Background/Objectives: Trimethylamine N-oxide (TMAO), a gut microbiota-derived metabolite influenced by diet, has been linked to cardiovascular disease. Endothelial dysfunction, an early sign of vascular damage, is common in hypertension. This study examined the relationship between serum TMAO levels and endothelial function, assessed by the vascular reactivity index (VRI), in patients with hypertension. Methods: In total, 110 patients with hypertension were enrolled. Fasting serum TMAO was measured using high-performance liquid chromatography–mass spectrometry. Endothelial function was evaluated via digital thermal monitoring, with VRI categorized as good (>2.0), intermediate (1.0–1.9), or poor (<1.0). Results: Of the participants, 10 (9.1%) exhibited poor vascular reactivity, 57 (51.8%) had intermediate reactivity, and 43 (39.1%) exhibited good vascular reactivity. Poor reactivity correlated with older age (p = 0.010), higher total cholesterol (p = 0.007), low-density lipoprotein cholesterol (p = 0.009), and higher TMAO levels (p < 0.001). In multivariate forward stepwise linear regression, the log-transformed TMAO level (log-TMAO) remained independently and inversely associated with VRI (p < 0.001). Logistic regression analyses demonstrated that elevated TMAO concentrations were significantly associated with an increased likelihood of vascular reactivity dysfunction (intermediate and poor groups combined; odds ratio [OR] = 1.10, 95% confidence interval [CI]: 1.047–1.155; p < 0.001) and, in particular, with poor vascular reactivity (OR = 1.58, 95% CI: 1.002–2.492; p = 0.049). Conclusions: Elevated serum TMAO is independently associated with endothelial dysfunction in hypertension.

Insertion of a double-lumen endotracheal tube (DLT) is the most commonly used method for one-lung ventilation (OLV). This meta-analysis was aimed at investigating the performance of lung ultrasound in assessing the DLT position in OLV. Electronic databases were searched for related trials from inception to October 2022. The primary outcome was the performance of ultrasound or clinical evaluation in confirming the correctness of the DLT position, using fiberoptic bronchoscopy or intraoperative direct visualization of lung collapse as the gold standard. The secondary outcome was the time required to confirm or adjust the DTL position. Five randomized controlled trials and three observational studies involving 771 patients were included in the meta-analysis. The pooled sensitivity and specificity of ultrasound were 0.93 (95% confidence interval [CI]: 0.79–0.98) and 0.61 (95% CI: 0.41–0.77), respectively, while those of clinical evaluation were 0.93 (95% CI: 0.73–0.99) and 0.35 (95% CI: 0.25–0.47), respectively. The pooled procedure duration was 122.27 s (95% CI: 20.85–223.69) with ultrasound and 112.03 s (95% CI: 95.30–128.76) with clinical evaluation. The area under the curve for discriminating the DLT position was 0.86 (95% CI: 0.82–0.88) for ultrasound and 0.52 (95% CI: 0.48–0.57) for clinical evaluation. Compared to clinical evaluation, ultrasound has a similar sensitivity but a better specificity for confirming the correctness of the DLT position. Ultrasound is an acceptable imaging tool for assessing DTL placement in OLV.

Background/Objectives: Phenylacetylglutamine (PAG), a gut microbiota-derived metabolite, may contribute to the development of cardiometabolic diseases. The diagnostic value of PAG for vascular dysfunction in hemodialysis (HD) remains unclear. This study assessed how serum PAG levels relate to carotid–femoral pulse wave velocity (cfPWV), which is a validated index of aortic stiffness, in patients on maintenance HD. Methods: A total of 138 patients on maintenance HD were enrolled. Participants with cfPWV values greater than 10 m/s were categorized as having aortic stiffness. Serum PAG levels were measured using high-performance liquid chromatography–mass spectrometry. Results: Aortic stiffness was present in 33.3% of patients. Those with aortic stiffness were older (p = 0.016), had a higher prevalence of diabetes mellitus (p = 0.030) and hypertension (p < 0.001), and had higher systolic (p < 0.001) and diastolic (p < 0.001) blood pressures, glucose (p = 0.005), and serum PAG (p < 0.001) levels. Multivariable analysis identified serum PAG (odds ratio [OR] = 1.903; 95% confidence interval [CI] = 1.171–3.094, p = 0.009) and age (OR = 1.042, 95% CI = 1.001–1.084, p = 0.044) as independent determinants of aortic stiffness. Linear regression revealed that PAG (p < 0.001), systolic blood pressure (p < 0.001), age (p = 0.013), and glucose level (p = 0.024) were positively associated with cfPWV. Conclusions: Among individuals undergoing maintenance HD, higher serum PAG levels independently predicted greater aortic stiffness. PAG may be a potential diagnostic biomarker for vascular stiffness and a tool for cardiovascular risk stratification in this population.

