骨粗鬆症症例に対するアレンドロネートとリセドロネートの短期薬効比較―尿中骨代謝吸収マーカー（NTX）・踵骨広帯領域超音波減衰率（BUA）の変化

Comparison between Treatment of Osteoporosis with Alendronate and Risedronate for Six Months. Changes in Bone Resorption Markers and Bone Quality Based on Ultrasound Measurements of the Calcaneus

　臨床所見および胸腰椎X線像，骨代謝吸収マーカー(尿中NTX/Cre)，広帯領域超音波減衰率(BUA)所見を総合的に勘案し，骨粗鬆症の薬物療法の開発基準に従いビスホスホネートが必要と判断した骨粗鬆症症例100例を対象に，処方後6カ月の尿中NTX/Cre，BUAを比較検討した．使用薬剤はアクトネル(RIS17.5mg/週)，ベネット(RIS17.5mg/週)，フォサマック(ALN35mg/週)である．投与後，RISおよびALNは尿中NTX/Creを有意に低下させた．3薬剤間の比較では尿中NTX/Cre，BUA，MSCに有意差はないが，減少率はALNが有意に高かった．しかし，RISでは尿中NTX/Creが35～40％減少で骨折発症率が最低になることを考慮すれば，短期成績はほぼ同等の薬剤であると推察された．

　We conducted a prospective comparative study of the efficacy of the bisphosphonates risedronate (RIS) and alendronate (ALN) in 100 osteoporosis patients who required treatment based on their clinical findings, thoracolumbar radiographs, urinary N-telopeptides of type I collagen (NTX)/Cre ratio, and broadband ultrasound attenuation (BUA) values.　Actonel (RIS；17.5mg/w) was prescribed for 36 patients, Benet (RIS；17.5mg/w) for 29 patients, and Fosamac (ALN；35mg/w) for 35 patients.　Both RIS and ALN had significantly reduced the NTX/Cre ratio by 6 months (p＜0.0001).　There were no significant differences between the three groups in NTX/Cre, BUA, or MSC values, but there was a significantly higher rate of decrease in NTX/Cre ratio in the ALN group (67.9%) than RIS groups (53.1%) (p＝0.002).　Since there was little further improvement in fracture benefit below 35～40% for NTX/Cre with RIS, both bisphosphonates seemed to have the same degree of efficacy.