Hindawi Publishing Corporation Journal of Obesity Volume 2010, Article ID 892081, 10 pages doi:10.1155/2010/892081
Research Article Adiponectin and Leptin Metabolic Biomarkers in Chinese Children and Adolescents Jie Mi,1 Mercedes Nancy Munkonda,2 Ming Li,3 Mei-Xian Zhang,1 Xiao-Yuan Zhao,1 Ponce Cedric Wamba Fouejeu,4 and Katherine Cianflone2 1 Department
of Epidemiology, Capital Institute of Pediatrics, Beijing 100020, China of Endocrinology, Peking Union Medical College Hospital, Peking Union Medical College and Chinese Academy of Medical Sciences, Beijing 100730, China 3 Centre de Recherche Institut, Universitaire de Cardiologie et Pneumologie de Quebec, Universit´ e Laval, 2725 Chemin Ste-Foy, Qu´ebec, QC, Canada G1V 4G5 4 Laboratory of Nutrition and Nutritional Biochemistry, University of Yaound´ e, Yaound´e, Cameroon 2 Department
Correspondence should be addressed to Katherine Cianflone,
[email protected] Received 25 June 2010; Accepted 6 September 2010 Academic Editor: Paul Trayhurn Copyright © 2010 Jie Mi et al. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited. Objective. To evaluate leptin and adiponectin as biomarkers of metabolic syndrome (MS) risk factors even in nonobese children/adolescents. Methods. Serum leptin, adiponectin, leptin:adiponectin ratio, lipids, glucose, and insulin concentrations as well as body size parameters and pubertal development were evaluated in a large population of Chinese children/adolescents (n = 3505, 6–18 years, 1722 girls and 1783 boys). Results. Leptin concentration increased while adiponectin decreased with obesity, both were influenced by pubertal development. Central obesity had an additive effect on leptin levels (above obesity alone). Leptin/adiponectin increased 8.4-fold and 3.2-fold in overweight/obesity, and 15.8- and 4.5-fold with obesity plus MS, in early and late puberty, respectively. Even in normal weight children/adolescents, higher leptin and lower adiponectin concentrations associated with increased risk profile. Conversely, overweight/obese with lower leptin or higher adiponectin concentrations had a less compromised metabolic profile. Conclusion. Leptin, adiponectin, and leptin:adiponectin ratio are informative biomarkers for obesity, central obesity, MS, and abnormal metabolic profile even in normal weight children/adolescents.
