Learning to treat the climate emergency together: social tipping interventions by the health community.

Accelerating the decarbonisation of local and national economies is a profound public health imperative. As trusted voices within communities around the world, health professionals and health organisations have enormous potential to influence the social and policy landscape in support of decarbonisation. We assembled a multidisciplinary, gender-balanced group of experts from six continents to develop a framework for maximising the social and policy influence of the health community on decarbonisation at the micro levels, meso levels, and macro levels of society. We identify practical, learning-by-doing approaches and networks to implement this strategic framework. Collectively, the actions of health-care workers can shift practice, finance, and power in ways that can transform the public narrative and influence investment, activate socioeconomic tipping points, and catalyse the rapid decarbonisation needed to protect health and health systems.

Hypertrophic olivary degeneration associated with bilateral vocal cord adductor dystonia.

BACKGROUND: Hypertrophic olivary degeneration (HOD) is a rare condition caused by lesions within the dentato-rubro-olivary pathway, resulting in ocular nystagmus and palatal myoclonus (oculopalatal tremor) but not usually dystonia. Dystonia is an uncommon association, and we present the first reported association of hypertrophic olivary degeneration with bilateral vocal cord dystonia. CASE PRESENTATION: A 33 year old male presented initially with acute hydrocephalus on the background of previous ventriculoperitoneal (VP) shunting for previously treated medulloblastoma. After revision of the VP shunt, the patient developed progressive hiccups and stridor leading to respiratory failure requiring intubation. Ocular pendular nystagmus and palatal myoclonus at 3 Hz was observed. Flexible nasendoscopy (FNE) demonstrated bilateral tonic adduction of the vocal folds with 3 Hz coarse supraglottic, pharyngeal and palatal rhythmic myoclonus. MRI imaging demonstrated T2 hyperintensity within the bilateral inferior olivary nuclei consistent with stage 3 radiological HOD. CONCLUSIONS: Dystonia is a rarely reported phenomenon in HOD but is not unexpected with the inferior olivary nucleus implicated in dystonic disorders. We report the association of HOD with bilateral vocal cord adductor dystonia, a potentially life threatening condition.

Two-country comparison of the prescription of bone protection medication before and early after hip fracture.

Pharmacological management of bone health warrants investigation into factors influencing initiation of bone protection medication (BPM) at discharge after a hip fracture. This sprint audit identified reasons attributed to low BPM treatment levels at hospital discharge which can guide improvement in the prevention of future fractures. PURPOSE: To compare patient characteristics and Australian and New Zealand approaches to prescribing bone protection medication (BPM) pre- or post-hip fracture, determine reasons why BPM was not prescribed earlier post-fracture, and assess the generalisability of sprint audit and the Australian and New Zealand Hip Fracture Registry (ANZHFR) patient cohorts. METHODS: A retrospective cohort study of hip fracture patients from the ANZHFR aged ≥ 50 years (2016-2020) and consecutive patients from the 2021 BPM sprint audit. Multivariable logistic regression was used to examine factors associated with not prescribing BPM. RESULTS: Of 55,618 patients admitted with a hip fracture in the ANZHFR, less than 10% of patients in Australia and New Zealand were taking BPM on admission, increasing to 22.4% in Australia and 27.8% in New Zealand on discharge. Registry patients who were younger (50-69 years), healthy (ASA grade 1), lived in a residential aged care facility, had impaired cognition, delirium identified, or were awaiting a specialist falls assessment were less likely to take BPM. Within the audit, 46.2% of patients in Australia and 39.2% in New Zealand did not have BPM in their discharge prescription. The most common reason for not prescribing BPM in Australia was low level of vitamin D (13.3%), and in New Zealand, renal impairment (14.8%). Sprint and registry patient characteristics were comparable in terms of patient age, sex, usual place of residence, and ASA grade. CONCLUSIONS: BPM prescription early after hip fracture is low. Opportunities exist to increase the rate of prescription of medications known to prevent future fractures in this high-risk population.

Everyone’s a winner if we test less: the CODA action plan.

