A Pilot Study On The Influence Mechanism Of Cold Air Incursion On Cardiovascular And Cerebrovascular Diseases

Objectives:1. In order to explore the pathogenesis of environmental temperature change on spontaneously hypertensive rats(SHRs), animal experiments were conducted to observe the influence of environmental temperature change on the heart rate(HR), systolic blood pressure(SBP), diastolic blood pressure(DBP), blood lipids and catecholamine of rats.2. To identify the influence mechanism of cold air incursion, human investigation was carried out to analyze the change of blood lipid and hemorheology indexes of patients suffering from cardiovascular and cerebrovascular diseases in the process of cold air transit.Materials and methods:1. Eighteen Wistar rats and eighteen SHRs were divided into six groups on the basis of similar weight and age. Every group, which was composed of male and female in equal, had half Wistar rats and half SHRs. The groups were put into the simulation boxes of meteorological environment randomly which simulate the process of temperature change when a cold air transit. The HR, SBP, DBP, blood lipids and catecholamines of rats were measured among the cold air process.2. Zhangye City in Gansu Province was taken as our research field. Twenty cardiovascular and cerebrovascular diseases patients aged40to70and twenty healthy controls were collected in December of2010when cold air passed. Ten cardiovascular and cerebrovascular diseases patients aged40to70and twenty healthy controls were collected in March of2011. The bloods of participants were collected before and in cold air passing respectively. Seven blood lipids indexes and nine hemorheology indexes were detected.Results:1. Results of animal experiments:It was showed that the HR of Wistar rats became faster and the level of their dopamine (DA) increased when the temperature decreased, the HR became slower and DA level decreased when the temperature increased; the SBP, diastolic blood pressure, blood lipids, adrenergic and norepinephrine of Wistar rats didn’t change significantly when the temperature changed; the SBP and DBP of SHR decreased, and the level of high density lipoprotein and low density lipoprotein increased when the temperature decreased. In contrast, the SBP and DBP of SHR increased, and the level of high density lipoprotein (HDL-C) and low density lipoprotein (LDL-C) decreased when the temperature increased, the catecholamines of SHR didn’t change significantly when the temperature changed (All the P values were more than0.05); the SBP, DBP and DA of Wistar rats and SHR changed significantly when the temperature changed (All the P values were less than0.05).2. Results of population observed:The blood lipids levels of cardiovascular and cerebrovascular diseases patients didn’t change significantly when cold air passed in December of2010(All the P values were more than0.05); the levels of HDL-C and apolipoprotein A1(Apo A1) decreased with statistical significance when the cold air passed (P=0.000, P=0.040); the concentrations of hemorheology indexes of patients and controls didn’t change significantly (P>0.05); the levels of blood lipids and hemorheology indexes didn’t change significantly when cold air passed in March of2011(All the P values were more than0.05). There was no significant difference in the changes of blood lipids and hemorheology indexes between cardiovascular and cerebrovascular diseases patients and healthy controls (P>0.05).Conclusions:1. The HR and DA concentration of Wistar rats rose when the environmental temperature decrease, and the SBP, DBP and DA concentration of SHR decrease, and the HDL-C and LDL-C levels of SHR increase. The SBP, DBP and DA of Wistar rats and SHR changed significantly when the temperature changed.2. The HDL and Apo A1of healthy human were affected by the cold air transit. but there were no effect on blood lipids indexes and hemorheology indexes of cardiovascular and cerebrovascular diseases patients. There was no significant difference in the changes of blood lipids and hemorheology indexes between cardiovascular and cerebrovascular diseases patients and healthy controls.