X-连锁低磷性低血磷症或肿瘤性骨软化所致的慢性特发性低磷血症（CIH）是一种罕见的遗传性或后天性疾病。然而，由于其罕见性，对CIH的流行病学和自然病程了解甚少。因此，我们的目标是确定CIH患者的患病率和长期健康结局。通过使用韩国健康保险审核和评估索赔数据库，我们评估了2003年至2018年初次诊断的低磷血症的发病率。排除可能导致血清磷水平变化的继发性疾病后，我们确定了154例（76男性，78女性）非继发性和非肾性低磷血症的患者。我们以1:10的比例将这些低磷血症患者与年龄、性别和索引年配对的对照组（n = 1,540）进行比较。在诊断年龄分布中，我们观察到1-4岁的患者中有一个较大的峰值，并且在40-70岁的年龄段中有一些小峰值。年龄标化的发病率从2003年的每100万人口0.24个逐渐上升到2018年的0.30个，但差异不具统计学意义。相较于对照组，低磷血症患者发生任何并发症（调整危险比 [aHR] 2.17；95%置信区间 [CI] 1.67-2.69）的风险更高，包括心血管结果、慢性肾脏病、甲状旁腺功能亢进、骨质疏松性骨折、牙周炎和抑郁症。低磷血症患者的死亡和住院风险也较对照组高（分别为aHR 3.26；95% CI 1.83-5.81；和aHR 2.49；95% CI 1.97-3.16）。这项韩国范围内首个CIH的研究发现了双峰型年龄分布，并且在患者中没有性别差异。相较于年龄和性别配对的对照组，低磷血症患者具有更高的并发症、死亡和住院风险。 版权 © 2023 Kim、Song、Kim、Hong、Kim、Lee和Rhee。

Chronic idiopathic hypophosphatemia (CIH) induced by X-linked hypophosphatemic rickets or tumor-induced osteomalacia is a rare inherited or acquired disorder. However, due to its rarity, little is known about the epidemiology and natural course of CIH. Therefore, we aimed to identify the prevalence and long-term health outcomes of CIH patients.Using the Korean Health Insurance Review and Assessment claims database, we evaluated the incidence of hypophosphatemia initially diagnosed from 2003 to 2018. After excluding secondary conditions that could change serum phosphorus levels, we identified 154 patients (76 men and 78 women) with non-secondary and non-renal hypophosphatemia. These hypophosphatemic patients were compared at a ratio of 1:10 with age-, sex-, and index-year-matched controls (n = 1,540).In the distribution of age at diagnosis, a large peak was observed in patients aged 1-4 years and small peaks were observed in ages from 40-70 years. The age-standardized incidence rate showed non-statistically significant trend from 0.24 per 1,000,000 persons in 2003 to 0.30 in 2018. Hypophosphatemic patients had a higher risk of any complication (adjusted hazard ratio [aHR], 2.17; 95% confidence interval [CI], 1.67-2.69) including cardiovascular outcomes, chronic kidney disease, hyperparathyroidism, osteoporotic fractures, periodontitis, and depression. Hypophosphatemic patients also had higher risks of mortality and hospitalization than the controls (aHR, 3.26; 95% CI, 1.83-5.81; and aHR, 2.49; 95% CI, 1.97-3.16, respectively).This first nationwide study of CIH in South Korea found a bimodal age distribution and no sex differences among patients. Hypophosphatemic patients had higher risks of complications, mortality, and hospitalization compared to age- and sex-matched controls.Copyright © 2023 Kim, Song, Kim, Hong, Kim, Lee and Rhee.