The Effect of Hypothyroidism on Blood Glucose Levels

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Hypothyroidism is a common endocrine disorder that results from low thyroid hormone levels. The disease affects different body processes, including glucose (sugar) metabolism, which often leads to reduced mental and physical activity.


According to Medscape, iodine deficiency and autoimmune thyroid disease are common causes of primary hypothyroidism. Secondary causes include other hormonal disorders that lead to a lack of thyroid hormone secretion.

General Functions

According to Colorado State University, thyroid hormones target all cells in the body. Although the hormones are not essential to sustain life, they have key roles in human development, growth and the metabolism of fats and carbohydrates.

Functions in Glucose Metabolism

Thyroid hormones help cells get the energy they need by enhancing glucose entry via insulin-dependent processes. They also stimulate glucose production in the body via processes known as gluconeogenesis and glycogenolysis.

Hypothyroidism and Glucose Metabolism

According to the American Geriatric Society, the physiologic effects of hypothyroidism on glucose metabolism include decreased glucose production in the liver (hepatic gluconeogenesis); prolonged circulation of insulin in the blood (longer half-life); and decreased glucose disposal.

Other Effects of Hypothyroidism

ProQuest notes that the physiologic effects of hypothyroidism generally translate into low blood sugar levels (hypoglycaemia), as well as fatigue, slowed digestion of food and constipation.


According to Medscape, treatment with thyroid hormone products, such as levothyroxine (LT4), can usually correct the metabolic disorders resulting from hypothyroidism. Medscape reports clinical benefits within three to five days of therapy.