Effect of creatine ingestion on glucose tolerance and insulin sensitivity in men

Purpose: This study investigated whether acute (5 d) and/or short-term (28 d) creatine (Cr) ingestion altered glucose tolerance or insulin action in healthy, untrained men (aged 26.9 ± 5.7 yr; SD). Methods : Subjects were randomly allocated to either a Cr (N = 8) or placebo group (N = 9) and were tested in the control condition (presupplementation), and after 5 and a further 28 d of supplementation. The Cr group ingested 20 g and 3 g·d-1 of Cr for the first 5 and following 28 d, respectively. The placebo group ingested similar amounts of glucose over the same time period. During each testing period, subjects underwent an oral glucose tolerance test (OGTT) to determine insulin sensitivity, and six subjects from each group underwent a muscle biopsy before each OGTT. Results : Cr supplementation resulted in an increased (P < 0.05) muscle TCr content after both the acute and short-term loading phase compared with placebo. Neither acute nor short-term Cr supplementation influenced skeletal muscle glycogen content, glucose tolerance, or measures of insulin sensitivity. Conclusions: These findings demonstrated that acute Cr supplementation (20 g·d-1 for 5 d) followed by short-term Cr supplementation (3 g·d-1 for 28 d) did not alter insulin action in healthy, active untrained men.

Do logbooks influence recall of physical activity in validation studies?

Purpose: To examine whether physical activity logbooks influence estimates of validity of 7-d recall physical activity questionnaires. Methods: A  convenience sample of 551 adults aged 18–75 yr wore an MTI  accelerometer for seven consecutive days and were then randomly administered two of four 7-d recall physical activity questionnaires that varied in length and format (Active Australia Survey (AAS), long and short  International Physical Activity Questionnaires (IPAQ-L and IPAQ-S), and Behavioral Risk Factor Surveillance System (BRFSS)). A subsample of 75% concurrently completed a physical activity logbook. Results: Correlations (rho) between self-reported and measured duration of moderate- and vigorous-intensity activity and total activity were similar among participants who received a logbook and those who did not for each of the four instruments. There was also no interaction between assessment method (survey, accelerometer) and the assignment of a logbook. For the IPAQ-L, however, variability in the difference between accelerometer data and responses to the vigorous items was smaller among those assigned a logbook (F = 4.128, df = 260, P = 0.043). Overall, there were no differences in percent agreement or kappa for participation in sufficient levels of physical activity according to receipt of a logbook for any of the surveys. Conclusion: The process of self-monitoring through completion of a logbook does not appear to influence estimates of validity for brief or long questionnaires with global questions. Whereas the magnitude of error in accuracy of recall of particular types of activity may be reduced by completion of a logbook that is similar in structure to the survey being validated, this does not appear to influence overall estimates of validity.

Lupin kernel fibre foods improve bowel function and beneficially modify some putative faecal risk factors for colon cancer in men.

Consumption of some dietary fibres may benefit bowel health; however, the effect of Australian sweet lupin (Lupinus angustifolius) kernel fibre (LKFibre) is unknown. The present study examined the effect of a high-fibre diet containing LKFibre on bowel function and faecal putative risk factors for colon cancer compared to a control diet without LKFibre. Thirty-eight free-living, healthy men consumed an LKFibre and a control diet for 1 month each in a single-blind, randomized, crossover study. Depending on subject energy intake, the LKFibre diet was designed to provide 17–30 g/d fibre (in experimental foods) above that of the control diet. Bowel function self-perception, frequency of defecation, transit time, faecal output, pH and moisture, faecal levels of SCFA and ammonia, and faecal bacterial [ß]-glucuronidase activity were assessed. In comparison to the control diet, the LKFibre diet increased frequency of defecation by 0·13 events/d (P = 0·047), increased faecal output by 21 % (P = 0·020) and increased faecal moisture content by 1·6 % units (P = 0·027), whilst decreasing transit time by 17 % (P = 0·012) and decreasing faecal pH by 0·26 units (P < 0·001). Faecal butyrate concentration was increased by 16 % (P = 0·006), butyrate output was increased by 40 % (P = 0·002) and [ß]-glucuronidase activity was lowered by 1·4 µmol/h per g wet faeces compared to the control diet (P < 0·001). Addition of LKFibre to the diet incorporated into food products improved some markers of healthy bowel function and colon cancer risk in men.

Mobile subjectivities positioning the nonunirary self in critical feminist and postmodern research

Most scholarly work is written from the perspective of the author being a unitary subject occupying a sole, rational, and unified position. This article argues that scholarship may be enhanced by the author adopting multiple subject positions as a methodological framework. Such an adoption is advantageous in working against the romance of the notion of a single truth while also maintaining teleological values congruent with critical and feminist agendas. This article outlines the conceptual development of this methodological framework, the rationale for its development, an explication of the concept of multiple subjectivity, and an exemplar of its application within nursing research.

