Forward Stepwise Linear Regression Analysis Research Articles

Serum Malondialdehyde-Modified Low-Density Lipoprotein Level May Be a Biomarker Associated with Aortic Stiffness Among Patients Undergoing Peritoneal Dialysis

Background: Serum malondialdehyde-oxidized low-density lipoprotein (MDA-oxLDL) is associated with atherosclerosis and increased risk of cardiovascular disease (CVD). Vascular calcification frequently occurs with arterial stiffness in patients on peritoneal dialysis (PD). This cross-sectional study aimed to elucidate the correlation between aortic stiffness and MDA-oxLDL levels in patients on PD. Methods: Overall, 92 patients on PD were included. The carotid–femoral pulse wave velocity (cfPWV) was evaluated using cuff-based volumetric displacement, and blood samples were obtained from all patients. Aortic stiffness was classified based on cfPWV values (>10 m/s indicating aortic stiffness). Serum MDA-ox-LDL levels were quantified using commercial enzyme-linked immunosorbent assay kits. Results: In total, 33 (35.9%) patients were classified into the aortic stiffness group. Factors, including systolic blood pressure (SBP), serum triglyceride levels, C-reactive protein levels, age, weight, body mass index (BMI), waist circumference, MDA-oxLDL levels, and diabetes mellitus (DM) prevalence, were significantly higher in the aortic stiffness group. Multivariable logistic regression analysis revealed significant associations between aortic stiffness and MDA-oxLDL levels, BMI, and SBP. Furthermore, multivariable forward stepwise linear regression analysis revealed serum MDA-oxLDL levels as a significant independent predictor of cfPWV values. Conclusions: Serum MDA-oxLDL levels correlate positively with cfPWV values and may predict aortic stiffness among PD patients, highlighting its potential role in assessing CVD risk in this population.

Sex differences in heat stress vulnerability among middle-aged and older adults (PSU HEAT Project).

Individuals over the age of 65 yr are the most vulnerable population during severe environmental heat events, experiencing worse health outcomes than any other age cohort. The risk is greater in older women than in age-matched men; however, whether that reflects a greater susceptibility to heat in women, or simply population sex proportionality, is unclear. Seventy-two participants (29 M/43 F) aged 40-92 yr were exposed to progressive heat stress at a metabolic rate designed to reflect activities of daily living. Experiments were conducted in both hot-dry (HD; up to 53°C; ≤25% rh) and warm-humid (WH; ∼35°C; ≥50% rh) environments. After critical limits were determined for each condition, forward stepwise multiple linear regression analyses were conducted with net metabolic rate (Mnet) and age entered into the model first, followed by sex, body mass (mb), maximal oxygen consumption (V̇o2max), body surface area, and LDL cholesterol. After accounting for Mnet and age, sex further improved the regression model in the HD environment ([Formula: see text] = 0.34, P < 0.001) and the WH environment ([Formula: see text] = 0.36, P < 0.005). Sex explained ∼15% of the variance in critical environmental limits in HD conditions and 12% in WH conditions. Heat compensability curves were shifted leftward for older women, indicating age- and sex-dependent heat vulnerability compared with middle-aged women and older men in WH (P = 0.007, P = 0.03) and HD (P = 0.001, P = 0.01) environments. This reflects the heterogeneity of thermal-balance thresholds associated with aging relative to those seen in young adults and suggests that older females are more vulnerable than their age-matched male counterparts.NEW & NOTEWORTHY In contrast to young adults, there are sex differences in critical environmental limits in middle-aged and older adults. Older women exhibit lower critical environmental limits in both humid and dry extreme environments demonstrated by a leftward shift in heat compensability curves. These data confirm a true sex difference in heat vulnerability of older adults and support the epidemiological mortality data from environmental heat waves.

Serum 25-Hydroxyvitamin D Level Is Positively Associated with Vascular Reactivity Index in Patients with Type 2 Diabetes Mellitus.

Circulating 25-hydroxyvitamin D (25(OH)D) significantly influences endothelial function. This study assessed the correlation between serum 25(OH)D and endothelial function using the vascular reactivity index (VRI) in patients with type 2 diabetes mellitus (T2DM). Fasting blood samples from 102 T2DM participants and VRI were assessed. Patients were divided into three categories based on VRI: low (VRI < 1.0), intermediate (1.0 ≤ VRI < 2.0), and good (VRI ≥ 2.0). Among these patients, 30 (29.4%) had poor, 39 (38.2%) had intermediate, and 33 (32.4%) exhibited good vascular reactivity. Higher serum fasting glucose (p = 0.019), glycated hemoglobin (p = 0.009), and urinary albumin-to-creatinine ratio (p = 0.006) were associated, while lower prevalence of hypertension (p = 0.029), lower systolic blood pressure (p = 0.027), lower diastolic blood pressure (p < 0.001), and lower circulation 25(OH)D levels (p < 0.001) were associated with poor vascular reactivity. Significant independent associations between diastolic blood pressure (p = 0.002) and serum 25(OH)D level (p < 0.001) and VRI were seen in T2DM patients according to multivariable forward stepwise linear regression analysis. Serum 25(OH)D positively correlated with VRI values, and lower levels of serum 25(OH)D were linked to endothelial dysfunction in T2DM patients.

