Multivariable Mixed Linear Regression Models Research Articles

Short communication: Association between prepartum subclinical magnesium imbalance and postpartum diseases in grazing dairy cows in Southern Chile.

This study aimed to evaluate the relationship between prepartum subclinical hypomagnesemia (pre-SHMg) and the occurrence of dystocia, metritis, clinical mastitis, lameness, and subclinical hypomagnesemia postpartum (post-SHMg) in pasture-based dairy cows. Also, the difference in means of prepartum magnesium (Mg) concentration by postpartum health events was evaluated. A total of 890 dairy cows from 32 commercial farms located in southern Chile were enrolled. Cows were examined twice, once between 30 and 3 days before and once between 3 and 30 days after calving. Blood samples were collected on both assessments, and cows were considered as having SHMg if serum total Mg < 0.65 mmol/L. On the postpartum visit, cows were evaluated for metritis and lameness. Information about clinical mastitis and dystocia was collected from on-farm records. Data were analyzed using multivariable mixed linear models and multivariable mixed logistic regression models. The overall prevalence of pre-SHMg was 9.9%, and its presence was associated with the occurrence of post-SHMg (odd ratio [OR] = 5.7; P < 0.0001) and metritis (OR = 3.1; P = 0.04). However, we did not detect an association between pre-SHMg and dystocia, clinical mastitis, or lameness after calving. Prepartum serum Mg concentrations were lower in cows that developed post-SHMg than those that did not (LSM ± SE = 0.75 ± 0.02 mmol/L vs. 0.83 ± 0.02 mmol/L; P < 0.0001). In conclusion, pre-SHMg was associated with a higher risk of post-SHMg and metritis in grazing dairy cows but not other postpartum health events.

Progesterone profiles in postpartum dairy cows with inflammatory disorders

The objective of this prospective cohort study was to determine if progesterone (P4) profiles differed between dairy cows with or without inflammatory disorders early postpartum. A total of 708 cows from 2 commercial herds were enrolled 3 wk before parturition and examined for clinical health disorders (retained placenta, metritis, displaced abomasum, mastitis, or lameness) until 5 wk postpartum. Serum haptoglobin (Hp) was measured in blood at 2 and 6 (±2) DIM, metritis was assessed at 4, 8, 11, and 15 DIM, and purulent vaginal discharge and endometritis (≥6% polymorphonuclear cells in endometrial cytology sampled by cytobrush) were assessed at 35 ± 3 DIM. As Hp ≥0.8 g/L or endometritis were associated with ovarian dysfunction in previous studies, cows with serum Hp ≥0.8 g/L at either time point and endometritis, regardless of clinical disease, were classified as the cohort with inflammatory disorders (INFLAM; n = 139). Clinically healthy cows without difficult calving or twin birth, with Hp <0.8 g/L at both sampling times, without endometritis, and BCS ≥3.00 (1 to 5 scale) were classified as healthy (n = 133). Cows with only one of the 2 conditions (high Hp or endometritis) were excluded. Cohorts had serum P4 measured twice weekly from 35 to 70 (±3) DIM, and the first detected luteal phase (LP) during the sampling period was defined as the interval from onset of luteal activity (P4 increase to ≥1 ng/mL) until decline of P4 to <1 ng/mL. The odds of prolonged LP (≥21 d), average LP length, peak P4, and time to P4 decline (hazard rate) were analyzed using multivariable mixed logistic, linear, or Cox proportional hazard regression models including INFLAM status, parity, sampling day (when applicable), and herd as a random effect considering the covariates of season, milk yield at first DHIA test, and DIM at onset of cyclicity or LP length (when applicable). Cows with INFLAM had greater odds of prolonged LP (LSM ± SEM; 67% vs. 37% ± 7), greater average LP length (17 vs. 15 ± 2 d), lesser P4 at d 4 (4.6 vs. 5.5 ± 0.3 ng/mL) and d 7 (6.0 vs. 7.7 ± 0.3 ng/mL) of the LP, and lesser peak P4 (6.9 vs. 8.2 ± 0.3 ng/mL) during the LP than healthy cows. Status of INFLAM was associated with time to P4 decline in multiparous but not primiparous cows; the LP of INFLAM multiparous cows was less likely to have luteolysis (P4 decline) by d 14 [adjusted hazard ratio (AHR) and 95% CI: 0.54; 0.31 to 0.94] or by d 21 (AHR: 0.32; 0.12 to 0.84) than in healthy multiparous cows. In conclusion, postpartum cows with markers of systemic inflammation at wk 1 and uterine inflammation at wk 5 had altered luteal function (prolonged LP and lower P4 concentrations) before first breeding, which is a possible pathway linking postpartum health disorders and infertility.