In this era of 'Choosing Wisely,' we present a four-step action plan to reduce unnecessary pathology testing and the associated patient harm (blood loss through repeated phlebotomy), economic cost and environmental impact. The authors are experts from the CODA group; a medical education and health-promotion charity that aims to build on the Choosing Wisely initiative to provide meaningful and sustainable actions to reduce the carbon footprint of healthcare, globally. Pathology testing is expensive and carbon-intensive, with as many as half of all tests being not clinically indicated. Reducing unnecessary testing is the only effective way to decrease the carbon footprint and other associated costs, as opportunities to reuse and recycle pathology specimens are limited. The four key steps for action are (i) auditing local practice; (ii) defining unnecessary testing including developing a clinical guideline for rational ordering; (iii) educating stakeholders; and (iv) measuring the impact of the intervention through re-audit. This proven method is designed to be used in any healthcare setting around the world; having a small group of passionate 'champions' is thought to be as important as strong clinical governance and more important than access to sophisticated equipment. Electronic medical record systems and other technological solutions offer new ways to help establish a sustainability mindset and reduce unnecessary testing. The Codachange.org/coda-earth/ website provides a dynamic crowdsourcing platform through which we can collectively learn to meet the diverse needs of our international medical community. Self-reported outcomes are gamified through collaborative feedback, amplification via social media and the ability to earn rewards, be uploaded to the CODA website, or added to the template as a success story. By combining our existing local networks with the emerging international CODA community, we can initiate meaningful change now and enter the era of environmental stewardship.

Skeletal muscle histidine-containing dipeptide contents are increased in freshwater turtles (C. picta bellii) with cold-acclimation.

Freshwater turtles found in higher latitudes can experience extreme challenges to acid-base homeostasis while overwintering, due to a combination of cold temperatures along with the potential for environmental hypoxia. Histidine-containing dipeptides (HCDs; carnosine, anserine and balenine) may facilitate pH regulation in response to these challenges, through their role as pH buffers. We measured the HCD content of three tissues (liver, cardiac and skeletal muscle) from the anoxia-tolerant painted turtle (C. picta bellii) acclimated to either 3 or 20 °C. HCDs were detected in all tissues, with the highest content shown in the skeletal muscle. Turtles acclimated to 3 °C had more HCD in their skeletal muscle than those acclimated to 20 °C (carnosine = 20.8 ± 4.5 vs 12.5 ± 5.9 mmol·kg DM-1; ES = 1.59 (95%CI: 0.16-3.00), P = 0.013). The higher HCD content shown in the skeletal muscle of the cold-acclimated turtles suggests a role in acid-base regulation in response to physiological challenges associated with living in the cold, with the increase possibly related to the temperature sensitivity of carnosine's dissociation constant.

Patient, surgical and hospital factors associated with the presence of a consultant surgeon during hip fracture surgery. Do we know the answer?

BACKGROUND: Provision of quality care can help to reduce adverse health outcomes following hip fracture. While surgical management by either a consultant or junior surgeon has shown inconclusive differences in patient outcomes, consultant presence is often recommended, yet little is known about the factors that influence whether a consultant surgeon is present during hip fracture surgery. The aim of this study is to examine patient, surgical and hospital factors associated with having a consultant surgeon present during hip fracture surgery. METHODS: An examination of hip fracture surgeries of adults aged ≥ 50 years admitted to hospitals in Australia and New Zealand between 1 January 2015 and 31 December 2018 using data from the Australia and New Zealand Hip Fracture Registry was conducted. Multivariable logistic regression was used to examine factors associated with the presence of a consultant surgeon during hip fracture surgery. RESULTS: There were 29 530 hip fracture surgeries 58.1% had a consultant surgeon present (range 8.5-100% by hospital). Patients were more likely to have a consultant surgeon present during surgery if they had private health insurance, were operated on after hours, required total hip replacements or were operated on in hospitals that conducted ≤150 surgeries per year. CONCLUSION: There is variation in the presence of consultant surgeons within Australia and New Zealand during hip fracture surgery, potentially associated with the complexity of surgery and hospital factors. However, further research is needed to determine the optimum level of supervision required based on patient factors and surgical complexity.

Impact of the coronavirus disease 2019 pandemic on critical care healthcare workers' depression, anxiety, and stress levels.

