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1.
J Surg Educ ; 79(5): 1088-1092, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-35581113

RESUMO

OBJECTIVE: The taxing nature of surgery residency is well-documented in the literature, with residents demonstrating high rates of burnout, depression, suicidal thoughts, sexual harassment, and racial discrimination. Mentoring has been shown to improve camaraderie, address challenges of underrepresentation in medicine, and be associated with lower burnout. However, existing formal mentoring programs tend to be career-focused and hierarchal without opportunity to discuss important sociocultural issues. An innovative approach is needed to address these cultural and anthropological issues in surgery residencies while creating camaraderie and learning alternative perspectives across different levels of training. We sought to describe the framework we used to fill these needs by creating and implementing a novel mentoring program. DESIGN: A vertical, near-peer mentoring system of 7 groups was created consisting of the following members: 1 to 2 medical students, a PGY-1 general surgery resident, a PGY-4 research resident, and a faculty member. Meetings occur every 3 to 4 months in a casual setting with the first half of the meeting dedicated to intentional reflection and the second half focused on an evidence-based discussion regarding a specific topic in the context of surgery (i.e., burnout, discrimination, allyship, and finding purpose). SETTING: Program implementation took place at the University of Michigan in Ann Arbor, MI. PARTICIPANTS: Medical students, general surgery residents, and general surgery faculty were recruited. CONCLUSIONS: We have successfully launched the pilot year of a cross-spectrum formal mentoring program in general surgery. This program emphasizes camaraderie throughout training while providing opportunities for evidence-based discussion regarding sociocultural topics. We have included increased opportunities for community inclusivity and mentoring while allowing trainees and faculty members to discuss sensitive topics in a supportive environment. We plan to continue developing the program with robust evaluation and to expand the program to other surgical specialties and to other institutions.


Assuntos
Esgotamento Profissional , Cirurgia Geral , Internato e Residência , Tutoria , Assédio Sexual , Estudantes de Medicina , Cirurgia Geral/educação , Humanos , Mentores , Avaliação de Programas e Projetos de Saúde
3.
J Surg Res ; 264: 173-178, 2021 08.
Artigo em Inglês | MEDLINE | ID: mdl-33836406

RESUMO

BACKGROUND: Larger opioid prescriptions are associated with increased consumption without improvements in pain, and the majority of opioids prescribed go unused. We examined postoperative opioid prescription and use in patients undergoing vascular access surgery, where preoperative opioid exposure is common. METHODS: A retrospective analysis was conducted in adult CKD patients who underwent outpatient vascular access surgery. Patients were surveyed by telephone >2 weeks after surgery to assess pain level and opioid and non-opioid medication use. RESULTS: Of 117 patients contacted, 76 responded (65% response rate), with a median (interquartile range) age of 56 (42-69) years. Sixty-three patients (83%) were prescribed an opioid postoperatively. Respondents were prescribed 60 (38-75) oral morphine equivalents (OMEs) and consumed 0 (0-15) OMEs over 1 day with a pain score of 5 out of 10. Thirty-nine patients (>50%) used no opioids. There were no differences in postoperative opioid prescribing or use in patients with recent opioid exposure compared to patients without. Patients who underwent arteriovenous fistula (AVF) creation (short surgical incision procedure) were prescribed 60 (38-75) OMEs, compared with 75 (56-111) OMEs for patients who underwent AVF superficialization, AVG, or BVT (long surgical incision procedure; P < 0.01) and consumed 0 (0-15) OMEs compared with 10 (0-43) OMEs, respectively (P = 0.07). CONCLUSION: Regardless of preoperative opioid exposure, CKD patients undergoing vascular access surgery consumed fewer opioids than prescribed, with a median of <10% of opioids used. Therefore, we've reduced our institutional prescribing recommendations to 4 and 6 oxycodone 5mg pills for short and long surgical incision procedures, respectively.


