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1.
S Afr Med J ; 114(2): e1306, 2024 Feb 13.
Artigo em Inglês | MEDLINE | ID: mdl-38525581

RESUMO

BACKGROUND: Low- and middle-income countries have a critical shortage of specialist anaesthetists. Most patients arriving for surgery are of low perioperative risk. Without immediate access to preoperative specialist care, an appropriate interim strategy may be to ensure that only high-risk patients are seen preoperatively by a specialist. Matching human resources to the burden of disease with a nurse-administered pre-operative screening tool to identify high-risk patients who might benefit from specialist review prior to the day of surgery may be an effective strategy. OBJECTIVE: To develop a nurse-administered preoperative anaesthesia screening tool to identify patients who would most likely benefit from a specialist review before the day of surgery, and those patients who could safely be seen by the anaesthetist on the day of surgery. This would ensure adequate time for optimisation of high-risk patients preoperatively and limit avoidable day-of-surgery cancellations. METHODS: A systematic review was conducted to identify preoperative screening questions for use in a three-round Delphi consensus process. A panel of 16 experienced full-time clinical anaesthetists representing all university-affiliated anaesthesia departments in South Africa participated to define a nurses' screening tool for preoperative assessment. RESULTS: Ninety-eight studies were identified, which generated 79 questions. An additional 14 items identified by the facilitators were added to create a list of 93 questions for the first round. The final screening tool consisted of 81 questions, of which 37 were deemed critical to identify patients who should be seen by a specialist prior to the day of surgery. CONCLUSION: A structured nurse-administered preoperative screening tool is proposed to identify high-risk patients who are likely to benefit from a timely preoperative specialist anaesthetist review to avoid cancellation on the day of surgery.


Assuntos
Técnica Delphi , Cuidados Pré-Operatórios , Humanos , Cuidados Pré-Operatórios/métodos , África do Sul , Consenso , Anestesia/métodos , Medição de Risco/métodos
2.
Pain Pract ; 24(5): 739-748, 2024 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-38379359

RESUMO

PURPOSE: Exercise prescriptions for chronic low back pain (CLBP) often utilize reductionistic, trunk-focused exercise aimed at addressing proposed pain mechanisms. It is unknown if the use of these trunk-focused exercises imply beliefs to people with CLBP about the rationale for their use (e.g., etiology), even without concurrent biomedical narratives. This study aimed to explore people's perceptions of specific and general exercise without an accompanying narrative when experiencing CLBP. METHODS: An anonymous online survey was distributed. Mixed methods were utilized for analysis. Six-point Likert scales categorized people's beliefs about individual exercises. Open-ended questions were used to gather further beliefs which were then coded into themes. RESULTS: People with CLBP perceived specific exercise as more beneficial than general exercise. Eight themes and five subthemes were defined. A high volume of positive beliefs were centered around strengthening the low back and abdominal musculature, emphasizing the importance of correct technique. Negative beliefs were held against spinal flexion and external load. Both positive and negative beliefs were underpinned by spinal/pelvic stability being important as well as certain exercises being achievable or not. CONCLUSION: This study demonstrated that people with CLBP consider specific exercises to be more beneficial than general exercises for CLBP. Specific exercises irrespective of an accompanying narrative can imply meaning about the intent of an exercise. Understanding this requires practitioners to be mindful when prescribing and communicating exercise.


