Cheng Jiayu, Luo Yingying, Li Yufeng, Zhang Fang, Zhang Xiuying, Zhou Xianghai, Ji Linong
Department of Endocrinology and Metabolism, Peking University People's Hospital, No. 11, Xizhimen South Street, Xicheng District, Beijing, 100044, China.
Department of Endocrinology and Metabolism, Capital Medical University Pinggu Teaching Hospital, No. 59, Xinping North Road, Pinggu District, Beijing, 101200, China.
Nutr Metab (Lond). 2022 Aug 8;19(1):54. doi: 10.1186/s12986-022-00689-x.
Leptin is a peptide hormone secreted by adipose tissue and is an important determinant of obesity and its complications. The purpose of this study was to establish sex- and body mass index (BMI)-specific reference intervals for serum leptin in a Chinese population and investigate the factors influencing leptin concentrations.
Fasting serum leptin levels were assayed in 469 men and 773 women from randomly sampled Chinese residents. Blood glucose, insulin, hemoglobin A1c (HbA1c), liver enzymes, blood lipid profiles, creatinine, and uric acid (UA) levels were measured. Pearson's correlation coefficient and multiple linear regression analyses were used to estimate the relationship between serum leptin level and other variables. The reference intervals were determined by the 2.5th and 97.5th percentiles.
The mean ± standard deviation serum leptin level was much higher in women (20.92 ± 12.96 ng/mL) than in men (6.45 ± 5.53 ng/mL). The reference interval of serum leptin was 0.33-19.85 ng/mL in men and 3.60-54.86 ng/mL in women. The specific reference intervals of serum leptin in men with BMI of 20 to < 25 and 25 to < 27.5 kg/m were 0.42-12.32 and 2.17-20.22 ng/ml, respectively. The specific reference intervals of serum leptin in women with BMI of 20 to < 25 and 25 to < 27.5 kg/m were 4.11-38.09 and 8.27-48.66 ng/ml, respectively. BMI was significantly correlated with Ln (leptin) both in men (r = 0.698, P < 0.001) and women (r = 0.626, P < 0.001). In multivariate linear regression analysis, serum leptin was correlated with BMI, homeostasis model assessment of insulin resistance (HOMA-IR), UA in women, and plus triglyceride (TG) in men. The variance in serum leptin levels could be partially explained by these variables in both women (adjusted R = 0.447) and men (adjusted R = 0.552). In participants with leptin levels higher than the reference intervals, significantly higher levels of HOMA-IR, low-density lipoprotein cholesterol (LDL-C), UA, a higher proportion of central obesity (waist circumference [WC] > 90 cm), and metabolic syndrome were found in men, and significantly higher levels of HOMA-IR, UA and a higher proportion of central obesity (WC > 85 cm) were found in women.
This is the first study to establish sex- and BMI-specific reference intervals of leptin for both sexes in a large Chinese population. Serum concentration of leptin was predicted by BMI, HOMA-IR, UA in women, and TG in men.
瘦素是一种由脂肪组织分泌的肽类激素，是肥胖及其并发症的重要决定因素。本研究的目的是建立中国人群血清瘦素的性别和体重指数（BMI）特异性参考区间，并调查影响瘦素浓度的因素。
对随机抽取的中国居民中的469名男性和773名女性进行空腹血清瘦素水平检测。测量血糖、胰岛素、糖化血红蛋白（HbA1c）、肝酶、血脂谱、肌酐和尿酸（UA）水平。采用Pearson相关系数和多元线性回归分析来估计血清瘦素水平与其他变量之间的关系。参考区间由第2.5百分位数和第97.5百分位数确定。
女性血清瘦素水平的平均值±标准差（20.92±12.96 ng/mL）显著高于男性（6.45±5.53 ng/mL）。男性血清瘦素的参考区间为0.33 - 19.85 ng/mL，女性为3.60 - 54.86 ng/mL。BMI为20至<25 kg/m²和25至<27.5 kg/m²的男性血清瘦素的特异性参考区间分别为0.42 - 12.32和2.17 - 20.22 ng/mL。BMI为20至<25 kg/m²和25至<27.5 kg/m²的女性血清瘦素的特异性参考区间分别为4.11 - 38.09和8.27 - 48.66 ng/mL。BMI在男性（r = 0.698，P < 0.001）和女性（r = 0.626，P < 0.001）中均与Ln（瘦素）显著相关。在多元线性回归分析中，血清瘦素与女性的BMI、胰岛素抵抗稳态模型评估（HOMA-IR）、UA以及男性的甘油三酯（TG）相关。这些变量在女性（调整R² = 0.447）和男性（调整R² = 0.552）中均可部分解释血清瘦素水平的差异。在瘦素水平高于参考区间的参与者中，男性的HOMA-IR、低密度脂蛋白胆固醇（LDL-C）及UA水平显著更高，中心性肥胖（腰围[WC]>90 cm）比例更高，代谢综合征患病率更高；女性的HOMA-IR、UA水平显著更高，中心性肥胖（WC>85 cm）比例更高。
这是首次在大量中国人群中建立男女两性瘦素的性别和BMI特异性参考区间的研究。女性的血清瘦素浓度可由BMI、HOMA-IR、UA预测，男性则由BMI、HOMA-IR、TG预测。
