Son H R, d'Avignon D A, Laflamme D P
Pet Products Research & Development, Ralston Purina Co, St Louis, MO 63164, USA.
Am J Vet Res. 1998 May;59(5):529-32.
To compare percentage of body fat (%BF) estimates from dual-energy x-ray absorptiometry (DEXA) with those derived from total body water (TBW) determination by deuterium oxide (D2O) dilution.
31 healthy, adult, purebred dogs of various ages and breeds (body weight, 15 to 39 kg).
The TBW was measured by D2O dilution and subsequent analysis via nuclear magnetic resonance (NMR). Blood was collected before and 2 hours after IV administration of 275 mg of D2O/kg of body weight. Plasma was separated and stored at -30 C until analysis by deuterium NMR. The DEXA scans were obtained immediately after blood collection from dogs under general anesthesia.
Measurements of %BF by DEXA averaged 15.8% higher than calculated estimates of TBW content by D2O dilution. The linear regression of %BF by TBW content on %BF by DEXA had a slope of 1.04 and a correlation coefficient of 0.84, indicating excellent relative agreement between methods despite the significant difference in absolute agreement between the 2 methods. The average difference between methods did not differ by breed, sex, body condition score, body weight, or %BF, as measured by DEXA.
Comparability of our data with those of previous studies suggest that DEXA is useful for in vivo estimation of body composition in healthy dogs. Body fat estimated by D2O dilution will be less than that determined by DEXA, despite excellent relative agreement between methods.
比较双能X线吸收法（DEXA）估算的体脂百分比（%BF）与通过氧化氘（D2O）稀释法测定总体水（TBW）得出的体脂百分比。
31只健康的成年纯种犬，年龄和品种各异（体重15至39千克）。
通过D2O稀释法及随后的核磁共振（NMR）分析来测量TBW。在静脉注射275毫克D2O/千克体重之前和之后2小时采集血液。分离血浆并在-30℃下保存，直至通过氘核磁共振进行分析。在全身麻醉下的犬只采血后立即进行DEXA扫描。
DEXA测量的%BF平均比D2O稀释法计算得出的TBW含量估算值高15.8%。TBW含量的%BF与DEXA的%BF的线性回归斜率为1.04，相关系数为0.84，表明尽管两种方法在绝对一致性上存在显著差异，但在相对一致性方面表现出色。两种方法之间的平均差异在品种、性别、身体状况评分、体重或DEXA测量的%BF方面并无差异。
我们的数据与先前研究的数据具有可比性，表明DEXA可用于健康犬活体身体成分的评估。尽管两种方法在相对一致性方面表现出色，但通过D2O稀释法估算的体脂将低于DEXA测定的体脂。