Influence of Individual Characteristics on Critical Environmental Limits in Middle-aged and Older Adults (PSU HEAT Project)

Critical environmental limits represent the temperature/humidity combinations at which heat balance can no longer be maintained for a given metabolic rate. Individual characteristics (e.g., sex, body weight and size, and aerobic fitness) are known to alter environmental heat exchange as well as thermoregulatory effector responses and therefore may modify critical environmental limits. PURPOSE: To determine which individual characteristics, if any, may be associated with higher or lower critical environmental limits [combinations of ambient dry-bulb temperature (Tdb) and relative humidity (rh)] in middle-aged and older adults. Methods: Forty-eight male (n=16) and female (n=32) participants (63±11 yrs; range: 40-92 yrs) were exposed to progressive heat stress at a low metabolic rate designed to reflect activities of daily living. Experiments were conducted in both hot-dry (HD; up to 53°C; ≤25% rh) and warm-humid (WH; ~35°C; ≥50% rh) environments. After determining critical limits for each age group and condition, forward stepwise multiple linear regression analyses were conducted with net metabolic rate (Mnet) and age entered into the model first, followed by sex, body mass, Vȯ2max, body surface area, and LDL cholesterol. Results: After accounting for Mnet and age, both sex and body mass further significantly improved the regression model in the HD environment (R2adj = 0.41, p &lt; 0.001) whereas only sex (R2adj = 0.51, P &lt; 0.001) added significantly to the WH model. Sex explained 11% of the variance in critical environmental limits in HD conditions and 14% of the variance in WH conditions. In both WH and HD environments, females exhibited lower critical combinations of Tdb and rh than their male counterparts. Additionally, body mass was negatively related to critical environmental limits in the HD environments and accounted for 8% of the variance after metabolic rate and age were accounted for. CONCLUSION: These data indicate a modest influence of individual characteristics, specifically sex and body mass, on critical environmental limits in both WH and HD environments in adults between the ages of 40 and 92. SIGNIFICANCE/NOVELTY: These results contrast previously published data in young adults showing no significant contribution of individual characteristics to the upper limits of heat balance at low metabolic rates reflecting activities of daily living. This reflects the heterogeneity of thermal-balance thresholds associated with aging relative to those seen in young adults. NIH R01 AG067471 (WLK) and NIA Grant T32 AG049676 (RMC). This is the full abstract presented at the American Physiology Summit 2024 meeting and is only available in HTML format. There are no additional versions or additional content available for this abstract. Physiology was not involved in the peer review process.

Students' mental health during the pandemic: results of the observational cross-sectional COVID-19 MEntal health inTernational for university Students (COMET-S) study.

The aim of the study was to search rates of depression and mental health in university students, during the COVID-19 pandemic. This is an observational cross-sectional study. A protocol gathering sociodemographic variables as well as depression, anxiety and suicidality and conspiracism was assembled, and data were collected anonymously and online from April 2020 through March 2021. The sample included 12,488 subjects from 11 countries, of whom 9,026 were females (72.2%; aged 21.11 ± 2.53), 3,329 males (26.65%; aged 21.61 ± 2.81) and 133 "non-binary gender" (1.06%; aged 21.02 ± 2.98). The analysis included chi-square tests, correlation analysis, ANCOVA, multiple forward stepwise linear regression analysis and Relative Risk ratios. Dysphoria was present in 15.66% and probable depression in 25.81% of the total study sample. More than half reported increase in anxiety and depression and 6.34% in suicidality, while lifestyle changes were significant. The model developed explained 18.4% of the development of depression. Believing in conspiracy theories manifested a complex effect. Close to 25% was believing that the vaccines include a chip and almost 40% suggested that facemask wearing could be a method of socio-political control. Conspiracism was related to current depression but not to history of mental disorders. The current study reports that students are at high risk for depression during the COVID-19 pandemic and identified specific risk factors. It also suggested a role of believing in conspiracy theories. Further research is important, as it is targeted intervention in students' groups that are vulnerable both concerning mental health and conspiracism.

