Prevalence of malnutrition in community-dwelling adults with Parkinson's disease

People with Parkinson’s disease (PD) have been reported to be at higher risk of malnutrition than an age-matched population due to PD motor and non-motor symptoms and pharmacotherapy side effects. The prevalence of malnutrition in PD has yet to be well-defined. Community-dwelling people with PD, aged > 18 years, were recruited (n = 97, 61 M, 36 F). The Patient-Generated Subjective Global Assessment (PGSGA) was used to assess nutritional status, the Parkinson’s Disease Questionnaire (PDQ-39) was used to assess quality of life, and the Beck’s Depression Inventory (BDI) was used to measure depression. Levodopa equivalent doses (LEDs) were calculated based on reported Parkinson’s disease medication. Weight, height, mid-arm circumference (MAC) and calf circumference were measured. Cognitive function was measured using the Addenbrooke’s Cognitive Examination. Average age was 70.0 (9.1, 35–92) years. Based on SGA, 16 (16.5%) were moderately malnourished (SGA B) while none were severely malnourished (SGA C). The well-nourished participants (SGA A) had a better quality of life, t(90) = −2.28, p < 0.05, and reported less depressive symptoms, t(94)= −2.68, p < 0.05 than malnourished participants. Age, years since diagnosis, cognitive function and LEDs did not signifi cantly differ between the groups. The well-nourished participants had lower PG-SGA scores, t(95) = −5.66, p = 0.00, higher BMIs, t(95) = 3.44, p < 0.05, larger MACs, t(95) = 3.54, p < 0.05 and larger calf circumferences, t(95) = 2.29, p < 0.05 than malnourished participants. Prevalence of malnutrition in community-dwelling adults with PD in this study is comparable to that in other studies with community-dwelling adults without PD and is higher than other PD studies where a nutritional status assessment tool was used. Further research is required to understand the primary risk factors for malnutrition in this group.

Risk factors for malnutrition in community-dwelling people with Parkinson’s disease

In the elderly, the risks for protein-energy malnutrition from older age, dementia, depression and living alone have been well-documented. Other risk factors including anorexia, gastrointestinal dysfunction, loss of olfactory and taste senses and early satiety have also been suggested to contribute to poor nutritional status. In Parkinson’s disease (PD), it has been suggested that the disease symptoms may predispose people with PD to malnutrition. However, the risks for malnutrition in this population are not well-understood. The current study’s aim was to determine malnutrition risk factors in community-dwelling adults with PD. Nutritional status was assessed using the Patient-Generated Subjective Global Assessment (PG-SGA). Data about age, time since diagnosis, medications and living situation were collected. Levodopa equivalent doses (LDED) and LDED per kg body weight (mg/kg) were calculated. Depression and anxiety were measured using the Beck’s Depression Inventory (BDI) and Spielberger Trait Anxiety questionnaire, respectively. Cognitive function was assessed using the Addenbrooke’s Cognitive Examination (ACE-R). Non-motor symptoms were assessed using the Scales for Outcomes in Parkinson's disease-Autonomic (SCOPA-AUT) and Modified Constipation Assessment Scale (MCAS). A total of 125 community-dwelling people with PD were included, average age of 70.2±9.3(35-92) years and average time since diagnosis of 7.3±5.9(0–31) years. Average body mass index (BMI) was 26.0±5.5kg/m2. Of these, 15% (n=19) were malnourished (SGA-B). Multivariate logistic regression analysis revealed that older age (OR=1.16, CI=1.02-1.31), more depressive symptoms (OR=1.26, CI=1.07-1.48), lower levels of anxiety (OR=.90, CI=.82-.99), and higher LDED per kg body weight (OR=1.57, CI=1.14-2.15) significantly increased malnutrition risk. Cognitive function, living situation, number of prescription medications, LDED, years since diagnosis and the severity of non-motor symptoms did not significantly influence malnutrition risk. Malnutrition results in poorer health outcomes. Proactively addressing the risk factors can help prevent declines in nutritional status. In the current study, older people with PD with depression and greater amounts of levodopa per body weight were at increased malnutrition risk.

