Influence of climatic variables on acute myocardial infarction hospital admissions
Introduction
Seasonal peaks in diseases incidence and mortality with a winter increase in deaths have been reported in different countries [1], [2], [3]. This phenomenon has been attributed to seasonal variations in respiratory, cardiovascular, and cerebrovascular mortality [3]. In particular, numerous studies have reported increased coronary heart disease (CHD) mortality during the winter [4], [5], [6].
Consensus is lacking, however, on whether this phenomenon reflects variations in incidence or in case fatality rate. Variations in emergency admission rates and trial recruitment of patients suffering from acute myocardial infarction (AMI) [4], [7] are well described, and a number of epidemiological studies have reported a greater winter AMI incidence, with similar seasonal trends in all studied subgroups, including men and women, middle-aged and elderly patients, patients from northern and southern states and those with Q wave and non-Q wave AMI [9], [10], [11]. This relation, besides, could be actually U-shaped, with higher mortality also in extremely hot summer [12], [13].
These seasonal changes do not seem universal [14], [15] as they are absent near the equator or in subpolar regions with less temperature fluctuations unlike those found in temperate regions. For this reason it seems inadequate to extrapolate the results in other parts of the world to any particular environment. Up to now the effect of climatic variables on AMI has not been assessed in Sicily, a country with a mild climate. Finally, meteorological factors other than atmospheric temperature were less frequently studied. A better understanding of these seasonal patterns may provide novel avenues in cardiovascular disease prevention.
The aim of this study is to explore the short term association between some meteorological variables and AMI hospital admissions in a Mediterranean location, the city of Trapani, Italy.
Section snippets
Materials and methods
We retrospectively analysed the number of daily emergency AMI hospital admission in a single centre with an intensive Coronary Care Unit (CCU) during a twelve year period (1/1/1987–31/12/1998).
Results
A total of 3918 patients have been admitted with AMI diagnosis over the studied period (2822 men, 1096 women; male/female ratio: 2,58; mean age 67.3+/− 8.2; mean age in males 62.8+/− 7.9, mean age in female 71.6+/− 9.1).
The number of admissions along the different years in both sexes is shown in Fig. 1. Fig. 2 shows monthly distribution of hospital AMI admissions, both total and by single gender. The existence of a greater number of admissions in winter (most in February in males and in December
Discussion
Although considerable advances in identifying the conditions that may predispose to atherosclerosis have occurred [16], less information is known about the incident events leading to plaque rupture. The classical risk factors only partially account for the variations in AMI incidence. Therefore, also other so far unknown elements influence AMI rates, among which could be meteorological factors.
Our data, according to other studies [7], [8], [9], [10], [11], confirm the greater AMI incidence in
Limitations
There are some potential limitations to our study. First, morbidity studies based on hospital admissions explore only selected events in patients surviving long enough to be hospitalised, not allowing to report true AMI incidence. Second, in a study where computer databases are the only data source, the quality in terms of completeness and accuracy can limit the conclusions. Third, the recorded ecologic temperature of a specified geographic area may not accurately represent the actual
Conclusions
The excess of AMI admissions associated with a cold and humid environment is a significant public health problem. The present results have several potential implications regarding the pathophysiological mechanisms of AMI and its prevention. Several public health actions have been proposed to prevent the negative health effects of temperature, such as educational programmes to produce behavioural changes in the population (clothing, time spent outdoors, adequate diet) and social measures (home
Acknowledgements
We are grateful to the 37th Airbrigate's Meteorological Office of the Italian Air Force of Trapani Birgi, and to the National Centre of Air Meteorology and Climatology of the Italian Air Force of Pratica di Mare, which provided the meteorological data, as well as to Rossella Alduino and Antonella Sferrazza, who performed the statistical analysis.
The authors of this manuscript have certified that they comply with the Principles of Ethical Publishing in the International Journal of Cardiology [44]
References (44)
- et al.
Seasonal distribution of acute myocardial infarction in the second National Registry of Myocardial Infarction
J Am Coll Cardiol
(1998) - et al.
Relationship between weather and myocardial infarction: a biometeorological approach
Int J Cardiol
(2005) - et al.
Seasonality and daily weather conditions in relation to myocardial infarction and sudden cardiac death in Olmsted County, Minnesota, 1979 to 2002
J Am Coll Cardiol
(2006) - et al.
Impact of weather and climate on the incidence of acute coronary syndromes
Int J Cardiol
(2007) Ethical authorship and publishing
Int J Cardiol
(2009)Cold exposure and winter mortality from ischaemic heart disease, cerebrovascular disease, respiratory disease, and all causes in warm and cold regions in Europe
Lancet
(1997)- et al.
Seasonal variation in mortality in Scotland
Int J Epidemiol
(2000) Cold periods and coronary events: an analysis of populations worldwide
J Epidemiol Community Health
(2005)- et al.
Circadian and seasonal factors in the pathogenesis of acute myocardial infarction: the influence of environmental temperature
Br Heart J
(1993) - et al.
Time changes in new cases of ischaemic heart disease in general practice
Family Practice
(2000)
Temperature, housing, deprivation and their relationship to excess winter mortality in Great Britain, 1986–1996
Int J Epidemiol
Vulnerability to winter mortality in elderly people in Britain: population based study
BMJ
Temperature and mortality in 11 cities of the eastern United States
Am J Epidemiol
Relation between elevated ambient temperature and mortality: a review of the epidemiologic evidence
Epidemiol Rev
Weather, climate, and public health
J Epidemiol Community Health
The Arctic Oscillation and incidence of acute myocardial infarction
J Internal Med
Changes in seasonal deaths for myocardial infarction
Q J Med
Inflammation and atherosclerosis: novel insights into plaque formation and destabilization
Stroke
Seasonal changes in platelets, fibrinogen and factor VII in elderly people
Age and Ageing
Seasonal variation in serum cholesterol levels. Treatment implications and possible mechanisms
Arch Intern Med
Cardiovascular risks from fine particulate air pollution
N Engl J Med
Climate change and infectious disease: stormy weather ahead?
Epidemiology
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