AIM: The aim of the study was to determine levels of depression, anxiety, and stress symptoms and factors associated with psychological burden amongst critical care healthcare workers in the early stages of the coronavirus disease 2019 pandemic. METHODS: An anonymous Web-based survey distributed in April 2020. All healthcare workers employed in a critical care setting were eligible to participate. Invitations to the survey were distributed through Australian and New Zealand critical care societies and social media platforms. The primary outcome was the proportion of healthcare workers who reported moderate to extremely severe scores on the Depression, Anxiety, and Stress Scale-21 (DASS-21). RESULTS: Of the 3770 complete responses, 3039 (80.6%) were from Australia. A total of 2871 respondents (76.2%) were women; the median age was 41 years. Nurses made up 2269 (60.2%) of respondents, with most (2029 [53.8%]) working in intensive care units. Overall, 813 (21.6%) respondents reported moderate to extremely severe depression, 1078 (28.6%) reported moderate to extremely severe anxiety, and 1057 (28.0%) reported moderate to extremely severe stress scores. Mean ± standard deviation values of DASS-21 depression, anxiety, and stress scores amongst woman vs men was as follows: 8.0 ± 8.2 vs 7.1 ± 8.2 (p = 0.003), 7.2 ± 7.5 vs 5.0 ± 6.7 (p < 0.001), and 14.4 ± 9.6 vs 12.5 ± 9.4 (p < 0.001), respectively. After adjusting for significant confounders, clinical concerns associated with higher DASS-21 scores included not being clinically prepared (ß = 4.2, p < 0.001), an inadequate workforce (ß = 2.4, p = 0.001), having to triage patients owing to lack of beds and/or equipment (ß = 2.6, p = 0.001), virus transmission to friends and family (ß = 2.1, p = 0.009), contracting coronavirus disease 2019 (ß = 2.8, p = 0.011), being responsible for other staff members (ß = 3.1, p < 0.001), and being asked to work in an area that was not in the respondents' expertise (ß = 5.7, p < 0.001). CONCLUSION: In this survey of critical care healthcare workers, between 22 and 29% of respondents reported moderate to extremely severe depression, anxiety, and stress symptoms, with women reporting higher scores than men. Although female gender appears to play a role, modifiable factors also contribute to psychological burden and should be studied further.

Chronic pantothenic acid supplementation does not affect muscle coenzyme A content or cycling performance.

This study determined if supplementation with pantothenic acid (PA) for 16 weeks could increase skeletal muscle coenzyme A (CoASH) content and exercise performance. Trained male cyclists (n = 14) were matched into control or PA (6 g·day-1) groups. At 0, 4, 8, and 16 weeks, subjects performed an incremental time to exhaustion cycle with muscle biopsies taken prior to and following exercise. Prolonged PA supplementation did not change skeletal muscle CoASH and acetyl-CoA contents or exercise performance. Novelty: Supplementation with pantothenic acid for 16 weeks had no effect on skeletal muscle CoASH and acetyl-CoA content or exercise performance in trained male cyclists.

24-Week ß-alanine ingestion does not affect muscle taurine or clinical blood parameters in healthy males.

PURPOSE: To investigate the effects of chronic beta-alanine (BA) supplementation on muscle taurine content, blood clinical markers and sensory side-effects. METHODS: Twenty-five healthy male participants (age 27 ± 4 years, height 1.75 ± 0.09 m, body mass 78.9 ± 11.7 kg) were supplemented with 6.4 g day-1 of sustained-release BA (N = 16; CarnoSyn™, NAI, USA) or placebo (PL; N = 9; maltodextrin) for 24 weeks. Resting muscle biopsies of the m. vastus lateralis were taken at 0, 12 and 24 weeks and analysed for taurine content (BA, N = 12; PL, N = 6) using high-performance liquid chromatography. Resting venous blood samples were taken every 4 weeks and analysed for markers of renal, hepatic and muscle function (BA, N = 15; PL, N = 8; aspartate transaminase; alanine aminotransferase; alkaline phosphatase; lactate dehydrogenase; albumin; globulin; creatinine; estimated glomerular filtration rate and creatine kinase). RESULTS: There was a significant main effect of group (p = 0.04) on muscle taurine, with overall lower values in PL, although there was no main effect of time or interaction effect (both p > 0.05) and no differences between specific timepoints (week 0, BA: 33.67 ± 8.18 mmol kg-1 dm, PL: 27.75 ± 4.86 mmol kg-1 dm; week 12, BA: 35.93 ± 8.79 mmol kg-1 dm, PL: 27.67 ± 4.75 mmol kg-1 dm; week 24, BA: 35.42 ± 6.16 mmol kg-1 dm, PL: 31.99 ± 5.60 mmol kg-1 dm). There was no effect of treatment, time or any interaction effects on any blood marker (all p > 0.05) and no self-reported side-effects in these participants throughout the study. CONCLUSIONS: The current study showed that 24 weeks of BA supplementation at 6.4 g day-1 did not significantly affect muscle taurine content, clinical markers of renal, hepatic and muscle function, nor did it result in chronic sensory side-effects, in healthy individuals. Since athletes are likely to engage in chronic supplementation, these data provide important evidence to suggest that supplementation with BA at these doses for up to 24 weeks is safe for healthy individuals.