Malnutrition in a sample of community-dwelling people with Parkinson’s disease

Objective: Malnutrition results in poor health outcomes, and people with Parkinson’s disease may be more at risk of malnutrition. However, the prevalence of malnutrition in Parkinson’s disease is not yet well defined. The aim of this study is to provide an estimate of the extent of malnutrition in community-dwelling people with Parkinson’s disease. Methods: This is a cross-sectional study of people with Parkinson’s disease residing within a 2 hour driving radius of Brisbane, Australia. The Subjective Global Assessment (SGA) and scored Patient Generated Subjective Global Assessment (PG-SGA) were used to assess nutritional status. Body weight, standing or knee height, mid-arm circumference and waist circumference were measured. Results: Nineteen (15%) of the participants were moderately malnourished (SGA-B). The median PG-SGA score of the SGA-B group was 8 (4 – 15), significantly higher than the SGA-A group, U=1860.5,p<.05. The symptoms most influencing intake were loss of appetite, constipation, early satiety and problems swallowing. Conclusions: As with other populations, malnutrition remains under-recognised and undiagnosed in people with Parkinson’s disease. Regular screening of nutritional status in people with Parkinson’s disease by health professionals with whom they have regular contact should occur to identify those who may benefit from further nutrition assessment and intervention.

Shear buckling characteristics of cold-formed steel channel beams

Cold-formed steel members are increasingly used as primary structural elements in the building industries around the world due to the availability of thin and high strength steels and advanced cold-forming technologies. Cold-formed lipped channel beams (LCB) are commonly used as flexural members such as floor joists and bearers. However, their shear capacities are determined based on conservative design rules. For the shear design of LCB web panels, their elastic shear buckling strength must be determined accurately including the potential post-buckling strength. Currently the elastic shear buckling coefficients of LCB web panels are determined by assuming conservatively that the web panels are simply supported at the junction between their flange and web elements. Hence finite element analyses were conducted to investigate the elastic shear buckling behavior of LCBs. An improved equation for the higher elastic shear buckling coefficient of LCBs was proposed based on finite element analysis results and included in the ultimate shear capacity equations of the North American cold-formed steel codes. Finite element analyses show that relatively short span LCBs without flange restraints are subjected to a new combined shear and flange distortion action due to the unbalanced shear flow. They also show that significant post-buckling strength is available for LCBs subjected to shear. New equations were also proposed in which post-buckling strength of LCBs was included.

Association between ambient ultraviolet radiation and risk of esophageal cancer

OBJECTIVES: Ecological studies have suggested an inverse relationship between latitude and risks of some cancers. However, associations between solar ultraviolet radiation (UVR) exposure and esophageal cancer risk have not been fully explored. We therefore investigated the association between nevi, freckles, and measures of ambient UVR over the life-course with risks of esophageal cancers. METHODS: We compared estimated lifetime residential ambient UVR among Australian patients with esophageal cancer (330 esophageal adenocarcinoma (EAC), 386 esophago-gastric junction adenocarcinoma (EGJAC), and 279 esophageal squamous cell carcinoma (ESCC)), and 1471 population controls. We asked people where they had lived at different periods of their life, and assigned ambient UVR to each location based on measurements from NASA's Total Ozone Mapping Spectrometer database. Freckling and nevus burden were self-reported. We used multivariable logistic regression models to estimate the magnitude of associations between phenotype, ambient UVR, and esophageal cancer risk. RESULTS: Compared with population controls, patients with EAC and EGJAC were less likely to have high levels of estimated cumulative lifetime ambient UVR (EAC odds ratio (OR) 0.59, 95% confidence interval (CI) 0.35-0.99, EGJAC OR 0.55, 0.34-0.90). We found no association between UVR and risk of ESCC (OR 0.91, 0.51-1.64). The associations were independent of age, sex, body mass index, education, state of recruitment, frequency of reflux, smoking status, alcohol consumption, and H. pylori serostatus. Cases with EAC were also significantly less likely to report high levels of nevi than controls. CONCLUSIONS: These data show an inverse association between ambient solar UVR at residential locations and risk of EAC and EGJAC, but not ESCC.

