Christensen K, Frederiksen H, Hoffman H J
Danish Twin Registry, Institute of Public Health, and the Danish Center for Demographic Research, Odense.
J Am Geriatr Soc. 2001 Nov;49(11):1512-7. doi: 10.1046/j.1532-5415.2001.4911245.x.
The aim of the present twin study was to estimate the relative importance of genetic and environmental factors in variation in self-reported reduced hearing among the old and the oldest old.
Self-reported hearing abilities of older twins assessed at intake interview in a population-based longitudinal survey.
Denmark.
Twins age 75 and older identified in the population-based Danish Twin Registry in 1995. An interview was conducted with 77% of 3,099 individuals in the study population. In 1997 and 1999, a follow-up contact to the survivors was made and an additional 2,778 twins, age 70-76, were included in the study.
Reduced hearing was assessed by the same question in all interview waves. Heritability (proportion of the population variance attributable to genetic variation) was estimated using structural-equation analyses.
The prevalence of self-reported reduced hearing corresponded to previous studies and showed the expected age and sex dependence. Concordance rates, odds ratios, and correlations were consistently higher for monozygotic twin pairs than for dizygotic twin pairs in all age and sex categories, indicating heritable effects. Structural-equation analyses revealed a substantial heritability for self-reported reduced hearing of 40% (95% CI = 19-53%). The remaining variation could be attributed to individuals' nonfamilial environments.
We found that genetic factors play an important role in self-reported reduced hearing in both men and women age 70 and older. Because self-reports of reduced hearing involve misclassification, this estimate of the genetic influence on hearing disabilities is probably conservative. Hence, genetic and environmental factors play a substantial role in reduced hearing among the old and oldest old. This suggests that clinical epidemiological studies of age-related hearing loss should include not only information on environmental exposures but also on family history of hearing loss and, if possible, biological samples for future studies of candidate genes for hearing loss.
本双胞胎研究旨在评估遗传因素和环境因素在老年人及高龄老人自我报告听力减退差异中的相对重要性。
在一项基于人群的纵向调查中，通过入组访谈评估老年双胞胎自我报告的听力能力。
丹麦。
1995年在基于人群的丹麦双胞胎登记处识别出的75岁及以上的双胞胎。对研究人群中3099名个体中的77%进行了访谈。1997年和1999年，对幸存者进行了随访，并将另外2778名年龄在70 - 76岁的双胞胎纳入研究。
在所有访谈波次中，通过相同问题评估听力减退情况。使用结构方程分析估计遗传力（人群方差中归因于遗传变异的比例）。
自我报告听力减退的患病率与先前研究一致，并呈现出预期的年龄和性别依赖性。在所有年龄和性别类别中，同卵双胞胎对的一致性率、优势比和相关性始终高于异卵双胞胎对，表明存在遗传效应。结构方程分析显示，自我报告听力减退的遗传力较高，为40%（95%可信区间 = 19 - 53%）。其余变异可归因于个体的非家庭环境。
我们发现遗传因素在70岁及以上男性和女性自我报告听力减退中起重要作用。由于听力减退的自我报告存在错误分类，因此对听力残疾遗传影响的这一估计可能较为保守。因此，遗传因素和环境因素在老年人及高龄老人听力减退中起重要作用。这表明，与年龄相关听力损失的临床流行病学研究不仅应包括环境暴露信息，还应包括听力损失家族史，如有可能，还应包括用于未来听力损失候选基因研究的生物样本。
