Reid I R, Murphy W A, Hardy D C, Teitelbaum S L, Bergfeld M A, Whyte M P
Department of Medicine, Jewish Hospital of St. Louis, Missouri 63110.
Am J Med. 1991 Jan;90(1):63-9. doi: 10.1016/0002-9343(91)90507-t.
X-linked hypophosphatemia (XLH) is the most common inherited form of rickets, yet its influence on skeletal mass in adulthood is controversial and incompletely characterized. Accordingly, we measured bone mass at several skeletal sites using histomorphometric and radiographic techniques in 19 adults (four men) with XLH (age range 20 to 66 years). Most subjects had not received medical therapy for XLH since puberty.
Eight of 14 subjects who underwent transiliac bone biopsy had an elevated cancellous bone volume (osteoid and calcified bone), and the group's mean value was supranormal (p less than 0.01). Mineralized bone volume, however, was above normal in only three subjects (NS). Another measure of trabecular bone density, vertebral mineral density by computed tomography, was elevated in three of 13 subjects, and the mean value of the group was increased (p = 0.05). Integral spine bone mineral density (BMD) assessed by dual photon absorptiometry (DPA) was elevated in six of 16 subjects, and the mean was also above normal (p less than 0.01). However, total body calcium, total body BMD (both by DPA), and forearm bone mineral content assessed by single photon absorptiometry (predominantly cortical bone) were normal in almost all subjects, as were the group means for these parameters. Mean regional BMD (by DPA) was below normal in the upper and lower limbs (p less than 0.001) and above normal in the spine (p less than 0.005) and ribs (p less than 0.01). There was no relationship between these indices of bone mass and either biochemical or clinical parameters of disease severity, although men tended to have higher z-scores for axial bone density than premenopausal women whose values, in turn, tended to be higher than those in postmenopausal women (NS).
We conclude that axial bone mass tends to be increased in adults with XLH, sometimes dramatically so, and this is only partially attributable to hyperosteoidosis. Peripheral bone mass, however, tends to be diminished. Despite these group trends, most adults with untreated XLH have normal indices of bone mass as assessed by a variety of techniques at the commonly used measurement sites. These findings suggest that "osteoporotic" fractures are unlikely to develop as a late complication of XLH in adults.
目的、患者及方法：X连锁低磷血症（XLH）是最常见的遗传性佝偻病形式，但其对成年期骨量的影响存在争议且特征不完全明确。因此，我们使用组织形态计量学和放射学技术对19名成年XLH患者（4名男性）（年龄范围20至66岁）的多个骨骼部位的骨量进行了测量。大多数受试者自青春期后未接受过XLH的医学治疗。
14名接受髂骨活检的受试者中有8名松质骨体积（类骨质和钙化骨）升高，该组平均值高于正常（p<0.01）。然而，仅3名受试者的矿化骨体积高于正常（无统计学意义）。另一种小梁骨密度测量方法，即计算机断层扫描测量的椎体矿物质密度，在13名受试者中有3名升高，该组平均值增加（p = 0.05）。通过双能光子吸收法（DPA）评估的脊柱整体骨矿物质密度（BMD）在16名受试者中有6名升高，平均值也高于正常（p<0.01）。然而，几乎所有受试者的全身钙、全身BMD（均通过DPA）以及通过单能光子吸收法评估的前臂骨矿物质含量（主要为皮质骨）均正常，这些参数的组平均值也是如此。上肢和下肢的平均局部BMD（通过DPA）低于正常（p<0.001），脊柱（p<0.005）和肋骨（p<0.01）高于正常。这些骨量指标与疾病严重程度的生化或临床参数之间无相关性，尽管男性轴向骨密度的z评分往往高于绝经前女性，而绝经前女性的值又往往高于绝经后女性（无统计学意义）。
我们得出结论，成年XLH患者的轴向骨量往往增加，有时增加显著，且这仅部分归因于骨样组织过多症。然而，外周骨量往往减少。尽管有这些组内趋势，但大多数未经治疗的成年XLH患者在常用测量部位通过多种技术评估的骨量指标正常。这些发现表明，“骨质疏松性”骨折不太可能作为成年XLH的晚期并发症发生。
