Comparison of Heart Rate Variability in Thai Older Adults with Hypertension, Pre-Hypertension, and Normotension.

Objectives: This study aims to compare HRV variables across three cohorts: normotensive (NT), prehypertensive (pre-HT), and hypertensive (HT) and to assess the relationship between the blood pressure (BP) and HRV parameters. Methods: Employing a cross-sectional design, 64 older participants were categorized based on the Joint National Committee's criteria into NT (n = 10), pre-HT (n = 33), and HT (n = 21) groups. Anthropometric data, lipid profiles, and HRV indices were evaluated. HRV data were obtained from the Polar V800 chest strap device using HRV Kubios software for data analysis of short-term recordings lasting 10 minutes. This analysis encompasses both time and frequency domain assessments. The time domain includes the standard deviation of NN intervals (SDNN), the root mean square of successive RR interval differences (RMSSD), and the percentage of successive RR intervals differing by over 50 ms (pNN50). The frequency domain includes low frequency (LF), high frequency (HF), and the ratio of LF-to-HF power (LF/HF). Data were statistically analyzed via one-way analysis of variance (ANOVA) and Pearson correlation. Results: The HT group exhibited significantly lower values in SDNN, pNN50, LF power, and HF power in comparison to the NT group (P < 0.05). Moreover, the HT group had a significantly lower SDNN value compared to the pre-HT group (P < 0.05). Inverse associations were uncovered between systolic and diastolic blood pressure and SDNN, pNN50, and HF power (P < 0.05). Multiple regression further highlighted the significance of systolic and pulse pressure concerning HF power (P < 0.05). Conclusions: HRV indices are reduced in Thai older adults with HT compared with those with NT. Monitoring HRV in older adults can provide valuable insights into autonomic function and cardiovascular disease risk.

Daily Step Count and its Association with Arterial Stiffness Parameters in Older Adults.

BACKGROUND: Daily step count is a simple parameter for assessing physical activity. However, the potential advantages of setting daily step goals below the traditional 10,000-step threshold remain unclear. The cross-sectional study aimed to determine the relationship between daily step counts and arterial stiffness outcomes in older individuals. METHODS: Forty-eight older adults recorded their daily step counts over a 7-day period using a pedometer. The participants were classified into two groups based on their daily step count: Group 1 (n = 28) consisted of individuals taking fewer than 5000 steps per day, while Group 2 (n = 20) included those who recorded 5,000 to 9,999 steps per day. To evaluate arterial stiffness parameters, we measured pulse wave velocity (PWV), cardio-ankle vascular index (CAVI), and ankle-brachial index (ABI). Hemodynamic and biochemical parameters were also determined. RESULTS: Participants who accumulated fewer daily steps exhibited higher PWV compared to each group. An inverse association was observed between average steps per day and PWV. However, no significant differences were found between daily step counts and CAVI or ABI. CONCLUSION: Conclusions: As individuals increase their daily step count, they may experience a reduction in arterial stiffness. Consequently, the assessment of daily steps has benefits for enhancing vascular health and overall well-being among older individuals.

A novel model of adenine-induced chronic kidney disease-associated gastrointestinal dysfunction in mice: The gut-kidney axis.

Although constipation is a common complication of chronic kidney disease (CKD), there is no animal model that can be used to study the association between renal impairment and gastrointestinal function without interfering with the gastrointestinal tract of the model. Therefore, we determined whether adenine could induce CKD in association with gastrointestinal dysfunction. Six-week-old ICR mice were intraperitoneally injected with saline, 25, 50, or 75 mg adenine/kg body weight for 21 days. Blood urea nitrogen (BUN), plasma creatinine, and renal histopathology were evaluated. Defecation status was evaluated from defecation frequency and fecal water content. Colonic smooth muscle contraction was measured by the organ bath technique, and transepithelial electrical resistance (TEER) was measured using an Ussing chamber. In the 50 mg/kg treatment group, BUN and creatinine were significantly increased compared with control, and inflammatory cell infiltration, glomerular necrosis, tubular dilatation, and interstitial fibrosis were observed in renal tissues. Mice in this group also showed a significant decrease in defecation frequency, fecal water content, colonic motility index, and TEER. Overall, 50 mg/kg of adenine was the best dose to induce CKD with associated constipation and intestinal barrier impairment. Therefore, this adenine administration model can be recommended for CKD-associated gastrointestinal dysfunction research.

Impact of Fasting Blood Glucose Levels on Blood Pressure Parameters among Older Adults with Prediabetes.

Prediabetes mellitus (pre-DM) is defined as blood glucose levels higher than normal but lower than the threshold for diabetes mellitus (DM) diagnosis. Four-limb blood pressure (BP) differences can help identify a significant risk for cardiovascular diseases (CVDs). The current study aimed to determine the importance of BP and the ankle-brachial index (ABI) between two patient groups and the association between fasting blood glucose (FBG) levels and four-limb BP, ABI, interarm BP difference (IAD), and interleg BP difference (ILD). Moreover, the effect of cardiovascular risk factors on the development of pre-DM among older adults was evaluated. The participants were divided into the normal fasting glucose (NFG) and impaired fasting glucose (IFG) groups. Data on physical characteristics, lipid profiles, four-limb BP, ABI, IAD, ILD, and cardiovascular risk factors were assessed. The IFG group had a significantly higher systolic blood pressure (SBP) and pulse pressure than the NFG group (p < 0.05). SBP was significantly positively correlated with FBG levels (p < 0.05). The IFG group had a lower ABI than the NFG group (p < 0.05). However, there was no significant difference in terms of IAD and ILD between the two groups. Furthermore, hypertension (HT), metabolic syndrome (MetS), and dyslipidemia were significantly correlated with a high prevalence of prediabetes (p < 0.05). Individuals with prediabetes had a higher BP than those with normoglycemia. Prediabetes was correlated with HT, MetS, and dyslipidemia.