Rationale and design of the national benchmarking and evidence-based national clinical guidelines for chronic heart failure management programs study

OBJECTIVES: The National Benchmarks and Evidence-Based National Clinical Guidelines for Heart Failure Management Programs Study is a national, multicenter study designed to determine the nature, range, and effect of interventions applied by chronic heart failure management programs (CHF-MPs) throughout Australia on patient outcomes. Its primary objective is to use these data to develop national benchmarks and evidence-based clinical guidelines and optimize their cost-effective application by reducing quality and outcome variability. DATA SOURCES/STUDY SETTING: Primary data will be collected from CHF-MP coordinators and CHF patients enrolled in these programs on a national basis. Secondary outcome data will be collected from a national morbidity record and from patients' medical records. STUDY DESIGN: Stage I of the study involves a prospective clinical audit of all CHF-MPs throughout Australia (n = 45) to determine the extent of variability in programs currently. Stage II is a prospective cross-sectional survey design enrolling 1,500 patients (average of 40 patients per program) to firstly determine the typical profile of patients being managed via a CHF-MP in Australia and, secondly, the subsequent morbidity and mortality during the 6-month follow-up. Outcome data will be subject to multivariate analysis to determine the key components of care in this regard. All study data will be then examined in the final stage of the study (III) to develop national benchmarks for the application and auditing of CHF-MPs in Australia. CONCLUSION: Variability in patient outcomes is a product of heterogeneity among CHF-MPs. The development of national benchmarks will minimize such heterogeneity and will provide a greater level of evidence for their cost-effective application.

Endurance training in humans leads to fiber type-specific increases in levels of peroxisome proliferator-activated receptor-[gamma] coactivator-1 and peroxisome proliferator-activated receptor-[alpha] in skeletal muscle

The peroxisome proliferator-activated receptor (PPAR)-γ coactivator-1 (PGC-1) can induce mitochondria biogenesis and has been implicated in the development of oxidative type I muscle fibers. The PPAR isoforms α, β/δ, and γ control the transcription of genes involved in fatty acid and glucose metabolism. As endurance training increases skeletal muscle mitochondria and type I fiber content and fatty acid oxidative capacity, our aim was to determine whether these increases could be mediated by possible effects on PGC-1 or PPAR-α, -β/δ, and -γ. Seven healthy men performed 6 weeks of endurance training and the expression levels of PGC-1 and PPAR-α, -β/δ, and -γ mRNA as well as the fiber type distribution of the PGC-1 and PPAR-α proteins were measured in biopsies from their vastus lateralis muscle. PGC-1 and PPAR-α mRNA expression increased by 2.7- and 2.2-fold (P < 0.01), respectively, after endurance training. PGC-1 expression was 2.2- and 6-fold greater in the type IIa than in the type I and IIx fibers, respectively. It increased by 2.8-fold in the type IIa fibers and by 1.5-fold in both the type I and IIx fibers after endurance training (P < 0.015). PPAR-α was 1.9-fold greater in type I than in the II fibers and increased by 3.0-fold and 1.5-fold in these respective fibers after endurance training (P < 0.001). The increases in PGC-1 and PPAR-α levels reported in this study may play an important role in the changes in muscle mitochondria content, oxidative phenotype, and sensitivity to insulin known to be induced by endurance training.

Energy system interaction and relative contribution during maximal exercise

There are 3 distinct yet closely integrated processes that operate together to satisfy the energy requirements of muscle. The anaerobic energy system is divided into alactic and lactic components, referring to the processes  involved in the splitting of the stored phosphagens, ATP and  phosphocreatine (PCr), and the nonaerobic breakdown of carbohydrate to lactic acid through glycolysis. The aerobic energy system refers to the combustion of carbohydrates and fats in the presence of oxygen. The anaerobic pathways are capable of regenerating ATP at high rates yet are limited by the amount of energy that can be released in a single bout of intense exercise. In contrast, the aerobic system has an enormous capacity yet is somewhat hampered in its ability to delivery energy quickly. The focus of this review is on the interaction and relative contribution of the energy systems during single bouts of maximal exercise. A particular emphasis has been placed on the role of the aerobic energy system during high intensity exercise.

Attempts to depict the interaction and relative contribution of the energy systems during maximal exercise first appeared in the 1960s and 1970s. While insightful at the time, these representations were based on calculations of anaerobic energy release that now appear questionable. Given repeated reproduction over the years, these early attempts have lead to 2 common misconceptions in the exercise science and coaching professions. First, that the energy systems respond to the demands of intense exercise in an almost sequential manner, and secondly, that the aerobic system responds slowly to these energy demands, thereby playing little role in determining performance over short durations. More recent research suggests that energy is derived from each of the energy-producing pathways during almost all exercise activities. The duration of maximal exercise at which equal contributions are derived from the anaerobic and aerobic energy systems appears to occur between 1 to 2 minutes and most probably around 75 seconds, a time that is considerably earlier than has traditionally been suggested.

