From the Guidelines
Individuals over 50 years of age with risk factors such as female sex, advancing age, white race, type 1 diabetes, Down syndrome, family history of thyroid disease, goiter, previous hyperthyroidism, and external-beam radiation in the head and neck area are at increased risk of developing hypothyroidism. The most common cause of hypothyroidism in the United States is chronic autoimmune (Hashimoto) thyroiditis 1.
Risk Factors for Hypothyroidism
- Female sex
- Advancing age
- White race
- Type 1 diabetes
- Down syndrome
- Family history of thyroid disease
- Goiter
- Previous hyperthyroidism
- External-beam radiation in the head and neck area
Screening and Diagnosis
The serum TSH test is the primary screening test for thyroid dysfunction, with multiple tests done over a 3- to 6-month interval to confirm or rule out abnormal findings 1.
Treatment and Management
Treatment typically involves levothyroxine (Synthroid, Levoxyl), starting at 25-50 mcg daily for older adults, taken on an empty stomach 30-60 minutes before breakfast 1.
Regular Monitoring
Regular monitoring is essential, with TSH checks every 6-12 months once stabilized 1.
Quality of Life
Hypothyroidism in older adults often results from autoimmune thyroiditis (Hashimoto's disease), previous thyroid surgery, radiation therapy, or certain medications, and treatment is generally lifelong, with most patients achieving good symptom control through proper medication management 1.
From the Research
Risk Factors for Hypothyroidism in Individuals Over 50 Years of Age
The development of hypothyroidism in individuals over 50 years of age can be attributed to several risk factors, including:
- Age: The risk of hypothyroidism increases with age, with a higher prevalence among individuals over 60 years old 2, 3
- Gender: Women are more likely to develop hypothyroidism than men, especially in the elderly population 3
- Autoimmune thyroiditis: This is a common cause of primary hypothyroidism, particularly in rich countries 4, 5
- Previous thyroid surgery or radioiodine therapy: These treatments can increase the risk of developing hypothyroidism 5, 3
- Medications: Certain medications, such as amiodarone, cytokines, and lithium, can induce hypothyroidism 3
- Iodine intake: Populations with high iodine intake are more likely to develop hypothyroidism 3
- Genetics: Hypothyroidism can be more common in certain ethnic groups, such as Caucasians 3
Diagnosis and Treatment of Hypothyroidism
The diagnosis of hypothyroidism is primarily based on clinical signs and symptoms, as well as measurement of thyroid-stimulating hormone (TSH) concentration and serum free thyroxine (fT4) levels 4, 5, 6. Treatment typically involves levothyroxine replacement therapy, with the goal of normalizing TSH levels and alleviating symptoms 4, 5, 6, 3. The initial replacement dose should be low, especially in elderly patients with suspected heart disease, and small dosage adjustments can be made as needed 4, 3.
Subclinical Hypothyroidism
Subclinical hypothyroidism is characterized by elevated TSH levels with normal serum fT4 levels, and is often asymptomatic 4, 5, 6. The risk of progression to overt hypothyroidism is approximately 3-4% per year, and treatment is generally recommended for patients with TSH levels above 10 mIU/L or those with symptoms suggestive of hypothyroidism 4, 5, 6. However, the decision to treat subclinical hypothyroidism should be individualized, taking into account the patient's age, symptoms, and other health factors 4, 5, 6, 3.