Assuntos
Procedimentos Cirúrgicos Ambulatórios/efeitos adversos , Analgésicos Opioides/uso terapêutico , Derivação Arteriovenosa Cirúrgica/efeitos adversos , Prescrições de Medicamentos/estatística & dados numéricos , Dor Pós-Operatória/tratamento farmacológico , Adulto , Idoso , Prescrições de Medicamentos/normas , Feminino , Humanos , Falência Renal Crônica/terapia , Masculino , Pessoa de Meia-Idade , Dor Pós-Operatória/etiologia , Guias de Prática Clínica como Assunto , Padrões de Prática Médica/normas , Padrões de Prática Médica/estatística & dados numéricos , Diálise Renal/métodos , Estudos Retrospectivos
4.
J Surg Educ ; 78(5): 1413-1418, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-33664009

RESUMO

OBJECTIVE: Underrepresented minority (URM) medical students face many educational challenges. Barriers include lack of equitable representation, scarce mentorship, and the effects of systemic racism. For students interested in diversity and health equity, perceptions of surgical culture may discourage pursuing surgical specialties. We describe a national pilot for a novel surgical pipeline program, Leadership Exposure for the Advancement of Gender and Underrepresented Minority Equity in Surgery (LEAGUES), which utilizes early exposure, mentorship, and community building to empower URM students in pursuit of academic surgical careers. DESIGN: A 4-week virtual program included pairing students with faculty research mentors, virtual skills sessions, and seminars on leadership, advocacy, and career development. Participants underwent semi-structured interviews before and after participation, assessing experiences with mentorship and research, interest in surgery, career aspirations, and perceived barriers to career goals. SETTING: Department of Surgery, Michigan Medicine, Ann Arbor, Michigan. PARTICIPANTS: Rising second-year medical students. RESULTS: All 3 participants were Latinx; 2 were first-generation college students. Participants had no surgical mentorship and limited research exposure, citing a desire to learn research methodology, connect with mentors, and build towards a career working with underserved communities as motivating factors for participation. Perceived barriers to a surgical career included surgical culture, burnout, and lack of research expertise or academic network necessary for success. At completion of the program, participants described several themes: (1) new positive perspective on academic surgical culture, (2) interest and confidence in research, (3) hope for improving health disparities, (4) networking and longitudinal mentorship connections contributing to a sense of surgical community, and (5) eagerness to share resources with colleagues at their home institutions. CONCLUSIONS: LEAGUES program participants acquired tools and motivation to pursue careers in surgery, and established valuable longitudinal network and mentor relationships. LEAGUES is a novel model for national surgical pipeline programs.


Assuntos
Pesquisa Biomédica , Estudantes de Medicina , Escolha da Profissão , Humanos , Liderança , Mentores , Grupos Minoritários
7.
J Surg Educ ; 78(1): 356-360, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-32739442

RESUMO

OBJECTIVE: We describe a multilevel, collaborative research group for trainees and faculty engaging in transplant surgery research within one institution. DESIGN: Transplant Research, Education, and Engagement (TREE) was designed to develop trainees' research skills and foster enthusiasm in transplant surgery along the educational continuum. Our research model intentionally empowers junior researchers, including undergraduates and medical students, to assume active roles on a range of research projects and contribute new ideas within a welcoming research and learning environment. SETTING: Section of Transplant Surgery, Department of Surgery, Michigan Medicine, Ann Arbor, Michigan. PARTICIPANTS: Undergraduate premedical students, first through fourth year medical students, general surgery residents, transplant surgery fellows, and transplant surgery faculty. RESULTS: TREE was founded in September 2019 and has grown to include over 30 active members who meet weekly and collaborate virtually on a range of research projects, many of which are led by students. Trainees can assume both mentee and mentor roles and build their research, presentation and writing skills while collaborating academically. CONCLUSIONS: Our model has increased trainees' engagement in transplant research projects and fosters early enthusiasm for the field. This model can be feasibly replicated at other institutions and within other subspecialties.