Assuntos
Dor Crônica , Terapia por Exercício , Dor Lombar , Humanos , Dor Lombar/terapia , Dor Lombar/psicologia , Masculino , Feminino , Terapia por Exercício/métodos , Adulto , Pessoa de Meia-Idade , Dor Crônica/psicologia , Dor Crônica/terapia , Inquéritos e Questionários , Idoso , Exercício Físico/fisiologia , Exercício Físico/psicologia , Adulto Jovem
3.
Mar Pollut Bull ; 188: 114648, 2023 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-36724670

RESUMO

Estuaries in rainfall poor regions are highly susceptible to climatic and hydrological changes. The Coorong, a Ramsar-listed estuarine-coastal lagoon at the end of the Murray-Darling Basin (Australia), has experienced declining ecological health over recent decades. Twenty years of environmental data were analysed to assess patterns and drivers of water quality changes. Large areas of the Coorong are now persistently hyper-saline (salinity >80 psu) and hypereutrophic (total nitrogen, TN > 4 mg L-1, total phosphorus, TP > 0.2 mg L-1, chlorophyll a > 50 µg L-1) which coincided with reduced flushing due to diminished freshwater inflows and increasing evapo-concentration. Sediment quality also was related to flushing, with higher concentrations of organic carbon, TN, TP and sulfides as salinity increased. While total nutrient levels are very high, dissolved inorganic nutrients are generally low. Increased lagoonal flushing would be beneficial to reduce the hypersalinisation and hypereutrophication and improve ecosystem health.


Assuntos
Ecossistema , Rios , Clorofila A/análise , Eutrofização , Austrália , Nitrogênio/análise , Fósforo/análise , Monitoramento Ambiental , Clorofila/análise
4.
Sci Total Environ ; 835: 155225, 2022 Aug 20.
Artigo em Inglês | MEDLINE | ID: mdl-35421465

RESUMO

The Murray River is Australia's longest river, draining the continent's largest exoreic catchment. The river is Australia's most economically valuable, but is highly degraded by water extraction. The Murray River's terminal lakes, Lakes Alexandrina and Albert, formed following the mid-Holocene marine transgression. These lakes are part of one of the most ecologically important wetland ecosystems on the Australian continent and are recognised as internationally significant by the Ramsar Convention. As a result of upstream water extraction, the Lower Lakes are threatened by rising salinity. To combat this threat, water is allocated to maintain the Lower Lakes as freshwater ecosystems. This practice is part of the Murray-Darling Basin Plan, one of the largest environmental water allocation plans in the world. The water allocations and the natural history of the Lower Lakes are the subject of academic and public debate, since the water would otherwise be used for consumptive purposes, particularly irrigated agriculture, upstream. Recent modelling postulated that the lakes were saline for much of the period between 8500 and 5000 years ago. However, using new sedimentary diatom and hydrodynamic modelling evidence, we demonstrate that the Lower Lakes were fresh for most of this time, particularly after 7200 years ago. Elevated Murray River discharge between 7200 and 6600 years ago prevented sea water ingress, despite sea levels +1 m higher than present. After 6600 years ago, the lakes remained predominately fresh. Current management is, therefore, consistent with the lakes' history before European colonisation.


Assuntos
Diatomáceas , Rios , Austrália , Ecossistema , Lagos , Água
5.
Sci Rep ; 11(1): 10527, 2021 05 18.
Artigo em Inglês | MEDLINE | ID: mdl-34006911

RESUMO

Kokumi taste is a well-accepted and characterised taste modality and is described as a sensation of enhancement of sweet, salty, and umami tastes. The Calcium Sensing Receptor (CaSR) has been designated as the putative kokumi taste receptor for humans, and a number of kokumi-active ligands of CaSR have been discovered recently with activity confirmed both in vivo and in vitro. Domestic cats (Felis catus) are obligate carnivores and accordingly, their diet is abundant in proteins, peptides, and amino acids. We hypothesised that CaSR is a key taste receptor for carnivores, due to its role in the detection of different peptides and amino acids in other species. Using in silico, in vitro and in vivo approaches, here we compare human CaSR to that of a model carnivore, the domestic cat. We found broad similarities in ligand specificity, but differences in taste sensitivity between the two species. Indeed our in vivo data shows that cats are sensitive to CaCl2 as a kokumi compound, but don't show this same activity with Glutathione, whereas for humans the reverse is true. Collectively, our data suggest that kokumi is an important taste modality for carnivores that drives the palatability of meat-derived compounds such as amino acids and peptides, and that there are differences in the perception of kokumi taste between carnivores and omnivores.


