p<0.05), and systolic blood pressure (SBP) (r=0.62, p<0.001). Higher plasma homocysteine concentration was independently associated with greater brachial-ankle PWV (β=0.388, p=0.01). We classified the subjects into high homocysteine (7.3 nmol/ml or over) and low homocysteine (7.2 nmol/ml or below) groups. Baseline SBP, plasma renin activity, aldosterone, and norepinephrine concentrations were similar between the two groups. However, the SBP values during stress and the recovery periods were higher in the high homocysteine group than the low homocysteine group even after adjusting for sex and age. The behavior of sympathetic vasomotor activity did not differ between the two groups. These data suggest that higher plasma homocysteine concentration is associated with increased systemic arterial stiffness, which may enhance blood pressure reactivity to stress in hypertensive patients.

Brachial-Ankle Pulse Wave Velocity as a Novel Measure of Arterial Stiffness: Present Evidences and Perspectives

Atherosclerotic cardiovascular disease is a leading cause of death in most developed countries. Cardiovascular risk factors such as hypertension, diabetes, and dyslipidemia initiate structural and functional abnormalities in the arterial wall, leading to the development of atherosclerosis. Atherosclerosis is characterized by the stiffening and/or thickening of the arterial wall. Aortic pulse wave velocity as evaluated by carotid and femoral arterial waves is the most established measure for arterial stiffness. Recently, a new arterial stiffness measure using brachial and tibial arterial waves has been developed. The measurement of the brachial-ankle wave velocity is fully automatic, needs no skill and is reproducible. Age and blood pressure are robust independent predictors for the brachial-ankle pulse wave velocity. Recent studies have shown that higher brachial ankle pulse wave velocity is associated with more advanced atherosclerotic changes of the arterial wall not only in the clinical patients but also in subclinical individuals. Thus, brachial-ankle pulse wave velocity may be a useful measure of vascular damage, which predisposes individuals to cardiovascular events. A multicenter trial examining the prognostic significance of the brachial-ankle pulse wave velocity is presently in progress.

Effects of personality traits on the manifestations of irritable bowel syndrome

ObjectivePrevious studies have reported that patients with irritable bowel syndrome (IBS) show high neuroticism. However, the precise association between the IBS subtypes and the degree of neuroticism in younger populations is largely unknown. We tested our hypothesis that subjects with diarrhea-predominant IBS may have a higher degree of neuroticism than subjects without IBS or those with other subtypes of IBS. We also verified the additional hypothesis that the severity of neuroticism might be correlated with the severity of IBS in younger populations.MethodsWe conducted a cross-sectional survey of 557 university students, ranging in age from 18 to 21 years. Presence/ absence of IBS and determination of the IBS subtype was by the Rome II Modular Questionnaire, while the severity of IBS was determined by the IBS severity index (IBS-SI). The degree of neuroticism was evaluated using the Maudsely Personality Inventory (MPI). The presence/absence of psychological distress was measured with the K6 scale.ResultsNeuroticism scores in the subjects with diarrhea-predominant IBS were significantly higher than those in the non-IBS subjects or subjects with constipation-predominant IBS. The neuroticism scores were significantly correlated with the IBS-SI scores in all subjects with IBS.ConclusionThese results suggest that neuroticism is involved in the pathophysiology of IBS in young subjects, especially in that of the diarrhea-predominant subtype.

Effect of baseline self-efficacy on physical activity and psychological stress after a one-week pedometer intervention

Physical activity and psychological stress were hypothesized to improve more in participants with high self-efficacy than in those with low and medium self-efficacy, after a one-week intervention. 39 female university students participated. The intervention had two steps: a lecture on self-monitoring and goal setting (160 min.) and a one-week pedometer intervention. Analyses were conducted on tertile groups according to self-efficacy at baseline. Pedometer step counts were higher in the high self-efficacy group than in the low self-efficacy group after intervention. Helplessness decreased time dependently after intervention only in the high-self-efficacy group. Because physical activity improved more in the high self-efficacy group after a one-week intervention, one hypothesis was supported.

Impact of Helicobacter pylori Immunoglobulin G Levels and Atrophic Gastritis Status on Risk of Metabolic Syndrome

