scholarly journals Application of Multivariate Generalized Linear Mixed Model to Identify Effect of Dialysate Temperature on Physiologic Indicators among Hemodialysis Patients

Author(s):  
Omid Hamidi ◽  
Seyed Reza Borzu ◽  
Saman Maroufizadeh ◽  
Payam Amini

Introduction: One of the complications of hemodialysis treatment is hypotension, which can increase morbidity and mortality and compromise dialysis efficacy. Dialysate temperature is an important factor that contributes to hemodynamic stability during hemodialysis. This study investigated the effect of dialysate temperature on the patients' blood pressure and pulse rate. Model-based approaches were used to produce more reliable results compared with traditional methods. Methods: A total of 30 patients were studied during 9 dialysis sessions. Dialysate temperatures were 37° C, 36° C and 35° C. A joint longitudinal model was used to analyze both responses of blood pressure and pulse rate, simultaneously. Results: The results showed that low-dialysate temperature was not significantly associated with higher systolic blood pressure (p>0.05) or a higher pulse rate (p>0.05) either during or after dialysis. Pulse rate and blood pressure were higher for women during dialysate (p<0.001). However, increasing age was associated with higher blood pressure and a lower pulse rate (p<0.001). Conclusion: Using several separate, repeated measure analysis of variances may produce misleading results, when there is more than one response variable measured over time, Multivariate statistical methods (including joint longitudinal models), should be used.  

Author(s):  
Yuni Wang ◽  
Kashinath G Metri ◽  
Amit Singh ◽  
Nagaratna Raghuram

AbstractBackgroundMind sound resonance technique (MSRT) is a yoga-based relaxation technique. Previous studies on MSRT demonstrated its potential health-benefiting effects in both clinical and nonclinical population. Present study intended to assess the acute effect of MSRT intervention on blood pressure, heart rate (HR), and state anxiety in patients with essential hypertension (HTN).MethodsThirty participants (13 females) with HTN, within the age range 30–60 years (with mean±SD: 57.23±11.3 years), who visited SVYASA University campus to attend 1-week residential yoga program for HTN treatment, were considered for this study based on inclusion and exclusion criteria. All participants received a 4-day MSRT orientation sessions prior to the study. Each participant underwent 30-min session of both MSRT and supine rest (SR) on 2 successive days. Systolic and diastolic blood pressures, pulse rate, and state anxiety were measured before and immediately after both MSRT and SR sessions. Data were analyzed using SPSS version 16. Repeated-measure analysis of variance was applied to assess within-subjects changes.ResultsAfter MSRT session, significant decrease in systolic blood pressure (SBP), diastolic blood pressure (DBP), HR, and state anxiety was observed compared to baseline. Similarly, after SR session, significant changes were found in HR and state anxiety. No significant change was seen in SBP and DBP following SR compared to SR session; MSRT session showed significantly better improvement in SBP, DBP, HR, and state anxiety.ConclusionPresent study demonstrated the usefulness of single session of MSRT in reducing blood pressure, HR, and state anxiety among individuals with HTN as compared to SR. These findings encourage the further studies with larger sample size and long-term intervention with a robust research design.


2021 ◽  
Vol 8 (7) ◽  
pp. 129
Author(s):  
Jennifer Davis ◽  
Anthea L. Raisis ◽  
Claire R. Sharp ◽  
Rachel E. Cianciolo ◽  
Steven C. Wallis ◽  
...  

Resveratrol has been shown to preserve organ function and improve survival in hemorrhagic shock rat models. This study investigated whether seven days of oral resveratrol could improve hemodynamic response to hemorrhage and confer benefits on risk of acute kidney injury (AKI) without inducing coagulopathy in a canine model. Twelve greyhound dogs were randomly allocated to receive oral resveratrol (1000 mg/day) or placebo for seven days prior to inducing hemorrhage until a targeted mean blood pressure of ≤40 mmHg was achieved. AKI biomarkers and coagulation parameters were measured before, immediately following, and two hours after hemorrhage. Dogs were euthanized, and renal tissues were examined at the end of the experiment. All investigators were blinded to the treatment allocation. A linear mixed model was used to assess effect of resveratrol on AKI biomarkers and coagulation parameters while adjusting for volume of blood loss. A significant larger volume of blood loss was required to achieve the hypotension target in the resveratrol group compared to placebo group (median 64 vs. 55 mL/kg respectively, p = 0.041). Although histological evidence of AKI was evident in all dogs, the renal tubular injury scores were not significantly different between the two groups, neither were the AKI biomarkers. Baseline (pre-hemorrhage) maximum clot firmness on the Rotational Thromboelastometry (ROTEM®) was stronger in the resveratrol group than the placebo group (median 54 vs. 43 mm respectively, p = 0.009). In summary, seven days of oral resveratrol did not appear to induce increased bleeding risk and could improve greyhound dogs’ blood pressure tolerance to severe hemorrhage. Renal protective effect of resveratrol was, however, not observed.


