RESUMO
Although preliminary estimates from published literature and expert surveys suggest striking agreement among climate scientists on the tenets of anthropogenic climate change (ACC), the American public expresses substantial doubt about both the anthropogenic cause and the level of scientific agreement underpinning ACC. A broad analysis of the climate scientist community itself, the distribution of credibility of dissenting researchers relative to agreeing researchers, and the level of agreement among top climate experts has not been conducted and would inform future ACC discussions. Here, we use an extensive dataset of 1,372 climate researchers and their publication and citation data to show that (i) 97-98% of the climate researchers most actively publishing in the field surveyed here support the tenets of ACC outlined by the Intergovernmental Panel on Climate Change, and (ii) the relative climate expertise and scientific prominence of the researchers unconvinced of ACC are substantially below that of the convinced researchers.
Assuntos
Mudança Climática/estatística & dados numéricos , Clima , Efeito Estufa , Bases de Dados Factuais , Ecologia/estatística & dados numéricos , Ecologia/tendências , Previsões , Humanos , Opinião Pública , Pesquisadores/estatística & dados numéricosRESUMO
Octreotide is widely used as medical therapy for acromegaly. It is known to markedly reduce growth hormone levels, improve symptoms and reduce tumor size. Common side effects include gastrointestinal symptoms, hepatobiliary disorders, dizziness, headaches, bradycardia, hyperglycemia or hypoglycemia and thyroid dysfunction. Although urticaria, allergy/hypersensitivity reactions and anaphylaxis have been noted as possible adverse reactions, there is a lack of data showing a causal relationship between octreotide and hypersensitivity reactions and there is no information on management when continued use of this medication is essential. We now report a case of a 60 year old male with acromegaly who had presented with a cutaneous hypersensitivity reaction to octreotide. In addition he failed treatment with surgery, radiation, and dopamine agonist and could no longer afford to continue treatment with pegvisomant. The patient underwent desensitization treatment for his octreotide allergy and was able to resume treatment without any further side effects. We believe this case represents the first report of successful desensitization treatment for octreotide allergy in an acromegalic patient.
Assuntos
Acromegalia/tratamento farmacológico , Octreotida/uso terapêutico , Feminino , Humanos , Imageamento por Ressonância Magnética , Pessoa de Meia-IdadeRESUMO
Article 2 of the United Nations Framework Convention on Climate Change [United Nations (1992) http://unfccc.int/resource/docs/convkp/conveng.pdf. Accessed February 9, 2009] commits signatory nations to stabilizing greenhouse gas concentrations in the atmosphere at a level that "would prevent dangerous anthropogenic interference (DAI) with the climate system." In an effort to provide some insight into impacts of climate change that might be considered DAI, authors of the Third Assessment Report (TAR) of the Intergovernmental Panel on Climate Change (IPCC) identified 5 "reasons for concern" (RFCs). Relationships between various impacts reflected in each RFC and increases in global mean temperature (GMT) were portrayed in what has come to be called the "burning embers diagram." In presenting the "embers" in the TAR, IPCC authors did not assess whether any single RFC was more important than any other; nor did they conclude what level of impacts or what atmospheric concentrations of greenhouse gases would constitute DAI, a value judgment that would be policy prescriptive. Here, we describe revisions of the sensitivities of the RFCs to increases in GMT and a more thorough understanding of the concept of vulnerability that has evolved over the past 8 years. This is based on our expert judgment about new findings in the growing literature since the publication of the TAR in 2001, including literature that was assessed in the IPCC Fourth Assessment Report (AR4), as well as additional research published since AR4. Compared with results reported in the TAR, smaller increases in GMT are now estimated to lead to significant or substantial consequences in the framework of the 5 "reasons for concern."
