Nawawi H, Girgis S I
Chemical Pathology Unit, Department of Pathology, Faculty of Medicine, University Kebangsaan Malaysia, Jalan Yaacob Latif, Cheras, 56000 Kuala Lumpur, Malaysia.
Southeast Asian J Trop Med Public Health. 2002;33 Suppl 2:124-30.
Vitamin D deficiency in adults causes osteomalacia where there is a defect in bone mineralization resulting in an excess of unmineralised osteoid in the bone matrix. The aim of this study was to evaluate the markers of bone formation: total (TALP), bone-specific alkaline phosphatase (BSALP) and procollagen type I carboxyterminal peptide (PICP) in vitamin D deficiency. We studied 100 vitamin D deficient subjects and 82 gender-matched controls. Vitamin D deficiency was defined as serum 25-hydroxyvitamin D level of less than 7 ng/ml, and greater than 10 ng/ml for normal controls. Serum TALP assay was performed by a standard automated method, BSALP and PICP were measured by enzyme immunoassays (Metra Biosystems) and vitamin D by radioimmunoassay. There was significant difference in the TALP between female vitamin D deficient and control subjects (mean +/- sem = 99.8 +/- 8.2 vs 70.5 +/- 2.8 iu/l, p<0.001). Elevated serum TALP (>130 iu/l) was found in 20% (20/100) of the vitamin D deficient patients. There were no significant differences in BSALP or PICP between vitamin D deficient patients and gender-matched control subjects. There was no correlation between vitamin D and PICP in patients but in control subjects, a significant negative correlation (r= -0.431, p<0.0001) was found. In conclusion, although elevated TALP was observed in a minority of vitamin D deficient patients, it is a better marker than PICP. The lack of PICP response in vitamin D deficient subjects suggests the possibility of vitamin D deficiency leading to a block in osteoblast differentiation.
成人维生素D缺乏会导致骨软化症，即骨矿化存在缺陷，致使骨基质中未矿化的类骨质过多。本研究的目的是评估维生素D缺乏时骨形成的标志物：总碱性磷酸酶（TALP）、骨特异性碱性磷酸酶（BSALP）和I型前胶原羧基末端肽（PICP）。我们研究了100名维生素D缺乏的受试者和82名性别匹配的对照组。维生素D缺乏定义为血清25-羟基维生素D水平低于7 ng/ml，正常对照组大于10 ng/ml。血清TALP检测采用标准自动化方法，BSALP和PICP通过酶免疫测定法（Metra Biosystems）测定，维生素D通过放射免疫测定法测定。女性维生素D缺乏受试者与对照组之间的TALP存在显著差异（均值±标准误=99.8±8.2 vs 70.5±2.8 iu/l，p<0.001）。20%（20/100）的维生素D缺乏患者血清TALP升高（>130 iu/l）。维生素D缺乏患者与性别匹配的对照组之间的BSALP或PICP无显著差异。患者中维生素D与PICP之间无相关性，但在对照组中，发现存在显著负相关（r = -0.431，p<0.0001）。总之，虽然少数维生素D缺乏患者观察到TALP升高，但它是比PICP更好的标志物。维生素D缺乏受试者中PICP无反应提示维生素D缺乏可能导致成骨细胞分化受阻。
