Background: Girls with precocious puberty have high LH levels and bone age was advanced over chronological age by 1 year. Obese children start puberty at an earlier age than non obese children. The mechanisms that cause obese children to grow faster starting from early childhood are not well defined.
Objective and hypotheses: We analysed the effects of obesity on luteinising hormone (LH) secretion by using gonadotropin-releasing hormone (GnRH) tests in girls with precocious puberty.
Method: A total of 621 subjects with idiopathic precocious puberty who completed gonadotropin-releasing hormone stimulation testing between 2007 and 2012 were included in the study. Subjects were divided into two groups based on BMI; the normal weight group (BMI between the 5th and 85th percentile) and the obese group (BMI greater than 85th percentile).
Results: In Tanner 2 girls, peak stimulated LH levels were 10.9±9.2 and 9.2±5.6 IU/L between normal weight and obese subjects, respectively (P=0.047). In Tanner 3 girls, peak stimulated LH levels were 15.5±11.7 and 11.1±7.5 IU/L, respectively (P=0.026). However, in Tanner 4 girls, peak stimulated LH levels were not significantly different between normal, overweight, and obese subjects. On multivariate analysis, BMI was significantly and negatively associated with peak LH in Tanner 2 and 3 girls.
Conclusion: In girls with CPP, increased BMI affects peak stimulated LH levels during the early pubertal stage (Tanner stages 2 and 3). However, BMI was not associated with LH secretion in Tanner stage 4 girls with CPP.
01 Oct 2015 - 03 Oct 2015