Assuntos
Poluição do Ar/prevenção & controle , Efeito Estufa , Cooperação Internacional , Poluição do Ar/legislação & jurisprudência , Atmosfera , Clima , Comportamento Perigoso , Previsões , Humanos , Nações UnidasRESUMO
Managed relocation (MR) has rapidly emerged as a potential intervention strategy in the toolbox of biodiversity management under climate change. Previous authors have suggested that MR (also referred to as assisted colonization, assisted migration, or assisted translocation) could be a last-alternative option after interrogating a linear decision tree. We argue that numerous interacting and value-laden considerations demand a more inclusive strategy for evaluating MR. The pace of modern climate change demands decision making with imperfect information, and tools that elucidate this uncertainty and integrate scientific information and social values are urgently needed. We present a heuristic tool that incorporates both ecological and social criteria in a multidimensional decision-making framework. For visualization purposes, we collapse these criteria into 4 classes that can be depicted in graphical 2-D space. This framework offers a pragmatic approach for summarizing key dimensions of MR: capturing uncertainty in the evaluation criteria, creating transparency in the evaluation process, and recognizing the inherent tradeoffs that different stakeholders bring to evaluation of MR and its alternatives.
Assuntos
Biodiversidade , Animais , IncertezaRESUMO
INTRODUCTION: Overweight men with diabetes often report erectile dysfunction (ED), but few studies have examined effects of weight loss on this problem. AIM: This study examined 1-year changes in erectile function (EF) in overweight/obese men with type 2 diabetes participating in the Look AHEAD (Action for Health in Diabetes) trial. METHODS: Participants in Look AHEAD were randomly assigned to a control condition involving diabetes support and education (DSE) or to intensive lifestyle intervention (ILI) involving group and individual sessions to reduce weight and increase physical activity. Men from five of the clinical sites in Look AHEAD completed the International Index of Erectile Function (IIEF) at baseline (N = 372) and at 1 year (N = 306) (82%). MAIN OUTCOME MEASURES: Changes in EF as reported on the EF subscale of the IIEF. RESULTS: At 1 year, the ILI group lost a greater percent of initial body weight (9.9% vs. 0.6 %) and had greater improvements in fitness (22.7% vs. 4.6%) than DSE. EF improved more in ILI (17.3 +/- 7.6 at baseline; 18.6 +/- 8.1 at 1 year) than in DSE (18.3 +/- 7.6 at baseline; 18.4 +/- 8.0 at 1 year); P = 0.04 and P = 0.06 after adjusting for baseline differences. Using established norms for none (i.e., normal EF), and three grades (i.e., mild, moderate, and severe) ED, 8% of men in ILI reported a worsening of EF from baseline to 1 year, 70% stayed in the same category, and 22% reported improvements. In contrast, 20% of DSE reported worsening, 57% stayed in the same category, and 23% improved (P = 0.006). CONCLUSION: In this sample of older overweight/obese diabetic men, weight loss intervention was mildly helpful in maintaining EF.
