Evaluation of body fluid-fat ratios in patients diagnosed with central puberty precox and premature thelarche

Objective: Precocious puberty (early puberty) is a common disease that affects children biologically, psychologically, and socially. GnRHa (gonadotropin-releasing hormone agonist) is the most common treatment used to reduce these effects. In this study, we aimed to evaluate the body fluid-fat distribution during follow-ups in cases diagnosed with premature thelarche, observe the rate of change in the follow-ups, and define prospectively the effect of GnRH agonists used in the treatment of central puberty precocious on body fluid-fat composition. Material and Method: Girls who applied to Çukurova University Faculty of Medicine Pediatric Endocrinology outpatient clinic with the complaint of precocious puberty between January 2021 and July 2021 and were diagnosed as 'Premature Thelarche' or 'Central Puberty Precocious' were included in the study. While children with a diagnosis of premature thelarche were followed without treatment, GnRH analogs were started for patients diagnosed with Central Puberty Precocious. Body fat-fluid ratios of the patients followed up with premature thelarche were measured three times at 3-month intervals with a bioimpedance device (Tanita BC480). Patients with central puberty precocious were weighed three times at the time of diagnosis, at the third month after the treatment, and at the sixth month after the treatment. At the time of initial diagnosis, the patients' chronological age, bone age, age at diagnosis, body weight (BW), bodyweight SD, height, height SD, body mass index (BMI), BMI SD, pubertal examination, radiological imaging, and treatment protocols were recorded. A total of 57 girls were evaluated, 11 patients in the premature thelarche group and 46 patients in the central prepubertal precocious group. Sixty-two completely healthy girls with age-appropriate pubertal findings were included in the study as the control group, anthropometric data were recorded, and body fat-fluid ratios were recorded with a bioimpedance device. Results: Anthropometric values (height, height SD, BW, BW SD, BMI, BMI SD) of the whole patient group diagnosed with premature thelarche and central precocious puberty were significantly higher than the control group. Central puberty precocious group, which is the treatment group; mean total body fat weight, body fat percentage, and total body fluid mass values increased statistically significantly after GnRHa treatment, but the fluid percentage did not change. Fat measurements in kilograms of the premature thelarche group decreased in the follow-ups. No significant change was detected in other measurements. Conclusion: BW, BW SD, BMI, BMI SD values of patients with early puberty complaints are higher than the prepubertal control group in the same age group. Our study suggests that high VA and BMI values may be one of the factors contributing to early puberty. In addition, it was shown that the use of GnRH agonists caused an increase in body fat mass, fat percentage, and fluid mass but did not cause a change in total body fluid percentage. This suggests that GnRH analog treatments may cause an increase in appetite. Key Words: Precocious puberty, Premature thelarche, GnRH agonist, body oil-fat ratio