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Biomedical subjects

K Rees

Publications and source records attributed to K Rees.

At least 19 recordsLinked to original sources
PubMed2005

Dietary advice for reducing cardiovascular risk.

BACKGROUND: Changes in population diet are likely to reduce cardiovascular disease and cancer, but the effect of dietary advice is uncertain. OBJECTIVES: To assess the effects of providing dietary advice to achieve sustained dietary changes or improved cardiovascular risk profile among healthy adults. SEARCH STRATEGY: We searched the Cochrane Controlled Trials Register on The Cochrane Library (Issue 2 2000), MEDLINE (January 1966 to December 2000), EMBASE (January 1985 to December 2000), DARE (December 2000), CAB Health (December 1999), dissertation abstracts, and reference lists of articles. We contacted researchers in the field. SELECTION CRITERIA: Randomised studies with no more than 20% loss to follow-up, lasting at least three months involving healthy adults comparing dietary advice with no advice or less intensive advice. Trials involving children, trials to reduce weight or those involving supplementation were excluded. DATA COLLECTION AND ANALYSIS: Two reviewers independently assessed trial quality and extracted data. Study authors were contacted for additional information. MAIN RESULTS: Twenty-three trials with 29 intervention arms (comparisons) comparing dietary advice with no advice were included in the review. Dietary advice reduced total serum cholesterol by 0.13 mmol/l (95% CI 0.03 to 0.23) and LDL cholesterol by 0.13 mmol/l (95% CI 0.01 to 0.25) after 3-12 months. Mean HDL cholesterol levels were unchanged. Dietary advice reduced blood pressure by 2.10 mmHg systolic (95% CI 1.37 to 2.83) and 1.63 mmHg diastolic (95% CI 0.56 to 2.71) and 24-hour urinary sodium excretion by 44.2 mmol (95% CI 33.6 to 54.7) after 3-36 months. Plasma triglycerides, ss-carotene and red cell folate were each measured in one small study which suggested no significant effect. Self-reported dietary intake may be subject to reporting bias, and there was significant heterogeneity in all the following analyses. Compared to no advice, dietary advice increased fruit and vegetable intake by 1.24 servings/day (95% CI 0.43 to 2.05). Dietary fibre intake increased with advice by 7.22 g/day (95% CI 2.84 to 11.60), while total dietary fat as a percentage of total energy intake fell by 6.18 % (95% CI 4.00 to 8.36) with dietary advice and saturated fat intake fell by 3.28 % (95% CI 1.92 to 4.64). AUTHORS' CONCLUSIONS: Dietary advice appears to be effective in bringing about modest beneficial changes in diet and cardiovascular risk factors over approximately 9 months but longer term effects are not known.

Cardiovascular Diseases↗
PubMed2004

Psychological interventions for coronary heart disease.

