[Association between circulating leptin level and anthropometric parameters in girls with adolescent idiopathic...

To investigate the correlation between the circulating leptin level and the anthropometric parameters and parameters related to pubertal growth, and to explore the role of leptin in the abnormal growth pattern in girls with adolescent idiopathic scoliosis (AIS).

One hundred and twenty AIS girls selected randomly from the out-patient and in-patient departments, divided into 2 groups: Group A1 (n = 73, aged 10 - 13) and Group A2 (n = 47, aged 14 - 17), and 80 14 - 17 year-old healthy girl students receiving physical examination underwent measurement of body height and weight. Body mass index (BMI) was calculated. Peripheral fasting blood samples were collected to detect the level of leptin. The anthropometric data, pubertal status, and circulating leptin level were compared between the AIS girls and the controls. The relationships between leptin and age, menstrual status, body weight, height, BMI and Risser sign were analyzed in the AIS girls.

Eighty-eight AIS girls (73%) and 14 healthy girls (18%) had a BMI score less than 18.0. The mean leptin level of Group A1 was 6.2 microg/L, significantly lower than of Group A2 (8.6 microg/L, P = 0.024). Compared with the healthy controls, the AIS girls had significantly greater corrected height (162.7 cm vs. 160.2 cm, P = 0.026), lower weight (44.3 kg vs. 53.6 kg, P = 0.01), lower BMI (17.5 kg/m(2) vs. 20.9 kg/m(2), P = 0.01), and lower circulating leptin (8.6 microg/L vs. 14.9 microg/L), even after the adjustment for age and menstrual status. An inverse correlation was observed between the leptin level and the age at menarche (AIS, r = -0.428, P < 0.001; controls, r = -0.280, P = 0.013). Whereas, positive correlations were found between leptin and age, menstrual status, body weight, height, BMI, and Risser sign (r = 0.234 - 0.506, P = 0.01 - < 0.001).

AIS girls have markedly decreased circulating leptin level. Circulating leptin level is associated with body weight, BMI, and other growth parameters, suggesting that leptin may play an important role in the lower body mass in AIS girls.