Relationships between regional retinal sensitivities assessed by microperimetry and their corresponding retinal layer thicknesses in healthy middle‐aged subjects

Aims/Purpose: To investigate relationships between regional differential light sensitivity (DLS) and inner and outer retinal layer (IRL and ORL) thicknesses in healthy middle‐aged adults.Methods: Measurements were made in 42 eyes of 42 healthy individuals of mean age 51.3 ± 5.4 years (range 40–59 years), spherical equivalent (SE) between ±3.50 D and good visual acuity. Mesopic fundus‐controlled perimetry was used to measure regional DLS. Spectral‐domain optical coherence tomography (SD‐OCT) was used to measure IRL (ganglion cell‐related layer) and ORL thicknesses. DLS and retinal thickness measurements were recorded for five subfields: central fovea (1 mm diameter) and the quadrants temporal, nasal, superior, and inferior of a parafoveal ring of outer diameter 3 mm and inner diameter 1 mm. Relationships between regional DLS and corresponding IRL and ORL thicknesses were assessed through univariate and multivariate analysis.Results: Mean DLS measured in the inferior parafoveal ring quadrant was significantly correlated with mean IRL thickness (rho = −0.50; p = 0.0045). This correlation was negative, meaning that a thicker IRL was related to a worse DLS. No significant correlations emerged between mean DLS and corresponding ORL or IRL thicknesses for the other subfields. Subsequent forward stepwise multiple linear regression analysis to correct for potential confounding factors revealed that IRL thickness and SE emerged as significant predictors of DLS in the inferior quadrant (R2 model = 33%; p = 0.0004).Conclusions: A thicker macular IRL, possibly indicating transient gliosis, was associated with a worse DLS in healthy middle‐aged eyes.

Serum Osteoprotegerin Levels and the Vascular Reactivity Index in Patients with Hypertension.

Background and Objectives: Osteoprotegerin (OPG), a soluble glycoprotein found in serum, has been associated with both the presence and severity of atherosclerosis. OPG is regarded as the mediator in the process of vascular endothelial dysfunction. Impaired endothelial function has an intimate link with hypertension (HTN) and is associated with significant morbidity and mortality. This study was to investigate the connection between OPG and endothelial dysfunction in patients having HTN. Materials and Methods: There are 102 patients with HTN included. For the purpose of determining the levels of OPG, a commercial enzyme-linked immunosorbent test kit was applied. The vascular reactivity index (VRI), which is assessed via the digital thermal monitoring, provides information on endothelial function. Results: Ten patients with HTN (9.8%) were classified as having poor vascular reactivity (VRI < 1.0), 46 HTN patients (45.1%) as having intermediate vascular reactivity (1.0 ≤ VRI < 2.0), and 46 HTN patients (45.1%) were classified as having high vascular reactivity (VRI ≥ 2.0). A greater serum OPG level (p < 0.001) and older age (p = 0.022) were linked to impaired vascular reactivity. The estimated glomerular filtration rate (r = 0.196, p = 0.048) was positively correlated with VRI values in hypertensive participants, while advanced age (r = -0.222, p = 0.025) and the log-transformed OPG level (log-OPG, r = -0.357, p < 0.001) were negatively correlated with VRI. Serum log-OPG level was shown to be strongly and independently correlated with VRI values in HTN individuals after multivariable forward stepwise linear regression analysis (β = -0.357, adjusted R2 change = 0.119, p < 0.001). Conclusions: In patients with HTN, serum OPG levels were adversely correlated with VRI and probably had a role in endothelial dysfunction.

Serum sclerostin level is positively associated with endothelial dysfunction measured by digital thermal monitoring in patients with type 2 diabetes: A prospective cross-sectional study.

Sclerostin and dickkopf-1 (DKK1), extracellular inhibitors of the canonical Wnt/β-catenin signaling pathway, have been associated with vascular aging and atherosclerosis. This study aimed to assess the correlation of sclerostin and DKK1 concentrations with endothelial function measured using vascular reactivity index (VRI) in patients with type 2 diabetes mellitus (T2DM). Fasting blood samples were collected from 100 patients with T2DM. Endothelial function and VRI were measured using digital thermal monitoring and circulating sclerostin and DKK1 levels by enzyme-linked immunosorbent assays. VRI values < 1.0, 1.0-1.9, and > 2.0 indicated poor, intermediate, and good vascular reactivity, respectively. Overall, 30, 38, and 32 patients had poor, intermediate, and good vascular reactivity, respectively. Older age, higher serum glycated hemoglobulin, urinary albumin-to-creatinine ratio, and sclerostin as well as lower hypertension prevalence, systolic blood pressure, and diastolic blood pressure (DBP) were associated with poor VRI. Multivariable forward stepwise linear regression analysis showed that DBP (β = 0.294, adjusted R2 change = 0.098, P < .001), log-glycated hemoglobin (β = -0.235, adjusted R2 change = 0.050, P = .002), log-urine albumin-to-creatinine ratio (β = -0.342, adjusted R2 change = 0.227, P < .001), and log-sclerostin level (β = -0.327, adjusted R2 change = 0.101, P < .001) were independently associated with VRI. Serum sclerostin, along with glycated hemoglobin and albumin-to-creatinine ratio, exhibited a negative correlation with VRI, while DBP showed a positive correlation with VRI. These factors can independently predict endothelial dysfunction in patients with T2DM.