Assuntos
Educação Médica , Transplante de Órgãos , Competência Clínica , Humanos , Mentores , Michigan
9.
J Appl Physiol (1985) ; 125(5): 1646-1659, 2018 11 01.
Artigo em Inglês | MEDLINE | ID: mdl-30236049

RESUMO

Habitual aerobic exercise enhances physiological function and reduces risk of morbidity and mortality throughout life, but the underlying molecular mechanisms are largely unknown. The circulating proteome reflects the intricate network of physiological processes maintaining homeostasis and may provide insight into the molecular transducers of the health benefits of physical activity. In this exploratory study, we assessed the plasma proteome (SOMAscan proteomic assay; 1,129 proteins) of healthy sedentary or aerobic exercise-trained young women and young and older men ( n = 47). Using weighted correlation network analysis to identify clusters of highly co-expressed proteins, we characterized 10 distinct plasma proteomic modules (patterns). In healthy young (24 ± 1 yr) men and women, 4 modules were associated with aerobic exercise status and 1 with participant sex. In healthy young and older (64 ± 2 yr) men, 5 modules differed with age, but 2 of these were partially preserved at young adult levels in older men who exercised; among all men, 4 modules were associated with exercise status, including 3 of the 4 identified in young adults. Exercise-linked proteomic patterns were related to pathways involved in wound healing, regulation of apoptosis, glucose-insulin and cellular stress signaling, and inflammation/immune responses. Importantly, several of the exercise-related modules were associated with physiological and clinical indicators of healthspan, including diastolic blood pressure, insulin resistance, maximal aerobic capacity, and vascular endothelial function. Overall, these findings provide initial insight into circulating proteomic patterns modulated by habitual aerobic exercise in healthy young and older adults, the biological processes involved, and their relation to indicators of healthspan. NEW & NOTEWORTHY This is the first study to assess the relation between plasma proteomic patterns and aerobic exercise status in healthy adults. Weighted correlation network analysis identified 10 distinct proteomic modules, including 5 patterns specific for exercise status. Additionally, 5 modules differed with aging in men, two of which were preserved in older exercising men. Exercise-associated modules included proteins related to inflammation, stress pathways, and immune function and correlated with clinical and physiological indicators of healthspan.


Assuntos
Envelhecimento/sangue , Exercício Físico/fisiologia , Envelhecimento Saudável/sangue , Proteoma , Adulto , Idoso , Biomarcadores , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Adulto Jovem
10.
Nutr Healthy Aging ; 4(4): 323-333, 2018 Jun 15.
Artigo em Inglês | MEDLINE | ID: mdl-29951592

RESUMO

BACKGROUND: Recent studies suggest curcumin is a promising nutraceutical for improving important clinical and physiological markers of healthy aging, including motor and cognitive function. OBJECTIVE: To determine if curcumin supplementation improves motor and cognitive function in healthy middle-aged and older adults. METHODS: 39 healthy men and postmenopausal women (45-74 yrs) were randomized to 12 weeks of placebo (n = 19) or curcumin supplementation (2000 mg/day Longvida®; n = 20) with motor and cognitive function assessed at week 0 and 12. RESULTS: Using measures of the NIH Toolbox and other standardized tests, there were no changes in muscle strength and rate of torque development, dexterity, fatigability, mobility, endurance, and balance between the placebo and curcumin groups after 12 weeks (all P > 0.05). Additionally, there were no changes after 12 weeks of placebo and curcumin supplementation in measures of fluid cognitive ability, a cognitive domain that declines with age, including processing speed, executive function, working memory, and episodic memory (all P > 0.3). There were marginal changes in language, a measure of crystallized cognitive ability that is stable with age, following the intervention, wherein reading decoding increased 3% in the curcumin group (post: 2428±35 vs. pre: 2357±34, P = 0.003), but was unchanged in the placebo group (post: 2334±39 vs. pre: 2364±40, P = 0.07). CONCLUSIONS: Overall, 12 weeks of curcumin supplementation does not improve motor and cognitive functions in healthy middle-aged and older adults. It is possible that curcumin may enhance these functions in groups with greater baseline impairments than those studied here, including adults greater than 75 years of age and/or patients with clinical disorders.