Physical Activity, Fitness, and Cardiovascular Disease Risk in Adolescent Childhood Cancer Survivors Compared to Controls: The Physical Activity in Childhood Cancer Survivors Study.

Purpose: Childhood cancer survivors have increased risk of cardiac late effects that can be potentially mitigated by physical activity and fitness. We aimed to (1) compare cardiovascular disease (CVD) risk between survivors and controls, and (2) examine whether the associations of moderate-to-vigorous physical activity (MVPA), cardiorespiratory fitness (CRF), and musculoskeletal fitness (MSF) with CVD risk factors differed between survivors and controls. Methods: Within the Physical Activity in Childhood Cancer Survivors (PACCS) study, we assessed CVD risk factors (android fat mass, systolic blood pressure [SBP], total cholesterol/high-density lipoprotein [HDL]-cholesterol, and glycosylated hemoglobin) in 157 childhood cancer survivors and 113 age- and sex-matched controls aged 9-18 years. We used multivariable mixed linear regression models to compare CVD risk factors between survivors and controls, and assess associations of MVPA, CRF, and MSF with CVD risk factors. Results: Compared with controls, survivors had more android fat mass (861 vs. 648 g, p = 0.001) and lower SBP (114 vs. 118 mmHg, p = 0.002). MVPA, CRF, and MSF were associated with lower levels of android fat mass and total cholesterol/HDL-cholesterol, and higher SBP in survivors. Associations of MVPA, CRF, and MSF with CVD risk factors were similar in survivors and controls (Pinteraction > 0.05), except the associations of CRF and MSF with android fat mass, which were stronger in survivors than in controls (Pinteraction ≤ 0.001). Conclusion: Owing to higher levels of android fat mass and its stronger association with physical fitness in childhood cancer survivors compared with controls, survivors should get targeted interventions to increase fitness to reduce future risk of CVD.

Abstract 049: The Effect Of Temperate Seasonality On Systolic Blood Pressure Is Amplified In Population Control Rates

Background: Temperate seasonal effects have a significant influence on blood pressure (BP). Changes in average systolic (S)BP have an exaggerated effect on population BP control (BP &lt;140/90) rates, in part due to patients bordering the control target. We assessed the influence of seasonal effects on average SBP, as well as the corresponding effect on control rates across a patient cohort. Methods: A prospective patient cohort was selected from six diverse healthcare organizations engaged in a quality improvement program. Patients with a diagnosis of hypertension (HTN), no medication changes, and at least one visit in each temperate season during the assessment period were included. The seasonal effect on average SBP and control was determined from multivariable mixed effects linear and logistic regression models, respectively. Results: A cohort of 60,676 patients, mean age 62.3±12.0 years, meeting all inclusion criteria was selected. The population had 453,787 qualifying visits, where SBP during winter months averaged 0.47 mmHg higher (95% CI [0.364-0.573]) than the yearly mean, with a significantly lower odds ratio for BP control (OR 0.92, 95% CI [0.91-0.94]). In contrast, average SBP was 0.92 mmHg lower during the summer - with a higher likelihood of BP control (OR 1.10, 95% CI [1.07-1.12]). Conclusion: The seasonal effect on SBP was confirmed in a diverse group of adults with hypertension. The novel observation is the nearly 5% variation in BP control related to seasonal SBP variation of 1.4 mmHg. From a practical perspective, BP control is typically defined by values at the last visit of the calendar year, which occur disproportionately in months with higher SBP and lower control.

Sexual Minority Status Disparities in Life's Essential 8 and Life's Simple 7 Cardiovascular Health Scores: A French Nationwide Population-Based Study.

Background A higher burden of cardiovascular disease risk factors has been reported in sexual minority populations. Primordial prevention may therefore be a relevant preventative strategy. The study's objectives are to estimate the associations of Life's Essential 8 (LE8) and Life's Simple 7 (LS7) cardiovascular health scores with sexual minority status. Methods and Results The CONSTANCES is a nationwide French epidemiological cohort study that recruited randomly selected participants older than 18 years in 21 cities. Sexual minority status was based on self-reported lifetime sexual behavior and categorized as lesbian, gay, bisexual, or heterosexual. The LE8 score includes nicotine exposure, diet, physical activity, body mass index, sleep health, blood glucose, blood pressure, and blood lipids. The previous LS7 score included 7 metrics without sleep health. The study included 169 434 cardiovascular disease-free adults (53.64% women; mean age, 45.99 years). Among 90 879 women, 555 were lesbian, 3149 were bisexual, and 84 363 were heterosexual. Among 78 555 men, 2421 were gay, 2748 were bisexual, and 70 994 were heterosexual. Overall, 2812 women and 2392 men declined to answer. In multivariable mixed effects linear regression models, lesbian (β=-0.95 [95% CI, -1.89 to -0.02]) and bisexual (β=-0.78 [95% CI, -1.18 to -0.38]) women had a lower LE8 cardiovascular health score compared with heterosexual women. Conversely, gay (β=2.72 [95% CI, 2.25-3.19]) and bisexual (β=0.83 [95% CI, 0.39-1.27]) men had a higher LE8 cardiovascular health score compared with heterosexual men. The findings were consistent, although of smaller magnitudes for the LS7 score. Conclusions Cardiovascular health disparities exist in sexual minority adults, particularly lesbian and bisexual women, who may represent a priority population for primordial cardiovascular disease prevention.