HIGH SERUM TRIMETHYLAMINE N-OXIDE LEVEL IS ASSOCIATED WITH ENDOTHELIAL DYSFUNCTION IN PATIENTS WITH HYPERTENSION

Objective: Trimethylamine N-oxide (TMAO) is a metabolite derived from gut microbial metabolism and dietary intake and plays important roles in cardiovascular disease pathogenesis. Endothelial dysfunction is associated with risk factors of cardiovascular disease in patients with hypertension. The present study aimed to determine the correlation between serum TMAO and endothelial function, measured by vascular reactivity index (VRI) in patients with hypertension. Design and method: The present study collected fasting blood samples from 110 patients with hypertension. Serum TMAO levels were determination of by high-performance liquid chromatography–mass spectrometry. The endothelial function and VRI values were measured using digital thermal monitoring test, and VRI values of &gt;2.0, 1.0–1.9 and &lt;1.0 indicated good, intermediate and poor vascular reactivity, respectively. Results: Ten hypertensive patients (9.1%) were categorized as poor vascular reactivity (VRI &lt; 1.0), 57 hypertensive patients (51.8%) were categorized as intermediate vascular reactivity (1.0 &lt; VRI &lt; 2.0), and 43 hypertensive patients had good vascular reactivity. Older age (P = 0.010), higher levels of serum total cholesterol (TCH, P = 0.007), low-density lipoprotein cholesterol (LDL-C, P = 0.009), and TMAO levels (P &lt; 0.001) were associated with poor vascular reactivity. Furthermore, after multivariable forward stepwise linear regression analysis noted that logarithmically transformed serum level of TMAO (log-TMAO, adjusted R2 change = 0.274, P &lt; 0.001) was significantly and independently associated with VRI values in hypertensive patients. Compared with good vascular reactivity index, patients with vascular reactivity dysfunction (intermediate vascular reactivity and poor vascular reactivity; odds ratio (OR) = 1.100; 95% confidence interval (CI) = 1.047–1.155; P &lt; 0.001) or poor vascular reactivity (OR = 1.580, 95% CI = 1.002–2.492, P = 0.049) also noted TMAO was positively associated with poor vascular reactivity after multivariate logistic regression analysis. Conclusions: Serum TMAO levels were negatively associated with VRI and associated with endothelial dysfunction in patients with hypertension.

SERUM N-TERMINAL PRO-B-TYPE NATRIURETIC PEPTIDE LEVEL IS NEGATIVELY ASSOCIATED WITH VASCULAR REACTIVITY INDEX BY DIGITAL THERMAL MONITORING IN PATIENTS WITH HYPERTENSION

Objective: B-type natriuretic peptide (BNP) participates in the coordination of endothelial regeneration/hypertrophy and the accompanying angiogenesis. Endothelial dysfunction is associated with increased mortality in patients on hypertension. The present study aimed to determine the relationship between serum N-terminal pro-B-type natriuretic peptide (NT-pro-BNP) level and endothelial dysfunction in patients with hypertension Design and method: The present cross-sectional, single-center study included 90 hypertension patients. An electrochemiluminescence immunoassay was used to measure NT-pro-BNP levels. The endothelial function and vascular reactivity index (VRI) were measured using digital thermal monitoring (DTM) test (VENDYS). In this study, VRI &lt; 1.0 was used as the poor vascular reactivity, 1.0 &lt; VRI &lt; 2.0 was used as the intermediate vascular reactivity, and VRI &gt; 2.0 was used as the good vascular reactivity. Results: Eight hypertensive patients (8.9%) were categorized as poor vascular reactivity (VRI &lt; 1.0), 39 hypertensive patients (43.3%) were categorized as intermediate vascular reactivity (1.0 &lt; VRI &lt; 2.0), and 43 hypertensive patients had good vascular reactivity. Older age (p = 0.012) and higher serum NT-pro-BNP level (p &lt; 0.001) was associated with poor vascular reactivity. Advanced age (r = -0.221, p = 0.036) and logarithmically transformed serum level of NT-pro-BNP (log-NT-pro-BNP, r = -0.505, p &lt; 0.001) was negatively associated with VRI values in hypertensive patients. After multivariable forward stepwise linear regression analysis noted that serum log-NT-pro-BNP level (adjusted R2 change = 0.246, p &lt; 0.001) was significantly and independently associated with VRI values in hypertensive patients. Conclusions: Serum log-NT-pro-BNP levels were negative associated with VRI and associated with endothelial dysfunction in patients with hypertension.

