The Thyroid Axis in Older Individuals With Persistent Subclinical Hypothyroidism: a Mechanistic, Randomized, Double-Blind, Cross-Over Study of Levothyroxine and Liothyronine Administration
试验速览
- 阶段
- 不适用
- 状态
- 已完成
- 入组人数
- 14
- 试验地点
- 1
- 主要终点
- Total T3 Level
研究概览
简要总结
Subclinical hypothyroidism, defined as an elevated TSH in the setting of normal thyroid hormone levels, is a common diagnosis in the elderly. The purpose of this study is to examine the hypothalamic-pituitary-thyroid axis in men and women aged 70 years and older with persistent subclinical hypothyroidism. To evaluate the mechanism behind this condition, participants will undergo thyrotropin releasing hormone stimulation testing at 3 visits: baseline and while taking two different thyroid hormone preparations, levothyroxine and liothyronine. The investigators will also assess physiologic responses to these two different thyroid hormone medications to help us understand how the thyroid works in advanced age.
研究设计
- 研究类型
- Interventional
- 分配方式
- Randomized
- 干预模型
- Crossover
- 主要目的
- Other
- 盲法
- Double (Participant, Investigator)
入排标准
- 年龄范围
- 70 Years 至 —（Older Adult）
- 性别
- All
- 接受健康志愿者
- 否
入选标准
- •men and women aged 70 and older
- •TSH between 4.5 and 19.9 mU/L as an outpatient
- •ability to provide informed consent
排除标准
- •Laboratory Tests:
- •TSH <4.5 mU/L or >20 mU/L on repeat testing at least four weeks later or free T4 level outside the reference range
- •thyroid peroxidase (TPO) antibody positive
- •abnormal liver function tests (LFTs >3 x upper limit of normal)
- •hemoglobin <11 g/dL
- •Surgeries or Procedures:
- •thyroid surgery
- •pituitary surgery
- •bariatric surgery
- •bowel resection involving the jejunum and upper ileum
- •radioactive iodine therapy
- •radiation treatments to head or neck
- •Medical Conditions:
- •diagnosis of pituitary disease
- •diagnosis of amyloidosis, sarcoidosis, hemochromatosis
- •diagnosis of adrenal insufficiency
- •obesity with BMI > 35 mg/kg2
- •history of stroke
- •chronic or ongoing angina, Class II or higher congestive heart failure, or uncontrolled hypertension with current blood pressure greater than 160/100
- •diabetes mellitus with hemoglobin A1C level greater than 8.0% in the past six months
- •celiac sprue, Crohn's disease, ulcerative colitis, Zollinger-Ellison syndrome
- •renal insufficiency with calculated glomerular filtration rate <45 cc/min
- •cognitive impairment with Mini Mental State Exam[30] <24/30
- •history of any seizures
- •unstable medical or psychological condition in the judgment of the principal investigator
- •Medications:
- •thyroid hormone preparations
- •antithyroid drugs
- •medications that interfere with the absorption or metabolism of thyroid hormone
- •medications that interfere with the TRH stimulation test
- •proton pump inhibitors
研究组 & 干预措施
Levothyroxine First
Participants will start on the thyroid hormone Levothyroxine prior to crossing over to Liothyronine
干预措施: Levothyroxine (Drug)
Levothyroxine First
Participants will start on the thyroid hormone Levothyroxine prior to crossing over to Liothyronine
干预措施: Liothyronine (Drug)
Levothyroxine First
Participants will start on the thyroid hormone Levothyroxine prior to crossing over to Liothyronine
干预措施: Thyrotropin-Releasing Hormone (Drug)
Liothyronine First
Participants will start on the thyroid hormone Liothyronine prior to crossing over to Levothyroxine
干预措施: Levothyroxine (Drug)
Liothyronine First
Participants will start on the thyroid hormone Liothyronine prior to crossing over to Levothyroxine
干预措施: Liothyronine (Drug)
Liothyronine First
Participants will start on the thyroid hormone Liothyronine prior to crossing over to Levothyroxine
干预措施: Thyrotropin-Releasing Hormone (Drug)
结局指标
主要结局
Total T3 Level
时间窗: An average of 7 months
Total triiodothyronine level when TSH is at goal on therapy
TSH Area Under the Curve
时间窗: 0, 5, 10, 15, 20, 30, and 60 min post TRH
TSH area under the curve within 60 minutes of TRH stimulation when TSH is at goal
TSH Max
时间窗: Between 0 and 180 min after TRH stimulation
The maximum concentration of TSH after TRH stimulation when TSH is at goal
Free T4 Level
时间窗: An average of 7 months after initiating therapy
Free thyroxine level when TSH level is at goal on therapy.
次要结局
未报告次要终点