Effects of Silirum®-Based Vaccination Programs on Map Fecal Shedding and Serological Response in Seven French Dairy Herds.

(1) Background: paratuberculosis is an important disease in ruminants, causing worldwide economic losses to the livestock industry. Although vaccination is known not to prevent transmission of the causative agent Mycobacterium avium subsp. paratuberculosis (Map), it is considered an effective tool for paratuberculosis in infected herds. The objectives of this controlled field study were to evaluate the effects of the whole-cell heat-killed Silirum® vaccine on Map fecal shedding and serological status in dairy herds infected with paratuberculosis. (2) Methods: The serological status (ELISA) and fecal shedding (qPCR) of 358 vaccinated cows were assessed over 3 years in 7 infected dairy herds in the Meuse department, France. Within each herd, cows from the last non-vaccinated birth cohort (n = 265) were used as controls. The probability and level of Map fecal shedding and the serological status were modeled using multivariable mixed general linear regression models. (3) Results: Overall, 34.7% of cows tested positive at least once on fecal qPCR, with significant differences between herds, but high shedding levels were observed in only 5.5% of cows. Compared to non-vaccinated seronegative cows, a statistically significant reduction in the probability of Map shedding was found only in cows vaccinated before 4 to 5 months of age that tested negative for Map antibodies throughout the study period (odds ratio = 0.5, 95% confidence interval: 0.3-0.9, p = 0.008), but no significant effect of vaccination on the amount of Map shedding could be evidenced. Finally, the younger the cows were when vaccinated, the less they tested positive on the serum ELISA. (4) Conclusions: a beneficial effect of vaccination on Map fecal shedding may exist in cows vaccinated before 4 to 5 months of age. The variability of the serum ELISA response in vaccinated cows remains to be investigated.

Sleep disturbances and emotional dysregulation in young children with autism spectrum, intellectual disability, or global developmental delay

ObjectiveSleep disturbance and emotional dysregulation (ED) are common and often functionally impairing in young children with neurodevelopmental disorders (NDD). This study investigated the relationship between sleep disturbance and ED in a sample of preschoolers with ASD, intellectual disability, or global developmental delay, and examined possible predictors of their persistence over time. MethodsAll children under 6 years of age clinically referred between July 2018 and May 2022 to two neuropsychiatric specialized centers for NDD received a comprehensive diagnostic evaluation, including the Child Behavior Checklist 1.5–5 (CBCL), the Autism Diagnostic Observation Schedule-2 (ADOS-2), and standardized tests of cognitive and global development. Sleep disturbances were assessed with the CBCL-sleep score, and ED with the CBCL Attention, Aggression, and Anxious/Depressed scales (CBCL-AAA). A reassessment of sleep and ED was conducted after 6 months or longer, including the Child Sleep Habits Questionnaire (CSHQ). Multivariate analyses and mixed linear regression models were conducted. ResultsA total of 136 children, 75.7% male, median age 38.27 months, IQR 15.39, 41.2% with global developmental disorder (GDD) or intellectual disability (ID) participated in the study. Of them, 64.7% were diagnosed with autism spectrum disorder (ASD) and 35.3% with other NDD (w/o ASD). Sleep disturbances (CBCL-Sleep) and ED (CBCL-AAA) were positively correlated (p < 0.001), after accounting for age, ID/GDD and autism symptom severity, in both the entire sample and separately in each diagnostic group (ASD and NDD w/o ASD). Seventy-five children (55%) were reassessed a mean 17.2 months afterwards. There was persistence of the positive correlation between sleep problems and ED (p < 0.001) in both the entire sample and each diagnostic group. The longitudinal mixed linear model showed that ED at follow-up was predicted by baseline sleep problems (p = 0.008), ED (p < 0.001), and ASD severity (p = 0.015). ConclusionsSleep disturbances are significantly associated with ED in young children with NDD, either with or without ASD, both cross-sectionally and prospectively over time. Sleep problems represent an important comorbidity and a potential treatment target for improving emotional stability in NDD.

Device-measured physical activity and cardiovascular disease risk in adolescent childhood cancer survivors. A physical activity in childhood cancer survivors (PACCS) study.

