Impact of Thyroid Hormones on Human Glucose and Energy Metabolism

The goal of this clinical trial to clarify the impact of changes in thyroid hormone levels on glucose and lipid metabolism.

Patients will be included in whom thyroid hormone levels are intentionally changed by treatment. In patients with Graves' disease, thyroid hormone levels will be lowered using medication, while in patients with thyroid cancer, thyroid hormone levels will be raised using medication. Oral glucose tolerance tests will be performed before treatment and at two time points after treatment begins to assess metabolic effects.

Study Overview

• Status: Recruiting
• Conditions: Graves Disease; Thyroid Cancer
• Intervention / Treatment: Other: Oral Glucose Tolerance Test

Detailed Description

This research project aims to clarify the role of changes in thyroid hormone levels in glucose and liver metabolism.

Thyroid hormones regulate endogenous glucose production, insulin sensitivity, lipid metabolism, and lipid storage in the liver. They also appear to enhance insulin sensitivity in other tissues. Furthermore, thyroid hormones stimulate lipolysis and reduce total and LDL-cholesterol levels. The impact of thyroid hormones on insulin secretion is controversial, with some trials demonstrating increased secretion and others showing decreased secretion. Most of this evidence is derived from animal trials, and prospective human trials are lacking.

Clinical scenarios where thyroid hormone levels are altered through therapeutic interventions will be used. In patients with Graves' disease, hyperthyroidism is pharmacologically reduced, whereas in patients with thyroid carcinoma, hyperthyroidism is pharmacologically induced. Before the start of treatment, two weeks and three months after start of treatment oral glucose tolerance tests will be performed for metabolic characterization. Using this approach, differences in glycemic, insulin sensitivity, insulin secretion, lipids, resting energy expenditure, respiratory quotient, hepatic steatosis, eating and exercise behavior will be assessed.

• Study Type: Interventional
• Enrollment (Estimated): 60
• Phase: Not Applicable

Contacts and Locations

• Study Contact: Name: Martin Heni, Prof; Phone Number: +4973150044505; Email: martin.heni@uniklinik-ulm.de
• Study Contact Backup: Name: Roza Sabia, MD; Phone Number: +4973150044719; Email: roza.sabia@uniklinik-ulm.de

Study Locations

• Germany
  • Baden-Wurttemberg
    • Ulm, Baden-Wurttemberg, Germany, 89081
      • Recruiting
      • Ulm University Hospital
      • Contact: Sabrina Wangler; Phone Number: +4973150044782; Email: sabrina.wangler@uniklinik-ulm.de
      • Contact: Roza Sabia, MD; Phone Number: +4973150044719; Email: roza.sabia@uniklinik-ulm.de

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: Child; Adult; Older Adult
• Accepts Healthy Volunteers: No

Description

Inclusion Criteria:

• patients with initial diagnosis of graves disease OR
• patients with initial diagnosis of thyroid carcinoma

Exclusion Criteria:

• contraindications for oral glucose tolerance test
• Diabetes mellitus
• Fasting glucose level ≥ 200 mg/dL
• Exogenous insulin administration with action at the time of the test
• Current disease with activation of stress hormones
• Post-aggressive metabolism
• Acute infectious disease

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Basic Science
• Allocation: N/A
• Interventional Model: Single Group Assignment
• Masking: None (Open Label)

Number of Arms

1

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Other: Phenotyping Cohort; Patients with Graves' disease and patients with thyroid carcinoma undergoing standard-of-care thyroid treatment.	Other: Oral Glucose Tolerance Test; Participants will receive a 75 g oral glucose tolerance (3h) before the start of treatment, two weeks and three months after start of treatment. Body composition will measured by bioimpedance analysis. Before and during the oral glucose tolerance test, indirect calometry will assess metabolic flexibility.