Assuntos
Diabetes Mellitus Tipo 2/reabilitação , Disfunção Erétil/reabilitação , Comportamentos Relacionados com a Saúde , Estilo de Vida , Obesidade/reabilitação , Sobrepeso/reabilitação , Redução de Peso , Idoso , Índice de Massa Corporal , Terapia Combinada , Diabetes Mellitus Tipo 2/mortalidade , Neuropatias Diabéticas/mortalidade , Neuropatias Diabéticas/reabilitação , Dieta Redutora , Ingestão de Energia , Disfunção Erétil/mortalidade , Humanos , Masculino , Pessoa de Meia-Idade , Atividade Motora , Obesidade/mortalidade , Sobrepeso/mortalidade , Educação de Pacientes como Assunto , Aptidão FísicaRESUMO
BACKGROUND: Although patients with diabetes may benefit from physical activity, few studies have examined sustained walking in this population. OBJECTIVE: To examine the factors associated with sustained walking among managed care patients with diabetes. DESIGN: Longitudinal, observational cohort study with questionnaires administered 2.5 years apart. PARTICIPANTS: Five thousand nine hundred thirty-five patients with diabetes walking at least 20 minutes/day at baseline. MEASUREMENTS: The primary outcome was the likelihood of sustained walking, defined as walking at least 20 minutes/day at follow-up. We evaluated a logistic regression model that included demographic, clinical, and neighborhood variables as independent predictors of sustained walking, and expressed the results as predicted percentages. RESULTS: The absence of pain was linked to walking behavior, as 62% of patients with new pain, 67% with ongoing pain, and 70% without pain were still walking at follow-up (p = .03). Obese patients were less likely (65%) to sustain walking than overweight (71%) or normal weight (70%) patients (p = .03). Patients > or =65 years (63%) were less likely to sustain walking than patients between 45 and 64 (70%) or < or =44 (73%) years (p = .04). Only 62% of patients with a new comorbidity sustained walking compared with 68% of those who did not (p < .001). We found no association between any neighborhood variables and sustained walking in this cohort of active walkers. CONCLUSIONS: Pain, obesity, and new comorbidities were moderately associated with decreases in sustained walking. Whereas controlled intervention studies are needed, prevention, or treatment of these adverse conditions may help patients with diabetes sustain walking behavior.
Assuntos
Diabetes Mellitus/fisiopatologia , Programas de Assistência Gerenciada , Caminhada/fisiologia , Idoso , Comorbidade , Diabetes Mellitus/terapia , Feminino , Humanos , Modelos Logísticos , Estudos Longitudinais , Masculino , Pessoa de Meia-Idade , Medição da Dor , Características de Residência , Fatores de Risco , Inquéritos e QuestionáriosRESUMO
Limitations imposed on species ranges by the climatic, ecological, and physiological effects of elevation are important determinants of extinction risk. We modeled the effects of elevational limits on the extinction risk of landbirds, 87% of all bird species. Elevational limitation of range size explained 97% of the variation in the probability of being in a World Conservation Union category of extinction risk. Our model that combined elevational ranges, four Millennium Assessment habitat-loss scenarios, and an intermediate estimate of surface warming of 2.8 degrees C, projected a best guess of 400-550 landbird extinctions, and that approximately 2150 additional species would be at risk of extinction by 2100. For Western Hemisphere landbirds, intermediate extinction estimates based on climate-induced changes in actual distributions ranged from 1.3% (1.1 degrees C warming) to 30.0% (6.4 degrees C warming) of these species. Worldwide, every degree of warming projected a nonlinear increase in bird extinctions of about 100-500 species. Only 21% of the species predicted to become extinct in our scenarios are currently considered threatened with extinction. Different habitat-loss and surface-warming scenarios predicted substantially different futures for landbird species. To improve the precision of climate-induced extinction estimates, there is an urgent need for high-resolution measurements of shifts in the elevational ranges of species. Given the accelerating influence of climate change on species distributions and conservation, using elevational limits in a tested, standardized, and robust manner can improve conservation assessments of terrestrial species and will help identify species that are most vulnerable to global climate change. Our climate-induced extinction estimates are broadly similar to those of bird species at risk from other factors, but these estimates largely involve different sets of species.