ObjectivesWe aimed to compare cardiovascular disease (CVD) risk factors in childhood cancer survivors (CCS) with age- and sex-stratified reference material and examine the association between physical activity (PA) intensities and CVD risk factors in CCS.Materials and methodsWithin the cross-sectional, multicenter Physical Activity in Childhood Cancer Survivors (PACCS) study, we collected data on CVD risk factors [VO2–peak (mL⋅kg–1⋅min–1), body mass index (BMI, kg/m2), systolic blood pressure (SBP, mmHg), and total-cholesterol/HDL-cholesterol (Total/HDL)] among CCS aged 9–18 years. CVD risk factors were compared to references with immediate t-tests. We transformed CVD risk factors into z-scores based on international references and generated an individual CVD risk score: [inverse ZVO2–peak + ZBMI + ZSBP + ZTotal/HDL)/4]. Multivariable mixed linear regression models were used to analyze the associations between device-measured PA intensities and CVD risk factors.ResultsWe included 157 CCS aged on average 13.4 years at inclusion and 8.2 years from diagnosis. Male CCS had lower VO2–peak compared to references (45.4 vs. 49.4 mL⋅kg–1⋅min–1, P = 0.001), higher diastolic BP (67 vs. 63 mmHg, P < 0.001), lower HDL (1.35 vs. 1.44 mmol/L, P = 0.012), as well as a tendency to higher CVD risk score (z-score=0.14 vs. 0.00, P = .075). Female CCS’ CVD risk factors were comparable to references. Vigorous-intensity PA (VPA) was associated with CVD risk factors. A 10-min increase in VPA was associated with higher VO2–peak (β = 4.9, 95% CI, 2.1–7.7), lower Total/HDL (β = −0.3, 95% CI, −0.6 to −0.1) and a lower CVD risk score (β = −0.4, 95% CI, −0.6 to −0.2).ConclusionMale adolescent CCS had less favorable values of CVD risk factors compared to references. VPA in adolescent CCS is associated with clinically meaningful favorable values of CVD risk factors.

Animal Health in Compost-Bedded Pack and Cubicle Dairy Barns in Six European Countries.

Simple SummaryDairy barns with compost-bedded pack housing systems are relatively new in Europe. They have housing systems that are vastly different from traditional tie-stall or cubicle housing and provide possibilities for improved animal welfare. However, it is important to investigate how actual cow health is influenced. We used readily available data from 32 dairy herds throughout Europe, half of which had compost-bedded pack housing and half cubicle housing, to investigate differences in dairy cow health. We found that herds with compost-bedded packs had poorer udder health than did herds with cubicles, while they seemed to have fewer problems with reproductive disorders. Our conclusion was that there were few, relatively minor differences between the systems. This knowledge is valuable for farmers interested in applying new housing systems for dairy cows and for consumers who want to stay informed about production conditions in dairy herds.The purpose of this study was to compare animal health in compost-bedded pack (CBP) and cubicle housing (CH) systems using data from dairy herd improvement associations. Thirty-two commercial dairy farms located in Austria, Germany, Italy, The Netherlands, Slovenia, and Sweden were included in the study. A matching design (pairing CBP and CH within country) according to herd selection criteria was used. We explored the following health indicators: somatic cell counts (SCC), high SCC, new high SCC, ketosis risk, prolonged calving intervals, dystocia, and stillbirth. Traits for culling and culling-related issues, such as length of life and length of productive life, were also included. We used multivariable (mixed) linear and logistic regression models to evaluate differences between the systems. Udder health, as measured by SCC, was inferior in CBP, although the geometric means were low in both systems. The incidence of stillbirths was higher in CBP, while prolonged calving intervals were fewer, indicating that there were fewer reproductive disorders. There were no differences in longevity between the systems, although CBP had lower proportions of first calvers. Overall, we conclude that there were few and minor differences in health and longevity between the CBP and CH systems in the European context.

Abstract 10181: The Effect of Immune Checkpoint Inhibitors for Cancer on Blood Pressure

