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Biomedical subjects

M Weatherall

Publications and source records attributed to M Weatherall.

At least 19 recordsLinked to original sources
PubMed2006

Inhaled fluticasone propionate and adrenal effects in adult asthma: systematic review and meta-analysis.

The dose-response relationship of inhaled fluticasone propionate (FP) for adrenal suppression in adults with asthma is not clear. The current authors carried out a systematic review and meta-analysis of placebo-controlled randomised dose-response studies of >or=4 weeks' duration, which assessed the adrenal effects of FP by cosyntropin stimulation tests in adult asthma. The main outcome measure was the proportion of subjects with adrenal function below the lower limit of the normal range. Five studies, with a total of 732 subjects with asthma, met the inclusion criteria. Data on daily doses >1,000 mug were limited to one study. The proportion of subjects with adrenal function below the lower limit of the normal range on placebo was 3.9%; for a 500-microg per day increase in FP dose the odds of an abnormality increased by 1.38 (95% confidence interval 1.01-1.59). The continuous secondary outcome measures showed an inverse linear relationship with the FP dose up to 2,000 microg.day(-1). In conclusion, for routine prescribing within the established therapeutic dose-response range (50-500 microg.day(-1)), fluticasone propionate has minimal effects on adrenal function. This conclusion is limited by the paucity of long-term studies of daily doses of fluticasone propionate >1,000 mug and by the considerable individual variability in the response.

Adrenal Insufficiency↗
PubMed2006

Abnormal glucose metabolism and features of the metabolic syndrome are common in patients presenting for elective cardiac catheterization.

BACKGROUND: Abnormalities of glucose metabolism and the metabolic syndrome, including excess bodyweight, are potentially modifiable risk factors for cardiac morbidity and mortality. This study aimed to determine the prevalence of these in a group of patients presenting for elective cardiac catheterization or percutaneous intervention. METHODS: Data were prospectively collected on 297 consecutive patients presenting for elective cardiac catheterization or percutaneous intervention at a single tertiary referral centre. Demographic data, risk factors, medications and coronary angiogram results were recorded. Fasting lipids, fasting glucose, HbA1c levels were measured and if necessary an oral glucose tolerance test was carried out. Logistic regression and contingency table analysis examined associations of these with ethnicity. RESULTS: Impaired glucose metabolism (diabetes, impaired glucose tolerance or impaired fasting glucose) was present in 46.1% with our screening programme detecting previously unknown impaired glucose metabolism in 22.9%. Impaired glucose metabolism was strongly associated with non-European ethnicity (P < 0.0001). The metabolic syndrome was present in 49.2%. When defined by ethnic specific cut-offs, overweight or obesity was present in >80% of patients in all ethnic groups. CONCLUSION: There is a very high prevalence of impaired glucose metabolism and the metabolic syndrome in patients presenting for cardiac catheterization. Impaired glucose metabolism is particularly prevalent in the Polynesian and the Indian and the Sri Lankan ethnic groups. Screening of patients undergoing elective cardiac catheterization identifies a significant number of patients with undiagnosed impaired glucose metabolism and should be carried out routinely.

Aged↗
PubMed2005

Determinants of plasma D-dimer levels in a traveling population.

BACKGROUND: Plasma D-dimer measurement is a widely used diagnostic test for assessing individuals with suspected venous thromboembolism (VTE). Whilst a negative test is helpful in ruling out thrombosis, the significance and determinants of an elevated plasma D-dimer level in otherwise healthy subjects are poorly understood. OBJECTIVES: To determine the association between recognized risk factors for VTE and plasma D-dimer levels in an adult population. SUBJECTS AND METHODS: Blood samples for measurement of plasma D-dimer levels were obtained from 1000 adults aged <70 years who were participating in a study investigating the incidence of VTE in long distance air travellers. The relationship between D-dimer levels and selected risks factors for VTE including thrombophilia status was investigated. RESULTS: The median (Inter-quartile range) D-dimer level was 243 ng mL(-1) (175-345). Multivariate analysis showed that plasma D-dimer levels were positively associated with increasing age, larger body mass index, female gender, the use of hormone therapy, thrombophilia state, and the presence of co-morbid conditions. CONCLUSION: Plasma D-dimer levels vary markedly between individuals and are associated with known risk factors for VTE, including the presence of thrombophilia conditions. The potential role for the measurement of plasma D-dimer as a marker for thrombosis risk requires further investigation.

