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

本子项目是利用由NIH/NCRR资助的中心赠款提供的资源的众多研究子项目之一。子项目和研究者（PI）可能已经从另一个NIH来源获得了主要资金，因此可以在其他CRISP条目中表示。列出的机构是中心的，不一定是研究者的机构。颈动脉内膜-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对这些相同受试者的颈动脉IMT进行的为期18个月的亚研究。通过b超检查获得IMT数据。测量右颈总动脉远端2cm在3个平面上，并取平均值作为综合评分。用IMT评分进行重复测量协方差分析，探讨避孕方法、时间和种族、年龄、体重调整后的IMT之间的关系。样本包括53名对照组，22名DMPA和50名OC受试者，他们完成了总共125名参与者的基线数据。115名受试者6个月的数据，96名受试者12个月的数据，44名受试者18个月的数据。每隔6个月，对参与者进行IMT、身高、体重、血压、总胆固醇和高密度脂蛋白胆固醇的测量，并询问吸烟状况。避孕组之间的IMT评分、低BMI和高BMI、血压、吸烟状况、总胆固醇或高密度脂蛋白胆固醇均无统计学差异。然而，随着时间的推移，各组平均IMT得分稳步下降（p=0.01）。各组在基线时的平均IMT为0.47mm (SE 0.0038)， 18个月时的平均IMT为0.44 mm (SE 0.0079)， 18个月的IMT下降了6.4%。我们之前的研究表明，这一发育时期的激素环境可能对心血管状态的表达有有利的影响。另一个推论是，激素避孕可能不是导致这些变化的关键因素。因此，为了证实我们关于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个额外的IMT测量是很重要的。同样的IMT测量将从大约22名仍未满18岁的对照受试者中获得。收集血清并分析总胆固醇和高密度脂蛋白胆固醇、身高、体重、吸烟史、间歇健康史和妊娠尿检。

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.