Chen Wei J, Liu Pi-Hua, Ho Yen-Yi, Chien Kuo-Liong, Lo Min-Tzu, Shih Wei-Liang, Yen Yu-Chun, Lee Wen-Chung
Institute of Epidemiology, College of Public Health, National Taiwan University, Taipei, Taiwan.
BMC Genet. 2003 Dec 31;4 Suppl 1(Suppl 1):S33. doi: 10.1186/1471-2156-4-S1-S33.
The purpose of this study was to estimate both cross-sectional sibling recurrence risk ratio (lambdas) and lifetime lambdas for the metabolic syndrome and its individual components over time among sibships in the prospectively followed-up cohorts provided by the Genetic Analysis Workshop 13. Five measures included in the operational criteria of the metabolic syndrome by the Adult Treatment Panel III were examined. A method for estimating sibling recurrence risk with correction for complete ascertainment was used to estimate the numerator, and the prevalence in the whole cohort was used as the denominator of lambdas.
Considerable variability in the lambdas was found in terms of different time-points for the cross-sectional definition, the times of fulfilling the criterion for lifetime definition, and different components. Obesity and hyperglycemia had the highest cross-sectional lambdas of the five components. Both components also had the largest slopes in the linear trend of the lifetime lambdas. However, the magnitudes of the lifetime lambdas were similar to that of the mean cross-sectional lambdas, which were <2. The results of nonparametric linkage analysis showed only suggestive evidence of linkage between one marker and lifetime diagnosis of low high-density lipoprotein cholesterol and metabolic syndrome, respectively.
The lambdas of the metabolic syndrome and its components varies substantially across time, and the lambdas of lifetime diagnosis was not necessarily larger than that of a cross-sectional diagnosis. The magnitude of lambdas does not predict well the maximum LOD score of linkage analysis.
本研究旨在在前瞻性随访的遗传分析研讨会13队列中的同胞关系中，估计代谢综合征及其各个组成部分随时间的横断面同胞复发风险比（λ值）和终生λ值。研究考察了成人治疗小组III制定的代谢综合征操作标准中包含的五项指标。采用一种校正完全确诊情况的同胞复发风险估计方法来估计分子，将整个队列中的患病率用作λ值的分母。
在横断面定义的不同时间点、达到终生定义标准的时间以及不同组成部分方面，λ值存在相当大的变异性。肥胖和高血糖在五个组成部分中具有最高的横断面λ值。这两个组成部分在终生λ值的线性趋势中也具有最大的斜率。然而，终生λ值的大小与平均横断面λ值相似，均小于2。非参数连锁分析结果仅显示一个标记与低高密度脂蛋白胆固醇终生诊断以及代谢综合征之间存在提示性的连锁证据。
代谢综合征及其组成部分的λ值随时间有很大变化，终生诊断的λ值不一定大于横断面诊断的λ值。λ值的大小并不能很好地预测连锁分析的最大LOD分数。