Sargassum plagiophyllum Extract Enhances Colonic Functions and Modulates Gut Microbiota in Constipated Mice.

Constipation is a symptom that is widely found in the world's population. Various dietary supplementations are used to relieve and prevent constipation. Seaweed is widely used for its health benefits. In this study, we aimed to investigate the effects of Sargassum plagiophyllum extract (SPE) on functions of the gastrointestinal tract and gut microbiota. The results show that SPE pretreatment increased the frequency of gut contraction, leading to reduce gut transit time. SPE pretreatment also significantly increased the secretion of Cl− and reduced Na+ absorption, increasing fecal water content in constipated mice (p < 0.05). In addition, the Bifidobacteria population in cecal contents was significantly higher in constipated mice pretreated with 500 mg/kg SPE for 14 days than in untreated constipated mice (p < 0.05). Our findings suggest that SPE can prevent constipation in loperamide-induced mice. This study may be useful for the development of human food supplements from S. plagiophyllum, which prevent constipation.

Aortic Pulse Wave Velocity, Ankle-Brachial Index, and Malondialdehyde in Older Adults with or without Metabolic Syndrome.

Metabolic syndrome is an important health problem associated with both subclinical atherosclerosis and an increased risk of cardiovascular disease and it leads to an elevated total mortality. Aortic pulse wave velocity (aPWV) is widely used for noninvasive assessment of arterial stiffness. Ankle-brachial index (ABI) predicts peripheral arterial disease (PAD) of the lower extremities. In addition, malondialdehyde (MDA) is thought to be involved in the development of arterial stiffness. The present study aimed to: (1) compare aPWV, ABI, and MDA between participants with MetS and those without MetS and (2) investigate the correlation of aPWV and ABI with the components of MetS and MDA. A total of 48 Thai elderly subjects were divided into 2 groups (MetS and non-MetS) according to the parameters set by the International Diabetes Federation (IDF). aPWV and ABI were measured using the VaSera VS-1500 system (Fukuda Denshi Co., Tokyo, Japan). MDA was determined by spectrophotometry. aPWV and MDA were significantly higher in the MetS group compared to the participants in the non-MetS group (9.33 ± 2.72 vs. 7.95 ± 1.37 m/s, p = 0.03, and 0.74 ± 0.71 vs. 0.45 ± 0.20 µmol, p = 0.02, respectively). However, ABI did not differ between the groups. Analysis of the risk factors of aPWV in each group revealed that there were no statistical associations between the components of MetS and MDA and aPWV in both the MetS and the non-MetS groups. A high aPWV is more prevalent among patients with MetS than among those without MetS. Monitoring of aPWV might help to explore potential detection of vascular damage in the elderly.

P2Y6 receptors are involved in mediating the effect of inactivated avian influenza virus H5N1 on IL-6 & CXCL8 mRNA expression in respiratory epithelium.

One of the key pathophysiologies of H5N1 infection is excessive proinflammatory cytokine response (cytokine storm) characterized by increases in IFN-ß, TNF-α, IL-6, CXCL10, CCL4, CCL2 and CCL5 in the respiratory tract. H5N1-induced cytokine release can occur via an infection-independent mechanism, however, detail of the cellular signaling involved is poorly understood. To elucidate this mechanism, the effect of inactivated (ß-propiolactone-treated) H5N1 on the cytokine and chemokine mRNA expression in 16HBE14o- human respiratory epithelial cells was investigated. We found that the inactivated-H5N1 increased mRNA for IL-6 and CXCL8 but not TNF-α, CCL5 or CXCL10. This effect of the inactivated-H5N1 was inhibited by sialic acid receptor inhibitor (α-2,3 sialidase), adenosine diphosphatase (apyrase), P2Y receptor (P2YR) inhibitor (suramin), P2Y6R antagonist (MRS2578), phospholipase C inhibitor (U73122), protein kinase C inhibitors (BIM and Gö6976) and cell-permeant Ca2+ chelator (BAPTA-AM). Inhibitors of MAPK signaling, including of ERK1/2 (PD98059), p38 MAPK (SB203580) and JNK (SP600125) significantly suppressed the inactivated-H5N1-induced mRNA expression of CXCL8. On the other hand, the inactivated-H5N1-induced mRNA expression of IL-6 was inhibited by SB203580, but not PD98059 or SP600125, whereas SN-50, an inhibitor of NF-κB, inhibited the effect of virus on mRNA expression of both of IL-6 and CXCL8. Taken together, our data suggest that, without infection, inactivated-H5N1 induces mRNA expression of IL-6 and CXCL8 by a mechanism, or mechanisms, requiring interaction between viral hemagglutinin and α-2,3 sialic acid receptors at the cell membrane of host cells, and involves activation of P2Y6 purinergic receptors.