The influence of familial factors on the intelligence-mortality association - A twin approach
The influence of familial factors on the intelligence-mortality association - A twin approach
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DOI：
10.1016/j.intell.2017.07.005
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发表时间：
2017-09-01
期刊：
影响因子：
3
通讯作者：
Christensen, K.
中科院分区：
文献类型：
--
作者：
Christensen, G. T.;Osler, M.;Christensen, K.
目的是调查广泛报道的逆智力-死亡率关联是否可以在双胞胎内对分析中复制，其中根据研究设计，遗传和共享环境因素受到控制。此外，通过比较双胞胎和单胞胎的相关性，研究了双胞胎研究结果对一般人群的普遍性问题。一个由7316名双胞胎和649,809名单胞胎组成的大型男性队列，在平均年龄19.5岁时评估了他们的智力，并对死亡率进行了随访，直到中年晚期（平均年龄：63.5岁）。在非配对分析中，每对双胞胎被视为一个个体，发现所有双胞胎（危险比（HR）（每1 SD下降）= 1.28; 95% CI：1.21，1.35），双卵（HR每1 SD下降= 1.24; 95% CI：1.16，1.33）和单卵（HR每1 SD下降= 1.33; 95% CI：1.18，1.50）双胞胎的智力测试评分每一个标准差下降的死亡风险都更高。观察到的相关性与单胞胎组（HRper 1 SD降低= 1.28; 95%CI：1.27，1.29）和卵型未知的双胞胎组（HRper 1 SD降低= 1.30; 95%CI：1.13，1.51）的相关性相似。根据研究设计，在对所有双胞胎和DZ双胞胎的对内分析中复制了反向智力死亡率关联，其中遗传和共享家族因素部分受控。在智力测验分数相差半个标准差或更多的双胞胎对中，得分较低的双胞胎首先死亡的比例为55%（95%CI：0.52，0.58）。这些发现表明，年轻人的智力与中年晚期之前的死亡率之间存在适度的负相关，遗传和共同环境只能解释这种关联的一小部分。此外，该研究表明，双胞胎的发现是普遍适用于单胞胎。
The aim was to investigate whether the widely reported inverse intelligence-mortality association could be replicated in twin intrapair analyses in which genetic and shared environmental factors are controlled for, as per the study design. Furthermore, the issue of generalizability of twin findings to the general population was investigated by comparing associations for twins and singletons. A large male cohort of 7316 twins and 649,809 singletons, for whom intelligence was assessed at a mean age of 19.5 years, was followed for information on mortality until late mid-life (mean age: 63.5 years). In unpaired analyses, where each twin was treated as an individual, a higher risk of mortality for each standard deviation decrease in intelligence test-score was found for all twins (hazards ratio (HR)(per1SDdecrease) = 1.28; 95% CI:1.21,1.35), dizygotic (HRper1SDdecrease = 1.24; 95% CI:1.16,1.33) and monozygotic (HRper1SDdecrease = 1.33; 95% CI:1.18,1.50) twins. The observed associations were of a similar magnitude to those found for singletons (HRper1SDdecrease = 1.28; 95% CI:1.27,1.29) and for the group of twins with unknown zygosity (HRper1SDdecrease = 1.30; 95% CI:1.13,1.51). The inverse intelligence mortality associations were replicated in intrapair analyses of all twins and DZ twins where genetic and shared familial factors were partly controlled for, as per the study design. For twin pairs with a difference in intelligence test-score of half a standard deviation or more, the proportion of twin pairs in which the lower-scoring twin died first was 55% (95% CI: 0.52,0.58). These findings suggest a modest inverse association between young adult intelligence and mortality until late mid-life, with genetics and shared environment explaining only a small part of the association. Furthermore, the study suggests that the twin findings were generalizable to singletons.