Age Factors↗
PubMed2005

Efficacy of bupropion in the indigenous Maori population in New Zealand.

BACKGROUND: Smoking rates are high in indigenous populations and contribute to their poor health. In New Zealand the indigenous Maori population has a high rate of smoking, with around 50% of adults being smokers compared with 20% of the adult European population. A study was undertaken to determine whether bupropion is effective in the treatment of smoking cessation in the indigenous Maori population in New Zealand. METHODS: A randomised, placebo controlled, double blind, parallel group study was performed in 134 Maori smokers aged 16-70 years who smoked more than 10 cigarettes per day. The main outcome measures were continued abstinence from smoking at 3 and 12 months. RESULTS: At each time point continued abstinence was better for the subjects allocated to bupropion, with a risk ratio for abstinence over all time points of 2.44 (95% CI 1.22 to 4.88). The rates of continued abstinence in the bupropion and placebo groups at 3 months were 44.3% and 17.4%, respectively, with a risk ratio of 2.54 (95% CI 1.30 to 5.00). The corresponding figures at 12 months were 21.6% and 10.9%, respectively, with a risk ratio of 1.99 (95% CI 0.79 to 5.00). CONCLUSION: Bupropion is an effective treatment for smoking cessation in the indigenous Maori population in New Zealand.

Adolescent↗
PubMed2005

Moderate dose inhaled corticosteroids plus salmeterol versus higher doses of inhaled corticosteroids in symptomatic asthma.

BACKGROUND: There is uncertainty as to the dose of inhaled corticosteroids (ICS) at which to start concomitant long acting beta agonist (LABA) treatment in patients with asthma not adequately controlled by ICS alone. METHODS: A meta-analysis was carried out of randomised, double blind clinical trials that compared the efficacy of adding salmeterol to moderate doses of ICS (fluticasone propionate 200 mug/day or equivalent) with increasing the ICS dose by at least twofold in symptomatic adult patients with asthma. The main outcome measures were the number of subjects withdrawn from the study due to asthma and the number of subjects with at least one moderate or severe exacerbation. RESULTS: Twelve studies with a total of 4576 subjects met the inclusion criteria for the analyses. The number of subjects withdrawn due to asthma and with at least one moderate or severe exacerbation was higher in the high dose ICS group (odds ratios 1.58, 95% CI 1.12 to 2.24 and 1.35, 95% CI 1.10 to 1.66, respectively). For the secondary outcome variables (forced expiratory volume in 1 second, morning and evening peak expiratory flow, and daytime beta agonist use) there was significantly greater benefit in the salmeterol group. CONCLUSIONS: This meta-analysis shows that the addition of salmeterol to moderate doses of ICS (fluticasone 200 mug/day or equivalent) in patients with asthma symptomatic at that dose results in significantly greater clinical benefit than increasing the dose of ICS by twofold or more.

Administration, Inhalation↗
PubMed2004

Effect of repeated intradermal injections of heat-inactivated Mycobacterium bovis bacillus Calmette-Guérin in adult asthma.

BACKGROUND: There are a number of reports in the Chinese medical literature from the last 30 years regarding the efficacy of repeated doses of heat-inactivated bacillus Calmette-Guérin (BCG) in established asthma. There is also epidemiological and experimental evidence that exposure to mycobacteria has the potential to suppress the development of asthma/atopy. METHODS: Thirty-one Mantoux-negative adults with stable moderately severe asthma who were skin prick test positive to house dust mite were randomized to receive one injection (0.1 mL) a week for 4 weeks of heat-inactivated BCG or normal saline. Markers of asthma severity (including peak flow, forced expiratory volume in 1 s, major and minor exacerbations, symptom scores and beta-agonist use), blood eosinophil and IgE levels were monitored for 3 months. RESULTS: There were no statistically significant differences between the treatment group and placebo for any of the outcome variables. The recruitment to the trial was halted early and the number of injections reduced in a number of patients due to excessive local reactions to BCG. CONCLUSIONS: In addition to the lack of efficacy of repeated heat-inactivated BCG injections, the occurrence of severe local reactions will limit the therapeutic application of this approach in asthma.

Adolescent↗
PubMed2004

Prevention of falls and fall-related fractures in community-dwelling older adults: a meta-analysis of estimates of effectiveness based on recent guidelines.