Introduction: Immune checkpoint inhibitors (ICIs) treat an expanding range of cancers and the use of ICIs has been associated with an increase in atherosclerotic cardiovascular disease (ASCVD) events. The mechanisms involved in the increase in ASCVD with ICIs are incompletely understood. These same immune checkpoints targeted for cancer also regulate vascular function, yet there are no data testing the effect of ICIs on blood pressure. Hypothesis: Based on basic data on the role of these immune checkpoints in vascular function, we hypothesize that the use of ICIs would increase systolic and diastolic blood pressure. Methods: This was a single academic medical center study of 8,724 patients treated with an ICI. The primary analysis evaluated whether exposure to ICIs was associated with changes in blood pressure using repeated measures multivariate mixed linear regression models. The secondary analysis evaluated the effect of changes in blood pressure on all cause mortality using Cox proportional hazard models. Results: Of the 8,724 patients, 4,812 (55.2%) had a diagnosis of hypertension at ICI start. The average blood pressure at ICI start was 128.3±18.1/72.5±10.1mmHg. Among the entire cohort, there was a decrease of 2.9 mmHg in systolic blood pressure (95% CI: 2.70-3.02) after starting an ICI, and a drop of 1.6 mmHg (95% CI: 1.52-1.70) in diastolic blood pressure (adjusted, p&lt;0.001 for both) (Figure 1). The effect of an ICI on blood pressure was independent of the development of any toxicity associated with an ICI. Patients who had an increase of ≥20 mmHg in systolic blood pressure after starting ICI had a lower risk of all-cause death (HR 0.74, 95% CI: 0.63-0.86) compared to patients with no or less than ≥20 mmHg increase. Conclusions: Among a large cohort of patients, ICI therapy is associated with a drop in systolic and diastolic blood pressure. However, patients who had an increase of at least ≥20 mmHg in systolic blood pressure had lower risk of all-cause death.

Enhanced recovery after surgery (ERAS) for open transforaminal lumbar interbody fusion: a retrospective propensity-matched cohort study

BACKGROUNDThe enhanced recovery after surgery (ERAS) protocol is a multidisciplinary, multimodal approach which has been shown to facilitate recovery of physiological function, and reduce postoperative pain, complication rates, and length of stay without adversely affecting readmission rates. Design and implementation of ERAS protocols in the recent spine surgery literature has primarily focused on patients undergoing minimally invasive lumbar surgery. However, conventional open transforaminal lumbar interbody fusion (TLIF) remains a common procedure and to date there are no studies assessing an ERAS protocol in this patient population. PURPOSEThis study presents a single surgeon experience implementing an ERAS protocol in patients undergoing 1- or 2-level open TLIF. STUDY DESIGN/SETTINGRetrospective consecutive patient cohort with controls propensity-matched for age, body mass index, sex, and smoking status. PATIENT SAMPLEConsecutive patients that underwent 1- or 2-level open TLIF for degenerative disease from 12/2018 – 02/2021 and controls from 12/2011-12/2017 by a single surgeon. ERAS was implemented in December 2018. OUTCOME MEASURESPrimary: length of stay; Secondary: first day to ambulate, first day to bowel movement, first day to void, daily average and maximum pain scores, opioid use, discharge disposition, 30-day readmission rate, and re-operations. METHODSDemographic, perioperative, clinical, radiographic data were collected. Multivariate mixed-linear regression models were developed for length of stay, physiological function, pain scales, and opiate use. RESULTSThere were 114 patients included with 57 in each cohort. After propensity matching, patient characteristics were similar between groups. Operative time decreased significantly after institution of ERAS (170±44 vs. 141±37 minutes, p <.0001) as did length of stay (4.6±1.7 vs. 3.6±1.6 days, p<.0001). First day of ambulation, bowel movement, and bladder voiding improved by 0.8 (p<.0001), 0.7 (p=.008), and 0.8 (p<.0001) days, respectively, in the ERAS cohort. Total daily intravenous morphine milligram equivalent (MME) (8±9 vs. 36±38, p<0.0001) and total 72-hour MME consumption (53±33 vs. 68±48, p<.0001) was significantly lower in the ERAS cohort; however, 72-hour MME consumption was not found to be significantly different in a sensitivity analysis controlling for preoperative MME. Average daily pain scores were similar between groups. CONCLUSIONSConsistent with other studies demonstrating benefit of an ERAS protocol for minimally invasive spine procedures, ERAS was associated with decreased operative time, reduced length of stay, decrease in IV opioid consumption, and improved physiological outcomes for open 1- and 2-level TLIF. ERAS can be a potentially effective strategy for improving patient outcome and efficiency of healthcare resources for common conventional spinal surgeries such as open TLIF.

Association of exposure to residential greenness with semen quality: A retrospective longitudinal study of sperm donation volunteers in Guangdong province, China

BackgroundExposure to residential greenness has been associated with benefits on certain reproductive health outcomes. However, its potential benefits on semen quality remain unknown. ObjectivesTo quantitatively explore the association between exposure to residential greenness and semen quality. MethodsWe investigated 9142 sperm donation volunteers who underwent 38,682 semen examinations at Guangdong provincial human sperm bank in China during 2016–2019. Exposure to residential greenness was assessed using mean daily Normalized Difference Vegetation Index (NDVI) at each subject’s residential address with a 400 m buffer during 0–90 days before each semen collection. Multivariate linear mixed models and linear regression models were used to assess the association between exposure to residential greenness and semen quality. ResultsAn interquartile range increase in exposure to residential greenness was significantly associated with a 0.034 (95% confidence interval [CI]: 0.005, 0.063) ml, 4.06 (95% CI: 0.76, 7.37) × 106, and 0.32% (95% CI: 0.22%, 0.41%) increase in semen volume, total sperm number, and normal forms, respectively; similar trends were observed across quartiles of exposure to residential greenness (all p-values for liner trend <0.05 except for semen volume). The association of greenness exposure with semen volume and total sperm number was stronger in subjects 18–25 years, while the association with normal forms was stronger in subjects 26 years or older. The association for sperm concentration, total sperm number, and normal forms were stronger in cool season, while the association for semen volume was stronger in warm season. ConclusionWe found that exposure to residential greenness was significantly associated with higher semen quality. Further studies are warranted to determine the causality of the association and its underlying mechanisms.