1. Introduction The alarming increase in obesity worldwide is of concern, due to the associations of obesity with metabolic syndrome (MS), insulin resistance, Type 2 diabetes, dyslipidaemia and cardiovascular disease [1, 2]. This increase is noted even in populations previously at reduced risk, such as Asia [3], even in children [4]. MS is characterized by central obesity, insulin resistance, hyperglycaemia, dyslipidaemia (increased triglyceride and decreased HDL), and hypertension; all risk factors for cardiovascular disease and Type 2 diabetes mellitus. Characterization of MS potentially identifies individuals predisposed to cardiovascular disease and Type 2 diabetes, allowing measures to be instituted early-on [3]. Adult urban versus rural populations are at higher MS risk [5] and prevalence varies with gender, age, ethnic background, and residence
[1, 5]. Puberty, with naturally occurring growth spurts and hormonal changes coupled to behavioural changes, is a critical period for development of obesity and childhood MS [6]. Further, the associated pathological processes and risk factors have been observed in obese children and adolescents [7–9]. Adipose tissue secretes adipokines influencing body weight, glucose, and lipid metabolism [7]. Adiponectin, a collagen-like protein exclusively expressed in adipose tissue, has antiatherogenic, antidiabetic and anti-inflammatory properties [10–12]. Increased adiponectin is associated with a lower risk of impaired glucose tolerance, decreased myocardial infarction risk, and has been proposed as a biomarker of early atherosclerosis [10, 11, 13]. Adiponectin decreases in obesity and related diseases, and may be involved
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Journal of Obesity
Table 1: Anthropometric and metabolic parameters in girls and boys. Data are expressed as mean ± SD where ∗∗ P < .01 and ∗∗∗ P < .001. For Tanner, the number (percentage) of participants is presented with χ 2 test. # Skewed distributions were logarithmically transformed for t-test. Variables n Age (years) Pubertal development Tanner stage I Tanner stage II Tanner stage III Tanner stage IV Tanner stage V Leptin (ng/ml)# Adiponectin (μg/ml)# Ratio leptin/adiponectin# Body mass index (kg/m2 ) Waist circumference (cm) Waist to height ratio Fat mass percentage (%) Systolic BP (mm Hg) Diastolic BP (mm Hg) Triglycerides (mmol/l)# Total cholesterol (mmol/l) HDL-C (mmol/l) LDL cholesterol (mmol/l) Glucose (mmol/l) Insulin (mU/l)# HOMA-IR#