BACKGROUND: Two recent falls prevention guidelines have been published but did not include quantitative estimates of effectiveness based on the published reports that were reviewed to support their recommendations. AIM: To produce quantitative estimates of effectiveness of falls prevention programs from the randomised controlled trials cited in the guidelines together with an updated search of the available published reports to August 2002. METHODS: A meta-analysis of randomised controlled trials cited in falls guidelines and studies identified by an updated search of the available published reports was carried out. Randomised controlled trials were identified from the falls guidelines and a search, which met the following criteria: trials in community-dwelling older people; 1-year follow up; and outcome measures reported as the number of subjects with at least one fall or the number of subjects with a fracture. RESULTS: The guidelines identified four studies of 'exercise as a sole intervention', which when combined with one further study identified in a search of the published reports, gave a fixed effects odds ratio (OR) favouring this strategy of 0.81 (95% confidence interval (CI) 0.58-1.14); the number of patients needed to be treated to prevent one person having a fall was 19.5. The guidelines identified seven studies of a 'multiple intervention' strategy that gave a random effects OR favouring this strategy of 0.64 (95% CI 0.47-0.88). Four further studies were identified by the search of the published reports. The updated OR favouring this intervention strategy was 0.65 (95% CI 0.52-0.81); the number of patients needed to be treated to prevent one person having a fall was 9.8. Only two studies had data for fracture and a fixed effects OR favouring falls interventions for fracture prevention was 0.50 (95% CI 0.18-1.40); the number of patients needed to be treated to prevent one person having a fracture was 45.5. CONCLUSION: Semiquantitative statements of evidence can both understate and overstate the effectiveness of falls prevention strategies. There is moderate evidence of efficacy for falls prevention particularly for multiple intervention strategies.

Accidental Falls↗
PubMed2004

Systematic review of the dose-response relation of inhaled fluticasone propionate.

AIMS: To examine the dose-response relation of inhaled fluticasone for both efficacy and adrenal function in children with asthma. METHODS: Systematic review of double blind randomised dose-response studies of fluticasone in children of at least 4 weeks duration. MAIN OUTCOME MEASURES: FEV1, morning peak expiratory flow, night awakenings, beta agonist use, major exacerbations, 12 or 24 hour urinary cortisol, peak plasma cortisol post-stimulation. RESULTS: Seven studies of 1733 children with asthma met the inclusion criteria for efficacy. The dose-response curve for each efficacy outcome measure suggested that the response began to plateau between 100 and 200 microg per day with additional efficacy at the 400 microg per day dose shown in one study of severe asthmatics. Five studies of 1096 children with asthma met the inclusion criteria for assessment of adrenal function. The largest placebo controlled study of 437 children reported no difference in 24 hour urinary cortisol between placebo and fluticasone at doses of 100 and 200 microg per day. The non-placebo controlled study of 528 children reported significant suppression of overnight urinary cortisol levels with fluticasone at 400 compared with 200 microg per day. CONCLUSIONS: There is insufficient data to determine the dose-response of fluticasone in children at doses >400 microg per day. The dose-response curve for fluticasone appears to plateau between 100 and 200 microg per day for efficacy. There was additional efficacy at the 400 microg per day dose in children with severe asthma; however there was evidence of adrenal suppression at this dose.

Administration, Inhalation↗
PubMed2004

Dose-response relationship of inhaled budesonide in adult asthma: a meta-analysis.

The aim of this study was to examine the dose-response relationship of inhaled budesonide in adolescents and adults with asthma. A meta-analysis was carried out on placebo-controlled, randomised clinical trials, presenting data on at least one outcome measure of asthma and using at least two doses of budesonide, delivered by turbuhaler or metered-dose inhaler + spacer twice daily. A total of six studies of 1,435 adolescents and adults, with mild to moderately severe asthma, met the inclusion criteria for the meta-analysis. A negative exponential model indicated that 80% of the benefit at 1,600 micrograms.day-1 was achieved at doses of approximately 200-400 micrograms.day-1 and 90% by 300-600 micrograms.day-1. Meta-regression with a quadratic term in dose showed that the maximum effect was obtained with doses of approximately 1,000 micrograms.day-1. In conclusion, the available published data indicate that, in adolescents and adults with mild to moderate asthma, most of the therapeutic benefit of budesonide delivered by turbuhaler or metered-dose inhaler + spacer is achieved with a dose of approximately 400 micrograms.day-1 and the maximum effect is achieved at approximately 1,000 micrograms.day-1. This conclusion is qualified by the recognition that there is considerable individual variability in the response to inhaled corticosteroids and that the subjects included in this meta-analysis had predominantly mild to moderate asthma.

