Obesity-related subclinical hypothyroidism in childhood: Elevated triglycerides but not basal metabolic rate

Abstract

Studies on the associations between obesity-related subclinical hypothyroidism with basal metabolic rate and risk factors of cardiovascular disease in children and adolescents are scarce. Retrospective cohort study of children with obesity (n = 294) from the Uppsala Longitudinal Study of Childhood Obesity cohort. Differences in basal metabolic rate quantified by indirect calorimetry, and the cardiovascular risk factors; body mass index, blood lipids, fasting and 2 h oral glucose tolerance test glucose, glycated haemoglobin and insulin resistance, between subjects with and without subclinical hypothyroidism were investigated. The associations of baseline thyroid stimulating hormone (TSH) and ΔTSH with change in cardiovascular risk factors over time were assessed. Subjects with subclinical hypothyroidism had elevated triacylglycerides but no alterations in basal metabolic rate or other measured cardiovascular risk factors. ΔTSH was positively associated with Δtriacylglycerides, Δtotal-cholesterol and ΔLDL-cholesterol, independently of age, sex, Δbody mass index and ΔT4. In the subclinical hypothyroidism group, 92% of individuals normalised their TSH 0.9–2.9 years later. Children with obesity and subclinical hypothyroidism did not have an altered basal metabolic rate but elevated triacylglycerides. During the follow-up period, TSH changed in parallel with several blood lipids. Elevated TSH often normalised without pharmaceutical intervention within 3 years.