Effect of cold water immersion after exercise in the heat on muscle function, body temperatures, and vessel diameter

Cold water immersion (CWI) is a popular recovery modality, but actual physiological responses to CWI after exercise in the heat have not been well documented. The purpose of this study was to examine effects of 20-min CWI (14 degrees C) on neuromuscular function, rectal (T(re)) and skin temperature (T(sk)), and femoral venous diameter after exercise in the heat. Ten well-trained male cyclists completed two bouts of exercise consisting of 90-min cycling at a constant power output (216+/-12W) followed by a 16.1km time trial (TT) in the heat (32 degrees C). Twenty-five minutes post-TT, participants were assigned to either CWI or control (CON) recovery conditions in a counterbalanced order. T(re) and T(sk) were recorded continuously, and maximal voluntary isometric contraction torque of the knee extensors (MVIC), MVIC with superimposed electrical stimulation (SMVIC), and femoral venous diameters were measured prior to exercise, 0, 45, and 90min post-TT. T(re) was significantly lower in CWI beginning 50min post-TT compared with CON, and T(sk) was significantly lower in CWI beginning 25min post-TT compared with CON. Decreases in MVIC, and SMVIC torque after the TT were significantly greater for CWI compared with CON; differences persisted 90min post-TT. Femoral vein diameter was approximately 9% smaller for CWI compared with CON at 45min post-TT. These results suggest that CWI decreases T(re), but has a negative effect on neuromuscular function.

Cold-water immersion decreases cerebral oxygenation but improves recovery after intermittent-sprint exercise in the heat

This study examined the effects of post-exercise cooling on recovery of neuromuscular, physiological, and cerebral hemodynamic responses after intermittent-sprint exercise in the heat. Nine participants underwent three post-exercise recovery trials, including a control (CONT), mixed-method cooling (MIX), and cold-water immersion (10 °C; CWI). Voluntary force and activation were assessed simultaneously with cerebral oxygenation (near-infrared spectroscopy) pre- and post-exercise, post-intervention, and 1-h and 24-h post-exercise. Measures of heart rate, core temperature, skin temperature, muscle damage, and inflammation were also collected. Both cooling interventions reduced heart rate, core, and skin temperature post-intervention (P < 0.05). CWI hastened the recovery of voluntary force by 12.7 ± 11.7% (mean ± SD) and 16.3 ± 10.5% 1-h post-exercise compared to MIX and CONT, respectively (P < 0.01). Voluntary force remained elevated by 16.1 ± 20.5% 24-h post-exercise after CWI compared to CONT (P < 0.05). Central activation was increased post-intervention and 1-h post-exercise with CWI compared to CONT (P < 0.05), without differences between conditions 24-h post-exercise (P > 0.05). CWI reduced cerebral oxygenation compared to MIX and CONT post-intervention (P < 0.01). Furthermore, cooling interventions reduced cortisol 1-h post-exercise (P < 0.01), although only CWI blunted creatine kinase 24-h post-exercise compared to CONT (P < 0.05). Accordingly, improvements in neuromuscular recovery after post-exercise cooling appear to be disassociated with cerebral oxygenation, rather reflecting reductions in thermoregulatory demands to sustain force production.

Markers of disease severity are associated with malnutrition in Parkinson's disease

Objective In Parkinson's disease (PD), commonly reported risk factors for malnutrition in other populations commonly occur. Few studies have explored which of these factors are of particular importance in malnutrition in PD. The aim was to identify the determinants of nutritional status in people with Parkinson's disease (PWP). Methods Community-dwelling PWP (>18 years) were recruited (n = 125; 73M/52F; Mdn 70 years). Self-report assessments included Beck's Depression Inventory (BDI), Spielberger Trait Anxiety Inventory (STAI), Scales for Outcomes in Parkinson's disease – Autonomic (SCOPA-AUT), Modified Constipation Assessment Scale (MCAS) and Freezing of Gait Questionnaire (FOG-Q). Information about age, PD duration, medications, co-morbid conditions and living situation was obtained. Addenbrooke's Cognitive Examination (ACE-R), Unified Parkinson's Disease Rating Scale (UPDRS) II and UPDRS III were performed. Nutritional status was assessed using the Subjective Global Assessment (SGA) as part of the scored Patient-Generated Subjective Global Assessment (PG-SGA). Results Nineteen (15%) were malnourished (SGA-B). Median PG-SGA score was 3. More of the malnourished were elderly (84% vs. 71%) and had more severe disease (H&Y: 21% vs. 5%). UPDRS II and UPDRS III scores and levodopa equivalent daily dose (LEDD)/body weight(mg/kg) were significantly higher in the malnourished (Mdn 18 vs. 15; 20 vs. 15; 10.1 vs. 7.6 respectively). Regression analyses revealed older age at diagnosis, higher LEDD/body weight (mg/kg), greater UPDRS III score, lower STAI score and higher BDI score as significant predictors of malnutrition (SGA-B). Living alone and higher BDI and UPDRS III scores were significant predictors of a higher log-adjusted PG-SGA score. Conclusions In this sample of PWP, the rate of malnutrition was higher than that previously reported in the general community. Nutrition screening should occur regularly in those with more severe disease and depression. Community support should be provided to PWP living alone. Dopaminergic medication should be reviewed with body weight changes.