BACKGROUND: Psychological interventions can form part of comprehensive cardiac rehabilitation programmes (CCR). These interventions may include stress management interventions, which aim to reduce stress, either as an end in itself or to reduce risk for further cardiac events in patients with heart disease. OBJECTIVES: To determine the effectiveness of psychological interventions, in particular stress management interventions, on mortality and morbidity, psychological measures, quality of life, and modifiable cardiac risk factors, in patients with coronary heart disease (CHD). SEARCH STRATEGY: We searched CCTR to December 2001 (Issue 4, 2001), MEDLINE 1999 to December 2001 and EMBASE 1998 to the end of 2001, PsychINFO and CINAHL to December 2001. In addition, searches of reference lists of papers were made and expert advice was sought. SELECTION CRITERIA: RCTs of non-pharmacological psychological interventions, administered by trained staff, either single modality interventions or a part of CCR with minimum follow up of 6 months. Adults of all ages with CHD (prior myocardial infarction, coronary artery bypass graft or percutaneous transluminal coronary angioplasty, angina pectoris or coronary artery disease defined by angiography). Stress management (SM) trials were identified and reported in combination with other psychological interventions and separately. DATA COLLECTION AND ANALYSIS: Studies were selected, and data were abstracted, independently by two reviewers. Authors were contacted where possible to obtain missing information. MAIN RESULTS: Thirty six trials with 12,841 patients were included. Of these, 18 (5242 patients) were SM trials. Quality of many trials was poor with the majority not reporting adequate concealment of allocation, and only 6 blinded outcome assessors. Combining the results of all trials showed no strong evidence of effect on total or cardiac mortality, or revascularisation. There was a reduction in the number of non-fatal reinfarctions in the intervention group (OR 0.78 (0.67, 0.90), but the two largest trials (with 4809 patients randomized) were null for this outcome, and there was statistical evidence of publication bias. Similar results were seen for the SM subgroup of trials. Provision of any psychological intervention or SM intervention caused small reductions in anxiety and depression. Few trials reported modifiable cardiac risk factors or quality of life. REVIEWERS' CONCLUSIONS: Overall psychological interventions showed no evidence of effect on total or cardiac mortality, but did show small reductions in anxiety and depression in patients with CHD. Similar results were seen for SM interventions when considered separately. However, the poor quality of trials, considerable heterogeneity observed between trials and evidence of significant publication bias make the pooled finding of a reduction in non-fatal myocardial infarction insecure.

Coronary Disease↗
PubMed2004

Exercise based rehabilitation for heart failure.

BACKGROUND: The prevalence of chronic heart failure is increasing, and increases with increasing age. Major symptoms include breathlessness and restricted activities of daily living due to reduced functional capacity, which in turn affects quality of life. Exercise training has been shown to be effective in patients with coronary heart disease and has been proposed as an intervention to improve exercise tolerance in patients with heart failure. OBJECTIVES: To determine the effectiveness of exercise based interventions compared with usual medical care on the mortality, morbidity, exercise capacity and health related quality of life, of patients with heart failure. SEARCH STRATEGY: We searched the Cochrane Controlled Trials Register (The Cochrane Library Issue 2, 2001), MEDLINE (2000 to March 2001), EMBASE (1998 to March 2001), CINAHL (1984 to March 2001) and reference lists of articles. We also sought advice from experts. SELECTION CRITERIA: RCTs of exercise based interventions. The comparison group was usual medical care as defined by the study, or placebo. Adults of all ages with chronic heart failure. Only those studies with criteria for diagnosis of heart failure (based on clinical findings or objective indices) have been included. DATA COLLECTION AND ANALYSIS: Studies were selected, and data were abstracted, independently by two reviewers. Authors were contacted where possible to obtain missing information. MAIN RESULTS: Twenty-nine studies met the inclusion criteria, with 1126 patients randomised. The majority of studies included both patients with primary and secondary heart failure, NYHA class II or III. None of the studies specifically examined the effect of exercise training on mortality and morbidity as most were of short duration. Exercise training significantly increased VO(2) max by (WMD random effects model) 2.16 ml/kg/min (95% CI 2.82 to 1.49), exercise duration increased by 2.38 minutes (95% CI 2.85 to 1.9), work capacity by 15.1 Watts (95% CI 17.7 to 12.6) and distance on the six minute walk by 40.9 metres (95% CI 64.7 to 17.1). Improvements in VO(2) max were greater for training programmes of greater intensity and duration. HRQoL improved in the seven of nine trials that measured this outcome. REVIEWERS' CONCLUSIONS: Exercise training improves exercise capacity and quality of life in patients mild to moderate heart failure in the short term. There is currently no information regarding the effect of exercise training on clinical outcomes. The findings are based on small-scale trials in patients who are unrepresentative of the total population of patients with heart failure. Other groups (more severe patients, the elderly, women) may also benefit. Large-scale pragmatic trials of exercise training of longer duration, recruiting a wider spectrum of patients are needed to address these issues.

Cardiac Output, Low↗
PubMed2004

Is there a familial association between obstructive sleep apnoea/hypopnoea and the sudden infant death syndrome?