Results of the COVID-19 mental health international for the health professionals (COMET-HP) study: depression, suicidal tendencies and conspiracism.

The current study aimed to investigate the rates of anxiety, clinical depression, and suicidality and their changes in health professionals during the COVID-19 outbreak. The data came from the larger COMET-G study. The study sample includes 12,792 health professionals from 40 countries (62.40% women aged 39.76 ± 11.70; 36.81% men aged 35.91 ± 11.00 and 0.78% non-binary gender aged 35.15 ± 13.03). Distress and clinical depression were identified with the use of a previously developed cut-off and algorithm, respectively. Descriptive statistics were calculated. Chi-square tests, multiple forward stepwise linear regression analyses, and Factorial Analysis of Variance (ANOVA) tested relations among variables. Clinical depression was detected in 13.16% with male doctors and 'non-binary genders' having the lowest rates (7.89 and 5.88% respectively) and 'non-binary gender' nurses and administrative staff had the highest (37.50%); distress was present in 15.19%. A significant percentage reported a deterioration in mental state, family dynamics, and everyday lifestyle. Persons with a history of mental disorders had higher rates of current depression (24.64% vs. 9.62%; p < 0.0001). Suicidal tendencies were at least doubled in terms of RASS scores. Approximately one-third of participants were accepting (at least to a moderate degree) a non-bizarre conspiracy. The highest Relative Risk (RR) to develop clinical depression was associated with a history of Bipolar disorder (RR = 4.23). The current study reported findings in health care professionals similar in magnitude and quality to those reported earlier in the general population although rates of clinical depression, suicidal tendencies, and adherence to conspiracy theories were much lower. However, the general model of factors interplay seems to be the same and this could be of practical utility since many of these factors are modifiable.

Independent predictors and equation of six-minute walk test in post-cardiac surgery

BackgroundThe six-minute walk test (6MWT) has been used to evaluate postsurgical recovery in cardiac patients. No previous study has compared the 6MWT at follow-up with a baseline, or evaluated the long-term effects of cardiac surgery on post-discharge 6MWT ObjectivesTo identify the factors independently associated with 6MWD, and to develop an equation to predict 6MWT at the 4–6-week follow-up after post-cardiac surgery hospital discharge. MethodsPatient data of elective coronary artery bypass graft (CABG) or non-CABG surgery patients were retrospectively collected. The 6MWT was performed at hospital discharge and at the 4–6-week follow-up. Available demographic and clinical data of patients were analyzed to determine the independent factors of 6MWT. An equation to predict 6MWT were generated by forward stepwise multiple linear regression analysis. ResultsThe data of 275 patients (mean age: 62.20±14.57 years, 64.7% male) were analyzed. The mean 6MWT was 179.14±92.18 m at discharge, and increased to 335.20±115.51 m at the 4–6-week follow-up. The 6MWT at the 4–6-week follow-up was independently correlated with 6MWT at discharge, regular exercise, age, gender, and preoperative New York Heart Association (NYHA) classification. ConclusionThe independent predictors: 6MWT at discharge, regular exercise, age, gender, and NYHA classification were used to generate an equation to predict 6MWT at 4–6 weeks after hospital discharge.

The relationship of retinal vessel calibres with cardiovascular risk factors in apparently healthy young eyes

AbstractPurpose: Although retinal vascular calibre has been linked to increased cardiovascular (CV) risk, it remains unclear whether retinal vascular morphologic changes are already evident in young adults and correlate with modifiable CV risk factors. The purpose of this study was to explore the relationship of retinal arteriolar and venular calibre with CV risk factors and ocular parameters in healthy young subjects.Methods: A cross‐sectional study was performed in 52 apparently healthy subjects (mean 21.6 ± 2.2 years of age). Retinal vascular calibres were measured from fundus photographs using semi‐automated imaging software and expressed as central retinal arteriolar (CRAE) or venular (CRVE) equivalent and arterio‐venous ratio (AVR). CV risk factors and ocular parameters were assessed. Forward stepwise multiple linear regression analysis was used to detect the independent relationship between retinal vascular calibre and CV and ocular parameters.Results: Means for CRAE and CRVE were 191 ± 15.4 μm and 209 ± 15.8 μm respectively. The mean CRAE but not CRVE was significantly higher in women than in men (p = 0.009). Systolic blood pressure (SBP) and spherical equivalent were significant contributing factors to CRAE (SBP: p &lt; 0.001; SE: p = 0.021). However, CRVE was not significantly predicted by CV risk factors or ocular parameters. SBP was the only one independent contributor to AVR (p = 0.018).Conclusions: In young adults, higher SBP was found to be related to narrower retinal arterioles, but not to retinal venules. Sex and other confounding CV or ocular factors had no effect on the relationship of SBP and retinal vessel calibre.