11.
Clin Sci (Lond) ; 132(16): 1765-1777, 2018 08 31.
Artigo em Inglês | MEDLINE | ID: mdl-29914938

RESUMO

Advancing age is associated with impairments in numerous physiological systems, leading to an increased risk of chronic disease and disability, and reduced healthspan (the period of high functioning healthy life). The plasma metabolome is thought to reflect changes in the activity of physiological systems that influence healthspan. Accordingly, we utilized an LC-MS metabolomics analysis of plasma collected from healthy young and older individuals to characterize global changes in small molecule abundances with age. Using a weighted gene correlation network analysis (WGCNA), similarly expressed metabolites were grouped into modules that were related to indicators of healthspan, including clinically relevant markers of morphology (body mass index, body fat, and lean mass), cardiovascular health (systolic/diastolic blood pressure, endothelial function), renal function (glomerular filtration rate), and maximal aerobic exercise capacity in addition to conventional clinical blood markers (e.g. fasting glucose and lipids). Investigation of metabolic classes represented within each module revealed that amino acid and lipid metabolism as significantly associated with age and indicators of healthspan. Further LC-MS/MS targeted analyses of the same samples were used to identify specific metabolites related to age and indicators of healthspan, including methionine and nitric oxide pathways, fatty acids, and ceramides. Overall, these results demonstrate that plasma metabolomics profiles in general, and amino acid and lipid metabolism in particular, are associated with ageing and indicators of healthspan in healthy adults.


Assuntos
Envelhecimento/metabolismo , Aminoácidos/metabolismo , Exercício Físico , Nível de Saúde , Lipídeos/sangue , Metabolômica/métodos , Envelhecimento/sangue , Envelhecimento/genética , Ácidos Graxos/sangue , Ácidos Graxos/metabolismo , Feminino , Redes Reguladoras de Genes/genética , Humanos , Metabolismo dos Lipídeos/genética , Masculino , Metaboloma/genética , Metionina/sangue , Metionina/metabolismo , Pessoa de Meia-Idade , Adulto Jovem
12.
Hypertension ; 71(6): 1056-1063, 2018 06.
Artigo em Inglês | MEDLINE | ID: mdl-29661838

RESUMO

Excess reactive oxygen species production by mitochondria is a key mechanism of age-related vascular dysfunction. Our laboratory has shown that supplementation with the mitochondrial-targeted antioxidant MitoQ improves vascular endothelial function by reducing mitochondrial reactive oxygen species and ameliorates arterial stiffening in old mice, but the effects in humans are unknown. Here, we sought to translate our preclinical findings to humans and determine the safety and efficacy of MitoQ. Twenty healthy older adults (60-79 years) with impaired endothelial function (brachial artery flow-mediated dilation <6%) underwent 6 weeks of oral supplementation with MitoQ (20 mg/d) or placebo in a randomized, placebo-controlled, double-blind, crossover design study. MitoQ was well tolerated, and plasma MitoQ was higher after the treatment versus placebo period (P<0.05). Brachial artery flow-mediated dilation was 42% higher after MitoQ versus placebo (P<0.05); the improvement was associated with amelioration of mitochondrial reactive oxygen species-related suppression of endothelial function (assessed as the increase in flow-mediated dilation with acute, supratherapeutic MitoQ [160 mg] administration; n=9; P<0.05). Aortic stiffness (carotid-femoral pulse wave velocity) was lower after MitoQ versus placebo (P<0.05) in participants with elevated baseline levels (carotid-femoral pulse wave velocity >7.60 m/s; n=11). Plasma oxidized LDL (low-density lipoprotein), a marker of oxidative stress, also was lower after MitoQ versus placebo (P<0.05). Participant characteristics, endothelium-independent dilation (sublingual nitroglycerin), and circulating markers of inflammation were not different (all P>0.1). These findings in humans extend earlier preclinical observations and suggest that MitoQ and other therapeutic strategies targeting mitochondrial reactive oxygen species may hold promise for treating age-related vascular dysfunction. CLINICAL TRIAL REGISTRATION: URL: http://www.clinicaltrials.gov. Unique identifier: NCT02597023.