Temperature Inversion and Ultrafine Particulate/Near Ultrafine Particulate Matter Concentrations in the Salt Lake Valley

Ultrafine particulate (UFP) matter exposures are associated with negative health outcomes. UFPs (&lt;100nm) and near UFP (NUFP) matter (4.5nm - 250nm) are trapped by the bowl-like geography of the Salt Lake Valley causing winter inversions (i.e., trapped particulate matter (PM)). Enmont PUFP C100 and Grimm 1.109 particle counters were used to define NUFP concentrations during inversion (n=5) and non-inversion (n=5) days at 7 sites. NUFP concentrations served as a proxy for the UFP fraction. NUFP concentrations were log-transformed and multivariable mixed effects linear regression models determined if NUFP concentration differed between inversion and non-inversion or by length of inversion. Difference in fraction NUFP was also analyzed. The mean NUFP concentration was 1.49-fold higher during inversions (95% CI 1.11–2.02), whereas the fraction declined by 0.22 (95% CI -0.31– -0.13). Increased NUFP concentrations during inversions may lead to increased adverse health outcomes. These findings have serious implications for inversion-prone regions.

Nocturnal Variability of Intraocular Pressure Monitored With Contact Lens Sensor Is Associated With Visual Field Loss in Glaucoma.

The aim was to determine whether 24-hour recording of intraocular pressure (IOP)-related ocular dimensional changes with a contact lens sensor (CLS, Triggerfish) is associated with the rate of visual field (VF) progression in primary open-angle glaucoma (POAG) patients. This was a retrospective, observational cohort study. Patients with POAG were included from the Glaucoma Clinic and Diagnostic Innovations in Glaucoma Study at the Hamilton Glaucoma Center at University of California, San Diego. A session of 24-hour CLS recording was acquired for 1 eye from each patient. The mean follow-up time was 9.9±4.0 years. The association between CLS variables and rate of change of mean deviation was determined by univariate and multivariate mixed linear regression models. Thirty-two patients, aged 69.8±13.6 years were included, 50% were female. An average of 11.6±5.6 standard automated perimetry examinations was available with a mean rate of mean deviation progression of -0.2±0.4 dB/year. Mean IOP was 17.8±4.2 mm Hg. The mean number of IOP-lowering medications were 1.2±1.0. Each 10-unit larger nocturnal variability of IOP-related ocular dimensional changes measured by CLS recording was significantly associated with -0.25±0.11 dB faster VF loss in POAG patients (P=0.035). Twenty-four-hour CLS recording of IOP-related ocular dimensional change was associated with faster VF progression. Such CLS recordings are useful to assess the risk of in progression in POAG patients.

Determinants of volume status in peritoneal dialysis: A longitudinal study.

In peritoneal dialysis (PD), fluid overload is frequent and associated with cardiac dysfunction and mortality. As it is considered a modifiable risk factor, we wished to describe clinical determinants of fluid overload in a longitudinal cohort of PD outpatients. We consecutively included PD outpatients treated with continuous ambulatory PD (CAPD) or automated PD (APD) attending for their routine clinical visit at a single tertiary hospital. Extracellular water (ECW) to total body water (TBW) ratio was measured by multifrequency bioelectrical impedance. Peritoneal transport characteristics were measured with a standard peritoneal equilibration test. Patients had a second follow-up visit with the same measurements. Univariable and multivariable mixed linear regression models were conducted with ECW/TBW as the dependent variable. A total of 155 patients were enrolled with a median follow-up time of 12 months. Median dialysis vintage was 13.5 ± 3.4 months. Overall mean value of ECW/TBW was 39.3% ± 1.1. In multivariable analysis, factors positively associated with ECW/TBW were: Age (P < .001), diabetes (P = .002), and SBP (P = .028). Factors negatively associated with ECW/TBW were: nPNA (P = .001), serum albumin (P < .001) and PTH (P = .014). None of the considered variable showed a significant interaction with time. We confirm a high prevalence of fluid overload in PD patients and show that it is strongly associated with older age, diabetes, hypoalbuminemia and protein energy wasting. In contrast, when PD prescription is tailored to patient's individual characteristics, residual renal function, PD modality and peritoneal characteristics are not decisive in controlling volume status.

