The debate on the link between subclinical hypothyroidism and childhood migraine: is initial endocrinological evaluation necessary for children with migraine?

Subclinical hypothyroidism (SH) is characterized by mildly elevated thyroid stimulating hormone (TSH) levels with normal serum-free thyroxine (fT4). While the prevalence of SH is 2 % in pediatric population, it has been reported much higher in children with migraine headache. In this study, the presence of subclinical hypothyroidism and associated endocrinological abnormalities in children with migraine naïve to treatment was investigated. Children with migraine who were diagnosed in Pediatric Neurology Clinic based on the second edition of the International Classification of Headache Disorders and who did not receive any medication were recruited in this cross-sectional study. All patients were examined by the same pediatric endocrinologist and anthropometric measurements, systemic blood pressure, pubertal stages were recorded. Fasting serum levels of thyroid function tests, lipids, glucose and insulin were obtained. Ninety-eight children (55 female) with a mean age of 11.45 ± 3.1 years were evaluated. Of those, 39 were prepubertal and 59 were pubertal. Subclinical hypothyroidism (TSH ≥ 5.0 mIU/L with normal fT4) was detected in five patients (5.1 %); none had positive thyroid antibodies. Other conditions were obesity (n = 6), hirsutism (n = 4), short stature (n = 3), polycystic ovaries (PCO, n = 3), precocious puberty (n = 2) and gynecomastia (n = 1). Of five patients with SH, only one had obesity. Our results revealed that the prevalence of SH in children with migraine is not as high as previously reported. Since no significant endocrinologic disturbance was found in those children, we suggest that the initial endocrinological evaluation or screening for SH is unnecessary.