Shear design of cold-formed steel beams using direct strength method

This paper presents the direct strength method (DSM) equations for cold-formed steel beams subject to shear. Light gauge cold-formed steel sections have been developed as more economical building solutions to the alternative heavier hot-rolled sections in the commercial and residential markets. Cold-formed lipped channel beams (LCB), LiteSteel beams (LSB) and hollow flange beams (HFB) are commonly used as flexural members such as floor joists and bearers. However, their shear capacities are determined based on conservative design rules. For the shear design of cold-formed web panels, their elastic shear buckling strength must be determined accurately including the potential post-buckling strength. Currently the elastic shear buckling coefficients of web panels are determined by assuming conservatively that the web panels are simply supported at the junction between the flange and web elements and ignore the post-buckling strength. Hence experimental and numerical studies were conducted to investigate the shear behaviour and strength of LSBs, LCBs and HFBs. New direct strength method (DSM) based design equations were proposed to determine the ultimate shear capacities of cold-formed steel beams. An improved equation for the higher elastic shear buckling coefficient of cold-formed steel beams was proposed based on finite element analysis results and included in the DSM design equations. A new post-buckling coefficient was also introduced in the DSM equation to include the available post-buckling strength of cold-formed steel beams.

Achilles tendinopathy modulates force frequency characteristics of eccentric exercise

Introduction Previous research has demonstrated that ground reaction force (GRF) recorded during eccentric ankle exercise is characterised by greater power in the 8-12Hz bandwidth when compared to that recorded during concentric ankle exercise. Subsequently, it was suggested that vibrations in this bandwidth may underpin the beneficial effect of eccentric loading in tendon repair. However, this observation has been made only in individuals without Achilles tendinopathy. This research compared the force frequency characteristics of eccentric and concentric exercises in individuals with and without Achilles tendinopathy., Methods Eleven male adults with unilateral mid-portion Achilles tendinopathy and nine control male adults without tendinopathy participated in the research. Kinematics and GRF were recorded while the participants performed a common eccentric rehabilitation exercise protocol and a concentric equivalent. Ankle joint kinematics and the frequency power spectrum of the resultant GRF were calculated. Results Eccentric exercise was characterised by a significantly greater proportion of spectral power between 4.5 and 11.5Hz when compared to concentric exercise. There were no significant differences between limbs in the force frequency characteristics of concentric exercise. Eccentric exercise, in contrast, was defined by a shift in the power spectrum of the symptomatic limb, resulting in a second spectral peak at 9Hz, rather than 10Hz in the control limb. Conclusions Compared to healthy tendon, Achilles tendinopathy was characterised by lower frequency vibrations during eccentric rehabilitation exercises. This finding may be associated with changes in neuromuscular activation and tendon stiffness which have been shown to occur with tendinopathy and provides a possible rationale for the previous observation of a different biochemical response to eccentric exercise in healthy and injured Achilles tendons., (C)2012The American College of Sports Medicine

Cardiac parasympathetic reactivation following exercise : implications for training prescription