Assuntos
Gatos/fisiologia , Percepção Gustatória , Sequência de Aminoácidos , Aminoácidos/análise , Animais , Cloreto de Cálcio/metabolismo , Glutationa/metabolismo , Humanos , Ligantes , Cloreto de Magnésio/metabolismo , Produtos da Carne/análise , Peptídeos/análise , Ligação Proteica , Receptores de Detecção de Cálcio/metabolismo , Papilas Gustativas/metabolismo
6.
Ochsner J ; 21(1): 25-29, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-33828423

RESUMO

Background: The impact of web-based patient portals on patient outcomes-specifically hospital readmissions in patients with atrial fibrillation (AF)-remains understudied. Methods: This single-center retrospective cohort study investigated the use of an online portal system (MyChart) by patients hospitalized from January 1, 2014 to June 30, 2017 for AF. During the study period, 11,334 unique AF admissions were identified; 50.3% were MyChart users and 49.7% were non-MyChart users. Patients who experienced inpatient mortality were excluded. The study groups were analyzed for demographic variables, comorbidities, readmission rates, and the frequency of MyChart use during the 3.5-year time frame. Results: MyChart users were younger (median age, 74 years, interquartile range [IQR] 66-82 vs 77 years, IQR 68-85; P<0.0001) and more likely to be white (91.9% vs 84.6%; P<0.0001), but the sex distribution was similar between groups, with 51.8% males in the MyChart group vs 53.2% in the non-MyChart group. MyChart users had a significantly higher rate of readmission compared to non-MyChart users at 1 year (43.0% vs 32.0%, respectively; P<0.0001). MyChart users who were readmitted had a higher median number of logins to MyChart (121 [IQR 32-270.5]) than MyChart users who were not readmitted (91 [IQR 26-205]; P<0.0001). Multivariable regression analysis demonstrated that MyChart use was associated with readmission (odds ratio 1.57, 95% CI 1.49-1.70; P<0.0001). Conclusion: Among patients with AF, MyChart use was associated with higher readmissions in this single-center cohort. Use and benefit of bespoke portals require further study.

7.
J Cogn Dev ; 22(1): 84-107, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-33519305

RESUMO

The present study had two aims. First, we set out to evaluate the structure of processing speed in children by comparing five alternative models: two conceptual models (a unitary model, a complexity model) and three methodological models (a stimulus material model, an output response model, and a timing modality model). Second, we then used the resulting models to predict multiple types of reading, a highly important developmental outcome, using other well-known predictors as covariates. Participants were 844 children enrolled in third through fifth grade in urban public elementary schools who received 16 measures of processing speed that varied in the above dimensions. A two-factor complexity model that differentiated between simple and complex processing speed was the preferred model and fit the data well. Both types of PS predicted reading fluency, and complex (but not simple) PS predicted single word reading and comprehension. Results offer insight to the structure of processing speed, its relation to closely related concepts (such as executive function), and provide nuance to the understanding of the way processing speed influences reading.

9.
S Afr Med J ; 109(7): 471-476, 2019 Jun 28.
Artigo em Inglês | MEDLINE | ID: mdl-31266571

RESUMO

For more than 70 years the default therapy for anaemia and blood loss was mostly transfusion. Accumulating evidence demonstrates a significant dose-dependent relationship between transfusion and adverse outcomes. This and other transfusion-related challenges led the way to a new paradigm. Patient blood management (PBM) is the application of evidence-based practices to optimise patient outcomes by managing and preserving the patient's own blood. 'Real-world' studies have shown that PBM improves patient outcomes and saves money. The prevalence of anaemia in adult South Africans is 31% in females and 17% in males. Improving the management of anaemia will firstly improve public health, secondly relieve the pressure on the blood supply, and thirdly improve the productivity of the nation's workforce. While high-income countries are increasingly implementing PBM, many middle- and low-income countries are still trying to upscale their transfusion services. The implementation of PBM will improve South Africa's health status while saving costs.


