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1.
PLoS One ; 18(11): e0294330, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-37963137

RESUMO

BACKGROUND: Ageing is associated with changes in body composition including an overall reduction in muscle mass and a proportionate increase in fat mass. Sarcopenia is characterised by losses in both muscle mass and strength. Body composition and muscle strength are at least in part genetically determined, consequently polymorphisms in pathways important in muscle biology (e.g., the activin/myostatin signalling pathway) are hypothesised to contribute to the development of sarcopenia. METHODS: We compared regional body composition measured by DXA with genotypes for two polymorphisms (rs10783486, minor allele frequency (MAF) = 0.26 and rs2854464, MAF = 0.26) in the activin 1B receptor (ACVR1B) determined by PCR in a cross-sectional analysis of DNA from 110 older individuals with sarcopenia from the LACE trial. RESULTS: Neither muscle mass nor strength showed any significant associations with either genotype in this cohort. Initial analysis of rs10783486 showed that males with the AA/AG genotype were taller than GG males (174±7cm vs 170±5cm, p = 0.023) and had higher arm fat mass, (median higher by 15%, p = 0.008), and leg fat mass (median higher by 14%, p = 0.042). After correcting for height, arm fat mass remained significantly higher (median higher by 4% padj = 0.024). No associations (adjusted or unadjusted) were seen in females. Similar analysis of the rs2854464 allele showed a similar pattern with the presence of the minor allele (GG/AG) being associated with greater height (GG/AG = 174±7 cm vs AA = 170 ±5cm, p = 0.017) and greater arm fat mass (median higher by 16%, p = 0.023). Again, the difference in arm fat remained after correction for height. No similar associations were seen in females analysed alone. CONCLUSION: These data suggest that polymorphic variation in the ACVR1B locus could be associated with body composition in older males. The activin/myostatin pathway might offer a novel potential target to prevent fat accumulation in older individuals.


Assuntos
Sarcopenia , Masculino , Feminino , Humanos , Idoso , Sarcopenia/genética , Miostatina , Receptores de Ativinas , Estudos Transversais , Composição Corporal/genética , Ativinas/genética , Músculo Esquelético
2.
PLoS One ; 18(10): e0292402, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-37862321

RESUMO

BACKGROUND: Angiotensin II (AII), has been suggested to promote muscle loss. Reducing AII synthesis, by inhibiting angiotensin converting enzyme (ACE) activity has been proposed as a method to inhibit muscle loss. The LACE clinical trial was designed to determine whether ACE inhibition would reduce further muscle loss in individuals with sarcopenia but suffered from low recruitment and returned a negative result. Polymorphic variation in the ACE promoter (I/D alleles) has been associated with differences in ACE activity and muscle physiology in a range of clinical conditions. This aim of this analysis was to determine whether I/D polymorphic variation is associated with muscle mass, strength, in sarcopenia or contributed to the lack of response to treatment in the LACE study. METHODS: Sarcopenic individuals were recruited into a 2x2 factorial multicentre double-blind study of the effects of perindopril and/or leucine versus placebo on physical performance and muscle mass. DNA extracted from blood samples (n = 130 72 women and 58 men) was genotyped by PCR for the ACE I/D polymorphism. Genotypes were then compared with body composition measured by DXA, hand grip and quadriceps strength before and after 12 months' treatment with leucine and/or perindopril in a cross-sectional analysis of the influence of genotype on these variables. RESULTS: Allele frequencies for the normal UK population were extracted from 13 previous studies (I = 0.473, D = 0.527). In the LACE cohort the D allele was over-represented (I = 0.412, D = 0.588, p = 0.046). This over-representation was present in men (I = 0.353, D = 0.647, p = 0.010) but not women (I = 0.458, D = 0.532, p = 0.708). In men but not women, individuals with the I allele had greater leg strength (II/ID = 18.00 kg (14.50, 21.60) vs DD = 13.20 kg (10.50, 15.90), p = 0.028). Over the 12 months individuals with the DD genotype increased in quadriceps strength but those with the II or ID genotype did not. Perindopril did not increase muscle strength or mass in any polymorphism group relative to placebo. CONCLUSION: Our results suggest that although ACE genotype was not associated with response to ACE inhibitor therapy in the LACE trial population, sarcopenic men with the ACE DD genotype may be weaker than those with the ACE I/D or II genotype.


