Frequency of Hypoglycemia in Children With Beta-blocker Treated Long QT-syndrome

Summary

The goal of this observational study is to investigate the frequency and characteristics of hypoglycemic episodes in children with long QT syndrome (LQTS) and beta-blocker treatment, specifically those receiving propranolol, compared to healthy controls. The study focuses on children under seven years with genetically confirmed LQTS and beta-blocker therapy, as well as healthy siblings as controls.

The main questions it aims to answer are:

* Does hypoglycemic episodes occur in children with LQTS who are treated with propranolol?
* Are there asymptomatic episodes of low blood glucose that could affect well-being and neurological development?
* Are there individual differences in susceptibility to hypoglycemia, and do genetic factors explain these differences?
* What is the incidence of hypoglycemia leading to emergency visits or hospitalizations among LQTS patients compared to healthy controls?

Researchers will compare children with LQTS on propranolol to healthy siblings to see if the frequency and severity of hypoglycemia differs between groups.

Participants will:

Have a Dexcom G7 continuous glucose monitor installed to record glucose profiles for ten days, both during an healthy episode and during an infection (when risk for hypoglycemia is increased).

If differences in susceptibility to hypoglycemia are observed, genetic data from the Helsinki biopank will be analyzed to explore potential genetic factors underlying these differences. Visits to emergency clinic and hospitalizations due to hypoglycemia will be retrospectively reviewed for all LQTS patients under 16 years old and compared to healthy controls.

Additional Details:

The study is conducted at Helsinki University Hospital (HUH) Children and Adolescents and the New Children's Hospital clinical research unit. The study aims to recruit 20-40 LQTS patients and 10 healthy controls.

The study is ethically justified, with no extra laboratory tests or costs for participants, and written consent will be obtained from parents and capable children.

The results are expected to improve the safety of propranolol treatment in LQTS children by identifying risk factors for hypoglycemia and informing preventive strategies, such as dietary guidance, use of glucose monitoring devices during illness, or considering selective beta-blockers for high-risk patients.

Conditions

• Long QT Syndrome
• Hypoglycemia

Interventions

DEVICE

Continuous Glucose Monitoring

All participants will have the continuous glucose monitoring device Dexcom G7 placed. The Dexcom G7 Glucose Monitoring System reports continuous interstitial blood glucose concentrations every 5 minutes and alerts for low glucose (\<3.1 mmol/l). Sensor low alarms are verified by finger prick tests. A single sensor is used up to 10 days and the sensoring is performed twice in each participant.

Sponsors & Collaborators

• Foundation for Paediatric Research, Finland

  collaborator OTHER

• Helsinki University Central Hospital

  lead OTHER

Principal Investigators

• Elina Hakonen, MD, PhD · New Children's Hospital, Helsinki University Hospital

Study Design

Allocation

NON_RANDOMIZED

Purpose

PREVENTION

Masking

NONE

Model

PARALLEL

Eligibility

Max Age

7 Years

Sex

ALL

Healthy Volunteers

Yes

Timeline & Regulatory

Start

2024-12-09

Primary Completion

2027-12-31

Completion

2027-12-31

Countries

• Finland

Study Locations