Assuntos
Transfusão de Sangue Autóloga/normas , Padrão de Cuidado , Anemia/terapia , Perda Sanguínea Cirúrgica , Países Desenvolvidos , Países em Desenvolvimento , Medicina Baseada em Evidências , Humanos , Segurança do Paciente , Desenvolvimento de Programas , África do Sul
10.
Int J Obstet Anesth ; 40: 119-127, 2019 11.
Artigo em Inglês | MEDLINE | ID: mdl-31230992

RESUMO

Post-caesarean pain is an important and often neglected outcome. It causes suffering, affects breastfeeding and is associated with postpartum depression and the development of chronic pain syndromes. Pain control is often difficult even in resource-rich environments; it is likely far worse in resource-limited settings, where emphasis is on reducing the high maternal mortality rate. Lack of adequate staffing, education, and postoperative monitoring severely limit the options in resource-limited settings. Resource-limited settings are further compromised by limited access to essential analgesic drugs and equipment for their administration. Solutions using affordable and accessible medications as part of a multimodal analgesic strategy are possible, supplemented by education and training programmes. More research is required, both to establish current practice and to test methods for improving maternal pain control. While government involvement is necessary to improve infrastructure and resources in individual countries, other solutions should also be sought, empowering local institutions and harnessing individual cultural characteristics.


Assuntos
Analgesia Obstétrica/métodos , Cesárea , Países em Desenvolvimento , Dor Pós-Operatória/tratamento farmacológico , Feminino , Humanos , Pobreza , Gravidez
11.
J Hum Nutr Diet ; 32(1): 108-118, 2019 02.
Artigo em Inglês | MEDLINE | ID: mdl-30264530

RESUMO

BACKGROUND: Guidance on choosing oral nutritional support strategies varies and the evidence for different approaches is discordant. The present study aimed to examine opinion and practice in the use of oral nutritional support amongst UK dietitians and to assess the factors that influence these clinical decisions. METHODS: The study comprised a cross-sectional, anonymous, national survey of UK dietitians. RESULTS: There were 207 completed responses (3% response rate). More dietitians reported using combined approaches (COMB) [n = 129 (62%)] over food-based (FB) strategies [n = 70 (34%)] or oral nutritional supplements (ONS) alone [n = 8 (4%)] (N = 207, P < 0.001). Intervention choice was associated with clinical setting and clinical speciality; community dietitians reported more frequent use of FB or ONS alone [n = 48 (59%)] versus COMB [n = 34 (41%)] compared to acute dietitians [COMB: n = 83 (78%) COMB versus FB or ONS alone: n = 24 (22%)] (N = 207, P < 0.0001). Specialist nutrition support dietitians reported more frequent use of FB or ONS alone [n = 22 (54%)] versus COMB [n = 19 (46%)] compared to nonspecialists [FB or ONS alone: n = 17 (45%) versus COMB: n = 21 (55%)] and other specialist dietitians [FB or ONS: n = 39 (30%) alone versus COMB: n = 89 (70%)] (P = 0.017). The greatest influences on choice were ease of implementation [n = 192 (93%)], departmental protocols [n = 184 (89%)], professional management pathways [n = 179 (87%)] and published research [n = 165 (80%)]. Patient circumstances [n = 117 (57%) and n = 99 (48%)] and ease of implementation [n = 35 (17%) and n = 48 (24%)] were reported as most influential in the first and second case scenarios, respectively. CONCLUSIONS: There is a need for further research on approaches to the dietetic management of adult malnutrition.


