Gupta Ravi, Ulfberg Jan, Allen Richard P, Goel Deepak
Department of Psychiatry, Himalayan Institute of Medical Sciences, Swami Ram Nagar, Jolly Grant, Dehradun 248016, India; Sleep Clinic, Himalayan Institute of Medical Sciences, Swami Ram Nagar, Jolly Grant, Dehradun 248016, India.
Sleep Clinic, Capio Medical Center, Hamnplan, Örebro, Sweden.
Sleep Med. 2017 Jul;35:7-11. doi: 10.1016/j.sleep.2017.02.031. Epub 2017 Apr 20.
At high altitude, prevalence of restless legs syndrome has been found to be greater than expected in small population-based studies, which did not use validated tools for identification of RLS. However, it is not known as to whether this increased prevalence is associated with altitude or increased risk factors for RLS in these populations or errors in identification of RLS.
This population based, door-to-door study was conducted at low altitude (400 m above sea level) and high altitudes (1900-2000 m and 3200 m above sea level) using random stratified sampling in Himalayan and sub-Himalayan region of India. Subjects between 18 and 84 years were screened for restless-legs-syndrome using the validated Cambridge-Hopkins RLS diagnostic questionnaire. Medical comorbidities were ascertained from their medical records. Their anthropometric measurements were obtained and wake resting oxygen saturation was monitored using finger pulse-oximeter. Physical activity during leisure time was evaluated by using the Goldin leisure time exercise questionnaire.
A total of 1689 subjects were included. Average age of the included subjects was 35.2 years; 55.2% were women. RLS was identified in 9.4% subjects with higher prevalence among women (13.6% women vs. 4.1% men; P < 0.001). RLS was significantly more prevalent at higher altitudes (12.2% at 1900-2000 m and 11.8% at 3200 m) compared to low altitude (2.5% at 400 m). The low altitude prevalence matched that reported in prior studies of RLS in India. Subjects with medical disorders sometimes related to RLS (eg, peripheral neuropathy, COPD, varicose veins and anemia) also had higher prevalence of RLS. Binary logistic regression controlling for female gender, number of pregnancies, peripheral neuropathy, varicose veins, anemia showed that high altitude independently significantly increased the likelihood of RLS (OR: 5.4, 95% CI: 2.8, 10.4).
RLS is about five times more prevalent at high than low altitudes even when controlling for effects of other medical conditions associated with increased risk of RLS.
在高海拔地区，基于小规模人群的研究发现不宁腿综合征的患病率高于预期，这些研究未使用经过验证的工具来识别不宁腿综合征。然而，尚不清楚这种患病率的增加是与海拔高度有关，还是与这些人群中不宁腿综合征的风险因素增加或不宁腿综合征识别中的误差有关。
在印度喜马拉雅和次喜马拉雅地区，采用随机分层抽样的方法，在低海拔（海拔400米）和高海拔（海拔1900 - 2000米和3200米）地区开展了这项基于人群的挨家挨户的研究。使用经过验证的剑桥 - 霍普金斯不宁腿综合征诊断问卷，对18至84岁的受试者进行不宁腿综合征筛查。从他们的病历中确定合并症。获取他们的人体测量数据，并使用手指脉搏血氧仪监测静息时的血氧饱和度。使用戈尔丁休闲时间运动问卷评估休闲时间的身体活动。
共纳入1689名受试者。纳入受试者的平均年龄为35.2岁；55.2%为女性。9.4%的受试者被诊断为不宁腿综合征，女性患病率更高（女性为13.6%，男性为4.1%；P < 0.001）。与低海拔（400米处为2.5%）相比，高海拔地区（1900 - 2000米处为12.2%，3200米处为11.8%）不宁腿综合征的患病率显著更高。低海拔地区的患病率与印度先前关于不宁腿综合征的研究报告相符。有时与不宁腿综合征相关的疾病（如周围神经病变、慢性阻塞性肺疾病、静脉曲张和贫血）患者中，不宁腿综合征的患病率也较高。在控制女性性别、怀孕次数、周围神经病变、静脉曲张、贫血等因素的二元逻辑回归分析中显示，高海拔独立显著增加了患不宁腿综合征的可能性（比值比：5.4，95%置信区间：2.8，10.4）。
即使控制了与不宁腿综合征风险增加相关的其他疾病的影响，高海拔地区不宁腿综合征的患病率仍比低海拔地区高出约五倍。
