This review explores the multifaceted role of thyroid hormones in regulating growth and development. It highlights that thyroid hormones influence growth through mechanisms such as feedback regulation of thyrotropin-releasing hormone (TRH) and thyrotropin (TSH), modulation of thyroid hormone receptors, and the activity of deiodinase enzymes that control local hormone availability.
This prospective study investigated the relationship between thyroid hormone levels and weight changes in 51 obese children undergoing a 1-year lifestyle intervention. The study found that higher baseline thyroid-stimulating hormone (TSH) levels were associated with greater weight loss during the intervention, while higher free triiodothyronine (fT3) levels correlated with weight
This 2016 prospective clinical study evaluated the effect of untreated primary hypothyroidism on reproductive hormone levels in women and the hormonal changes after levothyroxine therapy. The study included 59 women with hypothyroidism and 39 healthy controls. Results showed that hypothyroid patients had significantly elevated TSH and prolactin levels and significantly
This 2016 review by Dan Lukaczer critiques the traditional reliance on thyroid-stimulating hormone (TSH) levels for diagnosing and managing hypothyroidism, noting that many patients continue to experience symptoms despite normalized TSH. The article advocates for a more comprehensive approach that includes assessing gastrointestinal function, dietary habits, micronutrient status, and measuring
This 2010 randomized, double-blind crossover trial investigated the impact of levothyroxine (LT4) administration timing on thyroid hormone levels in 105 patients with primary hypothyroidism. Over a 6-month period, participants took LT4 either in the morning or at bedtime, switching regimens midway. Results from 90 completers indicated that bedtime intake led
This 2013 retrospective longitudinal study analyzed 1,751 individuals with subclinical hypothyroidism and 28,096 euthyroid subjects over a median follow-up of 36 months to assess the impact of seasonal variations on thyroid function. Findings revealed a biphasic pattern in TSH levels, increasing during winter-spring and decreasing in summer-fall. Notably, 57.9% of
This study examined the 24-hour hormone profiles of TSH, free T3, and free T4 in 20 hypothyroid patients, comparing those on combined T3/T4 therapy (n=10) with those on T4 monotherapy (n=10). Patients on combined therapy experienced a 42% increase in fT3 levels within 4 hours post-dose, while those on T4
This article discusses the clinical assessment of thyroid function, focusing on the measurement of free T4, T3, and TSH levels. It explains how these hormone levels correlate with thyroid activity, with lower levels of T4 and elevated TSH indicating hypothyroidism, and higher levels of T4 and T3 signaling hyperthyroidism. The