Assuntos
Antioxidantes/administração & dosagem , Artéria Braquial/fisiologia , Endotélio Vascular/metabolismo , Mitocôndrias/metabolismo , Estresse Oxidativo/efeitos dos fármacos , Rigidez Vascular/efeitos dos fármacos , Vasodilatação/efeitos dos fármacos , Idoso , Estudos Cross-Over , Suplementos Nutricionais , Método Duplo-Cego , Endotélio Vascular/efeitos dos fármacos , Feminino , Seguimentos , Voluntários Saudáveis , Humanos , Masculino , Pessoa de Meia-Idade , Espécies Reativas de Oxigênio/metabolismo
13.
Am J Physiol Heart Circ Physiol ; 313(5): H890-H895, 2017 Nov 01.
Artigo em Inglês | MEDLINE | ID: mdl-28971843

RESUMO

Cellular senescence is emerging as a key mechanism of age-related vascular endothelial dysfunction, but evidence in healthy humans is lacking. Moreover, the influence of lifestyle factors such as habitual exercise on endothelial cell (EC) senescence is unknown. We tested the hypothesis that EC senescence increases with sedentary, but not physically active, aging and is associated with vascular endothelial dysfunction. Protein expression (quantitative immunofluorescence) of p53, a transcription factor related to increased cellular senescence, and the cyclin-dependent kinase inhibitors p21 and p16 were 116%, 119%, and 128% greater (all P < 0.05), respectively, in ECs obtained from antecubital veins of older sedentary (60 ± 1 yr, n = 12) versus young sedentary (22 ± 1 yr, n = 9) adults. These age-related differences were not present (all P > 0.05) in venous ECs from older exercising adults (57 ± 1 yr, n = 13). Furthermore, venous EC protein levels of p53 (r = -0.49, P = 0.003), p21 (r = -0.38, P = 0.03), and p16 (r = -0.58, P = 0.002) were inversely associated with vascular endothelial function (brachial artery flow-mediated dilation). Similarly, protein expression of p53 and p21 was 26% and 23% higher (both P < 0.05), respectively, in ECs sampled from brachial arteries of healthy older sedentary (63 ± 1 yr, n = 18) versus young sedentary (25 ± 1 yr, n = 9) adults; age-related changes in arterial EC p53 and p21 expression were not observed (P > 0.05) in older habitually exercising adults (59 ± 1 yr, n = 14). These data indicate that EC senescence is associated with sedentary aging and is linked to endothelial dysfunction. Moreover, these data suggest that prevention of EC senescence may be one mechanism by which aerobic exercise protects against endothelial dysfunction with age.NEW & NOTEWORTHY Our study provides novel evidence in humans of increased endothelial cell senescence with sedentary aging, which is associated with impaired vascular endothelial function. Furthermore, our data suggest an absence of age-related increases in endothelial cell senescence in older exercising adults, which is linked with preserved vascular endothelial function.


Assuntos
Envelhecimento/fisiologia , Senescência Celular/fisiologia , Células Endoteliais/fisiologia , Endotélio Vascular/fisiologia , Exercício Físico/fisiologia , Adolescente , Adulto , Idoso , Feminino , Hábitos , Voluntários Saudáveis , Humanos , Estilo de Vida , Masculino , Pessoa de Meia-Idade , Proteína Oncogênica p21(ras)/biossíntese , Proteína Oncogênica p21(ras)/genética , Comportamento Sedentário , Proteína Supressora de Tumor p53/biossíntese , Proteína Supressora de Tumor p53/genética , Vasodilatação/fisiologia , Adulto Jovem
14.
Aging (Albany NY) ; 9(1): 187-208, 2017 01 03.
Artigo em Inglês | MEDLINE | ID: mdl-28070018

