INTIMA-MEDIA THICKNESS (IMT) IN ADOLESCENT GIRLS: A FOLLOW UP

这个子项目是利用由NIH/NCRR资助的中心拨款提供的资源的许多研究子项目之一。子项目和调查员(PI)可能从另一个NIH来源获得了主要资金，因此可能会出现在其他CRISE条目中。列出的机构是针对中心的，而不一定是针对调查员的机构。颈动脉内中膜厚度(IMT)是成人心血管疾病的重要预测指标。我们之前对12-18岁女孩的骨密度和激素避孕的研究包括了一项对这些受试者18个月的颈动脉IMT的子研究。通过B型超声检查获得IMT数据。在3个平面上测量右颈总动脉远端2 cm的长度，并取其平均值作为综合评分。使用IMT评分进行重复测量协方差分析，以探讨避孕方法、时间和IMT调整种族、年龄和体重之间的关系。样本由53名对照组、22名DMPA受试者和50名OC受试者组成，他们总共完成了125名参与者的基线数据。115名受试者有6个月的数据，96名受试者有12个月的数据，44名受试者有18个月的数据。每隔6个月，参与者都要测量IMT、身高、体重、血压、总胆固醇和高密度脂蛋白，并询问吸烟情况。避孕组之间的IMT评分以及低和高BMI、血压、吸烟状况、总胆固醇或高密度脂蛋白之间的差异均无统计学意义。然而，随着时间的推移，跨组的平均IMT评分稳步下降(p=0.01)。18个月时，所有组的平均IMT为0.47 mm(SE 0.0038)，平均IMT为0.44 mm(SE 0.0079)，18个月内IMT减少了6.4%。我们之前的研究表明，这一发育阶段的荷尔蒙环境可能对心血管状态的这种表达有有利的影响。另一个推论是，荷尔蒙避孕可能不是导致这些变化的关键因素。因此，为了证实我们的IMT随时间减少的发现，从我们的子研究样本的子组中获得一项额外的IMT测量是很重要的。同样的IMT测量将从大约22名18岁以下的对照组受试者身上获得。血清将被收集并分析总胆固醇和高密度脂蛋白、身高、体重、吸烟史、间歇性健康史和妊娠尿液测试。

This subproject is one of many research subprojects utilizing the resources provided by a Center grant funded by NIH/NCRR. The subproject and investigator (PI) may have received primary funding from another NIH source, and thus could be represented in other CRISP entries. The institution listed is for the Center, which is not necessarily the institution for the investigator. Carotid artery intima-media thickness (IMT) is an important predictor of cardiovascular disease in adults. Our previous study of bone density and hormonal contraception in girls aged 12-18 included a substudy of IMT of the carotid artery in these same subjects over 18 months. IMT data were obtained by B-mode ultrasound examination. Measurements of the distal 2-cm of the right common carotid artery were obtained in 3 planes and averaged for a composite score. Repeated measures analysis of covariance was conducted with the IMT score to explore the relationships among contraceptive methods, time, and IMT adjusting for race, age, and weight. The sample was comprised of 53 controls, 22 DMPA, and 50 OC subjects who completed baseline data for a total of 125 participants. Six-month data were available for 115 subjects, 12-month data for 96 subjects, and 18-month data for 44 subjects. At 6 month intervals, the participants had measurement of IMT, height, weight, blood pressure, total and HDL cholesterol, and were questioned about smoking status. No statistically significant difference was found in IMT score between contraceptive groups or with regards to low and high BMI, blood pressure, smoking status, total or HDL cholesterol. However, there was a steady decrease in the IMT score averaged across groups over time (p=0.01). The mean IMT for all groups at baseline was 0.47mm (SE 0.0038) At 18 months the mean IMT was 0.44 mm (SE 0.0079), a 6.4% decrease of IMT in 18 months. Our previous study suggests that the hormonal environment during this period of development may have a favorable effect on this expression of cardiovascular status. An additional inference is that hormonal contraception may not be a key component contributing to these changes. Therefore, in order to confirm our findings of a decrease in IMT over time, it is important to obtain one additional IMT measurement from a subgroup of our substudy sample. The same IMT measurement will be obtained from approximately 22 control subjects who are still under the age of 18. Serum will collected and analyzed for total and HDl cholesterol, height, weight, smoking history, interval health history, and a pregnancy urine test.