Author(s):  
Zi Di Lim ◽  
Edwin Pheng ◽  
Evelyn Tai Li Min ◽  
Hans Van Rostenberghe ◽  
Ismail Shatriah

Platelets are a primary source of pro- and anti-angiogenic cytokines. However, the evidence of their role in retinopathy of prematurity (ROP) is controversial. This retrospective study aimed to compare mean weekly platelet counts between infants with and without ROP over the first 6 weeks of life. A total of 93 infants matched by gestational age and birth weight were recruited (31 with ROP, 62 without ROP). Weekly mean platelet counts and other related risk factors were documented. The repeated measure analysis of variance (ANOVA) and the repeated measure analysis of covariance (ANCOVA) were used to compare mean platelet counts over time between the two groups, with and without adjusting for confounders. We found significant differences in the weekly mean platelet counts of infants with and without ROP over the first 6 weeks of life (p = 0.002). These differences disappeared after adjusting for covariates (p = 0.489). Lower mean platelet counts in ROP infants are not directly related to ROP, but rather to the presence of other risk factors for ROP, such as culture-proven sepsis, blood transfusion and bronchopulmonary dysplasia.


Author(s):  
Samer Mheissen ◽  
Haris Khan ◽  
Mohammed Almuzian ◽  
Emad Eddin Alzoubi ◽  
Nikolaos Pandis

Summary Background In orthodontic trials, longitudinal designs with multiple outcome measurements over time are common. The aim of this epidemiological study was to examine whether optimal statistical analysis approaches have been used in longitudinal orthodontic trials. Methods Pubmed was searched in August 2021 for longitudinal orthodontic trials with at least three time points of outcome assessment published in the 2017–20 period. Study selection and data extraction were done independently and in duplicate. The analysis approaches undertaken were tabulated and associations between study characteristics and the use of optimal analysis or not were assessed using Fisher’s exact test and logistic regression. Results One hundred forty-seven out of 563 unique records were deemed eligible for inclusion. Only 26.50% of these trials used an optimal statistical analysis for longitudinal data where the data structure is accounted for. None of the study characteristics except the statistical significance of the results were associated with the appropriateness of the statistical analysis. The odds of significant results in studies with suboptimal analyses were higher than that in studies with optimal longitudinal analyses (odds ratio: 3.48, 95% confidence interval: 1.62, 7.46, P = 0.001). For the studies with optimal analysis, the most frequent test was repeated-measure analysis of variance (RM-ANOVA). The reporting of the statistical analysis section was suboptimal in the majority of the trials. Conclusion Most longitudinal orthodontic trials are not analysed using optimal statistical approaches. Inferences and interpretation of their results are likely to be compromised.


Hypertension ◽  
2021 ◽  
Vol 77 (3) ◽  
pp. 823-832
Author(s):  
Neelakshi Hudda ◽  
Misha Eliasziw ◽  
Scott O. Hersey ◽  
Ellin Reisner ◽  
Robert D. Brook ◽  
...  

