Roy Debajyoti, Ng Chee Yong, Kog Zheng Xi, Yeon Wenxiang, Poh Cheng Boon, Koduri Sreekanth, Chionh Chang Yin, Sultana Rehena, Hai Kiat Puar Troy
Changi General Hospital, Department of Renal Medicine, Singapore, Singapore.
Centre for Quantitative Medicine, Duke-NUS Medical School, Singapore, Singapore.
Front Aging. 2022 Oct 21;3:1026663. doi: 10.3389/fragi.2022.1026663. eCollection 2022.
Vitamin D deficiency is common in chronic kidney disease (CKD) and is associated with lower bone mineral density (BMD), decreased muscle strength, and increased hip fracture risk. Guidelines have suggested targeting 25-OH vitamin D (25(OH)D) levels between 20 and 30 ng/ml. However, vitamin D metabolism is altered in CKD, and threshold levels for optimal BMD are unknown. We included 1097 patients with hip fractures. CKD was defined as estimated glomerular filtration rate <60 ml/min/1.73 m (Mucsi et al., Clin. Nephrol., 2005, 64(4), 288-294) and low BMD defined as T score ≤ -2.5 at femoral neck. We assessed the association of 25(OH)D with low BMD in patients with and without CKD: using the conventional threshold 25(OH)D < 30 ng/dl, as well as a new threshold. CKD was present in 479 (44%) patients. Using a threshold of 25(OH)D < 30 ng/ml, there were no significant differences in patients with CKD and low BMD when compared to the other groups. We identified 27 ng/ml as a better threshold with the Youden index. Using 25(OH)D < 27 ng/ml as a threshold, 360 of 482 patients (74.7%) with low 25(OH)D had low BMD, compared to only 185/276 (67%) of patients with adequate vitamin D, 0.02, which was irrespective of the presence or absence of CKD. Furthermore, patients with CKD and 25(OH)D < 27 ng/ml had a higher odds ratio of mortality upon follow-up, 1.61, 95% CI: 1.08-2.39, compared to those with CKD and 25(OH)D ≥ 27 ng/ml. We find that 25(OH)D < 27 ng/ml is associated with low BMD in patients with and without CKD. Further prospective studies targeting vitamin D repletion to at least 27 ng/ml and the outcome of hip fractures will be useful to validate these findings.
维生素D缺乏在慢性肾脏病（CKD）中很常见，与较低的骨矿物质密度（BMD）、肌肉力量下降以及髋部骨折风险增加有关。指南建议将25-羟基维生素D（25(OH)D）水平目标设定在20至30 ng/ml之间。然而，CKD患者的维生素D代谢会发生改变，最佳BMD的阈值尚不清楚。我们纳入了1097例髋部骨折患者。CKD定义为估计肾小球滤过率<60 ml/min/1.73 m²（Mucsi等人，《临床肾脏病学》，2005年，64(4)，288 - 294），低BMD定义为股骨颈T值≤ -2.5。我们评估了25(OH)D与有无CKD患者低BMD之间的关联：使用传统阈值25(OH)D < 30 ng/dl以及一个新阈值。479例（44%）患者存在CKD。使用25(OH)D < 30 ng/ml的阈值，与其他组相比，CKD合并低BMD的患者无显著差异。我们通过约登指数确定27 ng/ml为更好的阈值。以25(OH)D < 27 ng/ml为阈值，482例25(OH)D水平低的患者中有360例（74.7%）存在低BMD，而维生素D充足的患者中只有185/276例（67%），P = 0.02，无论是否存在CKD均如此。此外，与CKD且25(OH)D≥27 ng/ml的患者相比，CKD且25(OH)D < 27 ng/ml的患者随访时死亡的比值比更高，为1.61，95%置信区间：1.08 - 2.39。我们发现25(OH)D < 27 ng/ml与有无CKD患者的低BMD相关。进一步针对将维生素D补充至至少27 ng/ml以及髋部骨折结局的前瞻性研究将有助于验证这些发现。