Longitudinal changes in dietary patterns during adult life

Despite the growing interest in dietary patterns, there have been few longitudinal investigations. The objective of the present study was to extend an earlier method of dietary pattern assessment to longitudinal binary data and to assess changes in patterns over time and in relation to socio-demographic covariates. A prospective national cohort of 1265 participants completed a 5 d food diary at three time-points during their adult life (at age 36 years in 1982, 43 years in 1989 and 53 years in 1999). Factor analysis identified three dietary patterns for women (fruit, vegetables and dairy; ethnic foods and alcohol; meat, potatoes and sweet foods) and two patterns in men (ethnic foods and alcohol; mixed). Trends in dietary pattern scores were calculated using random effects models. Marked changes were found in scores for all patterns between 1989 and 1999, with only the meat, potatoes and sweet foods pattern in women recording a decline. In a multiple variable model that included the three time-points, socio-demographic variables and BMI time-dependent covariates, both non-manual social class and higher education level were also strongly associated with the consumption of more items from the ethnic foods and alcohol pattern and the mixed pattern for men (P<0[middle dot]0001) and the fruit, vegetables and dairy pattern and the ethnic foods and alcohol pattern for women (P<0[middle dot]01). In conclusion, longitudinal changes in dietary patterns and across socio-economic groups can assist with targeting public health initiatives by identifying stages during adult life when interventions to improve diet would be most beneficial to health.

Validation of a FFQ to estimate the intake of PUFA using plasma phospholipid fatty acids and weighed foods records

Due to the growing knowledge about the role of specific fatty acids in health and disease, dietary intake measurements of individual fatty acids or classes of fatty acids are becoming increasingly important. The objective of this study was to evaluate the ability of the Nambour FFQ to estimate intakes of specific fatty acids, particularly PUFA. The study population was a sub-sample of adult participants in a randomised controlled trial of [beta]-carotene and sunscreen in the prevention of skin cancer (n 43). Dietary intake was assessed by a self-administered FFQ and a weighed food record (WFR). Non-fasting blood samples were collected and analysed for plasma phospholipid fatty acids. Median intakes on the FFQ were generally higher than the WFR except for the n-3 PUFA groups, where the FFQ estimated higher intakes. Correlations between the FFQ and WFR were moderate (r 0–32-0-59) except for trans fatty acids (r 0–03). Correlations between each of the dietary assessment methods and the plasma phospholipids were poor for all fatty acids other than the PUFA. Using the methods of triads approach, the FFQ validity coefficients for total n-3 fatty acids, total long chain n-3 fatty acids, EPA, arachidonic acid, docosapentaenoic acid and DHA were 0–50, 0–63, 0–45 and 0–62 and 0–62, respectively. For most fatty acids, the FFQ adequately estimates group mean fatty acid intakes and can adequately rank individuals; however, the ability of this FFQ to estimate trans fatty acids was poor.

Effect of sodium bicarbonate on muscle metabolism during intense endurance cycling

Introduction: Sodium bicarbonate (NaHCO₃) ingestion has been shown to increase both muscle glycogenolysis and glycolysis during brief submaximal exercise. These changes may be detrimental to performance during more prolonged, exhaustive exercise. This study examined the effect of NaHCO₃ ingestion on muscle metabolism and performance during intense endurance exercise of ~60 min in seven endurance-trained men. Methods: Subjects ingested 0.3 g·kg^-1 body mass of either NaHCO₃ or CaCO₃ (CON) 2 h before performing 30 min of cycling exercise at 77 ± 1% [latin capital V with dot above]O_2peak followed by completion of 469 ± 21 kJ as quickly as possible (~30 min, ~80% [latin capital V with dot above]O_2peak). Results: Immediately before, and throughout exercise, arterialized-venous plasma HCO₃- concentrations were higher (P < 0.05) whereas plasma and muscle H⁺ concentrations were lower (P < 0.05) in NaHCO₃ compared with CON. Blood lactate concentrations were higher (P < 0.05) during exercise in NaHCO₃, but there was no difference between trials in muscle glycogen utilization or muscle lactate content during exercise. Reductions in PCr and ATP and increases in muscle Cr during exercise were also unaffected by NaHCO₃ ingestion. Accordingly, exercise performance time was not different between treatments. Conclusion: NaHCO₃ ingestion resulted in a small muscle alkalosis but had no effect on muscle metabolism or intense endurance exercise performance in well-trained men.