BACKGROUND: One postulated cause of the sudden infant death syndrome (SIDS) is upper airway obstruction during sleep. Several studies have suggested that SIDS may be more common in families with obstructive sleep apnoea/hypopnoea syndrome (OSAHS), but were limited by uncertainty as to whether the deaths were due to SIDS. We have tested the hypothesis that parents of true SIDS cases have an increased frequency of apnoeas and hypopnoeas during sleep. METHODS: The parents of 269 rigorously determined SIDS cases were invited for single night polysomnography and daytime ventilatory control measurement. RESULTS: Parents of 198 cases were identified but 152 did not respond or declined. Fifty five parents of 34 cases were studied and matched for age, height, and weight to 55 subjects from general practice registers. There was no difference in breathing during sleep between the parents of SIDS cases (median (IQR) 5.9 (3.2, 10.7) apnoeas+hypopnoeas/h) and controls (6.7 (4.0, 12.2) apnoeas+hypopnoeas/h; p = 0.47), but the SIDS parents had lower minimum nocturnal oxygen saturation (median (IQR) 92 (89, 93)%) than controls (92 (90, 94)%; p = 0.048). There were no major differences in control of breathing when awake between SIDS parents and controls. CONCLUSIONS: These results provide no evidence to support an association between SIDS and OSAHS. However, the minor impairment of oxygenation during sleep in SIDS parents requires further study.

Adult↗
PubMed2004

Provision, uptake and cost of cardiac rehabilitation programmes: improving services to under-represented groups.

OBJECTIVES: To estimate UK need for outpatient cardiac rehabilitation, current provision and identification of patient groups not receiving services. To conduct a systematic review of literature on methods to improve uptake and adherence to cardiac rehabilitation. To estimate cost implications of increasing uptake of cardiac rehabilitation. DATA SOURCES: Hospital Episode Statistics (England). Hospital Inpatient Systems (Northern Ireland). Patients Episode Database for Wales. British Association for Cardiac Rehabilitation/British Heart Foundation surveys. Cardiac rehabilitation centres. Patients from general hospitals. Electronic databases. REVIEW METHODS: The study analysed hospital discharge statistics to ascertain the population need for outpatient cardiac rehabilitation in the UK. Surveys of cardiac rehabilitation programmes were conducted to determine UK provision, uptake and audit activity, and to identify local interventions to improve uptake. Data were also examined from a trial estimating eligibility for cardiac rehabilitation and non-attendance. A systematic review of interventions to improve patient uptake, adherence and professional compliance in cardiac rehabilitation was conducted. Estimated costs of improving uptake were identified from national survey, systematic review and sampled cardiac rehabilitation programmes. RESULTS: In England, Wales and Northern Ireland nearly 146,000 patients discharged from hospital with primary diagnosis of acute myocardial infarction, unstable angina or following revascularisation were potentially eligible for cardiac rehabilitation. In England in 2000, 45-67% of these patients were referred, with 27-41% attending outpatient cardiac rehabilitation. If all discharge diagnoses of ischaemic heart disease were considered, nearly 299,000 patients would be potentially eligible and in England rates of attendance and referral would be 22-33% and 13-20% respectively. Rates of referral and attendance were similar in Wales, but somewhat lower in Northern Ireland. It was found that referral and attendance of older people and women at cardiac rehabilitation tended to be low. It was also suggested that patients from ethnic minorities and those with angina or heart failure were less likely to be referred to or join programmes. A wide range of local interventions suggested awareness of the problem of uptake. In an NHS-funded randomised controlled trial, possibly representing more optimal protocol-led care, medical and nursing staff identified 73-81% of patients with acute myocardial infarction as eligible for cardiac rehabilitation. Excluded patients tended to be older with more severe presentation of cardiac disease. Experiences of patients suggested that uptake may be improved by addressing issues of motivation and relevance of rehabilitation to future well-being, co-morbidities, site and time of programme, transport and care for dependents. Systematic review of studies supported the use of letters, pamphlets or home visits to motivate patients and the use of trained lay visitors. Self-management techniques showed some value in promoting adherence to lifestyle changes. Studies examining professional compliance found that professional support for practice nurses may have value in the coordination of postdischarge care. Average costs in 2001 of cardiac rehabilitation to the health service per patient completing a cardiac rehabilitation programme were about GBP350 (staff only) and GBP490 (total). If services were modelled on an intermediate multidisciplinary configuration with three to five key staff, approximately 13% more patients could be treated with the same budget. Depending on staffing configuration an approximate 200-790% budget increase would be required to provide cardiac rehabilitation to all potentially eligible patients. CONCLUSIONS: Provision of outpatient cardiac rehabilitation in the UK is low and little is known about the capacity of cardiac rehabilitation centres to increase this provision. There is an uncoordinated approach to audit data collection and few interventions aimed at improving the situation have been formally evaluated. Motivational communications and trained lay volunteers may improve uptake of cardiac rehabilitation, as may self-management techniques. Experience of low-cost interventions and good practice exists within rehabilitation centres, although cost information frequently is not reported. Increased provision of outpatient cardiac rehabilitation will require extra resources. Further trials are required to compare the cost-effectiveness of comprehensive multidisciplinary rehabilitation with simpler outpatient programmes, also research is needed into economic and patient preference studies of the effects of different methods of using increased funding for cardiac rehabilitation. An evaluation of a range of interventions to promote attendance in all patients and under-represented groups would also be useful. The development of standards is suggested for audit methods and for eligibility criteria, as well as regular and comprehensive data collection to estimate the need for and provision of cardiac rehabilitation. Further areas for intervention could be identified through qualitative studies, and the extension of low-cost interventions and good practice within rehabilitation centres. Regularly updated systematic reviews of relevant literature would also be useful.