The objective of exercise training is to initiate desirable physiological adaptations that ultimately enhance physical work capacity. Optimal training prescription requires an individualized approach, with an appropriate balance of training stimulus and recovery and optimal periodization. Recovery from exercise involves integrated physiological responses. The cardiovascular system plays a fundamental role in facilitating many of these responses, including thermoregulation and delivery/removal of nutrients and waste products. As a marker of cardiovascular recovery, cardiac parasympathetic reactivation following a training session is highly individualized. It appears to parallel the acute/intermediate recovery of the thermoregulatory and vascular systems, as described by the supercompensation theory. The physiological mechanisms underlying cardiac parasympathetic reactivation are not completely understood. However, changes in cardiac autonomic activity may provide a proxy measure of the changes in autonomic input into organs and (by default) the blood flow requirements to restore homeostasis. Metaboreflex stimulation (e.g. muscle and blood acidosis) is likely a key determinant of parasympathetic reactivation in the short term (0–90 min post-exercise), whereas baroreflex stimulation (e.g. exercise-induced changes in plasma volume) probably mediates parasympathetic reactivation in the intermediate term (1–48 h post-exercise). Cardiac parasympathetic reactivation does not appear to coincide with the recovery of all physiological systems (e.g. energy stores or the neuromuscular system). However, this may reflect the limited data currently available on parasympathetic reactivation following strength/resistance-based exercise of variable intensity. In this review, we quantitatively analyse post-exercise cardiac parasympathetic reactivation in athletes and healthy individuals following aerobic exercise, with respect to exercise intensity and duration, and fitness/training status. Our results demonstrate that the time required for complete cardiac autonomic recovery after a single aerobic-based training session is up to 24 h following low-intensity exercise, 24–48 h following threshold-intensity exercise and at least 48 h following high-intensity exercise. Based on limited data, exercise duration is unlikely to be the greatest determinant of cardiac parasympathetic reactivation. Cardiac autonomic recovery occurs more rapidly in individuals with greater aerobic fitness. Our data lend support to the concept that in conjunction with daily training logs, data on cardiac parasympathetic activity are useful for individualizing training programmes. In the final sections of this review, we provide recommendations for structuring training microcycles with reference to cardiac parasympathetic recovery kinetics. Ultimately, coaches should structure training programmes tailored to the unique recovery kinetics of each individual.

Evaluating MPPT converter topologies using a Matlab PV model

An accurate PV module electrical model is presented based on the Shockley diode equation. The simple model has a photo-current current source, a single diode junction and a series resistance, and includes temperature dependences. The method of parameter extraction and model evaluation in Matlab is demonstrated for a typical 60W solar panel. This model is used to investigate the variation of maximum power point with temperature and isolation levels. A comparison of buck versus boost maximum power point tracker (MPPT) topologies is made, and compared with a direct connection to a constant voltage (battery) load. The boost converter is shown to have a slight advantage over the buck, since it can always track the maximum power point.

Evaluating MPPT converter topologies using a MATLAB PV model

An accurate PV module electrical model is presented based on the Shockley diode equation. The simple model has a photo-current current source, a single diode junction and a series resistance, and includes temperature dependences. The method of parameter extraction and model evaluation in Matlab is demonstrated for a typical 60W solar panel. This model is used to investigate the variation of maximumpower point with temperature and insolation levels. A comparison of buck versus boostmaximum power point tracker (MPPT) topologies is made, and compared with a direct connection to a constant voltage (battery) load. The boost converter is shown to have a slight advantage over the buck, since it can always track the maximum power point.

Choroidal thickness in childhood

Purpose To examine choroidal thickness (ChT) and its spatial distribution across the posterior pole in pediatric subjects with normal ocular health and minimal refractive error. Methods ChT was assessed using spectral domain optical coherence tomography (OCT) in 194 children aged between 4-12 years, with spherical equivalent refractive errors between +1.25 and -0.50 DS. A series of OCT scans were collected, imaging the choroid along 4 radial scan lines centered on the fovea (each separated by 45°). Frame averaging was used to reduce noise and enhance chorio-scleral junction visibility. The transverse scale of each scan was corrected to account for magnification effects associated with axial length. Two independent masked observers manually segmented the OCT images to determine ChT at foveal centre, and averaged across a series of perifoveal zones over the central 5 mm. Results The average subfoveal ChT was 330 ± 65 µm (range 189-538 µm), and was significantly influenced by age (p=0.04). The ChT of the 4 to 6 year old age group (312 ± 62 µm) was significantly thinner compared to the 7 to 9 year olds (337 ± 65 µm, p<0.05) and bordered on significance compared to the 10 to 12 year olds (341 ± 61 µm, p=0.08). ChT also exhibited significant variation across the posterior pole, being thicker in more central regions. The choroid was thinner nasally and inferiorly compared to temporally and superiorly. Multiple regression analysis revealed age, axial length and anterior chamber depth were significantly associated with subfoveal ChT (p<0.001). Conclusions ChT increases significantly from early childhood to adolescence. This appears to be a normal feature of childhood eye growth.