肾移植受者去脂体重的预测

Prediction of Fat-Free Mass in Kidney Transplant Recipients.

作者信息

Størset Elisabet, von Düring Marit Elizabeth, Godang Kristin, Bergan Stein, Midtvedt Karsten, Åsberg Anders

机构信息

*Department of Transplant Medicine, Oslo University Hospital Rikshospitalet; †Institute of Clinical Medicine, University of Oslo; ‡Section of Specialized Endocrinology, Department of Endocrinology, Oslo University Hospital Rikshospitalet; §School of Pharmacy, University of Oslo; and ¶Department of Pharmacology, Oslo University Hospital, Norway.

出版信息

Ther Drug Monit. 2016 Aug;38(4):439-46. doi: 10.1097/FTD.0000000000000305.

DOI:10.1097/FTD.0000000000000305

PMID:27019101

Abstract

BACKGROUND

Individualization of drug doses is essential in kidney transplant recipients. For many drugs, the individual dose is better predicted when using fat-free mass (FFM) as a scaling factor. Multiple equations have been developed to predict FFM based on healthy subjects. These equations have not been evaluated in kidney transplant recipients. The objectives of this study were to develop a kidney transplant specific equation for FFM prediction and to evaluate its predictive performance compared with previously published equations.

METHODS

Ten weeks after transplantation, FFM was measured by dual-energy X-ray absorptiometry. Data from a consecutive cohort of 369 kidney transplant recipients were randomly assigned to an equation development data set (n = 245) or an evaluation data set (n = 124). Prediction equations were developed using linear and nonlinear regression analysis. The predictive performance of the developed equation and previously published equations in the evaluation data set was assessed.

RESULTS

The following equation was developed: FFM (kg) = {FFMmax × body weight (kg)/[81.3 + body weight (kg)]} × [1 + height (cm) × 0.052] × [1-age (years) × 0.0007], where FFMmax was estimated to be 11.4 in males and 10.2 in females. This equation provided an unbiased, precise prediction of FFM in the evaluation data set: mean error (ME) (95% CI), -0.71 kg (-1.60 to 0.19 kg) in males and -0.36 kg (-1.52 to 0.80 kg) in females, root mean squared error 4.21 kg (1.65-6.77 kg) in males and 3.49 kg (1.15-5.84 kg) in females. Using previously published equations, FFM was systematically overpredicted in kidney-transplanted males [ME +1.33 kg (0.40-2.25 kg) to +5.01 kg (4.06-5.95 kg)], but not in females [ME -2.99 kg (-4.07 to -1.90 kg) to +3.45 kg (2.29-4.61) kg].

CONCLUSIONS

A new equation for FFM prediction in kidney transplant recipients has been developed. The equation may be used for population pharmacokinetic modeling and clinical dose selection in kidney transplant recipients.

摘要

背景

肾移植受者的药物剂量个体化至关重要。对于许多药物，使用去脂体重（FFM）作为标化因子时，个体剂量能得到更好的预测。已经开发了多个基于健康受试者来预测FFM的方程。这些方程尚未在肾移植受者中进行评估。本研究的目的是开发一个针对肾移植受者的FFM预测方程，并与先前发表的方程相比评估其预测性能。

方法

移植后10周，采用双能X线吸收法测量FFM。将来自369例连续肾移植受者队列的数据随机分配到方程开发数据集（n = 245）或评估数据集（n = 124）。使用线性和非线性回归分析开发预测方程。评估开发的方程和先前发表的方程在评估数据集中的预测性能。

结果

开发了以下方程：FFM（kg）={FFMmax×体重（kg）/[81.3 +体重（kg）]}×[1 +身高（cm）×0.052]×[1 -年龄（岁）×0.0007]，其中男性的FFMmax估计为11.4，女性为10.2。该方程在评估数据集中对FFM提供了无偏、精确的预测：男性的平均误差（ME）（95%CI）为-0.71 kg（-1.60至0.19 kg），女性为-0.36 kg（-1.52至0.80 kg），男性的均方根误差为4.21 kg（1.65 - 6.77 kg），女性为3.49 kg（1.15 - 5.84 kg）。使用先前发表的方程，肾移植男性的FFM被系统性高估[ME +1.33 kg（0.40 - 2.25 kg）至+5.01 kg（4.06 - 5.95 kg）]，但女性没有[ME -2.99 kg（-4.07至-1.90 kg）至+3.45 kg（2.29 - 4.61）kg]。