Cost-Benefit Analysis↗
PubMed2003

Socioeconomic deprivation is a predictor of poor postoperative cardiovascular outcomes in patients undergoing coronary artery bypass grafting.

OBJECTIVE: To investigate the effects of socioeconomic deprivation on cardiovascular risk factors and postoperative clinical outcomes of patients undergoing coronary artery bypass grafting (CABG). DESIGN: Retrospective analysis of prospectively collected data. SETTING: Surgical population of the southwest of England, April 1996 and August 2000. STUDY GROUP: Data on 3578 consecutive patients undergoing CABG at the Bristol Royal Infirmary NHS Trust were abstracted. Data were retrieved from the Patient Analysis & Tracking System. Carstairs index was used to measure socioeconomic deprivation of area of residence and was divided into five quintiles, where quintile 1 denotes least deprived and 5 most deprived. OUTCOME MEASURES: End points were postoperative complications and 30 day mortality. RESULTS: Higher deprivation scores were associated with younger age (p < 0.004), greater body mass index, diabetes, smoking at time of surgery, and higher EuroSCOREs (all p < or = 0.001). After adjustment for EuroSCORE, socioeconomic deprivation was independently associated with postoperative myocardial infarction (p = 0.05) and combined postoperative myocardial infarction, stroke, and death (p = 0.016). Hospital length of stay for the patients in the highest quintiles was also significantly longer than for those in the lower quintiles (p = 0.04). CONCLUSION: Patients undergoing CABG living in areas with high deprivation scores are younger, have more clinical risk factors, and experience more postoperative cardiovascular complications than patients living in low deprivation score areas.

Coronary Artery Bypass↗
PubMed2002

Coronary artery bypass grafting in patients over 70 years old: the influence of age and surgical technique on early and mid-term clinical outcomes.

