Association of air pollution with daily GP consultations for asthma and other lower respiratory conditions in London.

BACKGROUND: Very few published studies have looked at the effects of air pollution on health in the primary care setting. As part of a large study to examine the association between air pollution and a number of health outcomes, the relationship between daily GP consultations for asthma and other lower respiratory diseases (LRD) and air pollution in London was investigated. METHODS: Time-series analysis of daily numbers of GP consultations controlling for time trends, seasonal factors, day of week cycles, influenza, weather, pollen levels, and serial correlation was performed. Consultation data were available from between 268 718 and 295 740 registered patients from 45-47 London practices contributing to the General Practice Research Database during 1992-4. RESULTS: Positive associations, weakly significant and consistent across lags, were observed between asthma consultations and nitrogen dioxide (NO2) and carbon monoxide (CO) in children and particulate matter of less than 10 microm in diameter (PM10) in adults, and between other LRD consultations and sulphur dioxide (SO2) in children. A consistently negative association with ozone in children was observed in both disease categories. The effect estimates of most pollutants were much larger when analysed separately by season, particularly in the children: percentage change in asthma consultations during the warm season (April-September) for a 10-90th percentile increase in 24 hour NO2 lagged by one day = 13.2% (95% CI 5.6 to 21.3), with CO = 11.4% (95% CI 3.3 to 20.0), and with SO2 = 9.0% (95% CI 2.2 to 16.2). In adults the only association consistent over different lag periods was with PM10 = 9.2% (3.7 to 15.1). The associations of pollution and consultations for LRD were increased mainly in the winter months: percentage change in consultations by children in winter with NO2 = 7.2% (95% CI 2.8 to 11.6), CO = 6.2% (95% CI 2.3 to 10.2), and SO2 = 5.8% (95% CI 1.6 to 10.2). CONCLUSIONS: There are associations between air pollution and daily consultations for asthma and other lower respiratory disease in London. The most significant associations were observed in children and the most important pollutants were NO2, CO, and SO2. In adults the only consistent association was with PM10.

Global assessment of El Niño's disaster burden.

BACKGROUND: Natural disasters have profound effects on health and require medical intervention as part of relief operations. The world's populations are becoming increasingly vulnerable to extreme weather events, which are responsible for most natural disasters. The El Niño Southern Oscillation (ENSO) is the most prominent global climate system associated with year-to-year weather variability and extreme events. We have estimated the burden on human health of natural disasters associated with ENSO. METHODS: We used time-series regression analysis of the relation between El Niño years and the annual rates of persons affected by natural disasters per 1000 population during 1964-93, globally and also by region and disaster type. Correlations between sea-surface temperature (SST) anomalies (index of ENSO) and the rates of persons affected by natural disasters per 1000 population were determined globally, by region and by disaster type. FINDINGS: The rate of persons affected by natural disasters worldwide is strongly associated with ENSO; rates are greater during the first El Niño year (p = 0.05) and the following year (p = 0.01) than in the pre-Niño year. The correlation between rates of persons affected by natural disasters and SST anomalies in the Eastern Pacific (a key ENSO indicator) is highest in the last quarter of the previous year (r = 0.53, p < 0.01). These associations are strongest in South Asia, the region where more than 50% of all disaster victims live. Worldwide, rates of persons affected by drought/famine (half of all disaster victims) and by volcanic eruptions show significant associations with the ENSO cycle, being highest in the post-Niño year and El Niño year, respectively, and being significantly associated with SST anomalies. INTERPRETATION: The strong relation between ENSO and populations affected by natural disasters can be described as a "natural disaster cycle". Determining the phase in this cycle, using SST from the Eastern Equatorial Pacific, could benefit disaster preparedness on a global scale, for South Asia in particular, and for all populations affected by drought/famine and volcanic disasters.

Thunderstorm-associated asthma: the effect on GP consultations.

Evidence shows that asthma attacks can be brought on by adverse weather conditions such as those experienced during a thunderstorm; a prime example of such an occasion being a thunderstorm episode on 24 June 1994, which resulted in a well-documented increase in medical attendances made by those suffering with asthma and respiratory disorders. However, most of these studies have concerned admissions to accident and emergency departments. The aim of this paper was to ascertain whether a similar increase in consultations was observed in the primary care setting.

Associations of urinary albumin excretion rate with vascular disease in europid nondiabetic subjects.

Microalbuminuria and its association with vascular disease has previously been reported in nondiabetic individuals. The aims of this study were to determine whether there is a cross-sectional relationship between urinary albumin excretion rate and cardiovascular disease in nondiabetic subjects and to investigate hereditary predisposition to microalbuminuria by studying offspring of the main study population. Europid patients, aged 40-70 years, were randomly selected from a large inner-city general practice; there was a 62.6% attendance rate, and a study population of 959 remained after exclusions. Blood pressure, ankle systolic pressure, height, and weight were measured. Albumin excretion rate was calculated from overnight and morning urine collections. Venous blood was taken for lipids, fibrinogen, and factor VII; and resting electrocardiograms were carried out. Offspring (aged 15-40 years) of those found to be microalbuminuric were invited to attend for the same tests, and controls were selected by age and sex matching the parents. There was no association between parents' albumin excretion rate with that of their offspring, and there were no significant differences in albumin excretion rate between offspring subjects and their controls. There were no statistically significant associations of prevalent coronary heart disease (CHD) with albumin excretion rate or microalbuminuria in either sex [CHD in women: odds ratio (OR) 1.85; 95% confidence interval (CI) 0.19,9.0] [CHD in men: OR 2.13; 95% CI (0.64, 6.59)]. In women, there were significant associations between albumin excretion rate and peripheral vascular disease (positive) and fibrinogen (negative). Because established risk factors may not be as strongly associated with CHD in cross-sectional studies, we intend to follow this group prospectively.

Microalbuminuria: associations with height and sex in non-diabetic subjects.

OBJECTIVES: To study the association(s) between microalbuminuria and cardiovascular risk factors in non-diabetic subjects. DESIGN: Patients aged 40-75 years were randomly selected from a general practice list and invited to participate. SETTING: Health centre in inner city London. SUBJECTS: Of those invited, 1046 out of 1671 (62.6%) attended. Subjects were excluded for the following reasons: not being white (44); urinary albumin excretion rate > 200 micrograms/min (3); having a urinary infection (5); taking penicillamine or angiotensin converting enzyme inhibitors (7); older than 75 (2); having diabetes (25); missing data on glucose concentration (1). MAIN OUTCOME MEASURES: Glucose tolerance test results, albumin excretion rate from overnight and timed morning collections of urine; blood pressure; height. RESULTS: Mean albumin excretion rate was significantly lower in women than men (mean ratio 0.8, 95% confidence interval (0.69 to 0.91)). Mean albumin excretion rate was significantly associated with age, blood pressure, and blood glucose concentration (fasting, 1 hour, and 2 hour) in men and inversely with height. Men who had microalbuminuria in both samples were significantly shorter (by 5 cm (1.3 to 9.3 cm)) than those who had no microalbuminuria in either sample when age was taken into account. In the case of women only systolic pressure was significantly associated with albumin excretion rate. CONCLUSIONS: Microalbuminuria and short stature in men are associated. Cardiovascular risk has been associated with both of these factors and with lower birth weight. The inverse association of microalbuminuria with height is compatible with the suggestion that factors operating in utero or early childhood are implicated in cardiovascular disease. The higher prevalence of microalbuminuria in men compared with women may indicate that sex differences in cardiovascular risk are reflected in differences in albumin excretion rate.