All 3505 12.4 ± 3.1 3388 1001(29.5) 486(14.3) 464(13.7) 813(24.0) 624(18.4) 10.0 ± 11.4 12.8 ± 7.4 1.24 ± 1.90 21.9 ± 4.9 72.4 ± 13.1 0.47 ± 0.07 24.4 ± 8.5 107.6 ± 13.9 67.8 ± 10.0 1.03 ± 0.56 4.09 ± 0.79 1.40 ± 0.32 2.54 ± 0.72 5.10 ± 0.62 10.46 ± 9.95 2.43 ± 2.62
Girls 1722 12.6 ± 3.1∗∗∗ 1693 336(19.8) 216(12.8) 208(12.3) 610(36.0) 323(19.1)∗∗∗ 11.0 ± 11.6∗∗∗ 13.2 ± 7.2∗∗∗ 1.33 ± 2.10∗∗∗ 21.0 ± 4.5∗∗∗ 68.6 ± 10.8∗∗∗ 0.46 ± 0.06∗∗∗ 25.6 ± 9.0∗∗∗ 104.7 ± 12.3∗∗∗ 66.8 ± 9.4∗∗∗ 1.03 ± 0.55 4.11 ± 0.81 1.42 ± 0.30∗∗ 2.56 ± 0.74 5.03 ± 0.67∗∗∗ 10.18 ± 8.92 2.33 ± 2.29
Boys 1783 12.2 ± 3.0 1695 665(39.2) 270(15.9) 256(15.1) 203(12.0) 301(17.8) 9.1 ± 11.2 12.3 ± 7.6 1.15 ± 1.68 22.8 ± 5.2 76.0 ± 14.0 0.49 ± 0.07 23.2 ± 7.8 110.4 ± 14.8 68.8 ± 10.5 1.02 ± 0.57 4.07 ± 0.78 1.39 ± 0.34 2.53 ± 0.71 5.15 ± 0.55 10.72 ± 10.84 2.52 ± 2.90
Table 2: Pearson correlation coefficients of leptin and adiponectin. # Skewed distributions logarithmically transformed for Pearson correlation. Significances are ∗ P < .05, ∗∗ P < .01, and ∗∗∗ P < .001. Leptin# Variables n Age Leptin# Adiponectin# Body mass index Waist circumference Waist to height ratio Fat mass percentage Systolic BP Diastolic BP Triglycerides# Total cholesterol HDL-C LDL cholesterol Glucose Insulin# HOMA-IR#
Girls NonOwt Owt/Ob 963 722 0.253∗∗∗ 0.517∗∗∗ — — −0.219∗∗∗ −0.097∗∗ 0.469∗∗∗ 0.691∗∗∗ ∗∗∗ 0.708 0.466∗∗∗ ∗∗∗ 0.375 0.354∗∗∗ 0.734∗∗∗ 0.498∗∗∗ ∗∗∗ 0.150∗∗∗ 0.294 ∗∗∗ 0.274 0.133∗∗∗ ∗∗∗ 0.342 0.218∗∗∗ NS NS −0.193∗∗∗ NS NS NS NS 0.121∗∗∗ 0.510∗∗∗ 0.425∗∗∗ 0.502∗∗∗ 0.409∗∗∗
Adiponectin# Boys
NonOwt 680 0.033 — −0.114∗∗ 0.377∗∗∗ 0.351∗∗∗ 0.432∗∗∗ 0.446∗∗∗ NS NS 0.281∗∗∗ 0.140∗∗∗ −0.088 0.153∗∗∗ NS 0.366∗∗∗ 0.364∗∗∗
Owt/Ob 1064 −0.172∗∗∗ — 0.018 0.272∗∗∗ 0.291∗∗∗ 0.466∗∗∗ 0.386∗∗∗ NS NS 0.272∗∗∗ 0.154∗∗∗ NS 0.153∗∗∗ NS 0.339∗∗∗ 0.326∗∗∗