Exposure to traffic-related air pollution (TRAP) may contribute to increased prevalence of hypertension and elevated blood pressure (BP) for residents of near-highway neighborhoods. Relatively few studies have investigated the effects of reducing TRAP exposure on short-term changes in BP. We assessed whether reducing indoor TRAP concentrations by using stand-alone high-efficiency particulate arrestance (HEPA) filters and limiting infiltration through doors and windows effectively prevented acute (ie, over a span of hours) increases in BP. Using a 3-period crossover design, 77 participants were randomized to attend three 2-hour-long exposure sessions separated by 1-week washout periods. Each participant was exposed to high, medium, and low TRAP concentrations in a room near an interstate highway. Particle number concentrations, black carbon concentrations, and temperature were monitored continuously. Systolic BP (SBP), diastolic BP, and heart rate were measured every 10 minutes. Outcomes were analyzed with a linear mixed model. The primary outcome was the change in SBP from 20 minutes from the start of exposure. SBP increased with exposure duration, and the amount of increase was related to the magnitude of exposure. The mean change in SBP was 0.6 mm Hg for low exposure (mean particle number and black carbon concentrations, 2500 particles/cm 3 and 149 ng/m 3 ), 1.3 mm Hg for medium exposure (mean particle number and black carbon concentrations, 11 000 particles/cm 3 and 409 ng/m 3 ), and 2.8 mm Hg for high exposure (mean particle number and black carbon concentrations, 30 000 particles/cm 3 and 826 ng/m 3 ; linear trend P =0.019). There were no statistically significant differences in the secondary outcomes, diastolic BP, or heart rate. In conclusion, reducing indoor concentrations of TRAP was effective in preventing acute increases in SBP.


2019 ◽  
Vol 10 (1) ◽  
pp. 9-17
Author(s):  
Martina Đodan ◽  
Tomislav Dubravac ◽  
Sanja Perić

Background and Purpose: Recently raised questions on adaptability of native tree species to climate changes pointed to Douglas-fir as a species suitable for rapid reforestation and increase of stand resistance. The first results on provenance research need to be confirmed in later stages of stand development, so the paper answers the following two questions: (i) are there differences in growth of 14 Douglas-fir provenances still in the fifth decade of stand development, and (ii) which provenances should be used and which omitted from further use in the hilly area of Croatia? Materials and Methods: Productivity of 14 provenances was evaluated on the basis of height, diameter at breast height and volume in the 46th year after planting. Growth dynamics was also statistically analysed using a repeated measure analysis of variance, for which purpose we partially used published data from the 2010. Results: The analysis excluded Castle Rock and Shady Cove (Oregon) provenances due to their low values of all analysed growth indicators, as well as Castle Rock, Elma and Hvidilde provenances due to their high values. Average values of tree volume ranged from 0.53 m3 (Shady Cove) to 2.05 m3 (Castle Rock), while the tallest trees belonged to Elma provenance (29.6 m). Conclusions: Different growth dynamics of provenances were confirmed for later development stage, so further monitoring is still required. Clear guidelines for the selection of provenances for practical forestry distinguish provenances from lower altitudes of the State of Washington, Denmark and Bulgaria as the most productive. Shady Cove and Salmon Arm provenances are not advised to be used in the future.


2020 ◽  
Vol 22 (12) ◽  
pp. 1176-1183
Author(s):  
Marco Fantinati ◽  
Julien Trnka ◽  
Amélia Signor ◽  
Séverine Dumond ◽  
Géraldine Jourdan ◽  
...  

Objectives The aim of the study was to evaluate the appetite-stimulating effect of gabapentin by comparing it with mirtazapine in healthy cats in the first 8 h after ovariectomy surgery. Methods This double-masked, placebo-controlled, prospective clinical trial included 60 healthy cats presented to the hospital for ovariectomy: 20 received gabapentin, 21 received mirtazapine and 19 received a placebo immediately before and 6 h after surgery. Food was offered at 2, 4, 6 and 8 h post-ovariectomy. After each meal, food intake was measured. Data were analysed using repeated-measure ANOVA and a linear mixed-model analysis. Post-hoc Tukey’s honest significant difference test was performed for multiple comparisons. Results Food intake increased in both treatment groups vs placebo. No statistically significant difference was found between cats treated with gabapentin or mirtazapine. Conclusions and relevance Cats receiving gabapentin ate more than cats in the placebo group. Thirty percent of cats in the gabapentin group covered their resting energy requirements, while none of the cats in the placebo group did. Gabapentin and mirtazapine produced similar effects on food intake.