Assuntos
Sarcopenia , Masculino , Humanos , Feminino , Idoso , Sarcopenia/tratamento farmacológico , Sarcopenia/genética , Perindopril/uso terapêutico , Peptidil Dipeptidase A/genética , Estudos Transversais , Leucina , Força da Mão , Genótipo , Inibidores da Enzima Conversora de Angiotensina/uso terapêutico
3.
J Cachexia Sarcopenia Muscle ; 13(2): 858-871, 2022 04.
Artigo em Inglês | MEDLINE | ID: mdl-35174663

RESUMO

BACKGROUND: This trial aimed to determine the efficacy of leucine and/or perindopril in improving physical function in older people with sarcopenia. METHODS: Placebo-controlled, parallel group, double-blind, randomized two-by-two factorial trial. We recruited adults aged ≥ 70 years with sarcopenia, defined as low gait speed (<0.8 m/s on 4 m walk) and/or low handgrip strength (women < 20 kg, men < 30 kg) plus low muscle mass (using sex and body mass index category-specific thresholds derived from normative UK BioBank data) from 14 UK centres. Eligible participants were randomized to perindopril 4 mg or placebo, and to oral leucine powder 2.5 g or placebo thrice daily. The primary outcome was the between-group difference in the short physical performance battery (SPPB) score over 12-month follow-up by repeated-measures mixed models. Results were combined with existing systematic reviews using random-effects meta-analysis to derive summary estimates of treatment efficacy. RESULTS: We screened 320 people and randomized 145 participants compared with an original target of 440 participants. For perindopril [n = 73, mean age 79 (SD 6), female sex 39 (53%), mean SPPB 7.1 (SD 2.3)] versus no perindopril [n = 72, mean age 79 (SD 6), female sex 39 (54%), mean SPPB 6.9 (SD 2.4)], median adherence to perindopril was lower (76% vs. 96%; P < 0.001). Perindopril did not improve the primary outcome [adjusted treatment effect -0.1 points (95%CI -1.2 to 1.0), P = 0.89]. No significant treatment benefit was seen for any secondary outcome including muscle mass [adjusted treatment effect -0.4 kg (95%CI -1.1 to 0.3), P = 0.27]. More adverse events occurred in the perindopril group (218 vs. 165), but falls rates were similar. For leucine [n = 72, mean age 78 (SD 6), female sex 38 (53%), mean SPPB 7.0 (SD 2.1)] versus no leucine [n = 72, mean age 79 (SD 6), female sex 40 (55%), mean SPPB 7.0 (SD 2.5)], median adherence was the same in both groups (76% vs. 76%; P = 0.99). Leucine did not improve the primary outcome [adjusted treatment effect 0.1 point (95%CI -1.0 to 1.1), P = 0.90]. No significant treatment benefit was seen for any secondary outcome including muscle mass [adjusted treatment effect -0.3 kg (95%CI -1.0 to 0.4), P = 0.47]. Meta-analysis of angiotensin converting enzyme inhibitor/angiotensin receptor blocker trials showed no clinically important treatment effect for the SPPB [between-group difference -0.1 points (95%CI -0.4 to 0.2)]. CONCLUSIONS: Neither perindopril nor leucine improved physical performance or muscle mass in this trial; meta-analysis did not find evidence of efficacy of either ACE inhibitors or leucine as treatments to improve physical performance.


Assuntos
Leucina , Perindopril , Desempenho Físico Funcional , Sarcopenia , Idoso , Feminino , Força da Mão/fisiologia , Humanos , Leucina/uso terapêutico , Masculino , Metanálise como Assunto , Perindopril/uso terapêutico , Sarcopenia/tratamento farmacológico , Sarcopenia/fisiopatologia , Resultado do Tratamento
4.
Addiction ; 2018 Jun 01.
Artigo em Inglês | MEDLINE | ID: mdl-29855105

RESUMO

AIMS: To test the effectiveness of a theoretically based text-message intervention to reduce binge drinking among socially disadvantaged men. DESIGN: A multi-centre parallel group, pragmatic, individually randomized controlled trial. SETTING: Community-based study conducted in four regions of Scotland. PARTICIPANTS: A total of 825 men aged 25-44 years recruited from socially disadvantaged areas who had two or more episodes of binge drinking (> 8 UK units on a single occasion) in the preceding 28 days: 411 men were randomized to the intervention and 414 to the control. INTERVENTION AND COMPARATOR: A series of 112 interactive text messages was delivered by mobile phone during a 12-week period. The intervention was structured around the Health Action Process Approach, a comprehensive model which allows integration of a range of evidence-based behaviour change techniques. The control group received 89 texts on general health, with no mention of alcohol or use of behaviour change techniques. MEASUREMENTS: The primary outcome measure was the proportion of men consuming > 8 units on three or more occasions (in the previous 28 days) at 12 months post-intervention. FINDINGS: The proportion of men consuming > 8 units on three or more occasions (in the previous 28 days) was 41.5% in the intervention group and 47.8% in the control group. Formal analysis showed that there was no evidence that the intervention was effective [odds ratio (OR) = 0.79, 95% confidence interval (CI) = 0.57-1.08; absolute reduction 5.7%, 95% CI = -13.3 to 1.9]. The Bayes factor for this outcome was 1.3, confirming that the results were inconclusive. The retention was high and similar in intervention (84.9%) and control (86.5%) groups. Most men in the intervention group engaged with the text messages: almost all (92%) replied to text messages and 67% replied more than 10 times. CONCLUSIONS: A theoretically based text-messaging intervention aimed at reducing binge drinking in disadvantaged men was not found to reduce prevalence of binge drinking at 12-month follow-up.

