Euthyroid sick syndrome and its association with complications of type 1 diabetes mellitus onset

OBJECTIVE: To evaluate (i) the prevalence and association of euthyroid sick syndrome (ESS) [decreased FT3 and/or FT4 and normal/decreased TSH] with severity indexes of type 1 diabetes mellitus (T1DM) onset such as diabetic ketoacidosis (DKA) and kidney damage [acute kidney injury (AKI) based on KDIGO criteria, acute tubular necrosis (ATN), renal tubular damage (RTD)], (ii) relationship between clinical/metabolic parameters at T1DM onset and thyroid hormones, and (iii) ESS as a prognostic indicator of delayed recovery from kidney damage. METHODS: A total of 161 children with T1DM onset were included. RTD was defined by abnormal urinary beta-2-microglobulin and/or neutrophil gelatinase-associated lipocalin (NGAL) and/or tubular reabsorption of phosphate <85% and/or fractional excretion of Na>2%. ATN was defined by RTD+AKI. RESULTS: Of 161 participants, 60 (37.3%) presented ESS. It was more prevalent in case of more severe T1DM presentation both in terms of metabolic derangement (DKA) and kidney function impairment (AKI, RTD and ATN). Only ATN, however, was associated with ESS at adjusted analysis. FT3 inversely correlated with serum triglycerides and creatinine, and urinary calcium/creatinine ratio and NGAL. Participants with euthyroidism showed earlier recovery from AKI than those with ESS. ESS spontaneously disappeared. CONCLUSIONS: ESS is associated with T1DM onset severity and spontaneously disappears. ESS delayed the recovery from AKI. IMPACT: This is the first longitudinal study describing in detail the relationship between clinical/metabolic factors at type 1 diabetes mellitus (T1DM) onset and thyroid hormones, with particular attention to the relationship between diabetic ketoacidosis (DKA)-related kidney function impairment and euthyroid sick syndrome (ESS). Participants with more severe T1DM onset presentation both in terms of metabolic derangement and kidney function impairment had an increased prevalence of ESS. Children with ESS had a slower recovery from acute kidney injury compared with those without ESS. ESS spontaneously disappeared in all participants.