健康人长波紫外线最小持续性黑化量的测定

Determination of minimal persistent pigment dose of normal skin to long-wave ultraviolet among healthy volunteers

目的 探讨广州地区健康人长波紫外线（UVA）最小持续性黑化量（MPPD）与性别、年龄、皮肤光生物学分型、季节、个体类型角（ITA）分级以及在广州地区生活时间长短的关系.方法 以Solar 601-300型日光紫外模拟系统为光源,测定316例健康人背部正常皮肤的MPPD值,结果在照射后2～3 h由2名经验丰富的观察者同时评定.结果 316例健康人的MPPD为（9.61±2.57）J/cm2,男性MPPD为（11.09±2.82）J/cm2,女性MPPD为（9.01±2.20）J/cm2,差异有统计学意义（P＜0.01）;不同季节测定的MPPD值差异有统计学意义（P＜0.01）,冬季（10.66±2.71）J/cm2最高,明显高于春季（9.37±2.39）J/cm2、夏季（9.53±2.66）J/cm2和秋季（8.98±2.25） J/cm2;ITA分级各级MPPD差异有统计学意义（P＜0.01）,ITA 3级（10.72±2.84）J/cm2明显高于1级（8.50±1.45） J/cm2和2级（9.12±2.31） J/cm2,但是与4级（11.87±2.73） J/cm2差异无统计学意义（P=0.93）;在广州地区生活10年以上的MPPD（8.97±1.88） J/cm2,显著低于≤1年和2～4年（P＜0.01）,但是和5～10年差异无统计学意义（P=0.47）.结论 广州地区健康人UVA的MPPD值与年龄、皮肤光生物学分型无相关性,但是与性别、季节、ITA分级和在广州地区生活时间长短均有关.

Objective To investigate the minimal persistent pigment dose （MPPD）of normal skin to UVA in Guangzhou city,and to observe its relationship to sex,age,skin type,seasons,ITA,and the years lived in Guangzhou.Methods 316 healthy subjects were exposed to Solar 601-300,and the MPPD was measured and observed by two professional technicians after 2-3 hours.Results The average MPPD value of all subjects was （9.61±2.57） J/cm2.In male and female,the average MPPD values were （11.09 ± 2.82） J/cm2 and （9.01 ± 2.20） J/cm2 respectively,and male was significantly higher than female （P〈0.01）.There was significant difference of the MPPD value in different seasons （P〈0.01）.The MPPD value in winter （10.66± 2.71） J/cm2） was significantly higher than spring （9.37±2.39） J/cm2,summer （9.53±2.66） J/cm2 and autumn （8.98±2.25） J/cm2.There was significant difference of the MPPD value between different ITA groups （P〈0.01）.ITA grade-3 （10.72± 2.84） J/cm2 was significantly higher than grade-1 （8.50±1.45） J/cm2 and grade-2 （9.12±2.31） J/cm2 （P〈0.01）,but there was no significant difference from grade-4 （11.87±2.73） J/cm2 （P =0.93）.The MPPD value in subjects lived in Guangzhou over 10 years （8.97± 1.88） J/cm2 was significantly lower than those whose residence was less than 1 year and from 1 to 5 years,respectively （P〈0.01）,but there was no significant difference from those lived from 5 to 10 years （P =0.47）.Conclusions The MPPD value of the subjects in Guangzhou is related to gender,seasons,ITA grade and the years lived in Guangzhou city,while there is no correlation with age and skin types.