Bogo Renata, Farah Ahmed, Karlsson Kjell K, Pedersen Nancy L, Svartengren Magnus, Skjönsberg Åsa
1Department of Clinical Science, Intervention and Technology, Section of Audiology, Karolinska Institutet, Huddinge, Sweden; 2Department of Audiology and Neurotology, Karolinska University Hospital, Huddinge, Sweden; 3Public Health Agency of Sweden, Stockholm, Sweden; 4Department of Medical Epidemiology and Biostatistics, Karolinska Institutet, Stockholm, Sweden; and 5Department of Medical Sciences, Occupational and Environmental Medicine Uppsala University, Uppsala, Sweden.
Ear Hear. 2017 May/Jun;38(3):292-300. doi: 10.1097/AUD.0000000000000397.
The purpose of this longitudinal twin study was to explore the effect of tinnitus on hearing thresholds and threshold shifts over two decades and to investigate the genetic contribution to tinnitus in a male twin cohort (n = 1114 at baseline and 583 at follow-up). The hypothesis was that participants with faster hearing deterioration had a higher risk for developing tinnitus and there is an underlying role of genetic influences on tinnitus.
Male mono- and dizygotic twin pairs, born between 1914 and 1958 were included. Mixed models were used for comparison of hearing threshold shifts, adjusted for age. A co-twin comparison was made within pairs discordant for tinnitus. The relative influence of genetic and environmental factors was estimated by genetic modeling.
The overall prevalence of tinnitus was 13.5% at baseline ((Equation is included in full-text article.)age 50) and 34.4% at follow-up ((Equation is included in full-text article.)age 67). The overall incidence proportion was 27.8%. Participants who reported tinnitus at baseline or at both time points were older. At baseline, the hearing thresholds differed between tinnitus cases and controls at all frequencies. New tinnitus cases at follow-up had the greatest hearing threshold shift at the high-frequency area compared with the control group. Within pairs, the tinnitus twin had poorer hearing than his unaffected co-twin, more so for dizygotic than monozygotic twin pairs. The relative proportion of additive genetic factors was approximately 0.40 at both time points, and the influence of individual-specific environment was 0.56 to 0.61. The influence of genetic factors on tinnitus was largely independent of genetic factors for hearing thresholds.
Our hypotheses were confirmed: The fastest hearing deterioration occurred for new tinnitus cases. A moderate genetic influence for tinnitus was confirmed.
这项纵向双胞胎研究的目的是探讨耳鸣在二十年间对听力阈值和阈值变化的影响，并调查男性双胞胎队列（基线时n = 1114，随访时n = 583）中耳鸣的遗传因素。假设是听力衰退较快的参与者患耳鸣的风险更高，并且遗传因素对耳鸣有潜在作用。
纳入1914年至1958年出生的男性同卵和异卵双胞胎对。使用混合模型比较听力阈值变化，并根据年龄进行调整。对耳鸣不一致的双胞胎对进行双胞胎内比较。通过遗传建模估计遗传和环境因素的相对影响。
基线时（年龄50岁）耳鸣的总体患病率为13.5%，随访时（年龄67岁）为34.4%。总发病率为27.8%。在基线或两个时间点报告耳鸣的参与者年龄更大。基线时，耳鸣病例和对照组在所有频率的听力阈值都有所不同。与对照组相比，随访时新出现的耳鸣病例在高频区域的听力阈值变化最大。在双胞胎对中，患耳鸣的双胞胎听力比未受影响的双胞胎差，异卵双胞胎对比同卵双胞胎对更明显。在两个时间点，加性遗传因素的相对比例约为0.40，个体特异性环境的影响为0.56至0.61。遗传因素对耳鸣的影响在很大程度上独立于听力阈值的遗传因素。
我们的假设得到证实：新出现的耳鸣病例听力衰退最快。证实了遗传因素对耳鸣有中度影响。
