Vivienne Crawford

Particulate air pollution and the blood

BACKGROUND Particulate air pollution has been associated with excess deaths from, and increases in hospital admissions for, cardiovascular disease among older people. A study was undertaken to determine whether this may be a consequence of alterations in the blood, secondary to pulmonary inflammation caused by the action of fine particles on alveolar cells, by repeatedly measuring haematological factors in older people and relating them to measurements of exposure to airborne particles. METHODS One hundred and twelve individuals aged 60+ years in two UK cities provided repeated blood samples over 18 months, 108 providing the maximum of 12 samples. Estimates of individual exposure to particles of less than 10 μm diameter (PM10), derived from a mathematical model based on activity diaries and comparative measurements of PM10 at multiple sites and during a variety of activities, were made for each three day period prior to blood sampling. The relationships between blood values and estimates of both personal exposure and city centre measurements of PM10 were investigated by analysis of covariance, adjusting for city, season, temperature, and repeated individual measurements. RESULTS Estimated personal exposure to PM10 over the previous three days showed negative correlations with haemoglobin concentration, packed cell volume (PCV), and red blood cell count (p<0.001), and with platelets and factor VII levels (p<0.05). The changes in red cell indices persisted after adjustment for plasma albumin in a sample of 60 of the subjects. City centre PM10 measurements over three days also showed negative correlations with haemoglobin and red cell count (p<0.001) and with PCV and fibrinogen (p<0.05), the relationship with haemoglobin persisting after adjustment for albumin. C reactive protein levels showed a positive association with city centre measurements of PM10 (p<0.01). Based on a linear relationship, the estimated change in haemoglobin associated with an alteration in particle concentration of 100 μg/m3 is estimated to have been 0.44 g/dl (95% CI 0.62 to 0.26) for personal PM10 and 0.73 g/dl (95% CI 1.11 to 0.36) for city centre PM10 measurements. CONCLUSIONS This investigation is the first to estimate personal exposures to PM10 and to demonstrate associations between haematological indices and air pollution. The changes in haemoglobin adjusted for albumin suggest that inhalation of some component of PM10may cause sequestration of red cells in the circulation. We propose that an action of such particles either on lung endothelial cells or on erythrocytes themselves may be responsible for changing red cell adhesiveness. Peripheral sequestration of red cells offers an explanation for the observed cardiovascular effects of particulate air pollution.

SEASONAL VARIATIONS IN FIBRINOGEN CONCENTRATIONS AMONG ELDERLY PEOPLE

Mortality and morbidity in elderly people are higher in winter than in summer months, with seasonal variations in rates of both fatal and non-fatal myocardial infarction and stroke. To identify factors that might contribute to the excess winter frequency of cardiovascular disease in the elderly, we studied 100 subjects aged 75 and over who lived in either their own homes or in sheltered or residential accommodation. Each person was visited each month for one year, body and environmental temperatures were noted, and cardiovascular risk factors were measured. 32 subjects withdrew from the study. Significant seasonal effects were found for fibrinogen, plasma viscosity, and HDL cholesterol (p less than 0.003, Bonferroni adjustment). Plasma fibrinogen concentrations showed the greatest seasonal change and were 23% higher in the coldest six months compared with summer months. Fibrinogen was significantly (p less than 0.05) and negatively related to core body temperature and all measures of environmental temperature. Those living in institutions had greater changes in plasma fibrinogen than those living in the community. The seasonal variation in plasma fibrinogen concentration is large enough to increase the risk of both myocardial infarction and stroke in winter.

Butyrylcholinesterase K variant is genetically associated with late onset Alzheimer's disease in Northern Ireland

