1 Glickman Urological and Kidney Institute , Cleveland Clinic, Cleveland, OH, USA.
2 Quantitative Health Sciences Department , Cleveland Clinic, Cleveland, Ohio.
J Endourol. 2018 Jun;32(6):559-564. doi: 10.1089/end.2017.0940. Epub 2018 Apr 24.
Thiazides and citrate prevent kidney stones and improve bone mineral density (BMD). The objective of this study was to opportunistically utilize the noncontrast CT (NCCT) scan used for stone detection to identify those with low BMD and follow the impact of potassium citrate and thiazides on longitudinal BMD measurements.
A retrospective analysis was performed on 299 kidney stone patients treated with thiazides and/or potassium citrate for a minimum of 1 year. For each patient, BMD was estimated at L1 with CT attenuation measured in HU. A level of 160 HU was chosen to distinguish normal from low BMD. Pairwise t-test was used to compare the continuous outcomes before and after treatment for the whole cohort and the low BMD subgroup. Linear regression was performed to find if any association exists between the duration of follow-up and the changes in HU. A matched pair t-test was performed to compare among the medications used and the impact of their doses on the HU outcomes.
Patients with low BMD (HU <160) comprised (n = 186, 62.2%) the cohort. A total of 16.1% normalized after 1 year of treatment and 68% had an increase in HU. The mean change in HU was 8.6 (p = 0.0001). Linear regression demonstrated no association between the duration of treatment and the HU changes (p = 0.64). Hydrochlorothiazide (HCTZ) 50 mg was more effective at improving BMD (HU +19.7, p = 0.04) compared with 25 mg (+2.9) or 12.5 mg (HU +6.4). Majority of the low BMD subgroup were either postmenopausal women (n = 88) or men with age older than 60 (n = 74) and both showed a significant increase in HU (3.125, 10.731), p-value (0.0453, 0.0007), respectively.
Stone health and bone health are synergistic. The impact of thiazides and citrates on BMD can be monitored opportunistically with the NCCT scan.
噻嗪类药物和柠檬酸盐可预防肾结石并提高骨密度（BMD）。本研究的目的是利用非对比 CT（NCCT）扫描来识别那些骨密度低的患者，并观察柠檬酸钾和噻嗪类药物对纵向 BMD 测量的影响。
对 299 例接受噻嗪类药物和/或柠檬酸钾治疗至少 1 年的肾结石患者进行回顾性分析。对每位患者，在 CT 衰减值以 HU 为单位测量的 L1 处估计 BMD。选择 160 HU 作为区分正常和低 BMD 的界限。对整个队列和低 BMD 亚组进行治疗前后的连续结果进行配对 t 检验。进行线性回归以确定随访时间与 HU 变化之间是否存在任何关联。对所用药物进行配对 t 检验，并比较其剂量对 HU 结果的影响。
低 BMD（HU <160）患者（n=186，占 62.2%）构成了队列。16.1%的患者在治疗 1 年后恢复正常，68%的患者 HU 增加。HU 的平均变化为 8.6（p=0.0001）。线性回归显示，治疗时间与 HU 变化之间无关联（p=0.64）。与 25 mg（HU+2.9）或 12.5 mg（HU+6.4）相比，氢氯噻嗪（HCTZ）50 mg 更能有效改善 BMD（HU+19.7，p=0.04）。大多数低 BMD 亚组患者为绝经后女性（n=88）或年龄大于 60 岁的男性（n=74），两者的 HU 均显著增加（3.125，10.731），p 值（0.0453，0.0007）。
结石健康和骨骼健康是协同的。可以利用 NCCT 扫描来监测噻嗪类药物和柠檬酸盐对 BMD 的影响。