Administration, Inhalation↗
PubMed2004

Clinical dose-response relationship of fluticasone propionate in adults with asthma.

BACKGROUND: A study was undertaken to examine the dose-response relation of inhaled fluticasone in adolescents and adults with asthma. METHODS: A meta-analysis was carried out of randomised clinical trials that presented data on at least one outcome measure of asthma and that used at least two doses of fluticasone given twice daily. The main outcome measures were forced expiratory volume in 1 second (FEV1), morning peak expiratory flow (amPEF), beta agonist use, and withdrawals due to exacerbations of asthma. RESULTS: Seven studies of 2431 adolescents and adults with moderate to severe asthma met the inclusion criteria for the meta-analysis. Four studies examined a dose of >500 microg/day. For all outcome measures there were no statistically significant differences between a dose of 200 v 500 microg/day, 500 v 1000 microg/day, and 200 v > or =500 microg/day, although the point estimates favoured the higher doses. The mean improvement for FEV1 and amPEF resulting from an increase in dose from 200 to > or =500 microg/day was 0.07 l (95% CI -0.01 to 0.14) and 5.9 l/min (95% CI -3.0 to 15.3), respectively. The odds ratio for withdrawals with 200 microg/day compared with > or =500 microg/day was 1.27 (95% CI 0.78 to 2.07). CONCLUSIONS: In adolescents and adults with asthma, most of the therapeutic benefit of fluticasone is achieved with a total daily dose of 200 microg/day with minimal further clinical benefit achieved with higher doses. This conclusion is qualified by the recognition that there is considerable individual variability in the response to inhaled corticosteroids in asthma, which would suggest that some patients may obtain a greater clinical benefit at higher doses.

Administration, Inhalation↗
PubMed2003

Frequency of venous thromboembolism in low to moderate risk long distance air travellers: the New Zealand Air Traveller's Thrombosis (NZATT) study.

BACKGROUND: The frequency and role of risk factors for venous thromboembolism related to air travel is uncertain. We aimed to establish the frequency of this disorder in a group of long distance air travellers and to investigate the role of potential risk factors. METHODS: We designed a prospective study into which we recruited individuals aged between 18 and 70 years, travelling for 4 h or more by aircraft. D-dimer measurement was done before and after travel. Participants with a negative D-dimer (<500 ng/L) before travel were included in the study. Those who became D-dimer positive or developed high clinical probability symptoms during the 3 months after travel were investigated with bilateral compression ultrasonography and CT pulmonary angiography. Suspected clinical and thrombophilic risk factors, and use of prophylactic measures, were assessed. FINDINGS: 1000 individuals were recruited, with 878 meeting inclusion criteria and completing the study. All participants travelled at least 10 h, with a mean total duration of air travel of 39 h (SD 12.5). 112 patients underwent radiological assessment on return. Frequency of venous thromboembolism associated with travel was 1.0% (9/878, 95% CI 0.5-1.9), which included four cases of pulmonary embolism and five of deep venous thrombosis. Six patients with venous thromboembolism had pre-existing clinical risk factors, two had a recognised thrombophilic risk factor, two travelled exclusively in business class, five used aspirin, and four wore compression stockings. INTERPRETATION: Our results suggest an association between multiple long distance air flights and venous thromboembolism, even in individuals at low to moderate risk. The role of traditional risk factors and prophylactic measures in air travel-related venous thromboembolism needs further investigation.

Adolescent↗
PubMed2003

Humidified nasal continuous positive airway pressure in obstructive sleep apnoea.

Heated humidification of nasal continuous positive airway pressure (nCPAP) reduces upper airway symptoms and improves initial use in obstructive sleep apnoea syndrome (OSAS). The present study aimed to assess the effect of heated humidification of nCPAP on upper airway symptoms and initial use in obstructive sleep apnoea. This study was of a randomised, crossover design. Subjects with polysomnographically confirmed OSAS were randomised to 3 weeks nCPAP treatment with heated humidification (nCPAP-humid) or placebo humidification (nCPAP pl-humid). Objective and subjective nCPAP use, upper airway symptoms, and treatment satisfaction were compared. Thirty seven of 42 patients completed the protocol. nCPAP-humid reduced the frequency of adverse upper airway symptoms. nCPAP use over 3 weeks was greater with nCPAP-humid compared with nCPAP pl-humid. No difference was found between the treatment arms in terms of subjective treatment satisfaction or alertness. Heated humidification of nasal continuous positive airway pressure reduces upper airway symptoms and is associated with a small increase in initial use but not subjective sleepiness or treatment satisfaction. The results support the use of heated humidification as a strategy to reduce side-effects related to continuous positive airway pressure but not routine initial use.