Author(s):  
Stanisław H. Czyż ◽  
Martin Zvonař ◽  
Zbigniew Borysiuk ◽  
Jiří Nykodým ◽  
Piotr Oleśniewicz

There are a limited number of studies focusing on the mechanisms explaining why variable practice gives an advantage in a novel situation and constant practice in performance in trained conditions. We hypothesized that this may be due to the different gaze behavior that is developed under different conditions. Twenty participants, randomly assigned to two different groups, practiced basketball free throws for three consecutive days, performing 100 throws per day. The constant group (n = 10) practiced at a free throw distance (4.57 m) only. The variable practice group (n = 10) randomly performed 20 shots per five throw distances (3.35, 3.96, 4.57, 5.18, and 5.79 m) on each day, also accumulating 100 shots per day. We analyzed the total gaze fixation duration, a number of fixations, and the average fixation duration on a basketball rim in a pretest and posttest at the 4.57 m distance. We computed a linear mixed model with test (pretest–posttest), group (constant–variable), and test × group interaction in order to analyze the total fixation duration and number of fixations. The average fixation duration was analyzed with a repeated measure two-way ANOVA, with practice conditions as a between-participants factor and test type as a within-participants factor. We found that the total fixation duration increased significantly in the posttest, regardless of the practice conditions (p < 0.001, effect size = 0.504). The number of fixations also increased significantly in the posttest (p = 0.037, effect size = 0.246). The average fixation duration increased in both groups; however, insignificantly. We also did not find any significant differences between groups. Our results suggest that variable and constant practice conditions may lead to the development of similar gaze behavior.


2001 ◽  
Vol 92 (1) ◽  
pp. 99-106 ◽  
Author(s):  
Gary C. Galbraith ◽  
Bernadine Bagasan ◽  
Jane Sulahian

The human brainstem frequency-following response reflects neural activity to periodic auditory stimuli. Responses were simultaneously recorded from one vertically oriented and three horizontally oriented electrode derivations. Nine participants each received a total of 16,000 tone repetitions, 4,000 for each of four stimulus frequencies: 222, 266, 350, and 450 Hz. The responses were digitally filtered, quantified by correlation and spectral analysis, and statistically evaluated by repeated measure analysis of variance. While the various horizontal derivation responses did not differ from each other in latency (values tightly clustered around M = 2.60 msec), the vertical derivation response occurred significantly later ( M = 4.38 msec). The smaller latency for the horizontal responses suggests an origin within the acoustic nerve, while the larger latency for the vertical response suggests a central brainstem origin. The largest response amplitude resulted from gold “tiptrode” electrodes placed in each auditory meatus, suggesting that this electrode derivation provided the most accurate (noninvasive) assessment of short-latency events originating at the level of the auditory nerve.


2015 ◽  
Vol 55 (2) ◽  
pp. 219 ◽  
Author(s):  
J. L. Pye ◽  
R. E. Doyle ◽  
M. A. Friend ◽  
M. S. Bhanugopan

Magnesium (Mg) supplementation has shown to modulate the stress responses to transport in other species. An experiment was designed to evaluate the effect of Mg for alleviating stress associated with road transportation in lambs. Two groups (n = 18 each) of 4-month old male crossbred lambs (24 ± 4.5 kg) were fed a basal diet comprising oaten hay, pellets and barley, that contained 0.17% Mg. One group was supplemented with magnesium oxide, such that dietary Mg was 0.41%. At the end of the 2-week supplementation period, the lambs were transported by road for 8 h. Blood samples were collected before supplementation, 1 h before transport, within 0.5 h post-transport, at 2 h post-transport and 5 days post-transport. Data were analysed using a repeated-measure analysis of variance and linear mixed model with treatment within time interaction. Supplementation with dietary Mg in the form of MgO increased serum Mg concentrations (1.16 mmol/L ± 0.012, compared with 1.09 mmol/L ± 0.013 in the control group; P < 0.05), but had no effect on alleviating stress during transportation. Transport resulted in a significant increase in serum cortisol, which returned to pre-transport levels 2 h after transport. The serum β-hydroxybutyrate was significantly higher 5 days after transport. The post-transport average feed intake and the average daily gain were significantly lower than pre-transport values, suggesting that the stress of transportation resulted in a decrease in feed intake post-transport, which could have implications on liveweight gain of animals after transportation.


Sign in / Sign up

Export Citation Format

Share Document