Assuntos
Aves/fisiologia , Ecossistema , Extinção Biológica , Altitude , Animais , Demografia , Efeito Estufa , Modelos BiológicosRESUMO
OBJECTIVE: The purpose of this systematic review was 2-fold: first, to perform a comprehensive review of relevant studies on the impact of self-monitoring of blood glucose (SMBG) on HbA1c levels for patients with type 2 diabetes mellitus and, second, to explore mediators and moderators within a self-regulation framework. DATA SOURCES: Five databases-Medline, PsychInfo, Cochrane Database of Systematic Reviews, Cochrane Central Register of Controlled Trials, and Cumulative Index to Nursing & Allied Health Literature (CINAHL)-were searched. STUDY SELECTION: Cross-sectional, longitudinal, and randomized control trials from 1990 to 2006, which included patients with type 2 diabetes not on insulin, were reviewed. In total, 6,769 studies were screened for inclusion, 89 were retrieved for detailed analysis, and 29 met criteria for inclusion in the review. DATA EXTRACTION: Data on the impact of SMBG on HbA1c, potential mediators and moderators, study design and participants, and limitations of each study were retrieved. DATA SYNTHESIS: Twenty-nine studies were included in this review: 9 cross-sectional studies, 9 longitudinal studies, and 11 randomized controlled trials. Evidence from the cross-sectional and longitudinal studies was inconclusive. Evidence from randomized controlled trials suggests that SMBG may lead to improvements in glucose control. Very few studies examined potential mediators or moderators of SMBG on HbA1c levels. CONCLUSIONS: SMBG may be effective in controlling blood glucose for patients with type 2 diabetes. There is a need for studies that implement all the components of the process for self-regulation of SMBG to assess whether patient use of SMBG will improve HbA1c levels.
Assuntos
Automonitorização da Glicemia , Diabetes Mellitus Tipo 2/sangue , Diabetes Mellitus Tipo 2/reabilitação , Autocuidado , HumanosRESUMO
Humans have continuously interacted with natural systems, resulting in the formation and development of coupled human and natural systems (CHANS). Recent studies reveal the complexity of organizational, spatial, and temporal couplings of CHANS. These couplings have evolved from direct to more indirect interactions, from adjacent to more distant linkages, from local to global scales, and from simple to complex patterns and processes. Untangling complexities, such as reciprocal effects and emergent properties, can lead to novel scientific discoveries and is essential to developing effective policies for ecological and socioeconomic sustainability. Opportunities for truly integrating various disciplines are emerging to address fundamental questions about CHANS and meet society's unprecedented challenges.
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Ecossistema , Meio Ambiente , Humanos , Política PúblicaRESUMO
Animal studies indicate Salacia reduces body weight, possibly due to its α-glucosidase inhibitor (α-GI) properties, but this has not been examined previously. In this study, a randomized, placebo-controlled, three-way cross-over design was used to evaluate whether Salacia Chinensis (SC) reduces appetite in healthy overweight/obese individuals (body mass index 28.8 ±3.6 kg/m²; 32 ± 12 years). Forty-eight participants were fasted overnight and consumed a dose of SC (300 or 500 mg) or placebo with a fixed breakfast meal at each visit. Appetite sensations, glycemic indices and gastrointestinal peptides were measured. Results indicated that SC had no effect on postprandial appetite. However, in women, hunger was reduced by SC compared to placebo at multiple time points (300 mg; p < 0.05), but not in men. Area under the curve (AUC) for serum glucose, insulin and amylin was attenuated with SC compared to placebo (p < 0.05). Glucagon like peptide-1 had two peaks after the meal, but the AUC did not differ between groups. The AUC of peak areas for peptide YY and ghrelin were greater for SC than placebo (p < 0.05). These findings indicate that Salacia decreases glycemic indices supporting its role as an α-GI, and affects certain gastrointestinal peptides suggesting it may be an appetite modulator.