OBJECTIVE: To investigate the influence of age and modern techniques of coronary artery bypass grafting with or without cardiopulmonary bypass on early and mid-term mortality and morbidity in a consecutive series of elderly patients. METHODS: From April 1996 to December 2000, data of 3842 patients undergoing coronary revascularisation were prospectively entered into a database. Data were extracted for 990 patients older than 70 years: (A) 70-74 years, (n=659); (B) 75 or more years, (n=331). RESULTS: A total of 990 elderly patients (> or = 70 years) underwent coronary revascularisation, 219 (22.1%) with off-pump surgery. Elderly patients were more likely to have higher CCS, NYHA and EuroScores, history of previous MI, unstable angina, renal dysfunction, left main stem disease > or = 50%, and to be urgent. However, they were less likely to be overweight. In-hospital mortality, occurrence of re-intubation, renal dysfunction, and hospital stay were significantly higher in this elderly group. Overall, the distribution of mortality was doubled in the female gender although this was not statistically significant. Patients undergoing on-pump surgery had lower EuroScore, were less likely to be >75 years of age, likely to have obesity or hypercholesterolaemia, or to have suffered a previous cerebro-vascular accident. However, they had more extensive coronary disease, were more likely to have unstable angina, and received more grafts than those undergoing off-pump surgery. After adjustment for prognostic variables, off-pump surgery was found to be associated with reduced inotropic use, intra-operative arrhythmias, blood loss and transfusion requirement when compared to on-pump coronary surgery (point estimates of odd ratios, 0.26-0.87) (all P<0.05). Mid-term mortality or cardiac-related events were similar in the two groups. CONCLUSIONS: Early but not mid-term mortality is higher in patients aged 75 or more years when compared with those aged 70-74 years. Off-pump coronary artery bypass surgery is safe and effective in the elderly population.

Age Factors↗
PubMed2001

Hypothermia to reduce neurological damage following coronary artery bypass surgery.

BACKGROUND: Coronary artery bypass surgery (CABG) may be life saving, but known side effects include neurological damage and cognitive impairment. The temperature used during cardiopulmonary bypass (CPB) may be important with regard to these adverse outcomes, where hypothermia is used as a means of neuroprotection. OBJECTIVES: To assess the effectiveness of hypothermia during CABG in reducing neurological damage and subsequent cognitive deficits. SEARCH STRATEGY: The Cochrane Controlled Trials Register was searched for randomised controlled trials (RCT) and this was updated by searching MEDLINE and EMBASE to December 1999 using database specific RCT filters. Reference lists of retrieved articles were searched and experts in the field were contacted. SELECTION CRITERIA: Only RCTs were considered. All patients undergoing CABG, either first time or revisions, elective or emergency procedures, were included. Any hypothermia protocol was considered. Only trials reporting neurological outcomes were included. DATA COLLECTION AND ANALYSIS: Studies were selected independently and data were extracted from the source papers independently by two reviewers. Authors were contacted for further information. Studies were combined with meta-analysis where appropriate, and meta-regression was used to explore heterogeneity. MAIN RESULTS: There was a trend towards a reduction in the incidence of non fatal strokes in the hypothermic group (OR 0.68 (0.43, 1.05)). Conversely, there was a trend for the number of non stroke related perioperative deaths to be higher in the hypothermic group (OR 1.46 (0.9, 2.37)). Hypothermia had no effect on the incidence of non fatal myocardial infarction (OR 1.05 (0.81, 1.37)), but the incidence of another marker of myocardial damage, low output syndrome, was higher in the hypothermic group (OR 1.21 (0.99, 1.48). When pooling all "bad" outcomes (stroke, perioperative death, myocardial infarction, low output syndrome, intra aortic balloon pump use) there was no significant advantage of either hypothermia or normothermia (OR 1.07 (0.92, 1.24)). Only 4 of 17 trials reported neuropsychological function as an outcome. REVIEWER'S CONCLUSIONS: This review could find no definite advantage of hypothermia over normothermia in the incidence of clinical events. Hypothermia was associated with a reduced stroke rate, but this is off set by a trend towards an increase in non stroke related perioperative mortality and myocardial damage. There is insufficient data to date to draw any conclusions about the use of mild hypothermia. Similarly, there is insufficient data to date to comment on the effect of temperature during CPB on subtle neurological deficits, and further trials are needed in these areas.