Resistance Exercise-induced Changes in Muscle Phenotype Are Load Dependent.

INTRODUCTION: Lower-load (LL), higher-repetition resistance exercise training (RET) can increase muscle mass in a similar degree as higher-load (HL), lower-repetition RET. However, little is known about how LL and HL RET modulate other aspects of the RET phenotype such as satellite cells, myonuclei, and mitochondrial proteins. We aimed to investigate changes in muscle mass, muscle strength, satellite cell activity, myonuclear addition, and mitochondrial protein content after prolonged RET with LL and HL RET. METHODS: We recruited 21 young men and randomly assigned them to perform 10 wk RET (leg press, leg extension, and leg curl) three times per week with the following conditions: 80FAIL (80% one-repetition maximum [1RM] performed to volitional fatigue), 30WM (30%1RM with volume matched to 80FAIL), and 30FAIL (30%1RM to volitional fatigue). Skeletal muscle biopsies were taken from the vastus lateralis pre- and post-RET intervention. RESULTS: After 10 wk of RET, only 30FAIL and 80FAIL showed an increase in peak torque and type I fiber cross-sectional area (P < 0.05). Moreover, only 30FAIL resulted in a significant decrease in the myonuclear domain of type II muscle fibers and an increase in mitochondrial proteins related to autophagy, fission, and fusion (all P < 0.05). CONCLUSION: We discovered that LL RET was effective at increasing the content of several mitochondrial proteins. Similar to previous research, we found that changes in muscle mass and strength were independent of load when repetitions were performed to volitional fatigue.

Comparative physiology investigations support a role for histidine-containing dipeptides in intracellular acid-base regulation of skeletal muscle.

Histidine containing dipeptides (HCDs: carnosine, anserine and balenine) have numerous therapeutic and ergogenic properties, but there is a lack of consensus on the mechanistic pathways through which they function. Potential roles include intracellular buffering, neutralisation of reactive species, and calcium regulation. Comparative investigations of the HCD content of various species provide unique insight into their most likely mechanisms of action. This review chronologically describes how the comparative physiology studies, conducted since the beginning of the 20th century, have shaped our understanding of the physiological roles of HCDs. The investigation of a wide range of physiologically distinct species indicates that those species with a strong reliance on non-oxidative forms of energy production are abundant in HCDs. These include: whales who experience long periods of hypoxia while diving; racehorses and greyhound dogs who have highly developed sprint abilities, and chickens and turkeys whose limited capacity for flight is largely fuelled by their white, glycolytic, muscle. Additionally, a higher HCD content in the Type 2 muscle fibres of various species (which have greater capacity for non-oxidative metabolism) was consistently observed. The pKa of the HCDs render them ideally suited to act as intracellular physicochemical buffers within the pH transit range of the skeletal muscle. As such, their abundance in species which show a greater reliance on non-oxidative forms of energy metabolism, and which experience regular challenges to acid-base homeostasis, provides strong evidence that intracellular proton buffering is an important function of the HCDs in skeletal muscle.

Comparison of sustained-release and rapid-release ß-alanine formulations on changes in skeletal muscle carnosine and histidine content and isometric performance following a muscle-damaging protocol.

