Dosing of LT4 in Older Individuals (DOT4)

University of Pennsylvania

Status and phase: Enrolling; Phase 4

Conditions: Hypothyroidism

Treatments: Drug: Levothyroxine Sodium

Study type: Interventional

Funder types: Other; NIH

Identifiers

NCT06073665

1R01AG081698-01

R01AG081698 (U.S. NIH Grant/Contract)

Details and patient eligibility

About

Our overall goal is to determine the clinical consequences of allowing greater flexibility in LT4 dosing in older individuals who take LT4.

Full description

Investigators will perform a randomized, parallel, double-blind clinical trial of two 6-month dosing strategies of levothyroxine (LT4) in patients aged 65 years and older who are already taking a stable dose of at least 1.2 mcg/kg/day of LT4 therapy, one to maintain a target thyroid stimulating hormone (TSH) level of 0.5-2.0 mU/L (lower TSH group) and another of a lower levothyroxine dose to achieve a target TSH of 5.5-7.0 mU/L (higher TSH group). Investigators will assess the effects of levothyroxine therapy at two different TSH targets on symptoms of hypothyroidism, mood, sleep, measures of memory and executive function, weight, lipids, and a marker of bone turnover.

Enrollment: 228 estimated patients

Sex: All

Ages: 65+ years old

Volunteers: No Healthy Volunteers

Inclusion criteria

1. Provision of signed and dated informed consent form
2. Stated willingness to comply with all study procedures and availability for the duration of the study
3. Male or female, community dwelling, aged 65 years or older
4. Diagnosed with hypothyroidism of any etiology for at least 6 months, taking 75-200 mcg per day LT4 and a minimum of 1.2 mcg/kg/day with no dose adjustment since the last TSH test.
5. Ability to take oral medication and be willing to adhere to the medication regimen

Exclusion criteria

1. Hypopituitarism
2. History of thyroid cancer requiring suppression of TSH secretion
3. Current use of liothyronine (LT3), thyroid extracts, Tirosint liquid or capsules, and medications that interfere with thyroid function or thyroid function tests
4. GFR <30 ml/min/1.73 m2 within the prior 12 months
5. Unable to understand and comply with study requirements, as assessed by study staff and the PI, will be excluded.
6. Other conditions which, in the opinion of the investigators, would prevent them from participating in the full duration of the study.

Trial design

Primary purpose: Treatment

Allocation: Randomized

Interventional model: Parallel Assignment

Masking: Quadruple Blind

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228 participants in 2 patient groups

Lower TSH Group

Active Comparator group

Description:

Target TSH level of 0.5-2.0 mU/L

Treatment:

Drug: Levothyroxine Sodium

Higher TSH group

Experimental group

Description:

Target TSH level of 5.5-7.0 mU/L

Treatment:

Drug: Levothyroxine Sodium