Association of social determinants of health with frailty, cognitive impairment, and self-rated health among older adults.

Recently, the role of social determinants of health on frailty and dementia has received increased attention. The aim of the present study is to explore the association of social determinants on cognitive impairment, frailty, and self-rated health. As health is influenced by many factors, we also examine other health determinants including lifestyle, health seeking behaviour, socio-demographics, and multimorbidity in the analysis. Cross-sectional analysis of the Healthy Older People Everyday (HOPE) study in Singapore was carried out on 998 older adults above the age of 65. We used forward stepwise multivariable logistic and linear regression analyses to assess the association of five health determinants (social determinants, lifestyle, health seeking behaviour, socio-demographics and multimorbidity) on frailty, cognitive impairment, and self-rated health. Mean age of participants was 71.1 ± 0.2 years; 154 (15.4%) were cognitively impaired; 430 (43.1%) were pre-frail or frail; mean self-rated health was 80.4 ± 15.6. Social determinants contributed between 29% to 57% of the overall variation found in the full model with all five health determinants adjusted for. Participants with higher education had significantly lower odds of cognitive impairment and frailty. Leisure physical activity was significantly associated with lower odds of frailty and cognitive impairment, and better self-rated health. Understanding the dynamics of different health determinants is crucial to protect the vulnerable in an ageing population. Our study highlights the need for a multidimensional, multidisciplinary and multisectoral approach in the prevention of frailty, cognitive impairment, and associated disability.

MO735: Increased Serum Adipocyte Fatty Acid Binding Protein Level Associated with Endothelial Dysfunction in Patients Undergoing Hemodialysis

Abstract BACKGROUND AND AIMS Adipocyte fatty acid binding protein (A-FABP) is independently associated with atherosclerosis. Endothelial dysfunction is one of the causes of cardiovascular morbidity and mortality in patients with hemodialysis (HD). This study evaluated the correlation between serum A-FABP level and endothelial function measured by vascular reactivity index (VRI) in patients with HD. METHOD Fasting blood samples were obtained from 90 HD patients. A commercial enzyme immunoassay kit was used to measure A-FABP levels. The endothelial function and VRI were measured using a digital thermal monitoring (DTM) test (VENDYS). In this study, VRI &amp;lt; 1.0 was used as the poor vascular reactivity, 1.0 ≤ VRI &amp;lt; 2.0 was used as the intermediate vascular reactivity, and VRI ≥ 2.0 was used as the good vascular reactivity. RESULTS A total of 14 HD patients (15.6%) were categorized as poor vascular reactivity (VRI &amp;lt; 1.0), 38 HD patients (42.2%) were categorized as intermediate vascular reactivity (1.0 ≤ VRI &amp;lt; 2.0) and 38 HD patients had good vascular reactivity. Decreased pre-HD body weight (P = 0.016), post-HD body weight (P = 0.013), body mass index (P = 0.034), serum creatinine level (P = 0.010) and higher serum A-FABP level (P = 0.001) were associated with poor vascular reactivity. After multivariable forward stepwise linear regression analysis noted that serum creatinine level (β = 0.234, adjusted R2 change = 0.043; P = 0.019) was positively associated with, and serum A-FABP level (β = −0.347, adjusted R2 change = 0.152; P = 0.001) was negatively associated with VRI values in patients undergoing HD. CONCLUSION After adjusting for significant confounders, the serum A-FABP level was negatively correlated, and the serum creatinine level was positively correlated with VRI values in patients undergoing HD.