Adult↗
PubMed2001

Does a delay in transfer to a rehabilitation unit for older people affect outcome after fracture of the proximal femur?

AIMS: To detemine the relationship between delay in transfer to rehabilitation wards and outcome for patients aged over 75 years with fracture of the proximal femur. METHODS: An observational study in a district general hospital of all patients admitted to hospital aged over 75 years with fracture of the proximal femur over 3 1/2 years. Outcome data collected included the number of patients discharged back to their usual residence and total hospital length of stay related to age, gender, usual residence and delay in transfer to a rehabilitation ward. RESULTS: 58% of 455 patients were transferred to a rehabilitation ward. For those patients who were transferred to a rehabilitation ward only age predicted discharge to a more dependent residence. The relative risk for discharge to a more dependent residence for people aged over 85 years compared to younger people was 1.47 (95% CI 1.15-1.88). Delay in transfer to rehabilitation was associated with a longer total hospital length of stay of 0.64 (95% CI 0.23-1.05) days per day of delay in transfer. CONCLUSIONS: Delay in transfer to a rehabilitation ward was associated with a disproportionate increase in total hospital length of stay for patients aged over 75 with fracture of the proximal femur.

Aged↗
PubMed2001

Dose-response relation of inhaled fluticasone propionate in adolescents and adults with asthma: meta-analysis.

OBJECTIVE: To examine the dose-response relation of inhaled fluticasone propionate in adolescents and adults with asthma. DESIGN: Meta-analysis of placebo controlled, randomised clinical trials that presented data on at least one outcome measure of asthma and that used at least two different doses of fluticasone. SETTING: Medline, Embase, and GlaxoWellcome's internal clinical study registers. MAIN OUTCOME MEASURES: FEV(1), morning and evening peak expiratory flow, night awakenings, beta agonist use, and major exacerbations. RESULTS: Eight studies, with 2324 adolescents and adults with asthma, met the inclusion criteria. Data on doses of >500 microg/day were limited. The dose-response curve for the raw data began to reach a plateau at around 100-200 microg/day and peaked by 500 microg/day. A negative exponential model for the data, without meta-analysis, indicated that 80% of the benefit at 1000 microg/day was achieved at doses of 70-170 microg/day and 90% by 100-250 microg/day. A quadratic meta-regression showed that the maximum achievable efficacy was obtained by doses of around 500 microg/day. The odds ratio for patients remaining in a study at a dose of 200 microg/day, compared with higher doses, was 0.73 (95% confidence interval 0.49 to 1.08). Comparison of the standardised difference in FEV(1 )for an inhaled dose of 200 microg/day against higher doses showed a difference in FEV(1) of 0.13 of a standard deviation (-0.02 to 0.29). CONCLUSIONS: In adolescent and adult patients with asthma, most of the therapeutic benefit of inhaled fluticasone is achieved with a total daily dose of 100-250 microg, and the maximum effect is achieved with a dose of around 500 microg/day. However, these findings were limited by the lack of data on individual patients and by the paucity of dose-response studies that included doses of >500 microg/day.

Administration, Inhalation↗
PubMed2001

The effect of delipidated deglycolipidated (DDMV) and heat-killed Mycobacterium vaccae in asthma.

Experimental and epidemiological evidence supports the hypothesis that exposure to mycobacteria has the potential to suppress the development of asthma and/or atopy and there are reports in the Chinese medical literature of repeated vaccination with inactivated BCG being effective in the management of asthma. Forty-three patients with stable moderately severe asthma who were skin prick test positive to house dust mite were randomized to receive two intradermal injections of either phosphate-buffered saline (placebo), heat-killed Mycobacterium vaccae (0.5 mg), or delipidated deglycolipidated Mycobacterium vaccae (DDMV) (0.05 mg). Markers of asthma severity were measured for 3 mo and blood eosinophil, IgE levels, and the T cell proliferative and cytokine responses were monitored. There were no significant differences between either treatment group and the placebo group for any of the outcome variables. There was also no difference between the treatment groups and placebo for eosinophil, IgE levels, or the T cell proliferative and cytokine response. The results indicate no effect of low dose intradermal DDMV or M. vaccae on asthma severity in patients with established asthma.

Adult↗