Objective Gitelman syndrome (GS) is the most frequent salt-wasting genetic tubulopathy and a source of hypokalaemia and hypomagnesemia. Chondrocalcinosis (CC) is a frequent feature of GS. The aim of our study was to determine the prevalence, distribution patterns, clinical phenotypes and risk factors for CC in GS. Methods This prospective study of a cohort of 57 patients with GS included a systematic screening for CC by peripheral joint radiography, cervical spine CT and joint US. The prevalence of cervical C1–C2 CC by CT was compared between 33 GS patients and sex- and age-matched controls. Clinical and biochemical features were analysed to identify factors associated with CC. Results Mean (S.d.) age of patients was 46.5 (12.4) years, 66.7% were women and 93.0% carried SLC12A3 mutations. Mean serum magnesium level was 0.60 (0.30) mmol/l. CC was observed in 79% of patients, with the highest prevalence at the cervical spine (81.8%) followed by the knee (52.6%), wrist (50.9%), ankle (38.6%), TM joint (36.4%), shoulder (33.3%), hip (22.8%), elbow (14.0%) and sclerochoroid (12.1%). Prevalence of CC at the C1–C2 level was higher in the GS cohort than control group (72.7% vs 9.1%) (adjusted odds ratio 21.0, 95% CI 2.8, 156.1, P = 0.003). Independent factors associated with CC were low serum magnesium level and age. Conclusion GS was associated with widespread CC, favoured by aging and hypomagnesemia. The C1–C2 level was the most affected site. Follow-up of this unique cohort will help understanding the clinical consequences of CC, especially the precise characterization of pyrophosphate arthropathy.

中文翻译：

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57 例 Gitelman 综合征患者队列中的焦磷酸钙晶体沉积

目的 Gitelman 综合征 (GS) 是最常见的耗盐性遗传性肾小管病，也是低钾血症和低镁血症的来源。软骨钙质沉着症 (CC) 是 GS 的常见特征。我们研究的目的是确定 GS 中 CC 的患病率、分布模式、临床表型和危险因素。方法 这项对 57 名 GS 患者队列的前瞻性研究包括通过外周关节 X 线片、颈椎 CT 和关节超声系统筛查 CC。比较了 33 名 GS 患者与性别和年龄匹配的对照组之间的 CT 宫颈 C1-C2 CC 的患病率。分析临床和生化特征以确定与CC相关的因素。结果患者的平均 (Sd) 年龄为 46.5 (12.4) 岁，66.7% 为女性，93.0% 携带 SLC12A3 突变。平均血清镁水平为 0.60 (0.30) mmol/l。在 79% 的患者中观察到 CC，颈椎 (81.8%) 的患病率最高，其次是膝 (52.6%)、腕 (50.9%)、踝 (38.6%)、TM 关节 (36.4%)、肩(33.3%)、髋关节 (22.8%)、肘关节 (14.0%) 和硬脉络膜 (12.1%)。GS 队列中 C1-C2 水平的 CC 患病率高于对照组（72.7% 对 9.1%）（调整优势比 21.0, 95% CI 2.8, 156.1, P = 0.003）。与CC相关的独立因素是低血清镁水平和年龄。结论 GS 与广泛的 CC 相关，易受衰老和低镁血症的影响。C1-C2 水平是受影响最大的部位。对这一独特队列的随访将有助于了解 CC 的临床后果，尤其是焦磷酸盐关节病的精确表征。8%) 其次是膝关节 (52.6%)、腕关节 (50.9%)、踝关节 (38.6%)、TM 关节 (36.4%)、肩关节 (33.3%)、髋关节 (22.8%)、肘关节 (14.0%) 和硬脉络膜(12.1%)。GS 队列中 C1-C2 水平的 CC 患病率高于对照组（72.7% 对 9.1%）（调整优势比 21.0, 95% CI 2.8, 156.1, P = 0.003）。与CC相关的独立因素是低血清镁水平和年龄。结论 GS 与广泛的 CC 相关，易受衰老和低镁血症的影响。C1-C2 水平是受影响最大的部位。对这一独特队列的随访将有助于了解 CC 的临床后果，尤其是焦磷酸盐关节病的精确表征。8%) 其次是膝关节 (52.6%)、腕关节 (50.9%)、踝关节 (38.6%)、TM 关节 (36.4%)、肩关节 (33.3%)、髋关节 (22.8%)、肘关节 (14.0%) 和硬脉络膜(12.1%)。GS 队列中 C1-C2 水平的 CC 患病率高于对照组（72.7% 对 9.1%）（调整优势比 21.0, 95% CI 2.8, 156.1, P = 0.003）。与CC相关的独立因素是低血清镁水平和年龄。结论 GS 与广泛的 CC 相关，易受衰老和低镁血症的影响。C1-C2 水平是受影响最大的部位。对这一独特队列的随访将有助于了解 CC 的临床后果，尤其是焦磷酸盐关节病的精确表征。GS 队列中 C1-C2 水平的 CC 患病率高于对照组（72.7% 对 9.1%）（调整优势比 21.0, 95% CI 2.8, 156.1, P = 0.003）。与CC相关的独立因素是低血清镁水平和年龄。结论 GS 与广泛的 CC 相关，易受衰老和低镁血症的影响。C1-C2 水平是受影响最大的部位。对这一独特队列的随访将有助于了解 CC 的临床后果，尤其是焦磷酸盐关节病的精确表征。GS 队列中 C1-C2 水平的 CC 患病率高于对照组（72.7% 对 9.1%）（调整优势比 21.0, 95% CI 2.8, 156.1, P = 0.003）。与CC相关的独立因素是低血清镁水平和年龄。结论 GS 与广泛的 CC 相关，易受衰老和低镁血症的影响。C1-C2 水平是受影响最大的部位。对这一独特队列的随访将有助于了解 CC 的临床后果，尤其是焦磷酸盐关节病的精确表征。