Assuntos
Apetite/efeitos dos fármacos , Trato Gastrointestinal/metabolismo , Inibidores de Glicosídeo Hidrolases/farmacologia , Obesidade/tratamento farmacológico , Extratos Vegetais/farmacologia , Salacia/química , Adulto , Estudos Cross-Over , Método Duplo-Cego , Regulação Enzimológica da Expressão Gênica/efeitos dos fármacos , Humanos , Extratos Vegetais/químicaRESUMO
CONTEXT: TNF increases plasma leptin in humans in vivo, but previous studies showed it decreases leptin in vitro. OBJECTIVE AND PARTICIPANTS: The objective of this study was to determine the effect of TNF on leptin release from human adipose tissue (AT) from healthy subjects undergoing elective surgery or needle aspirations of AT at a university hospital. DESIGN: Human omental and abdominal sc AT fragments from non- obese and obese subjects were placed in organ culture without or with TNF added in the presence or absence of insulin and/or dexamethasone (dex; a synthetic glucocorticoid) for up to 2 d. RESULTS: In the absence of hormones, culture with TNF decreased leptin release. In contrast, when added in the presence of dex, TNF increased secreted leptin and leptin mRNA abundance in AT from nonobese and obese subjects. The TNF + dex-stimulated increase in leptin was associated with an increase in p38 MAPK activity and was totally blocked by p38 MAPK inhibitors. In contrast, inhibition of p38 MAPK only partially blocked the effect of TNF on IL-6 production. Culture of obese AT with either p38 or p44/42 MAPK inhibitors also blunted the spontaneous increase in media leptin that occurred from d 1-2 of culture in omental AT of obese subjects. CONCLUSION: Synergistic effects of increased local or systemic TNF in combination with glucocorticoids may contribute to increased leptin expression in response to stress, including infection and obesity.
Assuntos
Tecido Adiposo/metabolismo , Glucocorticoides/farmacologia , Leptina/biossíntese , Fator de Necrose Tumoral alfa/farmacologia , Proteínas Quinases p38 Ativadas por Mitógeno/fisiologia , Adipócitos/enzimologia , Adipócitos/metabolismo , Tecido Adiposo/efeitos dos fármacos , Tecido Adiposo/enzimologia , Adulto , Tamanho Celular , Células Cultivadas , Citocinas/metabolismo , Dexametasona/farmacologia , Sinergismo Farmacológico , Inibidores Enzimáticos/farmacologia , Feminino , Regulação da Expressão Gênica/efeitos dos fármacos , Humanos , Imidazóis/farmacologia , Proteína Quinase 1 Ativada por Mitógeno/antagonistas & inibidores , Obesidade/enzimologia , Obesidade/metabolismo , Piridinas/farmacologia , RNA Mensageiro/biossíntese , RNA Mensageiro/genética , Transdução de Sinais/efeitos dos fármacos , Estimulação QuímicaRESUMO
OBJECTIVES: The aim of this study was to determine the impact of diabetes mellitus (DM) on short-term mortality and morbidity in patients undergoing coronary artery bypass surgery (CABG). BACKGROUND: Diabetes mellitus is present in approximately 20% to 30% of patients undergoing CABG, and the impact of diabetes on short-term outcome is unclear. METHODS: We performed a retrospective cohort study in 434 hospitals from North America. The study population included 146,786 patients undergoing CABG during 1997: 41,663 patients with DM and 105,123 without DM. The primary outcome was 30-day mortality. Secondary outcomes were in-hospital morbidity, infections and composite outcomes of mortality or morbidity and mortality or infection. RESULTS: The 30-day mortality was 3.7% in patients with DM and 2.7% in those without DM; the unadjusted odds ratio was 1.40 (95% confidence interval [CI], 1.31 to 1.49). After adjusting for other baseline risk factors, the overall adjusted odds ratio for diabetics was 1.23 (95% CI, 1.15 to 1.32). Patients treated with oral hypoglycemic medications had adjusted odds ratio 1.13; 95% CI, 1.04 to 1.23, whereas those on insulin had an adjusted odds ratio 1.39; 95% CI, 1.27 to 1.52. Morbidity, infections and the composite outcomes occurred more commonly in diabetic patients and were associated with an adjusted risk about 35% higher in diabetics than nondiabetics, particularly among insulin-treated diabetics (adjusted risk between 1.5 to 1.61). CONCLUSIONS: Diabetes mellitus is an important risk factor for mortality and morbidity among those undergoing CABG. Research is needed to determine if good control of glucose levels during the perioperative time period improves outcome.
