Causes of Precocious Puberty in Children Referred to an Endocrine Clinic in Qazvin City, Iran From 2006 to 2018

Puberty is an essential milestone in a person’s life. Studies show that precocious puberty is more common in girls than in boys. 

The aim of this study was to survey the causes of precocious puberty in children referred to the endocrine clinic in Qazvin city, Iran, from 2006 to 2018. 

This case-series study was performed from March 2006 to June 2018 on patients referred to the endocrine clinic of Qazvin University of Medical Sciences, Qazvin City, Iran, for precocious puberty. To diagnose premature puberty and find its causes, we surveyed sex steroids levels, thyroid function, and, if necessary, performed GnRH test. The patients’ height and weight were measured, and their BMIs (Body Mass Index) were calculated. Uterine ultrasound was performed for all girls. Additionally, brain MRI was performed for all boys and girls under age 6 with precocious puberty. X-ray of the left hand was performed to assess skeletal growth acceleration.Based on the type of puberty, the patients were divided into three groups: Central Precocious Puberty (CPP), Peripheral Precocious Puberty (PPP), and normal variant of puberty. The study data were collected from patients› electronic files and analyzed using SPSS 23.

Out of 724 cases, 642 (88.70%) were girls. The mean age of all children was 7.07 (95%CI: 6.99-7.15) years. About 70.5% of cases had CPP, 5% PPP, and 24.5% normal variant of puberty. Cases of Idiopathic Precocious Puberty (IPP), PPP, Neurogenic Central Precocious Puberty (NCPP), and premature pubarche were significantly higher in girls than boys (P<0.001). None of the boys had NCPP. Most girls had normal BMI, but boys were more obese. Mean bone age and bone age/age ratio were higher in girls with NCPP (P<0.001). 

In our study, most girls and boys had idiopathic precocious puberty, and none of the boys had brain lesions. About half of the cases were overweight or obese, indicating the role of obesity in increasing bone age and the onset of puberty.