Insulin resistance in adolescents with Turner syndrome is comparable to obese peers, but the overall metabolic risk is lower due to unknown mechanism

Purpose An increased risk of insulin resistance, hypertension and liver dysfunction is related to obesity (Ob), but may be also present in normal-weight Turner syndrome (TS) patients. The aim of the study was to compare metabolic risk in adolescents with TS and Ob. Methods The study included 21 non-obese with TS (all receiving human recombinant growth hormone, 17/21 estrogen/estrogen-progesterone), and 21 age-matched Ob girls (mean age 13.9 years). Glucose and serum insulin levels were assessed fasting and in 120' of standard oral glucose tolerance test. Levels of triglycerides (TG), total cholesterol (TC), low-density lipoprotein (LDL) and high-density lipoprotein (HDL) cholesterol, alanine aminotransferase (ALT), FGF19, FGF21 and FGF23 levels were measured fasting. Results Mean BMI SDS was significantly lower in TS patients (0.1 vs 4.8 SD, p < 0.001). The mean systolic and diastolic blood pressure was significantly lower in TS patients (102.6 vs 124.2 mmHg, p < 0.001 and 67.1 vs 76.5 mmHg, p = 0.02). There were no differences concerning mean fasting, and post-load glucose (4.5 vs 4.3, 5.1 vs 5.8 mmol/L), and insulin (14.97 vs 17.19 and 69.3 vs 98.78 mu IU/mL) levels, HOMA-IR (3.02 vs 3.4), TC (4.05 vs 4.4 mmol/L), TG (1.25 vs 1.37 mmol/L), ALT (26.9 vs 28.3 IU/L), FGF19 (232.8 vs 182.7 pg/mL), and FGF23 (12.3 vs 17.5 pg/mL) levels. Mean LDL (2.05 vs 2.7 mmol/L, p = 0.003) and FGF21 (293.9 vs 514.7 pg/mL, p = 0.007) levels were significantly lower, and HDL (1.7 vs 1.2 mmol/L, p < 0.001) level higher in TS group. Conclusions Insulin resistance in adolescents with TS on growth hormone treatment is comparable to Ob patients, but overall metabolic risk factors seem to be lower.