To observe the efficacy of low-dose triptorelin acetate injection combined with vitamin D drop in the treatment of central precocious puberty (CPP) in girls.

CPP children were divided into treatment group and control group using a cohort method. The treatment group received a low-dose of triptorelin acetate injection at 50 μg·kg^-1 via intramuscular injection every 4 weeks, along with oral vitamin D drop at 400 units. The control group received standard dose treatment, starting with an initial dose of 100 μg·kg^-1 via intramuscular injection, followed by a maintenance dose of 80 μg·kg^-1 every 4 weeks. Both groups were treated continuously for 12 months. The clinical efficacy, physical development, hormone levels, secretion levels of peptides and hormones related to the hypothalamic-pituitary-gonadal axis were compared between the two groups, along with safety evaluation.

During the trial, 42 cases were included in the treatment group and 37 cases in the control group. After treatment, the overall effective rates for the treatment and control groups were 90.48% (38 cases/42 cases) and 78.38% (29 cases/37 cases), respectively, with no statistically significant difference (P>0.05). After treatment, the predicted adult height for the treatment and control groups was (164.59±4.35) and (162.38±5.21) cm, respectively; the differences in bone age were (1.07±0.28) and (1.24±0.29) years; the growth rates were (5.35±1.17) and (5.93±1.24) cm·year^-1; estradiol levels were (13.11±5.67) and (16.08±4.73) pg·mL^-1; luteinizing hormone levels were (1.49±0.20) and (2.15±0.18) U·L^-1; follicle-stimulating hormone levels were (4.95±0.74) and (6.14±0.87) pg·mL^-1; neuropeptide kisspeptin levels were (1.02±0.19) and (1.20±0.40) μg·L^-1; neurokinin B levels were (0.35±0.08) and (0.41±0.08) μg·L^-1; anti-Müllerian hormone levels were (3.88±0.36) and (4.15±0.40) ng·L^-1; insulin-like growth factor-1 levels were (216.91±25.43) and (231.64±30.87) ng·mL^-1; 25-hydroxyvitamin D levels were (28.42±4.52) and (26.15±3.73) μg·L^-1, with statistically significant difference (all P<0.05). The main adverse drug reactions in the treatment group included nausea and vomiting, as well as pain and swelling at the injection site. In the control group, the main adverse drug reactions included slight vaginal bleeding, nausea and vomiting, pain and swelling at the injection site and rashes near the injection site. The overall incidence of adverse drug reactions in the treatment group and control group were 7.14% (3 cases/42 cases) and 16.22% (6 cases/37 cases), without statistically significant difference (P>0.05).

In children with CPP, the application of low-dose triptorelin combined with vitamin D drop can improve clinical efficacy, physical development, growth-related factors, hormone levels and the secretion levels of peptides and hormones associated with the hypothalamic-pituitary-gonadal axis. It can also slow the development of secondary sexual characteristics and inhibit gonadal development, while demonstrating good safety.