5.
Alcohol Alcohol ; 52(6): 677-684, 2017 Nov 01.
Artigo em Inglês | MEDLINE | ID: mdl-29016701

RESUMO

OBJECTIVES: Being obese and drinking more than 14 units of alcohol per week places men at very high risk of developing liver disease. This study assessed the feasibility of a trial to reduce alcohol consumption. It tested the recruitment strategy, engagement with the intervention, retention and study acceptability. METHODS: Men aged 35-64 years who drank >21 units of alcohol per week and had a BMI > 30 were recruited by two methods: from GP patient registers and by community outreach. The intervention was delivered by a face to face session followed by a series of text messages. Trained lay people (Study Coordinators) delivered the face to face session. Participants were followed up for 5 months from baseline to measure weekly alcohol consumption and BMI. RESULTS: The recruitment target of 60 was exceeded, with 69 men recruited and randomized. At baseline, almost all the participants (95%) exceeded the threshold for a 19-fold increase in the risk of dying from liver disease. The intervention was delivered with high fidelity. A very high follow-up rate was achieved (98%) and the outcomes for the full trial were measured. Process evaluation showed that participants responded as intended to key steps in the behaviour change strategy. The acceptability of the study methods was high: e.g. 80% of men would recommend the study to others. CONCLUSIONS: This feasibility study identified a group at high risk of liver disease. It showed that a full trial could be conducted to test the effectiveness and cost-effectiveness of the intervention. TRIAL REGISTRATION: Current controlled trials: ISRCTN55309164. TRIAL FUNDING: National Institute for Health Research Health Technology Assessment (NIHR HTA). SHORT SUMMARY: This feasibility study recruited 69 men at high risk of developing liver disease. The novel intervention, to reduce alcohol consumption through the motivation of weight loss, was well received. A very high follow-up rate was achieved. Process evaluation showed that participants engaged with key components of the behaviour change strategy.


Assuntos
Consumo de Bebidas Alcoólicas/epidemiologia , Consumo de Bebidas Alcoólicas/prevenção & controle , Intervenção Médica Precoce/métodos , Obesidade/epidemiologia , Obesidade/terapia , Saúde Pública/métodos , Adulto , Consumo de Bebidas Alcoólicas/psicologia , Estudos de Viabilidade , Seguimentos , Humanos , Masculino , Pessoa de Meia-Idade , Entrevista Motivacional/métodos , Obesidade/psicologia , Método Simples-Cego
6.
Health Technol Assess ; 21(19): 1-150, 2017 04.
Artigo em Inglês | MEDLINE | ID: mdl-28414020