Girls NonOwt Owt/Ob 986 725 −0.191∗∗∗ −0.201∗∗∗ −0.219∗∗∗ −0.097∗∗ — — −0.282∗∗∗ −0.240∗∗∗ −0.267∗∗∗ −0.288∗∗∗ ∗∗∗ −0.180 −0.141∗∗∗ −0.271∗∗∗ −0.230∗∗∗ ∗∗∗ −0.173 −0.109∗∗ ∗∗∗ −0.108 NS −0.144∗∗∗ −0.172∗∗∗ NS NS 0.246∗∗∗ 0.231∗∗∗ NS NS NS NS −0.201∗∗∗ −0.211∗∗∗ −0.200∗∗∗ −0.197∗∗∗
Boys NonOwt Owt/Ob 708 1066 −0.350∗∗∗ −0.366∗∗∗ −0.114∗∗ 0.018 — — −0.301∗∗∗ −0.329∗∗∗ −0.329∗∗∗ −0.346∗∗∗ NS −0.082∗∗ −0.157∗∗∗ NS ∗∗∗ −0.202 −0.225∗∗∗ ∗∗ −0.099 −0.126∗∗∗ ∗∗ −0.109 −0.144∗∗∗ NS NS 0.231∗∗∗ 0.326∗∗∗ NS NS NS 0.068 −0.201∗∗∗ −0.270∗∗∗ −0.196∗∗∗ −0.247∗∗∗
n Leptin (ng/mL)# Adiponectin (μg/mL)# Body mass index (kg/m2 ) Waist circumference (cm) Waist to height ratio Fat mass percentage (%) Systolic BP (mm Hg) Diastolic BP (mm Hg) Triglycerides (mmol/l)# Total cholesterol (mmol/l) HDL-C (mmol/l) LDL cholesterol (mmol/l) Glucose (mmol/L) Insulin (mU/L)# HOMA-IR#
Boys
n Leptin (ng/mL)# Adiponectin (μg/mL)# Body mass index (kg/m2 ) Waist circumference (cm) Waist to height ratio Fat mass percentage (%) Systolic BP (mm Hg) Diastolic BP (mm Hg) Triglycerides (mmol/l)# Total cholesterol (mmol/l) HDL-C (mmol/l) LDL cholesterol (mmol/l) Glucose (mmol/L) Insulin (mU/L)# HOMA-IR#
Girls
Q1 64 0.3 ± 0.1 18.9 ± 10.0 15.3 ± 1.2 54.6 ± 3.8 0.42 ± 0.02 13.1 ± 2.2 98.0 ± 13.9 63.1 ± 11.7 0.70 ± 0.30 4.12 ± 0.76 1.72 ± 0.40 2.38 ± 0.63 5.13 ± 1.52 3.71 ± 3.17 0.84 ± 0.74
Q1 56 0.4 ± 0.1 17.9 ± 8.8 14.6 ± 1.3 52.3 ± 3.8 0.41 ± 0.02 11.5 ± 3.1 94.3 ± 14.3 59.7 ± 10.7 0.74 ± 0.32 4.29 ± 0.98 1.60 ± 0.30 2.77 ± 0.86 4.75 ± 0.39 3.35 ± 1.96 0.72 ± 0.45
Q1 109 3.9 ± 1.4 14.2 ± 8.4 22.5 ± 2.3 73.1 ± 7.6 0.53 ± 0.04 25.4 ± 5.9 107.2 ± 11.5 68.0 ± 9.7 0.91 ± 0.43 4.11 ± 0.65 1.43 ± 0.31 2.57 ± 0.61 5.13 ± 0.48 7.74 ± 6.86 1.83 ± 1.95
Early puberty Q5 75 5.5 ± 4.2 16.5 ± 8.4 17.7 ± 1.8∗∗∗ 63.1 ± 6.2∗∗∗ 0.45 ± 0.03∗∗∗ 19.3 ± 5.4∗∗∗ 98.1 ± 9.7 61.2 ± 8.4 0.90 ± 0.40∗∗∗ 4.49 ± 0.91 1.64 ± 0.38 2.74 ± 0.86∗∗ 5.21 ± 0.53 6.60 ± 3.99∗∗∗ 1.53 ± 0.95∗∗∗
NonOwt
Q1 43 3.4 ± 1.2 13.1 ± 5.4 20.9 ± 1.8 67.4 ± 6.7 0.50 ± 0.04 25.6 ± 4.2 106.8 ± 10.3 68.7 ± 9.4 0.93 ± 0.40 3.94 ± 0.74 1.35 ± 0.30 2.50 ± 0.54 5.08 ± 0.44 7.70 ± 3.87 1.77 ± 0.95
Early puberty Q5 62 8.2 ± 6.3 14.8 ± 7.1 17.6 ± 1.6∗∗∗ 61.0 ± 5.2∗∗∗ 0.43 ± 0.03∗∗∗ 19.3 ± 3.9∗∗∗ 99.4 ± 9.9 62.6 ± 9.0 1.15 ± 0.48∗∗∗ 4.38 ± 0.83 1.47 ± 0.28 2.75 ± 0.82 4.96 ± 0.44∗∗ 6.56 ± 3.17∗∗∗ 1.46 ± 0.75∗∗∗
NonOwt