Cardiac Output, Low↗
PubMed2001

Risk factors for small-for-gestational-age babies: The Auckland Birthweight Collaborative Study.

OBJECTIVE: This case-control study determined whether internationally recognized risk factors for small-for-gestational-age (SGA) term babies were applicable in New Zealand. METHODOLOGY: All babies were born at 37 or more completed weeks of gestation in one of three hospitals in Auckland. Cases weighed less than the sex specific 10th percentile for gestational age at birth, and controls (appropriate-for-gestational-age (AGA)) were a random selection of heavier babies. Information was collected by maternal interview and from obstetric databases. RESULTS: Information from 1714 completed interviews (844 SGA and 870 AGA) was available for analysis. Computerized obstetric records were available for 1691 of the 1701 women who consented to such access. In a multivariate analysis allowing for sex, gestational age at birth, social class and other potential confounders, mothers who smoked had a significantly increased risk of an SGA baby (adjusted OR 2.41; 95% CI 1.78-3.28), as did primiparous mothers (adjusted OR 1.34; 95% CI 1.03-1.73), mothers of Indian ethnicity (adjusted OR 3.22; 95% CI 1.95-5.30), women with pre-eclamptic toxaemia (adjusted OR 2.42; 95% CI 1.08-5.40) and those with pre-existing hypertension toxaemia (adjusted OR 5.49; 95% CI 1.81-16.71). Mothers of SGA infants were shorter (P < 0.001) and reported lower prepregnancy body weights (P < 0.001) than mothers of AGA infants. The population attributable fraction for smoking suggests that up to 18% of SGA infants born in the ABC Study could be related to maternal smoking. CONCLUSIONS: Risk factors associated with SGA births in other countries are also important in New Zealand. Smoking in pregnancy is an important and potentially modifiable behaviour, and efforts to decrease the number of women who smoke during pregnancy should be encouraged.

Adult↗
PubMed2000

Exercise-based rehabilitation for coronary heart disease.