RESUMO

We hypothesized that curcumin would improve resistance and conduit artery endothelial function and large elastic artery stiffness in healthy middle-aged and older adults. Thirty-nine healthy men and postmenopausal women (45-74 yrs) were randomized to 12 weeks of curcumin (2000 mg/day Longvida®; n=20) or placebo (n=19) supplementation. Forearm blood flow response to acetylcholine infusions (FBFACh; resistance artery endothelial function) increased 37% following curcumin supplementation (107±13 vs. 84±11 AUC at baseline, P=0.03), but not placebo (P=0.2). Curcumin treatment augmented the acute reduction in FBFACh induced by the nitric oxide synthase inhibitor NG monomethyl-L-arginine (L-NMMA; P=0.03), and reduced the acute increase in FBFACh to the antioxidant vitamin C (P=0.02), whereas placebo had no effect (both P>0.6). Similarly, brachial artery flow-mediated dilation (conduit artery endothelial function) increased 36% in the curcumin group (5.7±0.4 vs. 4.4±0.4% at baseline, P=0.001), with no change in placebo (P=0.1). Neither curcumin nor placebo influenced large elastic artery stiffness (aortic pulse wave velocity or carotid artery compliance) or circulating biomarkers of oxidative stress and inflammation (all P>0.1). In healthy middle-aged and older adults, 12 weeks of curcumin supplementation improves resistance artery endothelial function by increasing vascular nitric oxide bioavailability and reducing oxidative stress, while also improving conduit artery endothelial function.


Assuntos
Curcumina/farmacologia , Endotélio Vascular/efeitos dos fármacos , Estresse Oxidativo/efeitos dos fármacos , Fluxo Sanguíneo Regional/efeitos dos fármacos , Acetilcolina/farmacologia , Idoso , Artéria Braquial/efeitos dos fármacos , Feminino , Antebraço/irrigação sanguínea , Humanos , Masculino , Pessoa de Meia-Idade , Óxido Nítrico/metabolismo , Vasodilatadores/farmacologia
15.
J Appl Physiol (1985) ; 122(1): 11-19, 2017 01 01.
Artigo em Inglês | MEDLINE | ID: mdl-27834671

RESUMO

Aging causes micro- and macrovascular endothelial dysfunction, as assessed by endothelium-dependent dilation (EDD), which can be prevented and reversed by habitual aerobic exercise (AE) in men. However, in estrogen-deficient postmenopausal women, whole forearm microvascular EDD has not been studied, and a beneficial effect of AE on macrovascular EDD has not been consistently shown. We assessed forearm blood flow in response to brachial artery infusions of acetylcholine (FBFACh), a measure of whole forearm microvascular EDD, and brachial artery flow-mediated dilation (FMD), a measure of macrovascular EDD, in 12 premenopausal sedentary women (Pre-S; 24 ± 1 yr; V̇o2max = 37.5 ± 1.6 ml·kg-1·min-1), 25 estrogen-deficient postmenopausal sedentary women (Post-S; 62 ± 1 yr; V̇o2max = 24.7 ± 0.9 ml·kg-1·min-1), and 16 estrogen-deficient postmenopausal AE-trained women (Post-AE; 59 ± 1 yr; V̇o2max = 40.4 ± 1.4 ml·kg-1·min-1). FBFACh was lower in Post-S and Post-AE compared with Pre-S women (135 ± 9 and 116 ± 17 vs. 193 ± 21 AUC, respectively, both P < 0.008), whereas Post-S and Post-AE women were not different (P = 0.3). Brachial artery FMD was 34% (5.73 ± 0.67%) and 45% (4.79 ± 0.57%) lower in Post-S and Post-AE, respectively, vs. Pre-S women (8.69 ± 0.95%, both P ≤ 0.01), but not different between Post-S and Post-AE women (P = 0.3). Post-AE women had lower circulating C-reactive protein and oxidized low-density lipoprotein compared with Post-S women (0.5 ± 0.1 vs. 1.1 ± 0.2 mg/l and 40 ± 4 vs. 55 ± 3 U/l, respectively, both P = 0.01), but these markers were not correlated to FBFACh (P = 0.3) or brachial artery FMD (P = 0.8). These findings are consistent with the idea that habitual AE does not protect against age/menopause-related whole forearm micro- and macrovascular endothelial dysfunction in healthy nonobese estrogen-deficient postmenopausal women, despite being associated with lower systemic markers of inflammation and oxidative stress. NEW & NOTEWORTHY: This is the first study to demonstrate that habitual aerobic exercise may not protect against age/menopause-related whole forearm microvascular endothelial dysfunction in healthy nonobese estrogen-deficient postmenopausal women, consistent with recent findings regarding macrovascular endothelial function. This is in contrast to what is observed in healthy middle-aged and older aerobic exercise-trained men.


