Jensen M D, Hensrud D, O'Brien P C, Nielsen S
Endocrine Research Unit, Mayo Foundation, Rochester, MN 55905, USA.
Obes Res. 1999 May;7(3):241-5. doi: 10.1002/j.1550-8528.1999.tb00402.x.
To reassess the relationship between body fat and plasma leptin concentrations when a) replicate measures of leptin are made; b) energy intake is controlled at isoenergetic levels before the study; and c) body fat and percent body fat are measured with dual energy X-ray absorptiometry (DXA).
Two separate studies were conducted. In the first study, four plasma samples were collected for measurement of leptin over 30 minutes on a single day in 43 lean and obese men and women. For the second study, plasma samples were collected on four consecutive days from a group of 50 lean and obese men and women. Percent body fat (and body fat mass) was related to log-transformed mean plasma leptin concentrations using linear regression analysis; multiple linear regression analysis was used to determine whether there was an effect of gender on this relationship, and the analysis of Choi was used to examine whether percent body fat or body fat mass better predicts plasma leptin concentrations.
For the first study, percent body fat was highly correlated (r=0.96, p<0.0001) with log-transformed mean leptin concentrations. No difference in the relationship between leptin and percent body fat in men and women was detected. The second study confirmed this observation; the relationship between ln leptin and percent body fat was virtually identical (r=0.93, p<0.001). Analysis of the pooled data suggests that percent body fat is a better predictor of plasma leptin concentration than body fat mass. The use of multiple (as opposed to a single) leptin measurements did not significantly improve the leptin/body fat relationship.
When robust body composition techniques and diet control measures are taken into consideration, the relationship between ln plasma leptin concentrations and percent body fat is not different in men and women.
当满足以下条件时，重新评估体脂与血浆瘦素浓度之间的关系：a）进行瘦素的重复测量；b）在研究前将能量摄入控制在等能量水平；c）使用双能X线吸收法（DXA）测量体脂和体脂百分比。
进行了两项独立研究。在第一项研究中，于同一天在43名瘦人和肥胖男女中，在30分钟内采集了四份血浆样本用于测量瘦素。在第二项研究中，从一组50名瘦人和肥胖男女中连续四天采集血浆样本。使用线性回归分析将体脂百分比（和体脂量）与对数转换后的平均血浆瘦素浓度相关联；使用多元线性回归分析确定性别对这种关系是否有影响，并使用Choi分析来检验体脂百分比或体脂量是否能更好地预测血浆瘦素浓度。
对于第一项研究，体脂百分比与对数转换后的平均瘦素浓度高度相关（r = 0.96，p < 0.0001）。未检测到男性和女性中瘦素与体脂百分比之间的关系存在差异。第二项研究证实了这一观察结果；ln瘦素与体脂百分比之间的关系几乎相同（r = 0.93，p < 0.001）。对汇总数据的分析表明，体脂百分比比体脂量是血浆瘦素浓度的更好预测指标。使用多次（而非单次）瘦素测量并未显著改善瘦素/体脂关系。
当考虑到可靠的身体成分技术和饮食控制措施时，男性和女性中ln血浆瘦素浓度与体脂百分比之间的关系并无差异。
