Reduced cancer incidence among the blind
Reduced cancer incidence among the blind
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DOI：
10.1097/00001648-199809000-00004
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发表时间：
1998-09-01
期刊：
影响因子：
5.4
通讯作者：
Ahlbom, A
中科院分区：
文献类型：
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作者：
Feychting, M;Österlund, B;Ahlbom, A
褪黑激素是一种激素，主要由松果体在夜间产生，暴露在光线下会受到抑制。实验研究表明，褪黑素可以预防癌症的发展。在大多数完全失明的人中，褪黑素永远不会被光照抑制。这项研究的目的是检验盲人癌症发病率降低的假设，并且这种影响在完全失明的人中比在严重视力受损的人中更明显。我们确定了1,567名完全失明的受试者和13,292名严重视力受损的受试者，并从瑞典癌症登记处获得了有关癌症发病率的信息。我们根据人口年数和特定于国家年龄、性别和日历年的发病率计算标准化发病率比(SIRS)。完全失明的人所有癌症的发病率都较低[SIR=0.69；95%可信区间(CI)=0.59-0.82]。这种风险降低在男性和女性中都观察到了，在激素依赖型肿瘤和其他类型的癌症中同样明显。重度视障患者的SIR为0.95(95%CI=0.91~1.00)。这些发现支持盲人癌症发病率较低的假设，尽管也必须考虑除较高的褪黑素暴露之外的其他解释。
Melatonin is a hormone primarily produced by the pineal gland at night and is suppressed by exposure to light. Experimental studies have indicated that melatonin may protect against cancer development. In the majority of totally blind people, melatonin is never suppressed by light exposure. The aim of this study was to test the hypothesis that blind people have a decreased cancer incidence, and that this effect is more pronounced in the totally blind than in the severely visually impaired. We identified a cohort of 1,567 totally blind and 13,292 severely visually impaired subjects and obtained information about cancer incidence from the Swedish Cancer Registry. We calculated standardized incidence ratios (SIRs) based on the number of person years and incidence rates specific for national age, sex, and calendar year. Totally blind people had a lower incidence of all cancers combined [SIR = 0.69; 95% confidence interval (CI) = 0.59-0.82]. The risk reduction was observed in both men and women and was equally pronounced in hormone dependent tumors as in other types of cancer. In the severely visually impaired, SIR was 0.95 (95% CI = 0.91-1.00). The findings support the hypothesis that blind people have a lower cancer incidence, although other explanations than the higher melatonin exposure must also be considered.