MO140: Lower Serum 25-Hydroxyvitamin D Levels are Associated with Peripheral Arterial Stiffness in Patients with Non‑Dialysis Chronic Kidney Disease Stage 3–5

Abstract BACKGROUND AND AIMS Vitamin D deficiency is associated with a higher mortality and incidence of cardiovascular disease. High brachial-ankle pulse wave velocity (baPWV) is independently associated with an increased risk of cardiovascular events, cardiovascular mortality and all-cause mortality in atherosclerotic cardiovascular disease patients. The aim of this study was to evaluate the relationship between serum 25-hydroxyvitamin D levels and baPWV in patients with CKD stage 3 to 5. METHOD Fasting blood samples and baseline characteristics were obtained from 180 CKD stage 3 to 5 patients. A commercial enzyme-linked immunosorbent assay was used to measure 25-hydroxyvitamin D levels. Automatic pulse wave analyzer (VaSera VS-1000) to measure baPWV values and both sides of baPWV value which is greater than 18.0 m/s was determined as peripheral arterial stiffness (PAS). RESULTS A total of 73 (40.6%) participants were assigned to the PAS group with baPWV of &amp;gt;18 m/s in CKD patients. There were more patients with diabetes mellitus (P = .036), old age (P &amp;lt; .001), higher systolic blood pressure (P &amp;lt; .001), diastolic blood pressure (P = .015), high serum intact parathyroid hormone (iPTH) (P = .009), elevated C-reactive protein (P &amp;lt; .001) and lower 25-hydroxyvitamin D (P &amp;lt; .001) levels in the PAS group compared with the control group in CKD participants. A multivariate logistic regression analysis discloses that 25-hydroxyvitamin D [odds ratio (OR): 0.895, 95% confidence interval (CI): 0.828–0.968, P = .005] and old age (OR: 1.140, 95% CI: 1.088–1.194, P &amp;lt; .001) were independently associated with PAS in in patients with CKD stage 3 to 5. Moreover, according to a multivariate forward stepwise linear regression analysis, OPN level is positively associated with cfPWV. By receiver operating characteristic (ROC) curve analysis, the area under the receiver operating characteristic curve of 25-hydroxyvitamin D level was 0.684 (95% CI: 0.611–0.751, P &amp;lt; .001) for predicting PAS in patients with CKD stage 3 to 5. CONCLUSION Lower serum 25-hydroxyvitamin D levels and older age were associated with PAS measured by baPWV in patients with CKD stage 3 to 5.

MO745: Serum Endocan as a Risk Factor for Aortic Stiffness in Patients on Maintenance Hemodialysis

Abstract BACKGROUND AND AIMS Endocan is secreted by the activated endothelium and plays a central role in inflammation and endothelial dysfunction, angiogenesis and vascular smooth muscle cell proliferation, it is associated with cardiovascular disease. This cross-sectional study aimed to assess the relationship between serum endocan levels and carotid–femoral pulse wave velocity (cfPWV) in patients on maintenance hemodialysis (HD). METHOD Blood samples and baseline characteristics were collected from 122 HD patients. Serum endocan concentrations were measured with an enzyme-linked immunosorbent assay kit. Aortic stiffness was defined as a cfPWV of more than 10 m/s. RESULTS Of the 122 HD patients, aortic stiffness was diagnosed in 53 (43.4%), and higher percentages of diabetes (P &amp;lt; 0.001) and hypertension (P = 0.030) were of older age (P = 0.007) and had higher systolic blood pressure (P = 0.011) and endocan levels (P &amp;lt; 0.001) in those with aortic stiffness than those without. After adjusting for factors significantly associated with aortic stiffness by multivariate logistic regression analysis, serum endocan [odds ratio (OR) 1.566, 95% confidence interval (95% CI) 1.224–2.002; P &amp;lt; 0.001], age (OR 1.040, 95% CI 1.001–1.080; P = 0.045), and diabetes (OR 4.067, 95% CI 1.532–10.798; P = 0.005) were independently associated with aortic stiffness in patients with chronic HD. Multivariable forward stepwise linear regression analysis also confirmed that the logarithmically transformed endocan level (β =0.405, adjusted R2 change = 0.152; P &amp;lt; 0.001) was an independent predictor of cfPWV values. The area under the receiver operating characteristic (ROC) curve predicting aortic stiffness by serum endocan level was 0.713 (95% CI 0.620–0.806; P &amp;lt; 0.001). CONCLUSION Serum endocan level positively correlates with cfPWV and is also an independent predictor of aortic stiffness in maintenance HD patients.