BACKGROUND: The burden of cardiovascular disease world-wide is one of great concern to patients and health care agencies alike. Circulatory diseases, including myocardial infarction (MI) and stroke, kill more people than any other disease. Cardiac rehabilitation aims to restore patients who have suffered myocardial infarction to optimal health through exercise only based rehabilitation or comprehensive cardiac rehabilitation (eg. smoking cessation advice, diet and counselling as well as exercise). Data from two published and widely cited meta-analyses (Oldridge 1988, O'Connor 1989) of over 4,000 patients each have demonstrated that patients randomised to exercise-based cardiac rehabilitation after MI have a statistically significant reduction in all-cause and cardiac mortality of about 20 to 25% compared to patients receiving conventional care. However, the trials included were small and often of poor methodological quality. Incomplete literature review methods may have resulted in publication bias thereby resulting in an over-estimate of the benefit of cardiac rehabilitation. The randomised controlled trials used in the reviews have focused almost exclusively on low-risk, middle-aged males post MI, thereby excluding women and the elderly. OBJECTIVES: To determine the effectiveness of exercise only rehabilitation and exercise in addition to other rehabilitation interventions (termed comprehensive cardiac rehabilitation) compared with usual care on the mortality, morbidity, health-related quality of life (HRQoL) and modifiable cardiac risk factors of patients with coronary heart disease. SEARCH STRATEGY: Electronic databases were searched for randomised controlled trials, using standardised trial filters, from the earliest date available to December 31st 1998. SELECTION CRITERIA: Men and women of all ages, in both hospital-based and community-based settings, who have had myocardial infarction, coronary artery bypass graft or percutaneous transluminal coronary angioplasty, or who have angina pectoris or coronary artery disease defined by angiography have been included. Studies involving participants following heart transplant, heart valve surgery or heart failure have been excluded. Follow up periods of less than 6 months were excluded. DATA COLLECTION AND ANALYSIS: Studies were selected independently by two reviewers, and data extracted independently. Authors were contacted where possible to obtain missing information. MAIN RESULTS: The current systematic review has allowed analysis of an increased number of patients from approximately 4500 in the earlier meta-analyses to 7683 (2582 in exercise only and 5101 in the comprehensive cardiac rehabilitation group). The quality of reporting overall was poor, with generally high losses to follow up. The pooled effect estimate for total mortality for the exercise only intervention shows a 27% reduction in all cause mortality (random effects model OR 0.73 (0.54, 0.98)). Similarly, comprehensive cardiac rehabilitation reduced all cause mortality compared to usual care, but to a lesser degree (OR 0.87 (0.71, 1.05)). Total cardiac mortality was reduced by 31% (random effects model OR 0.69 (0.51, 0.94)) and 26% (random effects model OR 0.74 (0.57, 0.96)) in the exercise only and comprehensive cardiac rehabilitation intervention groups respectively when compared to usual care. Neither intervention had any effect on the ocurrence of non-fatal myocardial infarction. There was a significant net reduction in total cholesterol in the comprehensive cardiac rehabilitation group (pooled WMD random effects model -0.57 mmol/l (-0.83, -0.31)), but not the exercise only rehabilitation group. Similarly, LDL was significantly reduced in the comprehensive cardiac rehabilitation group (pooled WMD random effects model -0.51 mmol/l (-0.82, -0.19). The effect of exercise only rehabilitation or comprehensive cardiac rehabilitation interventions on revascularisation rates, blood pressure or smoking behaviour could not be determined by this meta-analysis due to the small number of trials reporting these outcomes and heterogeneity between trials. It was not possible to combine the data from studies reporting HRQoL as an outcome. Eighteen different instruments were used to assess HRQoL in the 11 studies reporting it as an outcome. The data are presented qualitatively, only one trial reporting significant improvements with the intervention. REVIEWER'S CONCLUSIONS: Exercise-based cardiac rehabilitation appears to be effective in reducing cardiac deaths but the evidence base is weakened by poor quality trials. It is not clear from this review whether exercise only or a comprehensive cardiac rehabilitation intervention is more beneficial. The population studied in this review is still predominately male, middle aged and low risk. Identification of the ethnic origin of the participants was seldom reported. (ABSTRACT TRUNCATED)

Coronary Disease↗
PubMed2000

Frequency and significance of increased upper airway resistance during sleep.

Previous studies have shown that episodes of inspiratory flow limitation can be clinically important. We have challenged the hypothesis that patients with the "upper airway resistance syndrome" have more episodes of inspiratory flow limitation, associated with greater swings in pleural pressure and more arousals from sleep than normal subjects. We thus studied eight symptomatic patients with UARS (ESS > 10, AHI < 15) and eight matched asymptomatic subjects. All had overnight polysomnography with recording of pleural pressure and airflow derived from nasal pressure. Events scored visually using nasal pressure were termed flow limitation events and those using both signals "resistive events." The patients with UARS had no more episodes of flow limitation or resistive events than the controls. However, pleural pressure swings at resistive event termination were significantly more negative in the patient group (-15 [IQR 9-19]; -11 [8-12] cm H(2)O; p = 0.02) and the number of cortical arousals associated with resistive events was higher in the patients (median, 10 [5-15]; 3 [1-9]/h slept; p = 0.02). This study confirms that patients with UARS have periods of increased upper airway resistance associated with significant sleep fragmentation. However, resistive events are also common in normal subjects, although these are associated with less negative pleural pressure swings and fewer arousals. Thus, the clinical significance of resistive events needs to be interpreted with caution.

Adult↗
PubMed1999

The influences of age and caffeine on psychomotor and cognitive function.

