年龄26~54岁,平均39.6岁。 按不同年龄段分组,26~34岁178例,35~44岁185例,45~54岁137例。

• Methods:Five hundreds healthy people (268 male and 232 female with an average age of 39.6 years ranging from 26 to 54 years) were divided into three groups according to the age,including 178 people 26 to 34 years,185 people from 35 to 44 years,137 people from 45 to 54 years.