Q5 110 37.7 ± 11.9 11.0 ± 6.6∗∗ 26.8 ± 3.0∗∗∗ 86.8 ± 7.8∗∗∗ 0.58 ± 0.04∗∗∗ 31.8 ± 5.2∗∗∗ 114.2 ± 11.2∗∗∗ 71.3 ± 8.7∗∗ 1.39 ± 0.55∗∗∗ 4.24 ± 0.82 1.31 ± 0.28∗∗ 2.73 ± 0.68 5.13 ± 0.44 18.19 ± 14.34∗∗∗ 4.29 ± 3.98∗∗∗
Owt/Ob
Q5 43 31.5 ± 8.4 12.1 ± 5.6 23.7 ± 2.6∗∗∗ 75.2 ± 7.4∗∗∗ 0.53 ± 0.04∗∗∗ 32.2 ± 4.8∗∗∗ 105.2 ± 10.2 69.3 ± 8.1 1.36 ± 0.62∗∗∗ 4.42 ± 0.86∗∗ 1.36 ± 0.25 2.86 ± 0.76 4.94 ± 0.52 13.56 ± 7.46∗∗∗ 3.00 ± 1.71∗∗∗
Owt/Ob
Q1 28 0.3 ± 0.1 14.1 ± 8.3 18.7 ± 1.5 66.4 ± 3.3 0.39 ± 0.02 15.3 ± 3.3 110.3 ± 6.5 71.1 ± 7.3 0.67 ± 0.16 3.80 ± 0.85 1.45 ± 0.30 2.33 ± 0.76 5.37 ± 0.67 5.34 ± 3.05 1.28 ± 0.77
Q1 102 1.8 ± 0.5 15.6 ± 7.9 17.9 ± 1.8 61.9 ± 3.7 0.39 ± 0.02 19.0 ± 3.7 104.0 ± 10.8 66.2 ± 8.3 0.84 ± 0.37 4.23 ± 0.94 1.56 ± 0.31 2.58 ± 0.91 5.04 ± 0.68 7.27 ± 5.72 1.74 ± 2.09
Q1 60 2.0 ± 0.7 8.1 ± 4.4 26.0 ± 2.1 83.5 ± 5.3 0.49 ± 0.03 24.2 ± 4.7 121.3 ± 11.2 74.0 ± 8.6 0.98 ± 0.45 3.73 ± 0.77 1.25 ± 0.39 2.33 ± 0.68 5.15 ± 0.49 9.78 ± 9.29 2.33 ± 2.78
Late puberty Q5 37 6.7 ± 10.2 12.0 ± 5.6 21.2 ± 2.0∗∗∗ 73.7 ± 6.0∗∗∗ 0.43 ± 0.03∗∗∗ 20.5 ± 6.3∗∗∗ 112.2 ± 12.2 70.7 ± 7.1 1.15 ± 0.65∗∗∗ 4.26 ± 1.29 1.38 ± 0.28 2.67 ± 1.21 5.22 ± 0.48 10.40 ± 6.23∗∗∗ 2.46 ± 1.57∗∗∗
NonOwt
Q1 79 6.3 ± 2.2 10.6 ± 5.9 25.1 ± 2.1 77.5 ± 6.1 0.49 ± 0.03 32.8 ± 4.4 111.2 ± 9.7 70.2 ± 7.5 0.98 ± 0.66 4.00 ± 0.83 1.28 ± 0.25 2.59 ± 0.71 5.40 ± 1.82 10.54 ± 4.79 2.51 ± 1.26
Late puberty Q5 106 17.4 ± 7.3 12.8 ± 7.0∗∗ 21.2 ± 1.9∗∗∗ 70.0 ± 5.2∗∗∗ 0.44 ± 0.03∗∗∗ 27.4 ± 4.4∗∗∗ 105.6 ± 10.1 67.9 ± 7.6 1.17 ± 0.63∗∗∗ 4.28 ± 1.00 1.43 ± 0.30∗∗ 2.67 ± 0.94 5.08 ± 0.39 11.62 ± 7.96∗∗∗ 2.65 ± 1.83∗∗∗
NonOwt
Q5 62 24.7 ± 8.3 8.5 ± 4.4 31.7 ± 3.2∗∗∗ 99.0 ± 7.9∗∗∗ 0.58 ± 0.05∗∗∗ 31.0 ± 6.2∗∗∗ 128.9 ± 11.7∗∗∗ 77.5 ± 10.6 1.49 ± 0.91∗∗∗ 4.03 ± 0.79 1.14 ± 0.27 2.60 ± 0.61 5.37 ± 0.57∗ 22.29 ± 14.93∗∗∗ 5.46 ± 4.34∗∗∗
Owt/Ob
Q5 80 42.8 ± 11.2 10.3 ± 5.5 28.9 ± 3.8∗∗∗ 86.0 ± 9.0∗∗∗ 0.54 ± 0.06∗∗∗ 40.5 ± 7.0∗∗∗ 115.2 ± 10.7 73.2 ± 9.1 1.16 ± 0.48∗∗ 3.95 ± 0.73 1.28 ± 0.26 2.46 ± 0.66 5.26 ± 0.59 19.92 ± 11.76∗∗∗ 4.67 ± 2.82∗∗∗
Owt/Ob
Table 3: Metabolic profile in lower quintile (Q1) and upper quintile (Q5) of leptin according to weight status and puberty stage. Data are reported as mean ± SD for Q5 and Q1 where, ∗∗ P < .01 and ∗∗∗ P < .001. # Skewed distributions were logarithmically transformed for t-test.