RATIONALE: The response to caffeine is affected by a number of factors, including age. Older subjects may be more sensitive to the objective effects than younger but report fewer subjective effects. OBJECTIVE: This study assessed the influence of age on the effects of caffeine on a variety of psychomotor, cognitive and subjective tests. METHODS: Forty-eight healthy subjects, male and female, were recruited, 24 in the age range 20-25 and 24 in the range 50-65 years. All subjects were regular moderate caffeine drinkers and were not withdrawn from caffeine before entry to the study. A double-blind parallel group design was used with two groups of 12 subjects in each age range. One group in each age range received placebo and the other 250 mg caffeine B.P. A range of tests was used to assess psychomotor, cognitive and subjective functioning before and 1 h post-treatment. RESULTS: Before treatment, young subjects generally performed better than older on psychomotor and cognitive tests. On the subjective tests, however, older subjects rated themselves as more alert and less tired than the younger ones. After placebo, performance and alertness improved in the younger group but declined in the older. After caffeine there were improvements in psychomotor performance and cognitive functioning in both groups, particularly in offsetting declining performance over time in the older subjects. It also produced subjective improvements in alertness. One factor to emerge was that on most assessments older subjects were better earlier in the day whereas in younger subjects performance did not show the same magnitude of decline throughout the day. CONCLUSIONS: Caffeine induced small but significant improvements in vigilance and psychomotor performance.

Adult↗
PubMed1999

Expression of risk factors for breast cancer in women younger than 49.

The definition of women younger than 49 who are at increased risk for breast cancer would enable intensified efforts in surveillance and use of preventive measures for this group. In this survey of 32,123 members of Health Net, an increased risk for breast cancer was related to age, breast cancer in the immediate family (mother, sister), and previous biopsies for cystic lesions of the breast. No increased risk was related to menarche, nulliparity, first pregnancy after age 30, or breast feeding.

Adult↗
PubMed1998

Axillary node dissection in ductal carcinoma in situ.

Intraductal carcinoma of the breast has become a well-defined entity that has been more frequently diagnosed since the introduction of mammography. For many years, the usual treatment has been mastectomy, often with axillary lymph node dissection. Concurrent with documentation that breast conservation treatment has been effective for many invasive breast cancers, such treatment has been introduced for noninvasive breast cancers (ductal carcinoma in situ and lobular cancer in situ). However, there is no basis for axillary dissection because tumor cells are contained by the basement membrane and should not metastasize. In this study, 107 axillary dissections were carried out, with an average of 20 nodes identified, and a single metastasis was identified.

Breast Neoplasms↗
PubMed1998

Detection of apnoeas, hypopnoeas and arousals by the AutoSet in the sleep apnoea/hypopnoea syndrome.

Limited sleep study systems are increasingly being used to diagnose the sleep apnoea/hypopnoea syndrome, but validation is essential and detection of arousal's desirable. One such system (AutoSet) was validated on an event-by-event basis, and the hypothesis that sudden large breaths detected by this system mark arousal from sleep was also examined. Twenty consecutive patients (apnoea/hypopnoea index (AHI) 39+/-6 (SEM)) underwent polysomnography (PSG), which included real-time signals of AutoSet (Version 3.03) scored events. PSG respiratory events were defined using airflow and thoracoabdominal movement and AutoSet events using nasal pressure. All apnoeas were scored by both systems, but 41% more hypopnoeas were scored on PSG and these were clinically significant, with 78% ending in cortical arousal. Twenty per cent of apnoeas and hypopnoeas scored by the AutoSet occurred during wakefulness. Large breaths, defined as a two-thirds increase in ventilation, marked 77% of respiratory-associated but only 9% of spontaneous arousals. Large breaths also marked 48% of "autonomic" arousals following respiratory events without visible electroencephalographic changes. Twenty-seven per cent of large breaths occurred during wakefulness. This study shows that the AutoSet and the standard polysomnographic approach differ in their detection of hypopnoeas. The AutoSet underdetected hypopnoeas during sleep, but also included some hypopnoeas occurring during wakefulness. Detection of large breaths may potentially be useful for identifying respiratory arousals. Detection of periods of wakefulness may improve the accuracy of the system.

Adult↗