ß-alanine supplementation increases muscle carnosine content and improves anaerobic exercise performance by enhancing intracellular buffering capacity. ß-alanine ingestion in its traditional rapid-release formulation (RR) is associated with the symptoms of paresthesia. A sustained-release formulation (SR) of ß-alanine has been shown to circumvent paresthesia and extend the period of supply to muscle for carnosine synthesis. The purpose of this investigation was to compare 28 days of SR and RR formulations of ß-alanine (6 g day-1) on changes in carnosine content of the vastus lateralis and muscle fatigue. Thirty-nine recreationally active men and women were assigned to one of the three groups: SR, RR, or placebo (PLA). Participants supplementing with SR and RR formulations increased muscle carnosine content by 50.1% (3.87 mmol kg-1ww) and 37.9% (2.62 mmol kg-1ww), respectively. The change in muscle carnosine content in participants consuming SR was significantly different (p = 0.010) from those consuming PLA, but no significant difference was noted between RR and PLA (p = 0.077). Although participants ingesting SR experienced a 16.4% greater increase in muscle carnosine than RR, fatigue during maximal voluntary isometric contractions was significantly attenuated in both SR and RR compared to PLA (p = 0.002 and 0.024, respectively). Symptoms of paresthesia were significantly more frequent in RR compared to SR, the latter of which did not differ from PLA. Results of this study demonstrated that only participants consuming the SR formulation experienced a significant increase in muscle carnosine. Differences in the muscle carnosine response between these formulations may have practical significance for athletic populations in which small changes may have important implications on performance.

A kinetic model of carnosine synthesis in human skeletal muscle.

Drawing on previously published data, a mathematical model is proposed to describe the synthesis of carnosine in muscle using a slow release ß-alanine supplement (SR-CarnoSyn®). The model pre-supposes that the rate of synthesis for any given dose of ß-alanine (within the range 1.6-6.4 g day-1) is constant with time, but is first order with respect to daily ß-alanine dose. Simultaneously with synthesis, decay in carnosine is also assumed to be occurring, the rate in this case being a function of the concentration of carnosine. Decay in carnosine appears describable by first-order kinetics. By integration of the two rate reactions, a single mathematical equation was derived to describe the synthesis of carnosine and which closely fitted the experimental data over 56 days. The model, if validated by additional studies, could be used to compliment empirical observations of the changes in carnosine in muscle with supplementation, and allow objective examination of a number of possible influences affecting the rate constants of synthesis and decay.

High-Intensity Interval Training Augments Muscle Carnosine in the Absence of Dietary Beta-alanine Intake.

PURPOSE: Cross-sectional studies suggest that training can increase muscle carnosine (MCarn), although longitudinal studies have failed to confirm this. A lack of control for dietary ß-alanine intake or muscle fiber type shifting may have hampered their conclusions. The purpose of the present study was to investigate the effects of high-intensity interval training (HIIT) on MCarn. METHODS: Twenty vegetarian men were randomly assigned to a control (CON) (n = 10) or HIIT (n = 10) group. High-intensity interval training was performed on a cycle ergometer for 12 wk, with progressive volume (6-12 series) and intensity (140%-170% lactate threshold [LT]). Muscle carnosine was quantified in whole-muscle and individual fibers; expression of selected genes (CARNS, CNDP2, ABAT, TauT, and PAT1) and muscle buffering capacity in vitro (ßmin vitro) were also determined. Exercise tests were performed to evaluate total work done, V˙O2max, ventilatory thresholds (VT) and LT. RESULTS: Total work done, VT, LT, V˙O2max, and ßmin vitro were improved in the HIIT group (all P < 0.05), but not in CON (P > 0.05). MCarn (in mmol·kg dry muscle) increased in the HIIT (15.8 ± 5.7 to 20.6 ± 5.3; P = 0.012) but not the CON group (14.3 ± 5.3 to 15.0 ± 4.9; P = 0.99). In type I fibers, MCarn increased in the HIIT (from 14.4 ± 5.9 to 16.8 ± 7.6; P = 0.047) but not the CON group (from 14.0 ± 5.5 to 14.9 ± 5.4; P = 0.99). In type IIa fibers, MCarn increased in the HIIT group (from 18.8 ± 6.1 to 20.5 ± 6.4; P = 0.067) but not the CON group (from 19.7 ± 4.5 to 18.8 ± 4.4; P = 0.37). No changes in gene expression were shown. CONCLUSIONS: In the absence of any dietary intake of ß-alanine, HIIT increased MCarn content. The contribution of increased MCarn to the total increase in ßmin vitro appears to be small.