Assuntos
Ponte de Artéria Coronária , Diabetes Mellitus/mortalidade , Idoso , Estudos de Coortes , Complicações do Diabetes , Feminino , Cardiopatias/complicações , Cardiopatias/mortalidade , Cardiopatias/cirurgia , Mortalidade Hospitalar , Humanos , Tempo de Internação , Masculino , Pessoa de Meia-Idade , Morbidade , América do Norte/epidemiologia , Estudos Retrospectivos , Fatores de Risco , Análise de Sobrevida , Fatores de Tempo , Resultado do TratamentoRESUMO
BACKGROUND: Weight loss (WL) negatively affects bone mineral density (BMD) in older populations and has specifically been shown in women. OBJECTIVE: In this prospective controlled trial, we examined variables of bone quality and endocrine changes after intentional WL in men. DESIGN: Thirty-eight overweight and obese [mean ± SD body mass index (in kg/m²): 31.9 ± 4.4; age: 58 ± 6 y] men were recruited to either WL through caloric restriction or weight maintenance (WM) for 6 mo. RESULTS: There was a -7.9 ± 4.4% and +0.2 ± 1.6% change in body weight in the WL and WM groups, respectively. There was a greater increase in femoral neck and total body BMD and bone mineral content (BMC) in the WM group than in the WL group (P-interaction effect < 0.05). In contrast, there was a trend for the tibia cortical thickness and area to decrease more in the WM group than in the WL group (P ≤ 0.08). There was a decrease in the periosteal circumference in both groups over time (P < 0.01) and no statistically significant changes in trabecular bone. Circulating total, free, and bioavailable estradiol decreased in the WL group compared with the WM group, and changes were different between groups (P < 0.05). Serum total and bioavailable testosterone increased in both groups (P < 0.01). Serum 25-hydroxyvitamin D increased to a similar extent in both groups (P < 0.05). CONCLUSIONS: Moderate WL in overweight and obese men did not decrease BMD at any anatomical site or alter cortical and trabecular bone and geometry. Also, despite increased BMD at some sites when maintaining excess body weight, cortical bone showed a trend in the opposite direction.
Assuntos
Reabsorção Óssea/prevenção & controle , Restrição Calórica , Dieta Redutora , Obesidade/dietoterapia , Sobrepeso/dietoterapia , Absorciometria de Fóton , Idoso , Terapia Comportamental , Índice de Massa Corporal , Densidade Óssea , Reabsorção Óssea/diagnóstico por imagem , Reabsorção Óssea/epidemiologia , Reabsorção Óssea/etiologia , Restrição Calórica/efeitos adversos , Terapia Combinada/efeitos adversos , Dieta Redutora/efeitos adversos , Humanos , Masculino , Pessoa de Meia-Idade , Atividade Motora , New Jersey/epidemiologia , Ciências da Nutrição/educação , Obesidade/fisiopatologia , Obesidade/terapia , Sobrepeso/fisiopatologia , Sobrepeso/terapia , Educação de Pacientes como Assunto , Risco , Tíbia/diagnóstico por imagem , Redução de PesoRESUMO
Adipose tissue IL-6 expression is increased in obesity and is a strong predictor of abnormalities in adipocyte and systemic metabolism. We used adipose tissue organ culture to test the direct effects of IL-6 on leptin expression, lipolysis, and lipoprotein lipase activity. To assess possible interactions with the hormonal milieu, IL-6 effects were tested in the presence or absence of insulin and/or glucocorticoid [dexamethasone (dex)]. Because omental (Om) and abdominal sc depots differ in IL-6 expression, their responses to exogenous IL-6 were compared. Although IL-6 had no significant effects under basal conditions, culture with the combination of IL-6 and dex, compared with dex alone, for 2 d increased leptin in both depots [+95 +/- 30% (sc) and +67 +/- 19% (Om), P < 0.01]; IL-6 did not affect leptin production when added in the presence of insulin. Culture with IL-6 in the absence of hormones moderately increased lipolysis during culture in both sc and Om [+79 +/- 23% (sc) and +26 +/- 9% (Om), each P < 0.01]. IL-6 markedly reduced the high levels of lipoprotein lipase activity in tissue cultured with insulin plus dex. We conclude that high local concentrations of IL-6 can modulate leptin production and lipid metabolism in human adipose tissue.