Background and Objectives: Endothelial dysfunction represents an early indicator of cardiovascular disease in individuals with hypertension. Leptin, an adipokine that regulates vascular homeostasis and metabolism, has been linked to vascular impairment; however, its relationship with vascular reactivity in hypertensive patients remains unclear. Materials and Methods: A cross-sectional study was conducted involving 100 hypertensive patients recruited from the cardiovascular outpatient clinic of Hualien Tzu Chi Hospital between January and July 2021. Clinical profiles, anthropometric data, and laboratory results were collected. Endothelial function was evaluated through digital thermal monitoring, with vascular reactivity index (VRI) classified as poor (<1.0), intermediate (1.0–1.9), or good (≥2.0). The association between serum leptin levels and VRI was examined using correlation analysis, multivariable logistic regression, linear regression, and receiver operating characteristic (ROC) analysis. Results: Of the 100 participants, 10 (10%) exhibited poor VRI, 46 (46%) had intermediate VRI, and 44 (44%) had good VRI. Patients with impaired VRI were significantly older (p = 0.015), had higher waist circumference (p < 0.001), and showed higher serum leptin concentrations (p < 0.001). Multivariable logistic regression identified leptin as an independent factor associated with vascular reactivity dysfunction (OR = 1.096, 95% CI: 1.025–1.171, p = 0.007) and poor vascular reactivity (OR = 1.197, 95% CI: 1.034–1.387, p = 0.016). Serum leptin levels were negatively correlated with VRI (r = −0.408, p < 0.001), and stepwise linear regression confirmed leptin as an independent determinant of VRI (β = −0.296, p = 0.001). ROC analysis further demonstrated that leptin could predict vascular reactivity dysfunction (AUC = 0.724, 95% CI: 0.625–0.824, p < 0.001) and poor vascular reactivity (AUC = 0.770, 95% CI: 0.606–0.932, p = 0.0012). Conclusions: Higher serum leptin levels are independently associated with impaired vascular reactivity in hypertensive patients. Leptin may therefore serve as a potential biomarker for early impairment of vascular reactivity in this population.

Background and Objectives: Indoxyl sulfate (IS), a gut microbiota-derived metabolite of tryptophan, is implicated in vascular dysfunction through oxidative stress and inflammation. This study evaluated the association between serum IS levels and aortic stiffness (AS) in patients with type 2 diabetes mellitus (T2DM). Materials and Methods: This cross-sectional study enrolled 80 patients with T2DM from a medical center in eastern Taiwan, excluding patients with malignancy, acute infection, heart failure, or recent cardiovascular events. Serum IS concentrations were quantified using liquid chromatography–mass spectrometry. AS was assessed using carotid–femoral pulse wave velocity (cfPWV), with values > 10 m/s indicating AS. Results: A total of 30 patients (37.5%) had AS. IS levels were significantly higher in the AS group than in the control group (p < 0.001). After multivariate adjustment, IS remained an independent predictor of AS (odds ratio: 2.565, 95% confidence interval: 1.145–5.748, p = 0.022). Linear regression analysis confirmed IS as an independent contributor to cfPWV values (β = 0.261, p = 0.019). Receiver operating characteristic analysis showed fair discriminatory ability (area under the curve = 0.739, p < 0.001). Conclusions: In patients with T2DM, serum IS is an independent predictor of AS and may serve as a promising nontraditional biomarker for cardiovascular risk stratification.

Background/Objectives: Endothelial dysfunction represents an early stage of vascular injury in type 2 diabetes mellitus (T2DM) and contributes to increased cardiovascular risk. Leptin, a hormone involved in metabolic and inflammatory regulation, has been implicated in vascular dysfunction. However, its association with digital thermal monitoring (DTM)-derived peripheral vascular reactivity in T2DM remains unclear. Methods: This cross-sectional study enrolled 88 patients with T2DM to investigate the association between serum leptin levels and peripheral vascular reactivity, assessed using the digital thermal monitoring-derived vascular reactivity index (VRI). Based on the VRI values, patients were categorized as having good (VRI ≥ 2.0), intermediate (VRI of 1.0–1.9), or poor (VRI < 1.0) vascular reactivity. Serum leptin levels were quantified using an enzyme immunoassay. Results: Patients with poor vascular reactivity were older and had higher total cholesterol, triglyceride, fasting glucose, glycated hemoglobin, urine albumin-to-creatinine ratio, and leptin levels. In the primary parsimonious multivariable logistic regression model adjusted for age, sex, body mass index (BMI) and eGFR, higher serum leptin levels were associated with vascular reactivity dysfunction. Linear regression analysis also showed that log-transformed leptin levels were negatively associated with VRI. Exploratory analyses, including poor vascular reactivity models and penalized regression models, showed generally consistent findings but were interpreted cautiously because of the limited number of outcome events. Conclusions: Higher serum leptin levels were associated with impaired DTM-derived peripheral vascular reactivity in clinically stable patients with T2DM after adjustment for age, sex, BMI, and eGFR. These findings should be interpreted cautiously and require validation in larger prospective studies.