Study On The Relationship Of Meteorological Factors And Stroke Occurrence Of Nanchang

Objeetive: To analysis the incidence features and seasonal rules of stroke underthe weather conditions, explored the effect of8Meteorological Factors and extremeclimate on the stroke in Nanchang.Methods:We collected8-year hospitalized stroke cases information(from2003to2010)at3large comprehensive of hospitals and meteorological datas in Nanchang,used descriptive analysis and circular distribution to analysis monthly and seasonalregularity of stroke,used the single factor correlation and multiple stepwise regressionto analysis the relationship of meteorological factors and stroke in Nanchangcity,used one-way ANOVA to analysis the effect of variance of temperature, pressureand humidity and their change on the stroke, used1:1paired case crossover study toanalysis the effect of the extreme temperatures (extremely low temperature,extremelyhigh temperature, shock temperature) on the occurrence of stroke.Results:(1) This study collected16264cases of patients with stroke, included5504cases of cerebral hemorrhage,10760cases of cerebral infarction,10177weremale,6087female.the average age of cerebral hemorrhage was (60.54+13.67), thesex ratio was1.78:1; the average age of cerebral infarction patients was (65.79+12.35), sex ratio was1.62:1. The most of numbers of cerebral hemorrhage andcerebral infarction were at60-70age group.(2) The morbidity numbers of cerebral hemorrhage were in winter, the numberof cases of January and December were the most, the number of cases of summerwere the least, cerebral infarction had no obvious seasonal variation.(3) There was a trend of centralization from2003to2010of cerebralhemorrhage occurrence and total(P<0.05).the mean angel of total was11.24degree,equivalent to January12, only the mean Angles of cerebral infarction in2003,2005and2009were meaningful(P<0.05),8years total concentration trend was notstatistically significant (P>0.05).(4) The single factor analysis results showed that, cerebral hemorrhage was positively correlated with the average monthly pressure, average high pressure,average minimum pressure(r=0.62,P<0.05;r=0.61,P<0.05;r=0.61,P<0.05) andnegatively correlated with average temperature, average minimum and maximumtemperature(r=-0.59,P<0.05;r=-0.50,P<0.05;r=-0.56,P<0.05),cerebral infarction wasnegatively correlated with average relative wet, average monthly minimumwet(r=-0.36,P<0.05;r=-0.34,P<0.05).Multi-factor regression results showed that,cerebral hemorrhage was correlated with the monthly average temperature,minimumtemperature and average pressure, cerebral infarction was correlated with the monthlyaverage maximum, temperature, minimum pressure and average relative wet.(5) When the winter average temperature less than2degree and the mean dailyminimum temperature below-2degree, the numbers of cerebral hemorrhage patientincreased significantly(P<0.05), the numbers of cerebral infarction were not differentin the different grade (P>0.05); the numbers of cerebral hemorrhage and cerebralinfarction in different grades under high temperature were not different(P>0.05);when winter average temperature dropde6degrees or more, the numbers ofcerebral hemorrhage and cerebral infarction patients increased significantly (P<0.01);the numbers of Cerebral hemorrhage and cerebral infarction in different temperaturerises in summer were not different (P>0.05).(6)With changes in barometric pressure level increased, the numbers of cerebralhemorrhage and cerebral infarction patients increased significantly (P<0.05)(7)When the mean humidity was90%and above, the numbers of cerebralhemorrhage and cerebral infarction patients increased significantly (P<0.01); whenthe humidity variationded30%and above, the numbers of cerebral hemorrhagepatients increased significantly (P<0.01).(8) The exposure rate of extreme temperature of Nanchang from2003to2010was7.26%, The exposure rate of extreme low temperature was4.41%, The exposurerate of extreme high temperature was0.00%, The exposure rate of extreme cooling inwinter was1.95%, The exposure rate of extreme heating in summer was0.96%.If thedangerous period had extreme temperature exposure,OR values of the cerebralhemorrhage and cerebral infarction disease were:1.34(95%CI:1.26~1.42),1.18(95%CI:1.07~1.36). When the danger period appeared extreme low temperature, extreme cooling in winter and extreme heating in summer, OR values of cerebralhemorrhage were1.42(95%CI:1.28~1.58),1.29(95%CI:1.21~1.38) and1.02(95%CI：0.87~1.12),OR values of cerebral infarction was1.06(95%CI:0.93~1.13),1.39(95%CI:1.22~1.51) and1.05(95%CI：0.93~1.17).Conclusions:(1) Cerebral hemorrhage had obvious seasonal variations inNanchang area, highly incidenced in winter, lowly incidenced in summer; cerebralinfarction without significant seasonal differences.(2)The incidence of cerebralhemorrhage was associated with air temperature and barometric pressure, theincidence of cerebral infarction was associated with humidity; many kinds ofmeteorological factors had synergistic or antagonistic effects common to cerebralinfarction and cerebral hemorrhage.(3) Extreme low temperature under lowtemperature conditions, sudden cooling, pressure change, high humidity, humiditysudden variation lead to cerebral hemorrhage disease; sudden cooling under thecondition of low temperature, high humidity was easy to lead to the onset of cerebralinfarction.