Background Helicobacter pylori (HP) infection is implicated in gastric and extra-gastric diseases. While gastritis-related chronic inflammation represents a known trigger of metabolic disturbances, whether metabolic syndrome (MetS) is affected by gastritis status remains unclear. We aimed to clarify the effect of HP-related gastritis on the risk of MetS. Materials and Methods We retrospectively enrolled patients undergoing screening for MetS between 2014 and 2015. Investigations included HP-specific immunoglobulin G (IgG) antibody assays to detect HP infection, and serum pepsinogen assays to evaluate atrophic gastritis status. The risk of MetS was evaluated via multiple logistic regression analyses with two covariates: serum HP infection status (IgG levels) and atrophic gastritis status (two criteria were applied; pepsinogen I/II ratio < 3 or both pepsinogen I levels ≤ 70 μg/L and pepsinogen I/II ratio < 3). Results Of 1,044 participants, 247 (23.7%) were HP seropositive, and 62 (6.0%) had MetS. HP seronegative and seropositive patients had similar risks of MetS. On the other hand, AG (defined in terms of serum PG I/II <3) was significant risk of MetS (OR of 2.52 [95% CI 1.05–7.52]). After stratification according to HP IgG concentration, patients with low HP infection status had the lowest MetS risk (defined as an odds ratio [OR] adjusted for age, sex, smoking, drinking and physical activity status). Taking this result as a reference, patients with negative, moderate, and high HP infection status had ORs (with 95% confidence intervals [CI]) of 2.15 (1.06–4.16), 3.69 (1.12–16.7), and 4.05 (1.05–26.8). Conclusions HP-associated gastritis represents a risk factor for MetS. Research should determine why low and not negative HP infection status is associated with the lowest MetS risk.

Working Long Hours is Associated with Higher Prevalence of Diabetes in Urban Male Chinese Workers: The Rosai Karoshi Study

We investigated the relationship between number of weekly working hours and the prevalence of diabetes in the urban Chinese population. Data regarding anthropometric measurements, fasting blood glucose level and number of hours worked per week were collected from 2228 workers in Shanghai, China (Mage  = 44 years; 64% men). Participants were divided into three groups according to the number of hours worked per week (<45, 45-54 and ≥55), and multiple logistic regression analysis was conducted with diabetes as the dependent variable. Subjects with a HbA1c of 6.5% or above or those prescribed anti-diabetic medications were defined as having diabetes. The multivariate adjusted odds ratio for having diabetes was found to be significantly higher for those who worked ≥55 h per week compared with those who worked <45 h per week, but only for men. This finding indicates that working long hours could be a risk factor for diabetes in Chinese male workers.

Maladjustment to Academic Life and Employment Anxiety in University Students with Irritable Bowel Syndrome

The present study tested our hypothesis that university students with irritable bowel syndrome (IBS) may experience less satisfactory academic lives than those of students without IBS. We also verified the hypothesis that university students with IBS might have higher employment anxiety than students without IBS might. We conducted a cross-sectional study of 1,686 university students. Presence or absence of IBS was assessed via the Rome III Questionnaire. Two original items were used to evaluate academic life. The prevalence rates of IBS with diarrhea, IBS with constipation, mixed IBS, and unsubtyped IBS in the study population were 5%, 2%, 10%, and 3%, respectively. Regarding academic life, the proportions of participants who experienced maladjustment and employment anxiety were 29% and 50%, respectively. After adjusting for age, sex, and faculty, the odds ratios for maladjustment and employment anxiety were significantly higher in students who screened positively, relative to those who screened negatively, for IBS (OR, 1.62; 95% CI, 1.24–2.21; OR, 2.16; 95% CI, 1.68–2.81, respectively). In conclusion, maladjustment and anxiety over future employment were higher in university students with IBS relative to those without.

Intra-abdominal fat accumulation is a hypertension risk factor in young adulthood: A cross-sectional study

AbstractAccumulation of intra-abdominal fat is related to hypertension. Despite this, a relationship between hypertension and intra-abdominal fat in young adulthood is not clear. In this study, we verify whether intra-abdominal fat accumulation increases a hypertension risk in young adult subjects.In a cross-sectional study, intra-abdominal fat area was measured using a dual bioelectrical impedance analysis instrument in 697 university students (20.3 ± 0.7 years, 425 men). Blood pressure and anthropometric factors were measured. Lifestyle variables including smoking, drinking, physical activity, and eating behavior were assessed with questionnaire. High blood pressure risk (systolic blood pressure ≥130 mm Hg and/or diastolic blood pressure ≥85 mm Hg) with increasing intra-abdominal fat area was evaluated.Participants were divided into 5 groups according to their intra-abdominal fat area (⩽24.9, 25–49.9, 50–74.9, 75–99.9, and ≥100 cm2). As compared with the values of the smallest intra-abdominal fat area group, the crude and lifestyle-adjusted odds ratios (ORs) were elevated in larger intra-abdominal fat area groups [OR 1.31, 95% confidence interval (CI) 0.66–2.80; OR 3.38, 95% CI 1.60–7.57; OR 7.71, 95% CI 2.75–22.22; OR 18.74, 95% CI 3.93–105.64, respectively). The risk increase was observed only in men.Intra-abdominal fat accumulation is related to high blood pressure in men around 20 years of age. These results indicate the importance of evaluation and reduction of intra-abdominal fat to prevent hypertension.