人表皮厚度与皮肤衰老

Human epidermal thickness and skin aging

目的 探讨人表皮厚度与年龄、紫外线的关系，了解皮肤衰老过程中表皮形态结构的变化。方法 收集211例正常全厚皮肤标本，分为3个年龄组，HE染色后采用图像分析软件（Imageproplus6．0）测量表皮细胞层厚度与全层厚度。数据按部位、性别、年龄分类，采用SPSSl3．0软件进行统计学处理。结果 随着年龄的增长，表皮与真皮连接变平，角质层结构不紧密。表皮细胞层厚度和表皮全层厚度均与年龄呈负相关（表皮细胞层厚度与年龄的相关系数r=-0．207，P〈0．05；表皮全层厚度与年龄的相关系数r=-0．202，P〈0．05）。各年龄组男性与女性的表皮厚度差异（包括表皮细胞层厚度与表皮全层厚度）均无统计学意义。非曝光部位、半曝光部位、曝光部位的表皮细胞层厚度依曝光量的增加而递增，而表皮全层厚度间差异无统计学意义。不同曝光部位男性与女性的表皮厚度差异（包括表皮细胞层厚度与表皮全层厚度）均无统计学意义。结论 随着年龄的增长，表皮萎缩、角质层变薄。紫外线对表皮的影响体现于表皮细胞层厚度的增加。性别对表皮厚度无影响（包括表皮细胞层厚度与表皮全层厚度）。年龄对表皮厚度的影响与紫外线对表皮厚度的影响（包括表皮细胞层厚度与表皮全层厚度）无相互作用。

Objective To clarify the association of age and sun exposure with human epidermal thickness, and to probe deeply into the changes of skin histology and epidermal thickness with skin aging. Methods Two hundreds and eleven full thickness skin samples were collected from 3 different age groups of healthy volunteers and then stained with haematoxylin and eosin to study the changes of epidermal thickness using image analysis software （ Image pro plus 6.0 ）. The obtained values were analyzed with factorial design ANOVA and correlation analysis to detect any significant effects of age and sun exposure on epidermal thickness. Results With increasing age, the junction between epidermis and dermis became flattened, and stratum comeum got looser. There was a notable attrition of the epidermal thickness that could be correlated with age. The attrition of epidermal thickness attributed to age did not vary between female and male volunteers. Epidermal cell layers thickness increased with cumulated sun exposure, but epidermal total thickness was not associated with sun exposure. There was no difference for epidermal thickness of different sun exposure between female and male volunteers. Conclusion During chronological aging, epidermal cells decrease in thickness with lowered metabolism. With cumulated sun exposure, epidermal cell layer thickness becomes thicker. There is no interaction between the effect of age and sun exposure and the epidermal thickness.