Assuntos
Tecido Adiposo/metabolismo , Interleucina-6/farmacologia , Leptina/biossíntese , Metabolismo dos Lipídeos , Dexametasona/farmacologia , Feminino , Humanos , Insulina/farmacologia , Leptina/genética , Lipólise/efeitos dos fármacos , Lipase Lipoproteica/metabolismo , Masculino , RNA Mensageiro/análiseRESUMO
PURPOSE: This clinical trial assessed patient preference, satisfaction, and use of an insulin injector/glucose monitor combination device versus syringes and a separate glucose monitor. METHODS: In a randomized, multicenter, 2-period crossover study, 15 patients with type 1 diabetes were randomized to use either a combined injector/monitor device or syringes, a vial, and a separate glucose monitor, then switched to the alternate treatment. Efficacy, safety, preference, satisfaction, and actual use (via meter download) of the 2 systems were compared. RESULTS: Most of the patients preferred using the combination device to syringes and a separate meter. Results from the Handling of Delivery Systems questionnaire given at the end of the study indicated that 49% of patients felt they tested their blood glucose more often with the combination device than with a separate meter. A higher frequency of daily monitoring was reported with the combination device in patients overall (approximately 1 more reading per week). However, a large subset of patients (32%) showed substantial increases in their frequency of daily glucose monitoring (an average of 1 additional reading per day). CONCLUSIONS: Use of the combination device was associated with significant improvements in patient treatment satisfaction.
Assuntos
Atitude Frente a Saúde , Automonitorização da Glicemia/instrumentação , Diabetes Mellitus Tipo 1 , Hipoglicemiantes/administração & dosagem , Injeções Subcutâneas/instrumentação , Insulina/administração & dosagem , Adulto , Análise de Variância , Automonitorização da Glicemia/efeitos adversos , Automonitorização da Glicemia/psicologia , Estudos Cross-Over , Diabetes Mellitus Tipo 1/tratamento farmacológico , Diabetes Mellitus Tipo 1/metabolismo , Diabetes Mellitus Tipo 1/psicologia , Desenho de Equipamento , Feminino , Hemoglobinas Glicadas/metabolismo , Conhecimentos, Atitudes e Prática em Saúde , Humanos , Injeções Subcutâneas/efeitos adversos , Injeções Subcutâneas/psicologia , Masculino , Segurança , Autoadministração/instrumentação , Autoadministração/psicologia , Inquéritos e Questionários , Estados UnidosRESUMO
The scientific and policy worlds have different goals, which can lead to different standards for what constitutes "proof" of a change or phenomena, and different approaches for characterizing and conveying uncertainty and risk. These differences can compromise effective communication among scientists, policymakers, and the public, and constrain the types of socially compelling questions scientists are willing to address. In this paper, we review a set of approaches for dealing with uncertainty, and illustrate some of the errors that arise when science and policy fail to coordinate correctly. We offer a set of recommendations, including restructuring of science curricula and establishment of science-policy forums populated by leaders in both arenas, and specifically constituted to address problems of uncertainty.