Assuntos
Desnutrição/terapia , Apoio Nutricional/estatística & dados numéricos , Nutricionistas/estatística & dados numéricos , Padrões de Prática Médica/estatística & dados numéricos , Adulto , Estudos Transversais , Feminino , Humanos , Masculino , Desnutrição/prevenção & controle , Apoio Nutricional/métodos , Inquéritos e Questionários , Reino Unido
13.
Sci Rep ; 8(1): 9130, 2018 06 14.
Artigo em Inglês | MEDLINE | ID: mdl-29904060

RESUMO

Archaeological evidence suggests that dogs were introduced to the islands of Oceania via Island Southeast Asia around 3,300 years ago, and reached the eastern islands of Polynesia by the fourteenth century AD. This dispersal is intimately tied to human expansion, but the involvement of dogs in Pacific migrations is not well understood. Our analyses of seven new complete ancient mitogenomes and five partial mtDNA sequences from archaeological dog specimens from Mainland and Island Southeast Asia and the Pacific suggests at least three dog dispersal events into the region, in addition to the introduction of dingoes to Australia. We see an early introduction of dogs to Island Southeast Asia, which does not appear to extend into the islands of Oceania. A shared haplogroup identified between Iron Age Taiwanese dogs, terminal-Lapita and post-Lapita dogs suggests that at least one dog lineage was introduced to Near Oceania by or as the result of interactions with Austronesian language speakers associated with the Lapita Cultural Complex. We did not find any evidence that these dogs were successfully transported beyond New Guinea. Finally, we identify a widespread dog clade found across the Pacific, including the islands of Polynesia, which likely suggests a post-Lapita dog introduction from southern Island Southeast Asia.


Assuntos
Cães/genética , Genoma Mitocondrial , Animais , Oceania , Polinésia
14.
Risk Anal ; 37(2): 206-218, 2017 02.
Artigo em Inglês | MEDLINE | ID: mdl-28230267

RESUMO

Space weather describes the way in which the Sun, and conditions in space more generally, impact human activity and technology both in space and on the ground. It is now well understood that space weather represents a significant threat to infrastructure resilience, and is a source of risk that is wide-ranging in its impact and the pathways by which this impact may occur. Although space weather is growing rapidly as a field, work rigorously assessing the overall economic cost of space weather appears to be in its infancy. Here, we provide an initial literature review to gather and assess the quality of any published assessments of space weather impacts and socioeconomic studies. Generally speaking, there is a good volume of scientific peer-reviewed literature detailing the likelihood and statistics of different types of space weather phenomena. These phenomena all typically exhibit "power-law" behavior in their severity. The literature on documented impacts is not as extensive, with many case studies, but few statistical studies. The literature on the economic impacts of space weather is rather sparse and not as well developed when compared to the other sections, most probably due to the somewhat limited data that are available from end-users. The major risk is attached to power distribution systems and there is disagreement as to the severity of the technological footprint. This strongly controls the economic impact. Consequently, urgent work is required to better quantify the risk of future space weather events.

15.
Clin Pharmacol Ther ; 99(4): 356-9, 2016 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-26331445

RESUMO

The purpose of this commentary is to place probability of trial success, or assurance, in the context of decision making in drug development, and to illustrate its properties in an intuitive manner for the readers of Clinical Pharmacology and Therapeutics. The hope is that this will stimulate a dialog on how assurance should be incorporated into a quantitative decision approach for clinical development and trial design that uses all available information.


Assuntos
Ensaios Clínicos como Assunto/estatística & dados numéricos , Interpretação Estatística de Dados , Descoberta de Drogas/estatística & dados numéricos , Probabilidade , Animais , Teorema de Bayes , Humanos , Modelos Estatísticos
16.
J Hum Nutr Diet ; 28(6): 517-45, 2015 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-26300378