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n Adiponectin (μg/mL)# Leptin (ng/mL)# Body mass index (kg/m2 ) Waist circumference (cm) Waist to height ratio Fat mass percentage (%) Systolic BP (mm Hg) Diastolic BP (mm Hg) Triglycerides (mmol/l)# Total cholesterol (mmol/l) HDL-C (mmol/l) LDL cholesterol (mmol/l) Glucose (mmol/L) Insulin (mU/L)# HOMA-IR#
Boys
n Adiponectin (μg/mL)# Leptin (ng/mL)# Body mass index (kg/m2 ) Waist circumference (cm) Waist to height ratio Fat mass percentage (%) Systolic BP (mm Hg) Diastolic BP (mm Hg) Triglycerides (mmol/l)# Total cholesterol (mmol/l) HDL-C (mmol/l) LDL cholesterol (mmol/l) Glucose (mmol/L) Insulin (mU/L)# HOMA-IR#
Girls
Q5 74 32.6 ± 9.1 1.5 ± 2.0 16.0 ± 1.2 57.1 ± 4.2 0.43 ± 0.03 15.6 ± 3.9 96.0 ± 12.7 61.3 ± 11.3 0.71 ± 0.24 4.34 ± 1.00 1.75 ± 0.43 2.58 ± 0.87 5.10 ± 1.45 4.72 ± 4.04 1.05 ± 0.87
Q5 64 29.5 ± 4.6 1.9 ± 2.1 15.2 ± 1.4 53.8 ± 4.3 0.41 ± 0.02 13.0 ± 3.1 91.6 ± 10.6 58.2 ± 9.0 0.90 ± 0.50 4.29 ± 0.84 1.58 ± 0.36 2.63 ± 0.77 4.76 ± 0.43 4.25 ± 2.60 0.93 ± 0.61
Q1 111 4.9 ± 1.4 17.7 ± 13.2∗∗ 25.5 ± 2.6∗∗∗ 83.6 ± 8.2∗∗∗ 0.56 ± 0.05∗∗∗ 28.5 ± 5.6 112.9 ± 9.7∗∗∗ 70.4 ± 7.9 1.30 ± 0.65∗∗∗ 4.27 ± 0.69 1.29 ± 0.27∗∗∗ 2.77 ± 0.66 5.09 ± 0.54 16.37 ± 18.95∗∗∗ 3.85 ± 4.91∗∗∗
Owt/Ob
Q1 43 5.4 ± 1.9 15.3 ± 12.9 22.9 ± 2.6∗∗∗ 73.5 ± 8.1∗∗∗ 0.52 ± 0.04 29.8 ± 5.3∗∗ 107.4 ± 12.7 68.1 ± 7.5 1.31 ± 0.85 4.01 ± 0.78 1.22 ± 0.24∗∗∗ 2.61 ± 0.71 4.90 ± 0.53 12.08 ± 6.33∗∗ 2.64 ± 1.38
Owt/Ob
Q5 110 22.4 ± 7.0 13.2 ± 11.4 23.1 ± 2.7 75.2 ± 8.4 0.53 ± 0.04 27.1 ± 6.6 108.0 ± 11.8 68.2 ± 9.8 0.98 ± 0.41 4.37 ± 0.72 1.51 ± 0.28 2.74 ± 0.64 5.20 ± 0.37 8.13 ± 4.62 1.89 ± 1.13
Early puberty Q1 76 7.5 ± 2.0 2.1 ± 3.0 16.7 ± 1.8 60.1 ± 6.1∗∗∗ 0.42 ± 0.03 15.9 ± 5.1 99.3 ± 12.7 60.6 ± 10.3 0.82 ± 0.55 4.06 ± 0.78 1.57 ± 0.35∗∗ 2.40 ± 0.69 5.03 ± 0.51 5.02 ± 3.63 1.12 ± 0.84
NonOwt
Q5 44 21.6 ± 4.6 12.4 ± 9.3 21.1 ± 2.0 67.2 ± 6.5 0.50 ± 0.03 26.2 ± 4.3 103.1 ± 9.6 66.9 ± 8.5 0.95 ± 0.33 3.99 ± 0.60 1.42 ± 0.30 2.45 ± 0.53 5.00 ± 0.41 8.71 ± 4.52 1.94 ± 1.05
