Thyroid’s Central Role in Metabolic Health
April 06, 2026
Innovations in Diabetes & Endocrinology | Summer 2026
Thyroid function plays a central role in metabolic regulation. Patients concerned about their thyroid health can receive expert, comprehensive care for thyroid disorders, diabetes and metabolic dysfunction through the University Hospitals Diabetes & Metabolic Care Center and the Division of Clinical & Molecular Endocrinology, featuring board-certified endocrinologists, dietitians and educators
Erika Lundgrin, MD“The thyroid impacts so much of the body, and it can be an interesting dynamic to figure out the intersection between thyroid hormones and metabolic health,” says Erika Lundgrin, MD, an Adult and Pediatric Endocrinologist at UH Cleveland Medical Center and UH Rainbow Babies & Children’s Hospital and an Assistant Professor at Case Western Reserve University School of Medicine. “Endocrinologists are de facto thyroid experts in that we are trained to diagnose and treat a range of thyroid conditions, including hypothyroidism, hyperthyroidism, nodules and thyroid cancer.”
Disturbances in thyroid hormone levels can significantly influence metabolic health, including associations with energy expenditure, lipid metabolism, glucose regulation and body composition.
“Both under- and overactive thyroid can cause a multitude of symptoms because its functions span the entire body,” Dr. Lundgrin says. “However, a symptom might sometimes be misattributed to the thyroid, so it is a delicate balance to ensure we are correctly identifying the source of people’s concerns.”
Hypothyroidism
Reduced levels of thyroid hormones slow basal metabolic rate and impair lipid metabolism. Hypothyroidism has been linked to increased insulin resistance and may contribute to the development or worsening of metabolic syndrome.
“The thyroid is a key contributor to resting metabolic rate and impacts not only energy but how quickly the gut moves,” Dr. Lundgrin says. “In children, low thyroid levels can also affect growth.”
The most common cause of hypothyroidism is Hashimoto’s thyroiditis, an autoimmune disorder in which antibodies damage the thyroid gland.
“There are also congenital forms of hypothyroidism when a person is born with the inability to produce thyroid hormone, which is critical to a child’s brain development,” Dr. Lundgrin says. “Every state now has some form of congenital hypothyroid test as part of newborn screening.” Additional causes of hypothyroidism include surgical removal or iodine deficiency, which has largely been addressed by nutritional supplementation.
Treatment focuses on restoring normal thyroid hormone levels and addressing symptoms. Standard therapy is daily oral levothyroxine, a synthetic form of thyroxine (T4). Dosage is typically reassessed after six to eight weeks to ensure appropriate hormone replacement.
“As long as patients are taking a steady dose of the medication as recommended, the vast majority of individuals who need treatment for underactive thyroid do really well,” Dr. Lundgrin says. “Some individuals have differences in their ability to absorb the medication and might require either a higher dose or the addition of a synthetic form of T3 [triiodothyronine] to achieve a euthyroid state.”
Hyperthyroidism
Hyperthyroidism occurs due to overproduction of thyroid hormone, causing symptoms that can include weight loss, palpitations, heat intolerance and anxiety. The most common cause is Graves’ disease, an autoimmune disorder that stimulates excess thyroid hormone production. Other causes include autonomous thyroid nodules, thyroiditis and certain medications such as amiodarone.
Some causes of hyperthyroidism, such as thyroiditis, are transient or self-limiting. “Overactive thyroid can be more challenging because it can take time for dose titrations to achieve appropriate hormone levels,” Dr. Lundgrin says. “Autoimmune conditions like Graves’ disease can flare and relapse, so it is important to check in regularly with an endocrinologist for dose adjustments.”
Treatment for hyperthyroidism depends on the underlying cause and may include beta blockers, antithyroid medication, partial or total thyroidectomy, or radioactive iodine ablation. Mainstay antithyroid medications include methimazole and propylthiouracil.
Taking a Holistic Approach
“In endocrinology, we are always trying to mimic normal physiology as much as possible,” Dr. Lundgrin says. “There is an evolving understanding of the rise in autoimmunity over the last several decades, affecting not just the thyroid but also Type 1 diabetes and other conditions. I think there is a greater appreciation for underlying inflammation and its effects on how one is feeling.”
She points to food sensitivities, environmental triggers and stress as potential factors that may be contributing to patients’ inflammation levels. Experts at the UH Diabetes & Metabolic Institute partner with integrative medicine specialists at UH Conner Whole Health to help individuals reach their wellness goals.
“We are willing to have conversations with patients about ongoing concerns that are impacting their quality of life,” Dr. Lundgrin says. “If folks are saying, ‘My thyroid levels are normal, but I still don’t feel well,’ we have the opportunity to collaborate with experts within our health system who are taking an evidence-based, holistic approach to health and wellness.”