RESUMO

BACKGROUND: Supportive interventions for enhancing dietary intake in malnourished or nutritionally at risk adults are frequently recommended. A recent systematic review of randomised controlled trials identified limited and poor quality evidence to support their use. Observational studies have been shown to compliment and extend their evidence. This review aimed to synthesise evidence from nonrandomised studies aiming to improve nutritional intake in nutritionally vulnerable individuals and to describe their effects on cost, nutritional, clinical and patient centred outcomes. METHODS: Systematic searches of 10 electronic databases were undertaken to May 2013. Reference lists of identified studies and systematic reviews were scrutinised and hand searching of relevant meeting abstracts was undertaken. Titles and abstracts were reviewed, data extracted by two research-ers working independently and summarised using a structured narrative format. RESULTS: Forty-one studies (n = 3751 participants) were identified for inclusion. Interventions identified included changes to the organisation of nutritional care (n = 15), changes to the feeding environment (n = 11), modification to meals (n = 6), supplementation of meals (n = 7) and recipients of home delivered meals (n = 2). Eighteen of 23 studies reported improvements in nutritional intake; however, effects on nutritional status, clinical outcomes and costs were reported in few studies and findings were inconsistent. Eighteen studies reported patient experience, highlighting benefits to nutritional status most commonly as judged by the carers but the methods used lacked rigour. CONCLUSIONS: This systematic review describes a range of interventions that may be implemented in clinical practice. A limited range of outcomes are reported and it is difficult to draw any meaningful conclusions on the effect of the different methods.


Assuntos
Suplementos Nutricionais , Serviços de Alimentação , Desnutrição/dietoterapia , Desnutrição/prevenção & controle , Estado Nutricional , Avaliação de Resultados em Cuidados de Saúde , Adulto , Humanos , Desnutrição/economia , Risco
17.
Anaesthesia ; 70(9): 1028-38, 2015 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-25891669

RESUMO

Haemodynamic and cardiac structural changes in severe pre-eclampsia and in pregnant women with human immunodeficiency virus (HIV) infection have not been clearly established. We performed transthoracic echocardiography on 105 women. Women with pre-eclampsia demonstrated (mean (SD), untreated vs treated) preserved fractional shortening (40 (7.1)% vs. 41 (8.6)%), a non-dilated left ventricle (4.5 (0.49) cm vs. 4.4 (0.44) cm), increased mitral valve E/septal e' (10.5 (3.3) vs. 10.6 (2.8)), and preserved tricuspid annular plane systolic exertion (2.6 (0.36) cm vs. 2.4 (0.51) cm). Women with HIV infection demonstrated (mean (SD), HIV-positive vs healthy) a reduced cardiac index (2.8 (0.64) ml.min(-1) .m(-2) vs. 3.1 (0.7) ml.min(-1) .m(-2) , p = 0.029), reduced septal s' tissue Doppler velocity (8.5 (1.5) cm.s(-1) vs. 9.3 (1.7) cm.s(-1) , p = 0.042), increased left ventricular end-diastolic area (7.6 (2.1) cm2 vs. 6.3 (1.7) cm2 , p = 0.004), and reduced right ventricular s' and e' velocity (s' velocity 14.7 (3.1) cm.s(-1) vs. 7.0 (2.9) cm.s(-1) p = 0.001, e' velocity 16.3 (4.1) cm.s(-1) vs. 18.7 (3.4) cm.s(-1) , p = 0.013). The mitral value E/septal e' was > 8 in 39% of patients with HIV. Fractional shortening (< 28%) was reduced in 10% of healthy women, and mitral valve E/septal e' ratios were > 8 in 38% of that group. Women with pre-eclampsia demonstrated preserved systolic function, with diastolic dysfunction. Women with HIV demonstrated reduced left and right ventricular systolic function, with increased ventricular dilatation.