Assuntos
Endotélio Vascular/fisiologia , Estrogênios/metabolismo , Exercício Físico/fisiologia , Pós-Menopausa/fisiologia , Adulto , Envelhecimento/fisiologia , Artéria Braquial/metabolismo , Artéria Braquial/fisiologia , Proteína C-Reativa/metabolismo , Estudos Transversais , Endotélio Vascular/metabolismo , Feminino , Antebraço/irrigação sanguínea , Antebraço/fisiologia , Humanos , Lipoproteínas LDL/metabolismo , Pessoa de Meia-Idade , Pós-Menopausa/metabolismo , Pré-Menopausa/metabolismo , Pré-Menopausa/fisiologia , Fluxo Sanguíneo Regional/fisiologia , Comportamento Sedentário , Doenças Vasculares/metabolismo , Doenças Vasculares/fisiopatologia , Vasodilatação/fisiologia , Adulto Jovem
16.
Aging (Albany NY) ; 8(6): 1167-83, 2016 06.
Artigo em Inglês | MEDLINE | ID: mdl-27208415

RESUMO

We hypothesized that supplementation with trehalose, a disaccharide that reverses arterial aging in mice, would improve vascular function in middle-aged and older (MA/O) men and women. Thirty-two healthy adults aged 50-77 years consumed 100 g/day of trehalose (n=15) or maltose (n=17, isocaloric control) for 12 weeks (randomized, double-blind). In subjects with Δbody mass less than 2.3kg (5 lb.), resistance artery endothelial function, assessed by forearm blood flow to brachial artery infusion of acetylcholine (FBFACh), increased ~30% with trehalose (13.3±1.0 vs. 10.5±1.1 AUC, P=0.02), but not maltose (P=0.40). This improvement in FBFACh was abolished when endothelial nitric oxide (NO) production was inhibited. Endothelium-independent dilation, assessed by FBF to sodium nitroprusside (FBFSNP), also increased ~30% with trehalose (155±13 vs. 116±12 AUC, P=0.03) but not maltose (P=0.92). Changes in FBFACh and FBFSNP with trehalose were not significant when subjects with Δbody mass ≥ 2.3kg were included. Trehalose supplementation had no effect on conduit artery endothelial function, large elastic artery stiffness or circulating markers of oxidative stress or inflammation (all P>0.1) independent of changes in body weight. Our findings demonstrate that oral trehalose improves resistance artery (microvascular) function, a major risk factor for cardiovascular diseases, in MA/O adults, possibly through increasing NO bioavailability and smooth muscle sensitivity to NO.


Assuntos
Envelhecimento/fisiologia , Artéria Braquial/efeitos dos fármacos , Endotélio Vascular/efeitos dos fármacos , Fluxo Sanguíneo Regional/efeitos dos fármacos , Trealose/farmacologia , Acetilcolina/farmacologia , Idoso , Artéria Braquial/fisiologia , Método Duplo-Cego , Endotélio Vascular/fisiologia , Feminino , Antebraço/irrigação sanguínea , Humanos , Masculino , Pessoa de Meia-Idade , Estresse Oxidativo/efeitos dos fármacos , Estresse Oxidativo/fisiologia , Fluxo Sanguíneo Regional/fisiologia , Rigidez Vascular/efeitos dos fármacos , Rigidez Vascular/fisiologia
17.
J Appl Physiol (1985) ; 120(4): 416-25, 2016 Feb 15.
Artigo em Inglês | MEDLINE | ID: mdl-26607249