Alzheimers disease (AD) is a progressive neurodegenerative disorder that has been associated, sometimes controversially, with polymorphisms in a number of genes. Recently the butyrylcholinesterase K variant (BCHE K) allele has been shown to act in synergy with the apolipoprotein E ε4 (APOE ε4) allele to promote risk for AD. Most subsequent replicative studies have been unable to confirm these findings. We have conducted a case-control association study using a clinically well defined group of late onset AD patients (n=175) and age and sex matched control subjects (n=187) from the relatively genetically homogeneous Northern Ireland population to test this association. The BCHE genotypes of patients were found to be significantly different from controls (χ2=23.68, df=2, p<<0.001). The frequency of the K variant allele was also found to differ significantly in cases compared to controls (χ2=16.39, df=1, p<<0.001) leading to an increased risk of AD in subjects with this allele (OR=3.50, 95% CI 2.20-6.07). This risk increased in subjects 75 years and older (OR=5.50, 95% CI 2.56-11.87). At the same time the APOE ε4 associated risk was found to decrease from 6.70 (95% CI 2.40-19.04) in 65-74 year olds to 3.05 (95% CI 1.34-6.95) in those subjects 75 years and older. However, we detected no evidence of synergy between BCHE K and APOE ε4. The results from this study suggest that possession of the BCHE K allele constitutes a significant risk for AD in the Northern Ireland population and, furthermore, this risk increases with increasing age.

ACTIVE-LIFE EXPECTANCY AND TERMINAL DEPENDENCY: TRENDS IN LONG-TERM GERIATRIC CARE OVER 33 YEARS

To determine whether medical advances will result in an increasing number of dependent elderly people, or whether postponement of disability in a finite lifespan will lead to a decrease in terminal dependency, an analysis was made of 24,117 admissions to a geriatric unit from 1954 to 1986. During this period, the average age on admission for long-term care rose by 0.24 years per year for women and by 0.09 years per year for men. The median length of stay also increased, more for women than for men, as did the proportion of the total lifespan spent in long-term care. Active-life expectancy became longer and terminal dependency was postponed, but the duration of terminal dependency increased. Active-life expectancy increased more rapidly in women than in men, as did the length of terminal dependency. As life expectancy continues to increase, high priority will have to be given to reduction of disability and dependency in advanced old age.

Conservative podiatric medicine and disability in elderly people.

A survey was conducted of 248 noninstitutionalized people aged 75 years and older, residing in a designated geographical area. The effect of dependency and physical disability on the receipt of conservative podiatric medicine was examined, and, in addition, the prevalence of medical and podiatric conditions was determined.

Preparing tomorrow's doctors : the impact of a special study module in medical informatics

In response to the call for more informatics teaching in the medical curriculum, an elective special study module has been offered to first‐year students at Queen’s University since 1997.

A 6-month open-label study of the effectiveness and tolerability of galantamine in patients with Alzheimer's disease

The objective of this study was to assess the effectiveness and tolerability of galantamine in patients with mild‐to‐moderate Alzheimers disease (AD) in everyday clinical practice. Patient selection was made on 36 sequential patients attending Belfast City Hospital Memory Clinic between December 2000 and June 2001. Patients were treated with galantamine for 6 months, starting from 4 mg twice daily increasing to 8 mg twice daily and then to 12 mg twice daily at 4‐weekly intervals. Patients (25 females, 11 males), mean age 78 years (59–90), were diagnosed with probable AD and had a mini‐mental state examination (MMSE) score of 10–26. Efficacy was assessed using the MMSE, neuropsychiatric inventory (NPI), neuropsychiatric inventory caregiver distress (NPI‐D) scale and the Bristol activities of daily living (B‐ADL) scale at baseline and after 3 and 6 months of treatment. Mean improvements were noted on all four measures of efficacy at 3 and 6 months; improvements were significant on the MMSE, NPI and NPI‐D at 3 months and on the NPI‐D at 6 months. Galantamine was overall well tolerated. The most common adverse events were gastrointestinal, particularly nausea. Four patients stopped treatment due to adverse events, and seven were stabilised on 8 mg twice daily as they were unable to tolerate the target dose. This naturalistic study confirms clinical trial data, which shows galantamine improves cognition and behavioural symptoms and is overall well tolerated.

