Calcium Metabolism and Osteoporosis Program, Department of Internal Medicine, American University of Beirut, Beirut, Lebanon.
Bone. 2010 Aug;47(2):408-12. doi: 10.1016/j.bone.2010.05.002. Epub 2010 May 7.
It is unclear whether the relationship between 25-OHD and PTH is modulated by age or gender.
To assess the 25-OHD-PTH relationship in 340 adolescents (10-17 years) and 443 elderly (65-85 years) of the same ethnic group, and living in the same sunny country.
Calcium intake was estimated. Serum calcium, phosphorus, 25-OHD and PTH were measured. Body fat was determined by DXA.
25-OHD levels were lower in the elderly in the overall group (p<0.001) and within genders. 25-OHD levels were lower in females in the overall group and within age subgroups (p<0.05). PTH levels were higher in the elderly in the overall population and in both genders (p<0.001). There were no gender differences in PTH levels within age subgroups. For the same 25-OHD level, PTH levels were comparable across genders but were 1.5-2 folds higher in the elderly compared to adolescents (p<0.001). PTH correlated positively with age (p<0.001), body fat (p=0.02), and negatively with calcium intake (p<0.001), and 25-OHD (p<0.001). The magnitude of the correlation with 25-OHD decreased after adjustment for age but not for gender. In multivariate analyses, age, 25-OHD and fat mass were independent predictors for PTH. In the elderly, after adjustment for serum creatinine, only 25-OHD and creatinine were independent predictors of PTH.
The negative relationship between 25-OHD and PTH is modulated by age but not gender. Desirable 25-OHD levels derived from examining the 25-OHD-PTH relationship should therefore take into account the age of the population of interest.
25-羟维生素 D（25-OHD）与甲状旁腺激素（PTH）之间的关系是否受年龄或性别影响尚不清楚。
评估同一阳光充足国家的同一种族的 340 名青少年（10-17 岁）和 443 名老年人（65-85 岁）的 25-OHD-PTH 关系。
估计钙摄入量。测量血清钙、磷、25-OHD 和 PTH。使用 DXA 测定体脂肪。
总体人群中老年人的 25-OHD 水平较低（p<0.001），且在各性别中也是如此。总体人群中女性和各年龄亚组中女性的 25-OHD 水平较低（p<0.05）。总体人群及各性别中老年人的 PTH 水平较高（p<0.001）。各年龄亚组中，PTH 水平在性别间无差异。在相同的 25-OHD 水平下，各性别间的 PTH 水平相当，但老年人比青少年高 1.5-2 倍（p<0.001）。PTH 与年龄呈正相关（p<0.001），与体脂肪呈负相关（p=0.02），与钙摄入量呈负相关（p<0.001），与 25-OHD 呈负相关（p<0.001）。25-OHD 与 PTH 的相关性在调整年龄后显著降低，但不受性别影响。多元分析中，年龄、25-OHD 和脂肪量是 PTH 的独立预测因子。在老年人中，调整血清肌酐后，只有 25-OHD 和肌酐是 PTH 的独立预测因子。
25-OHD 与 PTH 之间的负相关受年龄影响，但不受性别影响。因此，从检查 25-OHD-PTH 关系中得出的理想 25-OHD 水平应考虑到感兴趣人群的年龄。