RESUMO

BACKGROUND: Obese men who consume alcohol are at a greatly increased risk of liver disease; those who drink > 14 units of alcohol per week have a 19-fold increased risk of dying from liver disease. OBJECTIVES: To develop an intervention to reduce alcohol consumption in obese men and to assess the feasibility of a randomised controlled trial (RCT) to investigate its effectiveness. DESIGN OF THE INTERVENTION: The intervention was developed using formative research, public involvement and behaviour change theory. It was organised in two phases, comprising a face-to-face session with trained laypeople (study co-ordinators) followed by a series of text messages. Participants explored how alcohol consumption contributed to weight gain, both through direct calorie consumption and through its effect on increasing food consumption, particularly of high-calorie foodstuffs. Men were encouraged to set goals to reduce their alcohol consumption and to make specific plans to do so. The comparator group received an active control in the form of a conventional alcohol brief intervention. Randomisation was carried out using the secure remote web-based system provided by the Tayside Clinical Trials Unit. Randomisation was stratified by the recruitment method and restricted using block sizes of randomly varying lengths. Members of the public were involved in the development of all study methods. SETTING: Men were recruited from the community, from primary care registers and by time-space sampling (TSS). The intervention was delivered in community settings such as the participant's home, community centres and libraries. PARTICIPANTS: Men aged 35-64 years who had a body mass index (BMI) of > 30 kg/m2 and who drank > 21 units of alcohol per week. RESULTS: The screening methods successfully identified participants meeting the entry criteria. Trial recruitment was successful, with 69 men (36 from 419 approached in primary care, and 33 from 470 approached via TSS) recruited and randomised in 3 months. Of the 69 men randomised, 35 were allocated to the intervention group and 34 to the control group. The analysis was conducted on 31 participants from the intervention group and 30 from the control group. The participants covered a wide range of ages and socioeconomic statuses. The average alcohol consumption of the men recruited was 47.2 units per week, more than twice that of the entry criterion (> 21 units per week). Most (78%) engaged in binge drinking (> 8 units in a session) at least weekly. Almost all (95%) exceeded the threshold for a 19-fold increase in the risk of dying from liver disease (BMI of > 30 kg/m2 and > 14 units of alcohol per week). Despite this, they believed that they were at low risk of harm from alcohol, possibly because they seldom suffered acute harms (e.g. hangovers) and made few visits to a general practitioner or hospital. INTERVENTION: The intervention was delivered with high fidelity. A high follow-up rate was achieved (98%) and the outcomes for the full RCT were measured. A process evaluation showed that participants engaged with the main components of the intervention. The acceptability of the study methods was high. CONCLUSIONS: This feasibility study developed a novel intervention and evaluated all of the stages of a RCT that would test the effectiveness of the intervention. The main stages of a trial were completed successfully: recruitment, randomisation, intervention delivery, follow-up and measurement of study outcomes. Most of the men recruited drank very heavily and were also obese. This places them at a very high risk of liver disease, making them a priority for intervention. FUTURE WORK: A RCT to test the effectiveness and cost-effectiveness of the intervention. TRIAL REGISTRATION: Current Controlled Trials ISRCTN55309164. FUNDING: This project was funded by the National Institute for Health Research (NIHR) Health Technology Assessment programme and will be published in full in Health Technology Assessment; Vol. 21, No. 19. See the NIHR Journals Library website for further project information.


Assuntos
Consumo de Bebidas Alcoólicas/terapia , Terapia Comportamental/métodos , Obesidade/terapia , Adulto , Consumo de Bebidas Alcoólicas/prevenção & controle , Aconselhamento/métodos , Estudos de Viabilidade , Humanos , Masculino , Pessoa de Meia-Idade , Avaliação de Resultados em Cuidados de Saúde , Envio de Mensagens de Texto/estatística & dados numéricos
7.
Oncogene ; 22(22): 3431-40, 2003 May 29.
Artigo em Inglês | MEDLINE | ID: mdl-12776195

RESUMO

The tumour suppressor activity of p53 in vivo can be subject to pressure from the physiological stress of hypoxia and we report on the development of a cell system to define the p53-dependent stages in the adaptation of cells to hypoxia. p53(+/+) cells exposed to hypoxia exhibited a transient arrest in G2/M, but escaped from this checkpoint and entered a long-term G(0)/G(1) arrest. By contrast, isogenic p53-null cells exposed to hypoxic conditions exhibited a 6-10-fold higher level of apoptosis, suggesting that p53 acts as a survival factor under limiting oxygen concentrations. Surprisingly, hypoxia-dependent growth arrest in p53(+/+) cells did not result in either p21(WAF1) or HIF-1 protein stabilization, but rather promoted a significant decrease in Ser(392)-site phosphorylation at the CK2/FACT site. However, chemically induced anoxia induced Ser(392)-site phosphorylation as well as stabilization of both p53 and HIF-1 proteins. In contrast to hypoxia, 5-flourouracil (5-FU)-induced p53-dependent cell death correlated with enhanced Ser(392) phosphorylation of p53 and elevated p21(WAF1) protein levels. Hypoxia inhibited 5-FU-induced p53-dependent cell death and attenuated p53 phosphorylation at the ATM and CK2/FACT phosphorylation sites. Although anoxia activates the p53 response, hypoxia silences the p53 transactivation pathway and identifies a physiological signalling model to study mechanisms of p53 inactivation under hypoxic conditions.


Assuntos
Apoptose/fisiologia , Hipóxia/metabolismo , Proteína Supressora de Tumor p53/metabolismo , Sobrevivência Celular/fisiologia , Regulação para Baixo/fisiologia , Fluoruracila/metabolismo , Humanos , Fosforilação , Células Tumorais Cultivadas
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