Bittar Fernanda Barros, Castro Charlles H M, Szejnfeld Vera Lúcia
Rheumatology Division, Universidade Federal de São Paulo - Escola Paulista de Medicina (UNIFESP-EPM), Rua Botucatu, 740 - 3° andar - Vila Clementino, CEP, São Paulo, SP, 04023-900, Brazil.
BMC Endocr Disord. 2018 Jul 3;18(1):44. doi: 10.1186/s12902-018-0272-0.
Vitamin D deficiency is pandemic while resources available to measure 25-hydroxyvitamin D (25OHD) are limited. The present study aimed to verify whether sun exposure measured by a structured questionnaire could predict serum 25OHD concentrations in healthy Caucasian individuals living in a tropical area.
A cross-sectional study was carried out in subjects living in the greater São Paulo area, Brazil. Two groups of 50 young (20 to 40 years old) and 50 older (60 to 80 years old) subjects (N = 200) answered a structured questionnaire on sun exposure and had blood samples drawn for serum 25OHD concentration measurement during both summer and winter. Anthropometric data were also recorded. Correlation between the questionnaire variables (duration of sun exposure, amount of exposed skin, total sun exposure score - TSES and other data) and serum 25OHD concentration was evaluated.
Mean serum 25OHD concentration was 17.60 ± 7.3 ng/mL with no difference between age groups (p = 0.293). TSES weakly correlated with serum 25OHD levels (r = 0.264; p < 0.001). Separate analyzes by age groups demonstrated that TSES correlated significantly with serum 25OHD concentration only in the older subjects during summer (r = 0.322; p = 0.023). Using linear regression analyses, TSES and body mass index (BMI) were significantly associated with serum 25OHD levels. On the other hand, Receiver operating characteristic (ROC) analysis for TSES showed no significance as a screening tool for vitamin D deficiency (p = 0.172).
Sun exposure questionnaire associated with BMI correlates with serum 25OHD concentration with very low accuracy. The use of the questionnaire does not discriminate between vitamin D sufficient and deficient individuals.
维生素D缺乏呈全球性流行，而用于检测25-羟基维生素D（25OHD）的资源有限。本研究旨在验证通过结构化问卷测量的阳光暴露情况能否预测居住在热带地区的健康白种人个体的血清25OHD浓度。
对居住在巴西大圣保罗地区的受试者进行了一项横断面研究。两组各50名年轻（20至40岁）和50名年长（60至80岁）的受试者（N = 200）回答了一份关于阳光暴露的结构化问卷，并在夏季和冬季采集血样以测量血清25OHD浓度。还记录了人体测量数据。评估了问卷变量（阳光暴露时长、暴露皮肤面积、总阳光暴露评分 - TSES及其他数据）与血清25OHD浓度之间的相关性。
血清25OHD平均浓度为17.60±7.3 ng/mL，各年龄组之间无差异（p = 0.293）。TSES与血清25OHD水平呈弱相关（r = 0.264；p < 0.001）。按年龄组进行的单独分析表明，仅在夏季年长受试者中TSES与血清25OHD浓度显著相关（r = 0.322；p = 0.023）。使用线性回归分析，TSES和体重指数（BMI）与血清25OHD水平显著相关。另一方面，TSES的受试者工作特征（ROC）分析显示其作为维生素D缺乏筛查工具无统计学意义（p = 0.172）。
与BMI相关的阳光暴露问卷与血清25OHD浓度的相关性非常低。使用该问卷无法区分维生素D充足和缺乏的个体。
