Mechanistic Study of Subclinical Hypothyroidism In the Elderly

What Was Tested

The trial (not phased) is built around TRH (Thyrotropin-Releasing Hormone).

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.

It had two arms (groups): Levothyroxine First (experimental) and Liothyronine First (experimental).

Participants will start on the thyroid hormone Levothyroxine prior to crossing over to Liothyronine.

Participants will start on the thyroid hormone Liothyronine prior to crossing over to Levothyroxine.

The registry classes the interventions as drug.

Who Took Part

Enrollment: 14 actual participants took part.

It was open to people of any sex aged from 70 years with no upper age limit.

Healthy volunteers were not accepted; participants needed the condition being studied.

Examples of who could join: Men and women aged 70 and older. TSH between 4.5 and 19.9 mU/L as an outpatient. Ability to provide informed consent.

The full record lists 3 inclusion and 27 exclusion criteria; among the exclusions: 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).

How the Study Was Run

Design: randomized, crossover and double-blind.

Because people in this TRH (Thyrotropin-Releasing Hormone) study were split into groups at random, differences between the groups are less likely to reflect who happened to join each one.

Each person switched between TRH (Thyrotropin-Releasing Hormone) and the comparison at some point, usually with a gap in between.

Neither the participants nor the staff measuring them knew who was on TRH (Thyrotropin-Releasing Hormone), so expectations could not easily colour the readings.

Those kept unaware of assignments: participant and investigator.

It started in 2015-01-01 with completion listed for 2019-09-30.

It ran at 1 site in United States.

Its stated primary purpose is other.

What Was Measured

Primary outcome: TSH Area Under the Curve (time frame: 0, 5, 10, 15, 20, 30, and 60 min post TRH). TSH Max (time frame: Between 0 and 180 min after TRH stimulation). Free T4 Level (time frame: An average of 7 months after initiating therapy).

What This Means in Plain Language

Put simply, this is a not phased, randomized trial of TRH (Thyrotropin-Releasing Hormone) in 14 people.

Its size is small, so on its own it can only give an early look.

The trial is marked completed; results are posted on the registry, and this page does not restate them.

More context: the TRH (Thyrotropin-Releasing Hormone) compound page, all human trials.