MO159: Serum Trimethylamine N-Oxide Level is Positively Associated with Aortic Stiffness Measuring by Carotid-Femoral Pulse Wave Velocity in Maintenance Haemodialysis Patients

Abstract BACKGROUND AND AIMS Trimethylamine-N-oxide (TMAO) acts as an evident predictor for the prevalence of cardiovascular disease and increased incidence of major adverse cardiovascular events. Aortic stiffness predicts cardiovascular disease and is associated with ageing-associated vascular diseases. The aim of this study was to evaluate the relationship between serum TMAO levels and carotid-femoral pulse wave velocity (cfPWV) in chronic haemodialysis (HD) patients. METHOD A total of 115 patients with HD were enrolled in this study. cfPWV was measured using the SphygmoCor system. Patients with cfPWV &amp;gt;10 m/s were defined as the aortic stiffness group. Serum TMAO level was performed with high-performance liquid chromatography and mass spectrometry. RESULTS Forty-two HD patients (36.5%) had aortic stiffness and higher percentages of diabetes (P &amp;lt; .001), hypertension (P = .026), were of older age (P = .028) and had higher systolic blood pressure (P = .025), serum glucose level (P = .029) and TMAO levels (P &amp;lt; .001) compared to control group. After adjusting for factors significantly associated with aortic stiffness by multivariate logistic regression analysis, serum TMAO [odds ratio (OR): 1.010, 95% confidence interval (CI): 1.003–1.017, P = .003) and age (OR: 1.046, 95% CI: 1.007–1.088, P = .021) were independently associated with aortic stiffness in patients with chronic HD. After multivariable forward stepwise linear regression analysis also noted that serum TMAO level (β = 0.355, adjusted R2 change = 0.198, P &amp;lt; .001) was positively associated with cfPWV values in HD patients. CONCLUSION Serum TMAO level is an independent marker of aortic stiffness and is positively associated with cfPWV values in patients with chronic HD.

MO188: Elevated Serum Soluble Urokinase-Type Plasminogen Activator Receptor Level is Linked to Aortic Stiffness in Chronic Haemodialysis Patients

Abstract BACKGROUND AND AIMS Soluble urokinase-type plasminogen activator receptor (suPAR) is associated with inflammation and contributing in the pathogenesis of atherosclerosis. Aortic stiffness is associated with aging-associated vascular diseases and is also an independent risk factor of cardiovascular morbidity and mortality. We evaluated the association between serum suPAR and aortic stiffness in patients with chronic haemodialysis (HD). METHOD A total of 135 patients with HD were enrolled in this study. Carotid–femoral pulse wave velocity (cfPWV) was measured using the SphygmoCor system. Patients with cfPWV &amp;gt;10 m/s were defined as the aortic stiffness group. Serum suPAR levels were measured using a commercial enzyme-linked immunosorbent assay kit. RESULTS Fifty-five HD patients (40.7%) had aortic stiffness and higher percentages of diabetes (P = .001), hypertension (P = .039), were of older age (P = .007) and had higher systolic blood pressure (P = .025), serum glucose level (P = .019), C-reactive protein (P = .039) and suPAR levels (P &amp;lt; .001) compared to control group. After adjusting for factors significantly associated with aortic stiffness by multivariate logistic regression analysis, serum suPAR [odds ratio (OR): 1.910, 95% confidence interval (CI): 1.485–2.458, P &amp;lt; .001] and age (OR: 1.040, 95% CI: 1.001–1.080, P = .048) were independently associated with aortic stiffness in patients with chronic HD. After multivariable forward stepwise linear regression analysis also noted that serum suPAR level (β = 0.442, adjusted R2 change = 0.250, P &amp;lt; .001) was positively associated with with cfPWV values in HD patients. CONCLUSION Serum suPAR level is positively associated with cfPWV values and is a biomarker for aortic stiffness in patients with chronic HD.

Negative Correlation of Serum Adiponectin Level with Aortic Stiffness in Elderly Diabetic Persons.

Adiponectin has anti-inflammatory activity against atherosclerosis. Aortic stiffness is a common manifestation of atherosclerosis in diabetes mellitus and elderly persons. This study aimed to evaluate whether low serum adiponectin levels were associated with aortic stiffness in geriatric diabetic patients. Blood samples were obtained from 130 diabetic participants aged ≥ 65 years. We defined high aortic stiffness based on a carotid–femoral pulse wave velocity (cfPWV) of >10 m/s. Circulating adiponectin concentrations were examined using enzyme-linked immunosorbent assays. Sixty-six participants (50.8%) had aortic stiffness. Patients with aortic stiffness had lower serum adiponectin concentrations than those in the control group (p < 0.001). Multivariate logistic regression analysis showed that the adiponectin level (odds ratio: 0.939, 95% confidence interval: 0.898–0.981, p = 0.005) was an independent predictor of aortic stiffness in elderly diabetic persons. Multivariate forward stepwise linear regression analysis also demonstrated that the adiponectin level (β = −0.256, adjusted R2 change = 0.100, p = 0.003) was negatively associated with cfPWV values in older diabetic patients. In conclusion, serum adiponectin is negatively correlated with cfPWV and is an independent predictor of aortic stiffness in elderly diabetic persons.