年輕痛風患者的腎髓質鈣化症

Medullary nephrocalcinosis in young subjects with gout

目的：描述伴隨有腎髓質鈣化症的年輕痛風患者的臨床特性。研究材料與方法：這個研究利用林口長庚醫院超音波報告系統搜尋所有具有腎髓質鈣化症診斷的病例，自1997至2006年為止共有78,576份報告。針對四十歲以下的年輕病患，進行病例回顧分析臨床及檢驗資料。病人分為痛風／高尿酸血症與非痛風兩組。結果：在林口長庚醫院超音波報告系統共有545份報告包含腎髓質鈣化症的診斷，其中四十歲以下的年輕患者共有123位。最常見的相關疾病依序是：不明原因的腎結石（38/123, 30.9%）、痛風（35/123, 28.5%）以及原發性副甲狀腺機能亢進（9/123, 7.3%）。在痛風或高尿酸血症患者中，86.0%（37/43）為男性。痛風患者中40.0%伴隨有高血壓，而且60.0%的患者已有腎功能不全。蛋白尿（36.1%）及血尿（50.0%）均常見在痛風／高尿酸血症患者中。除腎髓質鈣化症外，腎臟萎縮以及外型不規則可分別在4位（9.3%）及13位（30.2%）的年經痛風病患中觀察到。值得注意的是，合併腎髓質鈣化症的痛風病人中，雖然腎臟功能正常，卻有7.1%的病人腎臟已萎縮。結論：在腎髓質鈣化症中，痛風與高尿酸血症應被視為重要的相關疾病。腎臟傷害的標記，例如蛋白尿與腎臟縮小，常可見於年輕的痛風併發腎髓質鈣化症的病人中。他們應該要給予小心的治療以避免腎臟功能的進一步惡化。

Objective: To describe the characteristics of young subjects with gout associated with medullary nephrocalcinosis. Methods: A computerized search in the ultrasonography database of Chang-Gung Memorial Hospital identified 78,576 reports of kidney ultrasonography from 1997 to 2006. Clinical and laboratory data of subjects who were younger than 40 years old and had medullary nephrocalcinosis were analyzed. Subjects were divided into gout/hyperuricemia and non-gout groups. Results: Five hundred and forty five reports kidney ultrasonography contained diagnosis of medullary nephrocalcinosis. Of these, 123 subjects were aged younger than 40 years old and were diagnosed with medullary nephrocalcinosis. The most common diseases associated with medullary nephrocalcinosis were idiopathic urolithiasis (38/123, 30.9%) followed by gout (35/123, 28.5%) and primary hyperparathyroidism (9/123, 7.3%). Male subjects constituted 86.0% (37/43) of subjects in the gout/hyperuricemia group. Hypertension and azotemia were noted in 40.0% and 60.0% of subjects with gouty arthritis, respectively. Proteinuria (36.1 %) and hematuria (50.0%) were both common. Apart from medullary nephrocalcinosis, kidney shrinkage and irregular kidney contours noted by ultrasonography was demonstrated in 4 (9.3%) and 13 (30.2%) subjects, respectively. Of note, in gout/hyperuricemia subjects with normal renal function, 7.1% already had small kidney size. Conclusion: Gout and asymptomatic hyperuricemia should be considered important diseases associated with medullary nephrocalcinosis. Markers of kidney damage, such as proteinuria or small kidney size, can be observed in many young gout subjects with medullary nephrocalcinosis. They should be treated with caution to avoid further deterioration of renal function.