Functional state of the GH/IGF-1 system in adolescents with type 1 diabetes mellitus

Purpose: to study the level of growth hormone (GH) and insulin-like growth factor type 1 (IGF-1) in patients with type 1 diabetes mellitus (DM1) at the stages of puberty.

Material & Methods: 165 children (85 girls (51.5%) and 80 boys (48.5%), aged 8 to 18 years old, suffering from DM1 and staying in the endocrinology department of the State Institution "Institute of Health for Children and Adolescents”) of the National Academy of Medical Sciences of Ukraine" (State Institution "IOZGP NAMS"). The criterion for inclusion in the study was the duration of T1DM for more than one year (from 1 to 16 years). The level of GH and IGF-1 was determined in 165 children 8-18 years old (85 girls and 80 boys) with DM1, taking into account gender, the level of sexual development at the time of the survey, the duration of DM1 and the level of glycemic control. Study participants were divided into groups depending on the level of sexual development (T1-T4) at the time of the study, assessed by the Marshall & Tanner scale (Marshall, & Tanner, 1969; Marshall, & Tanner, 1970); duration of DM1 (<5 years, 5 to 10 years, >10 years); level of glycemic control (optimal (HbA1c<7.5%), suboptimal (7.5%≤HbA1c≤9.0%), high-risk (HbA1c>9.0%) according to ISPAD 2018 recommendations (DiMeglio, et al., 2018)

Results: in adolescents with DM1, a physiological type of activation of the GH/IGF-1 system was established with an increase in its activity during the period of puberty proper. Sexual characteristics were determined in the levels of GH and IGF-1 at the stages of puberty. Girls had higher levels of IGF-1 than boys, especially during prepuberty. During prepuberty and puberty proper, GH values were higher in boys, and in late puberty, in girls. It has been established that in girls and boys with an increase in the duration of diabetes, there is an increase in the level of GH and a decrease in IGF-1. The nature of the state of GH/IGF-1 in patients with different experience of DM1 is affected by the level of sexual development at the time of the examination and the sex of adolescents. In boys aged 14-18 years (the period of proper and late puberty), with an increase in the duration of the disease, an increase in the level of GH (pk-w<0.05) and a decrease in IGF-1 (p<0.05) occur. In girls, an increase in GH (pk-w<0.05) and a decrease in IGF-1 (pk-w<0.05) with an increase in the duration of DM1 were recorded only in the group of patients aged 16-18 years (late puberty). The relationship between HbA1c and GH and IGF-1 levels has gender specifics: in the state of decompensation, the guys showed a tendency to decrease in GH, and in girls – to increase GH and IGF-1.

Conclusions: the functional state of the GH/IGF-1 system in adolescents with DM1 depends on gender, the level of sexual development, the duration of diabetes and the state of carbohydrate metabolism compensation, which coincides with the data of domestic and foreign studies.