Assuntos
Meio Ambiente , Formulação de Políticas , Ciência , Incerteza , Currículo , Humanos , Relações Interprofissionais , Condições SociaisRESUMO
CONTEXT: Obesity is associated with lower serum concentrations of 25-hydroxyvitamin D (25OHD) and higher intact PTH. The threshold of 25OHD needed to maximally suppress intact PTH has been suggested as a marker of optimal vitamin D status. OBJECTIVE: In this study, we hypothesized that whereas the obese have a higher serum PTH and lower 25OHD, suppression of serum PTH by 25OHD would be independent of body weight. DESIGN, SETTING, AND PARTICIPANTS: We performed a retrospective analysis on 383 women (ages 24-75 y) with a wide range of body weights (43-185 kg) who were stabilized to 1-1.2 g calcium/d for 1 month before blood draw. Body composition, serum PTH, 25OHD, calcium, and creatinine were measured. Locally weighted regression and smoothing scatterplots were used to depict the association between serum PTH and 25OHD. A nonlinear exponential model determined the point for near maximal suppression of PTH by 25OHD. RESULTS: The point for near maximal suppression of PTH by 25OHD for all women (body mass index, 31.4 ± 7.7 kg/m²) occurred at a 25OHD concentration of 21.7 ng/mL (95% confidence interval, 28-48 ng/mL). No point of maximal suppression was found for nonobese women, yet in the obese women (n = 207; body mass index, >30 kg/m²) suppression of PTH occurred at a 25OHD concentration of 11.1 ng/mL (95% confidence interval, 4.7-17.5 ng/mL). CONCLUSIONS: These results suggest that if PTH is suppressed at a lower serum 25OHD in the obese compared to the entire population, the lower average 25OHD concentrations in the obese may not have the same physiological significance as in the general population.
Assuntos
25-Hidroxivitamina D 2/sangue , Calcifediol/sangue , Modelos Biológicos , Obesidade/sangue , Hormônio Paratireóideo/sangue , Deficiência de Vitamina D/complicações , Adulto , Idoso , Algoritmos , Biomarcadores/sangue , Índice de Massa Corporal , Feminino , Humanos , Pessoa de Meia-Idade , Estado Nutricional , Obesidade/complicações , Estudos Retrospectivos , Adulto JovemRESUMO
BACKGROUND: Weight loss (WL) is associated with a decrease in calcium absorption and may be one mechanism that induces bone loss with weight reduction. OBJECTIVE: Because vitamin D supplementation has been shown to increase true fractional calcium absorption (TFCA), the goal of this study was to examine the effect of vitamin D during WL or weight maintenance (WM). DESIGN: A randomized, placebo-controlled, double-blind 6-wk study was conducted in 82 postmenopausal women [BMI (in kg/m(2); ±SD): 30.2 ± 3.7] with 25-hydroxyvitamin D [25(OH)D] concentrations <70 nmol/L during either WL or WM. All women were given 10 µg vitamin D(3)/d and 1.2 g Ca/d and either weekly vitamin D(3) (375 µg) or a placebo equivalent to 63 µg (2500 IU)/d and 10 µg (400 IU)/d, respectively. We measured TFCA with the use of dual-stable isotopes, 25(OH)D, parathyroid hormone, estradiol, calcitriol, and urinary calcium at baseline and 6 wk in weight loss and vitamin D(3)-supplementation (WL-D; n = 19), weight maintenance and vitamin D(3)-supplementation (WM-D; n = 20), weight loss and placebo (n = 22), and weight maintenance and placebo (n = 21) groups. RESULTS: WL groups lost 3.8 ± 1.1% of weight with no difference between vitamin D(3) supplementation and the placebo. The rise in serum 25(OH)D was greatest in the WL-D group (19.8 ± 14.5 nmol/L) compared with in WM-D (9.1 ± 10.3 nmol/L) and placebo groups (1.5 ± 10.9 nmol/L). TFCA increased with vitamin D(3) supplementation compared with placebo treatment (P < 0.01) and decreased during WL compared with WM. Serum 25(OH)D or 1,25-dihyroxyvitamin D did not correlate with TFCA. CONCLUSION: These data show that vitamin D supplementation increases TFCA and that WL decreases TFCA and suggest that, when calcium intake is 1.2 g/d, either 10 or 63 µg vitamin D/d is sufficient to maintain the calcium balance. This trial was registered at clinicaltrials.gov as NCT00473031.