The effect of patient characteristics upon uptake of the influenza vaccination: a study comparing community-based older adults in two healthcare systems

BACKGROUND the uptake of influenza vaccination represents a simple marker of proactive care of older people. However, many still do not receive the vaccine. To understand this challenge better, we investigated the relationship between patient characteristics (demographic, physical and psychological health and health service use) and vaccination uptake in a sample of community-dwelling older people in two adjacent but differently structured healthcare systems (Northern Ireland (NI) and the Republic of Ireland (RoI)). METHODS a total of 2,033 randomly selected community-dwelling older adults (65 years and older) were interviewed in their homes. RESULTS rates of uptake were 78% in NI and 72% in RoI. The uptake was greater with older age (odds ratio (OR) 1.6, 95% confidence interval (CI) = 1.3-2.1, P < 0.0005), widowhood (OR = 1.5, 95% CI = 1.1-2.3, P = 0.02), living in NI (OR = 0.77, 95% CI = 0.6-0.9, P = 0.04), greater functional impairment (OR RoI 2.0, 95% CI = 0.8-3.5, P = 0.03), more frequent use of family doctor (OR RoI 0.5, 95% CI = 0.3-0.6, P = 0.0001; NI 0.6, 95% CI = 0.4-0.9, P = 0.01) and greater use of services such as chiropody (OR NI 0.6, 95% CI = 0.4-0.9, P = 0.01), meals-on-wheels (OR RoI 1.3, 95% CI = 0.4-2.2, P = 0.03), social work (OR RoI 1.2, 95% CI = 0.3-1.9, P = 0.05) and occupational therapy (OR RoI 1.3, 95% CI = 0.5-2.5, P = 0.02). CONCLUSION the uptake rates in both healthcare systems exceeded targets. Higher rates of vaccination were found among older people, those who were married and those who made greater use of hospital and community services. Increased exposure to health services may enhance trust in health care leading to higher vaccination uptake.

Measurement of fibrinogen in frozen plasma.

Several large studies have compared fibrinogen measurements determined over a particular time interval. These assays are subject to difficulties encountered by all laboratories on tests carried out over a period of time such as assay drift. To avoid this problem, plasma can be stored frozen and fibrinogen determined in a large number of samples simultaneously. However, a thorough comparison of measurements carried out in fresh and frozen plasma has not yet been performed. Fibrinogen concentration was therefore determined in fresh plasma samples and then at a later date in the same samples after storage at -70 degrees C. A good correlation was observed between the two measurements, however, bias increased at the higher fibrinogen levels which are most critical in the determination of thrombotic risk. An increase in measurement error as a result of freezing was also observed. These effects may, therefore, be important considerations in future studies of this nature.

Stroke Presentation and Hospital Management Comparison of Neighboring Healthcare Systems With Differing Health Policies

Background and Purpose— Acute stroke care is shaped by healthcare policies. Differing policies in similar populations allow for assessment of policy impact on health and healthcare outcomes. The purpose of this study was to compare stroke presentation and hospital care in two adjacent healthcare systems with differing healthcare policies. Methods— Interviews and chart review of consecutive acute stroke admissions in Northern Ireland (n=103) and the Republic of Ireland (n=100). Results— Marked regional contrasts were evident for key aspects of hospital care. Northern Ireland performed significantly better on 15 of 16 quality of care (Sentinel Audit) items. Delivery on standards was significantly better in Northern Ireland for early assessment (Northern Ireland 72%; Republic of Ireland 54%, P<0.01), multidisciplinary review (Northern Ireland 69%; Republic of Ireland 31%, P<0.001), medications review (Northern Ireland 54%; Republic of Ireland 19%, P<0.001), and for discharge-rehabilitation planning (Northern Ireland 83%; Republic of Ireland 8%, P<0.001). Preadmission prescription of advised cardiovascular medications was similar between regions for antihypertensives and anticoagulants but significantly higher in Northern Ireland for antiplatelets (Northern Ireland 65%; Republic of Ireland 38%, P=0.001) and lipid-regulating medication (Northern Ireland 44%; Republic of Ireland 26%; P=0.006). Prescribing levels increased in both regions and all medication categories by discharge but with significantly lower levels in Northern Ireland for antihypertensives (Northern Ireland 60%; Republic of Ireland 75%, P=0.025). Northern Ireland patients were more functionally dependent (mean Barthel Index 10.5 versus 12.7 [Republic of Ireland], P=0.013) and less aphasic (mean Frenchay Aphasia Screening Test 17.8 versus 16.8 [Republic of Ireland], P=0.022). Conclusions— In similar neighboring acute stroke populations, differing healthcare policies were associated with significant differences in processes of patient care. Policy reform is an important tool in ensuring optimal stroke care delivery.