Managing intravenous medications in the non-hospital setting: an ethnographic investigation

Little published information exists about the issues involved in conducting complex intravenous medication therapy in patients’ homes. An ethnographic study of a local hospital-in-the-home program in the Australian Capital Territory explored this phenomenon to identify those factors that had an impact on the use of medicine in the home environment. This article focuses on one of the three themes identified in the study—Clinical Practice. Within this theme, topics related to the organization and management of intravenous medications, geography and diversity of patient caseload, and communication in the practice setting are discussed. These findings have important implications for policy development and establishment of a research agenda for hospital-in-the-home services.

Energy system contribution during 200- to 1500-m running in highly trained athletes

Purpose: The purpose of the present study was to profile the aerobic and anaerobic energy system contribution during high-speed treadmill exercise that simulated 200-, 400-, 800-, and 1500-m track running events.

Methods: Twenty highly trained athletes (Australian National Standard) participated in the study, specializing in either the 200-m (N = 3), 400-m (N = 6), 800-m (N = 5), or 1500-m (N = 6) event (mean O₂ peak [mL·kg^-1·min^-1] ± SD = 56 ± 2, 59 ± 1, 67 ± 1, and 72 ± 2, respectively). The relative aerobic and anaerobic energy system contribution was calculated using the accumulated oxygen deficit (AOD) method.

Results: The relative contribution of the aerobic energy system to the 200-, 400-, 800-, and 1500-m events was 29 ± 4, 43 ± 1, 66 ± 2, and 84 ± 1% ± SD, respectively. The size of the AOD increased with event duration during the 200-, 400-, and 800-m events (30.4 ± 2.3, 41.3 ± 1.0, and 48.1 ± 4.5 mL·kg^-1, respectively), but no further increase was seen in the 1500-m event (47.1 ± 3.8 mL·kg^-1). The crossover to predominantly aerobic energy system supply occurred between 15 and 30 s for the 400-, 800-, and 1500-m events.

Conclusions: These results suggest that the relative contribution of the aerobic energy system during track running events is considerable and greater than traditionally thought.

Does balance or motor impairment of limbs discriminate the ambulatory satus of stroke survivors?

Objective: This study was performed to determine if ambulatory function is governed by motor impairment of limbs or balance ability in subjects with hemiplegia caused by stroke.
Design: Seven patients who walked with physical assistance (FIM(TM) 4) after stroke and 13 who walked independently with assistive devices (FIM 6) were compared with 13 healthy subjects. Motor impairment of limbs was evaluated with the Fugl-Meyer Assessment. The Berg Balance Scale and limit of stability test of the Smart Balance Master were used to evaluate balance ability.
Results: The FIM 6 group and the controls were best differentiated by motor impairment of the paretic limbs and limit of stability in the backward direction. Motor impairment of the upper limb and limit of stability in direction toward the paretic side separated the FIM 4 from the FIM 6 group. Upper limb motor impairment and the Berg Balance Scale consistently separated the three subject groups.
Conclusions: Motor impairment in the paretic upper limb and balance dysfunction should be addressed in treatments working toward independent ambulation.

A theoretical discussion about the clinical value of phenomenology for nurses

This article develops a theoretical discussion related to the value of a phenomenological framework in contributing to contemporary nursing knowledge. Nursing is based on the understanding of patients' personal experiences and their responses to their illness. Phenomenological methodology utilizes the patient's own language to reflect meanings embedded in their health experience.

Obesity prevention and public health

More than 22 million children under five are now obese or overweight. Globally, an estimated 10% of school-aged children, between five and 17 years old, are overweight or obese, and the situation is getting worse. Although recognised clinically for some time as an important condition that increases risk of ill-health in affected individuals, it is only recently, that obesity has been recognised as a population-wide problem that requires preventive action. Obesity is a major contributor to diseases and disability, the associated health costs are enormous, obesity has already reached epidemic proportions in many countries, and incidence is continuing to increase in children and adults. Disturbingly the epidemic is not confined to developed countries, with many developing countries and those in transition affected. While recognised as a major population health problem, our understanding of the causes of the epidemic is poor, there has been relatively little population-based research that has focused on the prevention of unhealthy weight gain, and as a consequence knowledge regarding how and where best to intervene is limited. This book draws together the existing literature and expertise and with a view to helping set the agenda for public health action. The book is divided into three sections. Part 1 provides an overview of the context of the problem. It examines the epidemiology of obesity, the role of behavioural factors, socio-cultural factors and environmental factors in the obesity epidemic. Part 2 reviews interventions across a range of key settings and in different population groups - drawing on existing research that has aimed to increase physical activity, promote healthy eating and prevent obesity at a population level. Given how little research there is that has specifically examined the effectiveness of interventions aimed at preventing obesity per se, Part 3 explores potential opportunities to prevent obesity