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Insulin sensitivity	Effect of changes in thyroid hormone levels on whole-body insulin sensitivity, assessed from glucose and insulin measurements during the 75 g oral glucose tolerance test.	Baseline, 2 weeks, 3 months
Insulin secretion	Effect of changes in thyroid hormone levels on insulin secretion, assessed from glucose and insulin/c-peptide measurements during the 75 g oral glucose tolerance test.	Baseline, 2 weeks, 3 months

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Resting energy expenditure.	Effect of changes in thyroid hormone levels on resting energy expenditure assessed by indirect calometry before and during the 75 g oral glucose tolerance test.	Baseline, 2 weeks, 3 months
Respiratory Quotient	Effect of changes in thyroid hormone levels on respiratory quotient assessed by indirect calometry before and during the 75 g oral glucose tolerance test.	Baseline, 2 weeks, 3 months
Lipid metabolism	Effect of changes in thyroid hormone levels on lipid metabolism assessed from lipid measurements during the 75 g oral glucose tolerance test.	Baseline, 2 weeks, 3 months
Hepatic steatosis	Presence of hepatic steatosis assessed by liver ultrasound including elastography.	baseline
Heart rate variability	Effect of changes in thyroid hormone levels on heart rate variability assessed by electrocardiography during the 75 g oral glucose tolerance test.	Baseline, 2 weeks, 3 months
Eating behavior	Effect of changes in thyroid hormone levels on eating behavior assessed by dietary protocols before the start of treatment and 3 months later.	Baseline, 3 months

Other Outcome Measures

Outcome Measure	Measure Description	Time Frame
Perceived quality of life	Quality of life assessed by the World Health Organization Quality of Life- Brief (BREF) Questionnaire on a 0-100 scale where higher values indicate better quality of life.	either at baseline, two weeks or three months
Perceived chronic stress	Perceived chronic stress in the last three months assessed through the trier inventory for chronic stress (TICS-9) on a 0-45 scale on which higher values indicate higher chronic stress.	cross-sectional either at baseline, two weeks or three months
Perceived Stress in the last month	Perceived stress in the last months assessed through Perceived Stress Scale (PSS) on a 0-40 scale where higher values indicate higher perceived stress	cross-sectional either at baseline, two weeks or three months
Somatization, anxiety and depression	Somatization, anxiety and depression assessed through the Brief symptom inventory (BSI-18) on a 0-77 scale where higher values indicate higher distress	cross-sectional either at baseline, two weeks or three months

Collaborators and Investigators

• Sponsor: University of Ulm
• Investigators: Principal Investigator: Martin Heni, University of Ulm

Study record dates

Study Major Dates

• Study Start (Actual): February 4, 2026
• Primary Completion (Estimated): February 1, 2031
• Study Completion (Estimated): June 1, 2031

Study Registration Dates

• First Submitted: February 5, 2026
• First Submitted That Met QC Criteria: February 12, 2026
• First Posted (Actual): February 13, 2026

Study Record Updates

• Last Update Posted (Actual): February 13, 2026
• Last Update Submitted That Met QC Criteria: February 12, 2026
• Last Verified: February 1, 2026

More Information

Terms related to this study

• Keywords: lipid metabolism; thyroid cancer; glucose metabolism; thyroid hormones; hyperthyroidism; graves disease
• Additional Relevant MeSH Terms: Endocrine System Diseases; Neoplasms by Site; Neoplasms; Autoimmune Diseases; Immune System Diseases; Eye Diseases; Endocrine Gland Neoplasms; Head and Neck Neoplasms; Exophthalmos; Orbital Diseases; Goiter; Thyroid Diseases; Graves Disease; Hyperthyroidism; Thyroid Neoplasms; Investigative Techniques; Clinical Laboratory Techniques; Diagnostic Techniques and Procedures; Diagnosis; Blood Chemical Analysis; Clinical Chemistry Tests; Diagnostic Techniques, Endocrine; Glucose Tolerance Test
• Other Study ID Numbers: 173/23

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: NO

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: No