De Ferrari Aldo, Miranda J Jaime, Gilman Robert H, Dávila-Román Victor G, León-Velarde Fabiola, Rivera-Ch Maria, Huicho Luis, Bernabé-Ortiz Antonio, Wise Robert A, Checkley William
From the Division of Pulmonary and Critical Care, School of Medicine, Johns Hopkins University, Baltimore, MD.
CRONICAS Centre of Excellence for Chronic Diseases, Universidad Peruana Cayetano Heredia, Lima, Peru; Departamento de Medicina, Escuela de Medicina, Universidad Peruana Cayetano Heredia, Lima, Peru.
Chest. 2014 Nov;146(5):1327-1336. doi: 10.1378/chest.14-0298.
Excessive erythrocytosis (EE) is a prevalent condition in populations living at high altitudes (> 2,500 m above sea level). Few large population-based studies have explored the association between EE and multiple subject-specific traits including oxygen saturation, iron status indicators, and pulmonary function.
We enrolled a sex-stratified and age-stratified sample of 1,065 high-altitude residents aged ≥ 35 years from Puno, Peru (3,825 m above sea level) and conducted a standardized questionnaire and physical examination that included spirometry, pulse oximetry, and a blood sample for multiple clinical markers. Our primary objectives were to estimate the prevalence of EE, characterize the clinical profile and iron status indicators of subjects with EE, and describe subject-specific traits associated with EE.
Overall prevalence of EE was 4.5% (95% CI, 3.3%-6.0%). Oxygen saturation was significantly lower among EE than non-EE group subjects (85.3% vs 90.1%, P < .001) but no difference was found in iron status indicators between both groups (P > .09 for all values). In multivariable logistic regression, we found that age ≥ 65 years (OR = 2.45, 95% CI, 1.16-5.09), male sex (3.86, 1.78-9.08), having metabolic syndrome (2.66, 1.27-5.75) or being overweight (5.20, 1.95-16.77), pulse oximetry < 85% (14.90, 6.43-34.90), and % predicted FVC < 80% (13.62, 4.40-41.80) were strongly associated with EE. Attributable fractions for EE were greatest for being overweight (26.7%), followed by male sex (21.5%), pulse oximetry < 85% (16.4%), having metabolic syndrome (14.4%), and % predicted FVC < 80% (9.3%).
We found a lower prevalence of EE than in previous reports in the Peruvian Andes. Although the presence of hypoxemia and decreased vital capacity were strongly associated with excessive erythrocytosis, being overweight or having metabolic syndrome were associated with an important fraction of cases in our study population.
红细胞增多症（EE）在生活在高海拔地区（海拔>2500米）的人群中较为普遍。很少有基于大样本人群的研究探讨EE与包括血氧饱和度、铁状态指标和肺功能在内的多个个体特异性特征之间的关联。
我们从秘鲁普诺（海拔3825米）纳入了1065名年龄≥35岁的高海拔居民，按性别和年龄分层抽样，并进行了标准化问卷调查和体格检查，包括肺活量测定、脉搏血氧饱和度测定以及采集用于多项临床指标检测的血样。我们的主要目标是估计EE的患病率，描述EE患者的临床特征和铁状态指标，并描述与EE相关的个体特异性特征。
EE的总体患病率为4.5%（95%CI，3.3%-6.0%）。EE组患者的血氧饱和度显著低于非EE组患者（85.3%对90.1%，P<.001），但两组间铁状态指标无差异（所有值P>.09）。在多变量逻辑回归分析中，我们发现年龄≥65岁（OR=2.45，95%CI，1.16-5.09）、男性（3.86，1.78-9.08）、患有代谢综合征（2.66，1.27-5.75）或超重（5.20，1.95-16.77）、脉搏血氧饱和度<85%（14.90，6.43-34.90）以及预测的FVC%<80%（13.62，4.40-41.80）与EE密切相关。EE的归因分数超重最高（26.7%），其次是男性（21.5%）、脉搏血氧饱和度<85%（16.4%）、患有代谢综合征（14.4%）以及预测的FVC%<80%（9.3%）。
我们发现秘鲁安第斯山脉地区EE的患病率低于先前报告。尽管低氧血症和肺活量降低与红细胞增多症密切相关，但在我们的研究人群中，超重或患有代谢综合征与相当一部分病例相关。