Comparison of Two ß-Alanine Dosing Protocols on Muscle Carnosine Elevations.

OBJECTIVE: ß-alanine (BA) is a nonproteogenic amino acid that combines with histidine to form carnosine. The amount taken orally in individual doses, however, is limited due to symptoms of paresthesia that are associated with higher doses. The use of a sustained-release formulation has been reported to reduce the symptoms of paresthesia, suggesting that a greater daily dose may be possible. The purpose of the present study was to determine whether increasing the daily dose of BA can result in a similar increase in muscle carnosine in a reduced time. METHODS: Eighteen men and twelve women were randomized into either a placebo (PLC), 6-g BA (6G), or 12-g BA (12G) groups. PLC and 6G were supplemented for 4 weeks, while 12G was supplemented for 2 weeks. A resting blood draw and muscle biopsy were obtained prior to (PRE) and following (POST) supplementation. Plasma and muscle metabolites were measured by high-performance liquid chromatography. The loss in peak torque (ΔPT) was calculated from maximal isometric contractions before and after 250 isokinetic kicks at 180°·sec-1 PRE and POST. RESULTS: Both 12G (p = 0.026) and 6G (p = 0.004) increased muscle carnosine compared to PLC. Plasma histidine was decreased from PRE to POST in 12G compared to PLC (p = 0.002) and 6G (p = 0.001), but no group x time interaction (p = 0.662) was observed for muscle histidine. No differences were observed for any hematological measure (e.g., complete blood counts) or in symptoms of paresthesia among the groups. Although no interaction was noted in ΔPT, a trend (p = 0.073) was observed. CONCLUSION: Results of this investigation indicate that a BA supplementation protocol of 12 g/d-1, using a sustained-release formulation, can accelerate the increase in carnosine content in skeletal muscle while attenuating paresthesia.

Fragility fractures at Auckland City Hospital: we can do better.

This study describes in detail the burden of caring for patients aged ≥ 50 years seen in one year with a fragility fracture in a large urban environment and shows that these fractures result in a long length of stay and significant mortality. Intervention to prevent further fracture was poorly done. PURPOSE: To examine the epidemiology of fragility fracture in patients over age 50 years and record the number who received appropriate secondary prevention treatment. METHODS: All patients aged ≥ 50 years presenting with a fracture during the 12 months following July 1st 2011, to Auckland City Hospital or residing in central Auckland at the time of their fracture, were identified from hospital and Accident Compensation Corporation records. A random sample of 55% of these patient's records were reviewed to establish the type of fracture, prior fracture and falls history, and use of bisphosphonates in the 12 months before presentation. Their length of stay (LOS) by type of fracture was recorded. The use of bisphosphonate drugs in the following 12 months was obtained from centralised national records of prescriptions. RESULTS: 2729 patients aged ≥ 50 years presented with a fragility fracture in the central Auckland region in one year. Fifty-six percent of these patients were seen at Auckland Hospital and of these, 82% patients required admission with a mean LOS of 20 days (SD ± 24 days).The remaining 44% of patients were looked after in the private outpatient sector. Approximately 30% of the admissions were for hip fracture. Sixty-four percent of patients with a fragility fracture did not receive a potent bisphosphonate, 12% were considered not appropriate for treatment, and 24% received a potent bisphosphonate during their admission or in the next 12 months. CONCLUSIONS: Approximately 1 in 18 people aged ≥ 50 years presented in one year with a fragility fracture.Secondary prevention strategies were poorly implemented. Additional resources for identifying and initiating secondary fracture prevention care such as a Fracture Liaison Service are urgently needed.

ß-alanine supplementation improves in-vivo fresh and fatigued skeletal muscle relaxation speed.