High blood pressure predicts hippocampal atrophy rate in cognitively impaired elders.

IntroductionUnderstanding relationships among blood pressure (BP), cognition, and brain volume could inform Alzheimer's disease (AD) management.MethodsWe investigated Alzheimer's Disease Neuroimaging Initiative (ADNI) participants: 200 controls, 346 mild cognitive impairment (MCI), and 154 AD. National Alzheimer's Co‐ordinating Center (NACC) participants were separately analyzed: 1098 controls, 2297 MCI, and 4845 AD. Relationships between cognition and BP were assessed in both cohorts and BP and atrophy rates in ADNI. Multivariate mixed linear‐regression models were fitted with joint outcomes of BP (systolic, diastolic, and pulse pressure), cognition (Mini‐Mental State Examination, Logical Memory, and Digit Symbol) and atrophy rate (whole‐brain, hippocampus).ResultsADNI MCI and AD patients with greater baseline systolic BP had higher hippocampal atrophy rates ([r, P value]; 0.2, 0.005 and 0.2, 0.04, respectively). NACC AD patients with lower systolic BP had lower cognitive scores (0.1, 0.0003).DiscussionHigher late‐life BP may be associated with faster decline in cognitively impaired elders.

Effects of Calliandra and Sesbania supplementation on weight gain in dairy calves on smallholder farms in Kenya

The growth rate of female calves on dairy farms is one of the crucial factors which influence age at first calving, affecting lifetime lactation productivity of a dairy cow. Diets with adequate crude protein are necessary to support calf growth. The study objective was to determine the effects of nutritional advice and diet supplementation with Calliandra calothyrsus and Sesbania sesban on average daily weight gain in dairy calves on semi-commercial smallholder dairy farms in Kenya. This trial involved 155 calves from 73 smallholder dairy farms, in Kenya, randomly selected and allocated to either intervention or control groups. The intervention group received nutritional advice and seedlings of Calliandra calothyrsus and Sesbania sesban, while the control group did not receive these interventions. Every 1–2 months for 16 months, data on farm nutritional practices and management were collected in a questionnaire, and physical examinations were done to monitor weight and health status. Descriptive and univariable statistical analyses were conducted, and multivariable mixed linear regression models were used for identification of factors associated (P < 0.05) with the natural log transformation of weight gain of calves on a given farm, controlling for clustering of visits within calves. Feeding at least 0.2 kg/day (wet weight) of Calliandra or Sesbania to calves <6 months old resulted in 33.2% increase in daily weight gain, while controlling for confounding by breed and sex of the calf. For calves ≥6 months, there was a significant interaction between amount of hay fed and if calves were also fed on Calliandra or Sesbania. When no Calliandra or Sesbania supplementation was provided, the mean weight gain was low and relatively constant even with increasing amounts of hay. When Calliandra or Sesbania supplement was added to the diet, the mean weight gain increased from 0.17 kg to 0.48 kg when hay was fed at 1 and 5 kg, respectively, while controlling for confounding by amount of maize silage fed and the prevailing season. In conclusion, supplementation of calf diets with at least 0.2 kg/calf/day of Calliandra or Sesbania is beneficial for faster weight gains.

Assessment of farmers’ compliance in implementing recommended cow comfort changes and their effects on lying time, stall and cow cleanliness within smallholder dairy farms in Kenya

Our study aimed to evaluate farmers’ compliance in implementing recommendations of farm-specific cow comfort changes, and the effects of these changes on lying time, stall cleanliness and cow cleanliness using a randomized controlled trial carried out on 100 smallholder dairy farms in Kenya, with 62 and 11 farms remaining in the intervention and control groups, respectively.On the first farm visit, data loggers were attached on lactating cows to determine lying time and questionnaires utilized to collect baseline data. Three days later, stall design and management recommendations were given to the intervention group of farmers orally and in written form. After an average of 39 ± 7 days, data loggers were re-attached, compliance was assessed, and a post-intervention questionnaire was administered to the intervention group on the third visit. Three days subsequent to the first and third visits, data loggers were removed from all cows.Data were analysed in Stata 14.2® using proportion tests and Kruskal-Wallis rank tests to compare cleanliness scores and lying time, respectively. Interaction effects between treatment groups and visits were assessed using multivariable mixed linear and logistic regression models. While 46 of the 62 intervention farmers (74%) made at least one recommended change to cow comfort, 63% of the 324 overall recommendations were implemented. The odds of a recommendation being implemented were significantly higher when:1) major recommendations were given relative to minor recommendations (OR = 6.28); 2) recommendations were related to floor characteristics (floor softness and flatness) in comparison to recommendations related to stall design (OR = 3.14). The odds of compliance were lower on: 1) farms where the farm-hands received the recommendations compared to farms that had the female principal farmer receive the recommendations (OR = 0.01); 2) farms that had recommended changes related to roof, alley and sharps fixes relative to stall design fixes (OR = 0.13). Post-intervention, stall, udder and upper hind-leg cleanliness scores improved significantly (p < 0.0001, p = 0.021 and p = 0.017, respectively) in the intervention farms but not in the control farms. There was no significant difference in lying times between intervention and control farms, with 0.6 and 0.2 h/day increases being recorded in the intervention and control groups, from the 10.9 and 10.4 h/day at baseline, respectively.Giving farm-specific cow comfort recommendations to smallholder dairy farmers in Kenya, and providing them with a participatory role in the formulation and implementation of improvement recommendations ensured good acceptance and a high degree of implementation, and led to a subsequent improvement in cow comfort and cleanliness.