Assuntos
Ecocardiografia/métodos , Infecções por HIV/fisiopatologia , Hemodinâmica , Pré-Eclâmpsia/fisiopatologia , Complicações Infecciosas na Gravidez/fisiopatologia , Adulto , Velocidade do Fluxo Sanguíneo , Comorbidade , Feminino , Infecções por HIV/epidemiologia , Ventrículos do Coração/diagnóstico por imagem , Humanos , Pré-Eclâmpsia/epidemiologia , Gravidez , Complicações Infecciosas na Gravidez/epidemiologia , Estudos Prospectivos , África do Sul/epidemiologia , Volume Sistólico
19.
CPT Pharmacometrics Syst Pharmacol ; 3: e138, 2014 Oct 01.
Artigo em Inglês | MEDLINE | ID: mdl-25271939

RESUMO

Body weight/body surface area-based and/or tiered fixed dosing strategies are widely utilized for monoclonal antibodies with linear clearance to scale adult clinical doses to children. However, there is limited knowledge on whether or not body weight-based dosing strategies also yield comparable dose-concentration-response relationships in adults and children for monoclonal antibodies that exhibit target-mediated drug disposition. Our findings indicate that it is important to interpret pharmacokinetics information in a pharmacokinetics/pharmacodynamics context as similar systemic drug exposure in adults and children may not be reflective of the corresponding target occupancy. They further indicate that BW-based dosing is superior to fixed dosing for the same target concentration, whereas the opposite holds true for the same target amount in adults and children. Michaelis-Menten approximations yielded similar profiles compared to the full target-mediated drug disposition model for all simulation scenarios and may be used to guide the selection of appropriate dosing regimens in children.

20.
Osteoporos Int ; 25(3): 933-41, 2014 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-23982802

RESUMO

SUMMARY: This analysis assessed whether seasonal change in 25-hydroxyvitamin D concentration was associated with bone resorption, as evidenced by serum parathyroid hormone and C-terminal telopeptide concentrations. The main finding was that increased seasonal fluctuation in 25-hydroxyvitamin D was associated with increased levels of parathyroid hormone and C-terminal telopeptide. INTRODUCTION: It is established that adequate 25-hydroxyvitamin D (25(OH)D, vitamin D) concentration is required for healthy bone mineralisation. It is unknown whether seasonal fluctuations in 25(OH)D also impact on bone health. If large seasonal fluctuations in 25(OH)D were associated with increased bone resorption, this would suggest a detriment to bone health. Therefore, this analysis assessed whether there is an association between seasonal variation in 25(OH)D and bone resorption. METHODS: The participants were (n = 279) Caucasian and (n = 88) South Asian women (mean (±SD); age 48.2 years (14.4)) who participated in the longitudinal Diet, Food Intake, Nutrition and Exposure to the Sun in Southern England study (2006-2007). The main outcomes were serum 25(OH)D, serum parathyroid hormone (sPTH) and serum C-terminal telopeptide of collagen (sCTX), sampled once per season for each participant. RESULTS: Non-linear mixed modelling showed the (amplitude/mesor) ratio for seasonal change in log 25(OH)D to be predictive of log sPTH (estimate = 0.057, 95 % CI (0.051, 0.063), p < 0.0001). Therefore, individuals with a higher seasonal change in log 25(OH)D, adjusted for overall log 25(OH)D concentration, showed increased levels of log sPTH. There was a corresponding significant ability to predict the range of seasonal change in log 25(OH)D through the level of sCTX. Here, the corresponding parameter statistics were estimate = 0.528, 95 % CI (0.418, 0.638) and p ≤ 0.0001. CONCLUSIONS: These findings suggest a possible detriment to bone health via increased levels of sPTH and sCTX in individuals with a larger seasonal change in 25(OH)D concentration. Further larger cohort studies are required to further investigate these preliminary findings.


Assuntos
Reabsorção Óssea/sangue , Hormônio Paratireóideo/sangue , Estações do Ano , Vitamina D/análogos & derivados , Adulto , Idoso , Reabsorção Óssea/fisiopatologia , Colágeno Tipo I/sangue , Feminino , Humanos , Estudos Longitudinais , Pessoa de Meia-Idade , Dinâmica não Linear , Peptídeos/sangue , Vitamina D/sangue
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