TSHR and obesity due to melanocortin 4 receptor deficiency: Suggested causes of subclinical hyperthyrotropinemia in a person with obesity are iodine deficiency, thyroid autoimmunity, mitochondrial dysfunction, thyroid hormone resistance, mutation in the TSH-receptor gene, impaired hypothalamic pituitary axis, or adaptation of increased energy expenditure mediated by leptin [12, 20–22].