RESUMO

Insufficient nitric oxide (NO) bioavailability plays an important role in endothelial dysfunction and arterial stiffening with aging. Supplementation with sodium nitrite, a precursor of NO, ameliorates age-related vascular endothelial dysfunction and arterial stiffness in mice, but effects on humans, including the metabolic pathways altered, are unknown. The purpose of this study was to determine the safety, feasibility, and efficacy of oral sodium nitrite supplementation for improving vascular function in middle-aged and older adults and to identify related circulating metabolites. Ten weeks of sodium nitrite (80 or 160 mg/day, capsules, TheraVasc; randomized, placebo control, double blind) increased plasma nitrite acutely (5- to 15-fold, P < 0.001 vs. placebo) and chronically (P < 0.10) and was well tolerated without symptomatic hypotension or clinically relevant elevations in blood methemoglobin. Endothelial function, measured by brachial artery flow-mediated dilation, increased 45-60% vs. baseline (P < 0.10) without changes in body mass or blood lipids. Measures of carotid artery elasticity (ultrasound and applanation tonometry) improved (decreased ß-stiffness index, increased cross-sectional compliance, P < 0.05) without changes in brachial or carotid artery blood pressure. Aortic pulse wave velocity was unchanged. Nitrite-induced changes in vascular measures were significantly related to 11 plasma metabolites identified by untargeted analysis. Baseline abundance of multiple metabolites, including glycerophospholipids and fatty acyls, predicted vascular changes with nitrite. This study provides evidence that sodium nitrite supplementation is well tolerated, increases plasma nitrite concentrations, improves endothelial function, and lessens carotid artery stiffening in middle-aged and older adults, perhaps by altering multiple metabolic pathways, thereby warranting a larger clinical trial.


Assuntos
Envelhecimento/efeitos dos fármacos , Aorta/efeitos dos fármacos , Artérias Carótidas/efeitos dos fármacos , Endotélio Vascular/efeitos dos fármacos , Endotélio Vascular/metabolismo , Nitrito de Sódio/farmacologia , Idoso , Envelhecimento/metabolismo , Aorta/metabolismo , Pressão Sanguínea/efeitos dos fármacos , Índice de Massa Corporal , Artéria Braquial/efeitos dos fármacos , Artéria Braquial/metabolismo , Artérias Carótidas/metabolismo , Suplementos Nutricionais , Método Duplo-Cego , Elasticidade/efeitos dos fármacos , Feminino , Humanos , Masculino , Metemoglobina/metabolismo , Pessoa de Meia-Idade , Óxido Nítrico/metabolismo , Análise de Onda de Pulso/métodos , Rigidez Vascular/efeitos dos fármacos , Vasodilatação/efeitos dos fármacos
18.
Adv Physiol Educ ; 38(4): 296-307, 2014 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-25434012

RESUMO

Cardiovascular diseases (CVDs) remain the leading cause of death in the United States and other modern societies. Advancing age is the major risk factor for CVD, primarily due to stiffening of the large elastic arteries and the development of vascular endothelial dysfunction. In contrast, regular aerobic exercise protects against the development of large elastic artery stiffness and vascular endothelial dysfunction with advancing age. Moreover, aerobic exercise interventions reduce arterial stiffness and restore vascular endothelial function in previously sedentary middle-aged/older adults. Aerobic exercise exerts its beneficial effects on arterial function by modulating structural proteins, reducing oxidative stress and inflammation, and restoring nitric oxide bioavailability. Aerobic exercise may also promote "resistance" against factors that reduce vascular function and increase CVD risk with age. Preventing excessive increases in abdominal adiposity, following healthy dietary practices, maintaining a low CVD risk factor profile, and, possibly, selective use of pharmaceuticals and nutraceuticals also play a major role in preserving vascular function with aging.


Assuntos
Envelhecimento/fisiologia , Endotélio Vascular/fisiologia , Exercício Físico/fisiologia , Comportamento de Redução do Risco , Rigidez Vascular/fisiologia , Humanos , Estilo de Vida , Fatores de Risco
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