The incidence of non-thyroidal illness syndrome in children with type 1 diabetes mellitus and correlated factors analysis / 中华实用儿科临床杂志

ABSTRACT

Objective:To explore the incidence of non-thyroidal illness syndrome (NTIS) in children with type 1 diabetes mellitus (T1DM) and the correlation between triiodothyronine level and the severity of T1DM, thus providing evidence for clinical diagnosis and treatment.Methods:A total of 125 children initially diagnosed as T1DM at the Department of Endocrinology and Genetic Metabolism of Children′s Hospital of Shanghai Jiao Tong University from January 2015 to December 2019 were recruited.The data were retrospectively analyzed.The incidence of NTIS in T1DM children was explored.T1DM children were classified into euthyroid group and NTIS group, two independent sample t-test were used to compare the differences in multiple factors between euthyroid group and NTIS group in children with T1DM, and Spearman correlation analysis was used to further analyze the correlation between the levels of free triiodothyronine (FT3), total triiodothyronine (TT3) and the severity of children with primary T1DM. Results:The incidence of NTIS in 125 T1DM children was 26.4%(33/125 cases). FT3, TT3, total thyroxine (TT4), thyrotropin (TSH), pH value, HCO 3- and high density lipoprotein cholesterol (HDL-C) levels in NTIS group were significantly lower than those of euthyroid group [(3.10±0.45) pmol/L vs.(4.85±0.75) pmol/L, (0.60±0.28) nmol/L vs.(1.05±0.38) nmol/L, (65.77±23.41) nmol/L vs.(89.57±18.23) nmol/L, (0.91±0.89) mIU/L vs.(2.05±0.76) mIU/L, 7.21±0.17 vs.7.31±0.18, (11.49±7.54) mmol/L vs.(16.80±8.38) mmol/L, (1.08±0.49) mmol/L vs.(1.28±0.44) mmol/L]( t=4.56, 5.67, 4.48, 5.61, 2.82, 2.68, and 2.53, all P<0.05). Moreover, the anion gap (AG) level, blood glucose (BG) and triglyceride in NTIS group were significantly higher than those of euthyroid group [(22.53±8.33) mmol/L vs.(16.94±7.52) mmol/L, (24.85±4.71) mmol/L vs.(21.46±6.64) mmol/L, (2.72±2.05) mmol/L vs.(2.33±3.05) mmol/L]( t=3.22, 2.67 and 2.04, all P<0.05). The incidence of diabetic ketoacidosis (DKA) was statistically significant in euthyroid group, NTIS group and abnormal thyroid disease group (33.3% vs.63.6% vs.35.7%)( χ2=8.990, P<0.05). In T1DM children, FT3 was positively correlated with pH value and HCO 3-, and negatively correlated with AG level ( r=0.376 9, 0.439 7 and -0.411 9, all P<0.05). In addition, TT3 was positively correlated with pH value and HCO 3-, and negatively correlated with AG and BG ( r=0.513 2, 0.539 8, -0.482 4 and -0.211 5, all P<0.05). Conclusions:Children with T1DM are prone to have abnormal thyroid hormone levels, and the incidence of NTIS was 26.4%.The incidence of DKA differed in T1DM children with different thyroid functions.FT3 or TT3 level may contribute to evaluate the disease severity of T1DM children.