Relationships between Skin Pigmentation, Vitamin D and Blood Pressure

描述（由申请人提供）：本研究的目的是表征皮肤色素沉着对血清25-羟基胆钙化醇（维生素D）水平的影响，进而确定其与年龄增长的女性血压的关系。这项博士研究将使用现有数据、存储库资源和全国妇女健康研究（SWAN）新获得的数据来测试肤色和维生素D与血压之间的假设关系。文献表明，维生素D可以调节肾素-血管紧张素系统，进而调节血压。皮肤黑色素的含量决定了通过紫外线蓝光转化维生素D的量。远离赤道的人季节性地缺乏足够的紫外线来合成维生素D，这使得维生素D的产生和吸收随着年龄的增长而下降。这些发现为以下假设奠定了基础：种族间血压差异的一个缺失环节是，许多非裔美国人的皮肤大多比白人深，由于地理位置和户外暴露的限制，他们获得的阳光不足，导致健康调节血压所需的维生素D不足。这与衰老的影响更为复杂。该研究将在SWAN中实施，SWAN是一项正在进行的多种族、多地点、以社区为基础的纵向研究，在美国7个地点招募了42-52岁的女性，目前已进入第13个年头。这项研究将使用密歇根网站的数据，其中包括218名白人女性和325名黑人女性。可用的资源包括血压、食物频率、膳食补充剂历史和血清样本，可用于评估维生素d。本博士研究将确定基于访谈的身体暴露于阳光下的测量和反射计测定的皮肤颜色。重复测量分析将用于处理主题内的相关性。了解肤色、行为因素和慢性疾病风险的交叉关系对于解决种族/民族血压差异的潜在原因非常重要。

DESCRIPTION (provided by applicant): The goal of this study is to characterize the effect of skin pigmentation on serum 25- hydroxycholecalciferol (vitamin D) levels, and, in turn, ascertain their association with blood pressure among women as they age. This doctoral research will test hypothesized relationships of skin color and vitamin D with blood pressure using existing data, repository resources, and newly-acquired data from the Study of Women's Health Across the Nation (SWAN). Literature suggests that vitamin D regulates the renin-angiotensin system and, by extension, blood pressure. Skin melanin content determines the amount of Vitamin D conversion via ultraviolet blue. Persons geographically distant from the equator seasonally lack ultraviolet-blue for adequate vitamin D synthesis, which compounds the decline in vitamin D production and absorption with age. These findings form the basis for the hypothesis that a missing link in the racial disparity in blood pressure is that many African Americans, who largely have darker skin than whites, obtain insufficient sunlight due to geographical location and limited outdoor exposure which, leads to inadequate vitamin D for healthy regulation of blood pressure. This is compounded by the effects of aging. The study will be implemented in SWAN, an ongoing multi-ethnic, multi-site longitudinal community-based study of women (aged 42-52 at baseline) recruited at seven United States sites, now in its 13th year. This study will use Michigan site data where the sample includes 218 white and 325 black women. Available resources include blood pressures, food frequency, dietary supplement history, and serum samples available to evaluate vitamin D. Interview-based measures of body exposure to sunlight and reflectometer-determined skin coloration will be ascertained for this doctoral research. Repeated measures analysis will be used to address within-subject correlations. Understanding the intersection of skin color, behavioral factors and chronic disease risk is important in addressing underlying causes of race/ethnic disparities in blood pressure. PUBLIC HEALTH RELEVANCE: This study will combine blood pressures, food frequency, dietary supplement history from existing data, serum samples to assay vitamin D from repository resources, and newly-acquired skin color data from the longitudinal, multi-ethnic Study of Women's Health Across the Nation (SWAN) to characterize the effect of skin pigmentation on serum 25-hydroxycholecalciferol (vitamin D) and blood pressure among women as they age.