Early puberty Q1 67 7.6 ± 2.3 3.0 ± 3.7 16.3 ± 2.0∗∗∗ 56.9 ± 6.1∗∗∗ 0.42 ± 0.03 15.6 ± 5.0∗∗∗ 96.5 ± 11.5 60.8 ± 9.4 0.97 ± 0.56 4.05 ± 0.61 1.49 ± 0.26 2.44 ± 0.55 4.78 ± 0.39 5.42 ± 3.17 1.17 ± 0.73
NonOwt
∗∗∗
Q1 106 5.6 ± 1.7 8.9 ± 6.9∗∗ 20.2 ± 2.1∗∗∗ 68.1 ± 5.1∗∗∗ 0.43 ± 0.03∗∗∗ 25.0 ± 5.1∗∗∗ 106.1 ± 10.3 67.4 ± 7.7 1.12 ± 0.59∗∗∗ 4.17 ± 0.91 1.38 ± 0.31∗∗∗ 2.60 ± 0.83 5.10 ± 0.55 10.36 ± 7.35 2.41 ± 1.98
Q1 38 4.6 ± 1.5 1.3 ± 1.4 20.2 ± 2.1 71.5 ± 5.6 0.42 ± 0.03 18.9 ± 6.2 111.0 ± 9.7 69.9 ± 9.2 1.01 ± 0.60 3.94 ± 0.67 1.32 ± 0.32 2.45 ± 0.66 5.12 ± 0.44 8.61 ± 5.72 2.00 ± 1.43
Q1 79 4.4 ± 1.2 19.8 ± 11.5 27.3 ± 3.5 83.4 ± 8.2∗∗ 0.52 ± 0.05 37.2 ± 6.4 112.2 ± 10.3 72.2 ± 8.7 1.26 ± 0.96∗∗ 4.06 ± 0.86 1.16 ± 0.21∗∗∗ 2.67 ± 0.79 5.30 ± 0.97 18.54 ± 10.98∗∗∗ 4.35 ± 2.61∗∗∗
Owt/Ob Q5 Q1 61 60 15.7 ± 4.4 3.7 ± 1.2 8.4 ± 7.5 7.4 ± 6.5 27.3 ± 3.1 28.7 ± 3.5 87.7 ± 7.5 91.6 ± 9.5 0.52 ± 0.05 0.53 ± 0.05 26.4 ± 6.1 27.3 ± 5.1 122.2 ± 11.4 123.6 ± 14.2 73.9 ± 10.5 73.9 ± 9.0 1.01 ± 0.43 1.20 ± 0.57 3.80 ± 0.71 3.87 ± 0.76 1.27 ± 0.38 1.09 ± 0.18∗∗ 2.38 ± 0.62 2.57 ± 0.66 5.33 ± 0.52 5.09 ± 0.44∗∗ 12.47 ± 11.57 15.95 ± 13.27 3.10 ± 3.68 3.62 ± 2.89
Late puberty
Q5 84 18.2 ± 4.4 22.3 ± 15.3 26.3 ± 3.3 79.5 ± 8.2 0.51 ± 0.05 35.4 ± 6.1 113.7 ± 9.2 71.3 ± 7.6 0.94 ± 0.39 3.99 ± 0.71 1.36 ± 0.25 2.52 ± 0.67 5.23 ± 0.43 13.72 ± 7.54 3.20 ± 1.78
Owt/Ob
P < .001. # Skewed distributions were
Late puberty
P < .01 and
NonOwt Q5 39 21.4 ± 5.0 1.3 ± 1.0 19.8 ± 1.8 70.2 ± 5.3 0.41 ± 0.03 17.4 ± 4.3 113.0 ± 13.3 70.7 ± 8.8 0.83 ± 0.41 3.96 ± 1.03 1.36 ± 0.21 2.46 ± 1.00 5.23 ± 0.41 7.04 ± 3.80 1.67 ± 1.00
Q5 105 25.9 ± 7.0 7.0 ± 6.5 19.0 ± 2.1 65.3 ± 5.3 0.41 ± 0.03 22.1 ± 4.8 103.2 ± 9.5 67.1 ± 6.7 0.91 ± 0.30 4.31 ± 0.82 1.63 ± 0.30 2.57 ± 0.77 5.09 ± 0.57 8.93 ± 6.15 2.12 ± 2.11
∗∗
NonOwt
Table 4: Metabolic profile in lower (Q1) versus upper quintile (Q5) of adiponectin. Data are reported as mean±SD where, logarithmically transformed for t-test.