Association of long-term exposure to traffic-related PM10 with heart rate variability and heart rate dynamics in healthy subjects

BackgroundEpidemiological evidence on the influence of long-term exposure to traffic-related particulate matter (TPM10) on heart rate variability (HRV) is weak. ObjectiveTo evaluate the association of long-term exposure (10 years) with TPM10 on the regulation of the autonomic cardiovascular system and heart rate dynamics (HRD) in an aging general population, as well as potential modifying effects by the a priori selected factors sex, smoking status, obesity, and gene variation in selected glutathione S-transferases (GSTs). MethodsWe analyzed data from 1593 SAPALDIA cohort participants aged ≥ 50 years. For each participant, various HRV and HRD parameters were derived from 24-hour electrocardiogram recordings. Each parameter obtained was then used as the outcome variable in multivariable mixed linear regression models in order to evaluate the association with TPM10. Potential modifying effects were assessed using interaction terms. ResultsNo association between long-term exposure to TPM10 and HRV/HRD was observed in the entire study population. However, HRD changes were found in subjects without cardiovascular morbidity and both HRD and HRV changes in non-obese subjects without cardiovascular morbidity. Subjects without cardiovascular morbidity with homozygous GSTM1 gene deletion appeared to be more susceptible to the effects of TPM10. ConclusionThis study suggests that long-term exposure to TPM10 triggers adverse changes in the regulation of the cardiovascular system. These adverse effects were more visible in the subjects without cardiovascular disease, in whom the overall relationship between TPM10 and HRV/HRD could not be masked by underlying morbidities and the potential counteracting effects of related drug treatments.

Preweaned heifer management on US dairy operations: Part II. Factors associated with colostrum quality and passive transfer status of dairy heifer calves

Passive transfer of immunity is essential for the short- and long-term health of dairy calves. The objective of this study was to evaluate factors associated with colostrum quality and passive transfer status of US heifer calves. This study included 104 operations in 13 states that participated in the calf component of the National Animal Health Monitoring System's Dairy 2014 study. This 18-mo longitudinal study included 1,972 Holstein heifer calves from birth to weaning. Multivariable mixed linear regression models were selected using backward elimination model selection after univariate screening to determine which factors were associated with colostrum IgG and serum IgG concentrations. The mean colostrum IgG concentration was 74.4 g/L with 77.4% of colostrum samples having IgG concentrations >50 g/L. The final model for colostrum IgG included colostrum source and a categorized temperature-humidity index value (cTHI) for the month before calving. Mean colostrum IgG concentrations were highest for dams in third and higher lactations (84.7 g/L) and lowest for commercial colostrum replacers (40.3 g/L). Colostrum IgG concentrations were highest for cTHI ≥70 (72.6 g/L) and lowest for cTHI <40 (64.2 g/L). The mean serum IgG concentration was 21.6 g/L, with 73.3% of calves having serum IgG concentrations >15 g/L. The final model for serum IgG concentration included region, heat treatment of colostrum, colostrum source, timing to first feeding, volume of colostrum fed in the first 24 h, age of the calf at blood sampling, and colostrum IgG concentration. Mean serum IgG concentrations were highest for calves that received colostrum from first-lactation dams (25.7 g/L) and lowest for calves fed commercial colostrum replacer (16.6 g/L). Serum IgG concentrations were higher for calves fed heat-treated colostrum (24.4 g/L) than for calves fed untreated colostrum (20.5 g/L). Serum IgG concentration was positively associated with the volume of colostrum fed in the first 24 h and colostrum IgG concentration, and negatively associated with the number of hours from birth to colostrum feeding and age (days) at blood collection. Dairy producers should be encouraged to measure the quality of colostrum before administering it to calves and to measure serum IgG or a proxy such as serum total protein or Brix to evaluate passive immunity and colostrum management programs.