An epidemiological research on risk factors for post-polio syndrome

脊髓灰质炎后综合征（PPS）通常定义为急性麻痹性脊髓灰质炎恢复后出现的新的虚弱、疲劳和疼痛的临床综合征。PPS是指30 ~ 40年后发生的脊髓灰质炎急性流行病。由于日本上一次急性脊髓灰质炎流行（20世纪60年代）比北美（20世纪50年代）晚10年，PPS问题在日本也晚了大约10年。由于PPS的病因目前尚不清楚，预防PPS的策略可以针对PPS的潜在危险因素进行干预。本研究的目的是检查目前与PPS相关的症状，并确定生活在日本的脊髓灰质炎幸存者PPS的危险因素。我们在最初的队列中登记了37名脊髓灰质炎幸存者（17名男性和20名女性;平均年龄为53岁），并进行了医学检查。主诉过度疲劳（81%）、肌无力（73%）、爬楼梯困难（68%）等，对上述队列进行巢式病例对照研究，发现近5年新出现的潜在危险因素。与PPS显著相关的危险因素的比值比（OR）如下：体重增加（OR 1.30）、呼吸急促（OR 1.34）、肌肉疼痛（OR 1.45）、肌无力（OR 1.99）和爬楼梯困难（OR 1.83）。这些因素应在频繁的体检中检测出来，以便进行干预。从病例系列研究中，特别是在工作场所，PPS个人需要康复医学和职业健康服务的特殊支持，包括改善营养，达到理想的体重，定期和合理的锻炼，以及改善工作条件。

Post-polio syndrome (PPS) is generally defined as a clinical syndrome of new weakness, fatigue and pain in individuals who have previously recovered from acute paralytic poliomyelitis. PPS is occurred 30 or 40 years later acute epidemic of poliomyelitis. Because the last epidemic of acute poliomyelitis in Japan (1960s) occurred 10 years later than in North America (1950s), issues on PPS also appeared approximately 10 years later in Japan. Since the causation of PPS is not clearly known today, the strategy preventing from PPS could targeted the intervention for potential risk factors of PPS. The purpose of this study was to examine the current symptoms related with PPS and identified risk factors of PPS with polio survivors living in Japan. We registered 37 polio survivors (17 men and 20 women; average age of 53 years) in the initial cohort, and did medical examination. They complained the excessive fatigue (81%), muscle weakness (73%), difficulties in climbing stairs up (68%), and so on. Nested case-control study in the subjects (the above cohort) revealed the potential risk factors that have been newly occurred in recent 5 years. The odds ratios (OR) of risk factors significantly associated with PPS were as follows: weight gain (OR 1.30), shortness of breath (OR 1.34), muscular pain (OR 1.45), muscle weakness (OR 1.99) and difficulties in climbing stairs up (OR 1.83). These factors should be detected for intervention at frequent medical check-ups. From the case-series study, particularly at the workplace, PPS individuals need special supports from both rehabilitation medicine and occupational health services, including improved nutrition, achieving ideal body weight, regular and sensible exercise, and modifying working conditions.