4 Journal of Obesity
Journal of Obesity in cardiovascular disease and Type 2 diabetes mellitus pathology [14]. Leptin, a cytokine-like molecule secreted by adipose tissue, regulates adipose mass and body weight by inhibiting food intake and stimulating energy expenditure [15, 16]. Leptin increases in obesity, Type 2 diabetes mellitus, hypertension and MS. Numerous publications in adults suggest leptin as a biomarker for obesity, insulin resistance, and MS [15, 16]. Obesity, MS prevalence and associated risk factors in children and adolescents have increased dramatically over decades [4, 8], including in Chinese populations [1, 2, 17, 18]. This relationship is difficult to evaluate as obesityinduced acute insulin resistance is usually identified later, and many changes are associated with pubertal and socioeconomic changes [6, 19, 20]. Leptin and adiponectin are proposed as biomarkers in children for predicting MS, Type 2 diabetes, or cardiovascular disease [21]; however, the lack of defined cutoff markers complicates this [22]. Many studies on leptin and/or adiponectin in children [12, 23–25], including Asian children [5, 26, 27], suffer from small sample sizes, with only two studies over 800–1000 children, limiting subgroup analysis. Recently, leptin-to-adiponectin ratio was proposed as a biomarker with the benefits of both indices [28–30] included in Chinese adults [5]. In Hispanic youth [31] leptin-toadiponectin ratio provided an independent predictor of insulin sensitivity during growth [31]. In this study, we evaluated adipokines, anthropometric, and lipid parameters in a large study of 3505 Chinese children and adolescents aged 6–18 years old. We demonstrate that even in normal weight children and adolescents, leptin and adiponectin are informative biomarkers of risk, and also discriminate between lower versus higher risk in overweight/obese subjects.
2. Materials/Subjects and Methods 2.1. Subjects and Samples Collection. Subjects were recruited from a cross-sectional population-based survey: the Beijing Child and Adolescent Metabolic Syndrome (BCAMS) study as described elsewhere [32]. The cohort included 3505 children, 1722 girls, and 1783 boys of normal weight, overweight, and obese defined by age-gender-specific BMI according to the International Obesity Task Force (IOTF) [33]. Signed informed consent was obtained from participants and/or parents/guardians. The BCAMS study was approved by the Ethics Committee at Capital Institute of Pediatrics in Beijing. Subjects were evaluated for height, weight, waist circumference, Tanner stage, and fat mass % (by bioimpedance analysis). 2.2. Clinical and Metabolic Parameters. Venous blood samples were collected by direct venipuncture after an overnight (minimum 12 h) fast. The samples were centrifuged, serum and plasma aliquoted and immediately frozen and maintained at −80◦ C for later analysis of lipids and hormones. Samples were collected and analysed over a two-year period.
5 Blood samples were analyzed for glucose, triglyceride (TG), total cholesterol (TC), high-density lipoprotein cholesterol (HDL-C), low-density lipoprotein cholesterol (LDL-C), insulin, adiponectin, and leptin. Serum lipids (enzymatic methods) and plasma glucose (glucose oxidase method) were assayed using the Hitachi 7060 C automatic biochemistry analysis system. HDL-C and LDL-C were measured directly. Serum insulin was measured by monoclonal antibody-based sandwich enzyme-linked immunosorbent assays (ELISA) [34], developed in Key Laboratory of Endocrinology, Peking Union Medical College Hospital with interassay CVs of
