ClinicaI and biochemical risk factors in children with untreated long-term idiopathic subclinical hypothyroidism

Background: Subclinical hypotbyroidism (SH) is a biochemical condition characterized by increased serum levels ofTSH witb nonnal values ofFT4. In adults SH has been associated witb high low-density lipoprotein-cholesterol (LDL-C) and homocysteine (Hcy) levels and increased risk ofatberosclerosis, while data in untreated SH children are scanty. Objective: To investigate clinical and biochemical atherosclerotic risk factors in children with untreated idiopathic SH. Methods: Fourty-nine children with long-tenn (3.I±OA years) idiopatbic SH, agcd 7.8±O.5 years, underwcnt height, weight, waist and hip circumfcrence measurements. The degree of overall adiposity was expressed as BMI. Waist to hip ratio (WHR) and waist to height ratio (WHtR) were used as illdicators of abdominal adiposity. Lipid profile, Hcy levels atld atberogenic index (AI) were evaluated. Forty-nine healtby euthyroid children, matched for age and sex, were enrolled as controls. Results: In SH children and in controls BMI and WHR were similar. WHtR was higher in SH subjects than in controls (0.52±0.01 vs OAI±O.03,p < 0.01)and was positively correlated 10 TSII levels at study entry (1""'0.3, p< 0.05). Te and LOL-C levels were similar in the Iwo groups, while HOL-C was lower in SH children compared with controls (53.1±2.0 VB 61.8±2.0 mg/dl, p< 0.04) and AI was higher (3.2±O.l VB 2.7±O.I, p< 0.005). A trelld 10ward higher triglycerides levels was observed in SII subjects compared 10 controls (69.2:1:4.7 vs 59.1±3.4, p< 0.09). Serum Hcy levels were significantly higher in SH subjects tban in healtby children (8.7±0.3 vs 7.8±0.2, p< 0.02). Serum HDL-C and Hcy were correlaled with tbe duration ofSII (1""'-0.32, p< 0.03;r=O.38, p < 0.007, respectively), while AI was correlated with mean TSH levels from time of SH diagnosis 10 study entry (r=O.37, p < 0.05). Concluslons: Untreated SH in children is associated witb increased abdominal adiposity, pro-atberogenic abnonnalities ofIipid profile and increased I1cy levels.