Decrease in TSH levels after lactose restriction in Hashimoto's thyroiditis patients with lactose intolerance.

Area of Science:

• Endocrinology
• Gastroenterology
• Immunology

Background:

• Hashimoto's thyroiditis (HT) is an autoimmune disease.
• Lactose intolerance (LI) is common, but its prevalence in HT patients is not well-established.
• Thyroid function can be influenced by various dietary factors.

Purpose of the Study:

• To determine the prevalence of LI in HT patients.
• To investigate the impact of lactose restriction on thyroid function in HT patients with LI.

Main Methods:

• Eighty-three HT patients on L-thyroxine (LT4) therapy were assessed for LI using lactose tolerance tests.
• Patients diagnosed with LI underwent an 8-week lactose-restricted diet.
• Thyroid-stimulating hormone (TSH) levels were monitored before and after the dietary intervention.

Main Results:

• Lactose intolerance was diagnosed in 75.9% of HT patients.
• A significant decrease in TSH levels was observed in euthyroid and subclinical hypothyroid HT patients with LI after adopting a lactose-restricted diet (P<0.05).
• No significant changes in TSH levels were noted in HT patients without LI.

Conclusions:

• Lactose intolerance is highly prevalent in patients with Hashimoto's thyroiditis.
• Lactose restriction can lead to reduced TSH levels in HT patients with LI.
• Consider LI in HT patients with difficult-to-manage hypothyroidism, irregular TSH, or resistance to LT4 therapy.