PURPOSE: In fresh muscle, supplementation with the rate-limiting precursor of carnosine, ß-alanine (BA), results in a decline in muscle half-relaxation time (HRT) potentially via alterations to calcium (Ca2+) handling. Accumulation of hydrogen cation (H+) has been shown to impact Ca2+ signalling during muscular contraction, carnosine has the potential to serve as a cytoplasmic regulator of Ca2+ and H+ coupling, since it binds to both ions. The present study examined the effect of BA supplementation on intrinsic in-vivo isometric knee extensor force production and muscle contractility in both fresh and fatigued human skeletal muscle assessed during voluntary and electrically evoked (nerve and superficial muscle stimulation) contractions. METHODS: Twenty-three males completed two experimental sessions, pre- and post- 28 day supplementation with 6.4 g.day-1 of BA (n = 12) or placebo (PLA; n = 11). Isometric force was recorded during a series of voluntary and electrically evoked knee extensor contractions. RESULTS: BA supplementation had no effect on voluntary or electrically evoked isometric force production, or twitch electromechanical delay and time-to-peak tension. There was a significant decline in muscle HRT in fresh and fatigued muscle conditions during both resting (3 ± 13%; 19 ± 26%) and potentiated (1 ± 15%; 2 ± 20%) twitch contractions. CONCLUSIONS: The mechanism for reduced HRT in fresh and fatigued skeletal muscle following BA supplementation is unclear. Due to the importance of muscle relaxation on total energy consumption, especially during short, repeated contractions, BA supplementation may prove to be beneficial in minimising contractile slowing induced by fatigue. TRIAL REGISTRATION: The trial is registered with Clinicaltrials.gov, ID number NCT02819505.

Twenty-four Weeks of ß-Alanine Supplementation on Carnosine Content, Related Genes, and Exercise.

INTRODUCTION: Skeletal muscle carnosine content can be increased through ß-alanine (BA) supplementation, but the maximum increase achievable with supplementation is unknown. No study has investigated the effects of prolonged supplementation on carnosine-related genes or exercise capacity. PURPOSE: This study aimed to investigate the effects of 24 wk of BA supplementation on muscle carnosine content, gene expression, and high-intensity cycling capacity (CCT110%). METHODS: Twenty-five active males were supplemented with 6.4 g·d of sustained release BA or placebo for a 24 wk period. Every 4 wk participants provided a muscle biopsy and performed the CCT110%. Biopsies were analyzed for muscle carnosine content and gene expression (CARNS, TauT, ABAT, CNDP2, PHT1, PEPT2, and PAT1). RESULTS: Carnosine content was increased from baseline at every time point in BA (all P < 0.0001; week 4 = +11.37 ± 7.03 mmol·kg dm, week 8 = +13.88 ± 7.84 mmol·kg dm, week 12 = +16.95 ± 8.54 mmol·kg dm, week 16 = +17.63 ± 8.42 mmol·kg dm, week 20 = +21.20 ± 7.86 mmol·kg dm, and week 24 = +20.15 ± 7.63 mmol·kg dm) but not placebo (all P > 0.05). Maximal increases were +25.66 ± 7.63 mmol·kg dm (range = +17.13 to +41.32 mmol·kg dm), and absolute maximal content was 48.03 ± 8.97 mmol·kg dm (range = 31.79 to 63.92 mmol·kg dm). There was an effect of supplement (P = 0.002) on TauT; no further differences in gene expression were shown. Exercise capacity was improved in BA (P = 0.05) with possible to almost certain improvements across all weeks. CONCLUSIONS: Twenty-four weeks of BA supplementation increased muscle carnosine content and improved high-intensity cycling capacity. The downregulation of TauT suggests it plays an important role in muscle carnosine accumulation with BA supplementation, whereas the variability in changes in muscle carnosine content between individuals suggests that other determinants other than the availability of BA may also bear a major influence on muscle carnosine content.

Am I too old for this, Doctor? Using population life expectancy to guide clinical decision-making.

OBJECTIVE: Prognostication is important in clinical decision-making, especially for older people. The aim was to present estimates of life expectancy for older people in New Zealand. METHODS: Statistics New Zealand age-sex-specific death rates were used to derive quartiles of expected years of life remaining in people aged over 65 years. RESULTS: Given current patterns and trends in New Zealand death rates, 50% of women reaching age 80 years in 2016 can expect to live at least another 10.5 years, 25% will live over 14.7 years, and 25% will die within 6.2 years. Comparable results for men reaching age 80 years in 2016 are 8.5 years, 12.7 years and 4.6 years, respectively. Of those reaching age 90 years in 2016, median expected years of life left is 4.2 years for women and 3.4 years for men. CONCLUSION: Demographic norms are useful as a guide when specific predictive tools are unavailable.