# Continuous Glucose Monitoring under standardised conditions regarding diet, exercise and stress in Healthy Young People (CGM-HYPE study): An exploratory clinical trial

## TL;DR

This study explores how diet, exercise, and stress affect glucose levels in healthy young adults using continuous glucose monitoring, revealing how lifestyle choices impact metabolic health.

## Contribution

The study introduces the Glucose Recovery Time to Baseline (GRTB) metric to quantify individual glucose responses to lifestyle factors in healthy adults.

## Key findings

- Anaerobic exercise caused significantly greater glucose excursions compared to aerobic exercise.
- Carbohydrate-rich foods triggered the highest glucose increases in healthy participants.
- Psychological stress induced significant glucose changes, highlighting its metabolic impact.

## Abstract

Continuous glucose monitoring (CGM) in healthy adults is becoming part of healthy lifestyle activities for preventing cardio-vascular and metabolic diseases. However, there is a lack in describing individual glucose responses to everyday situations, with appropriate metrics. The aim of this study was to provide metrics which describe individual glucose responses to lifestyle factors including diet, exercise, and stress in healthy, young adults. Ten participants wore a CGM device (FreeStyle Libre3®) for 14 consecutive days while completing nine standardized interventions (challenges) consisting of food, anaerobic and aerobic sport, and the Trier Social Stress Test (TSST) in an exploratory, clinical trial. Individual glucose responses after each challenge were assessed over four hours, using the following metrics: AUC0–4, max glucose, time to max glucose, glucose excursion, and time required for glucose levels to return to baseline (Glucose Recovery Time to Baseline (GRTB)). The study has been registered in the German clinical trial registry (Study number: DRKS00032821). Anaerobic exercise resulted in a significantly greater glucose excursion (28.7 ± 21.46 mg/dL) compared to aerobic exercise (8.8 ± 4.91 mg/dL, p = 0.0228). Food with a rich carbohydrate content caused the highest glucose increase (161.4 ± 15.59 mg/dL). TSST resulted in a significant difference in baseline-corrected glucose concentrations over time as revealed by a two-factor repeated measures ANOVA (p = 0.0113). We provide reference data of glucose response to lifestyle factors such as diet and exercise in healthy adults. Psychobiological stress revealed a substantial glucose response. Using GRTB metrics may quantify the lifestyle stimulus on the important metabolic pathway and can be utilized alongside kinetic metrics for describing individual glucose responses.

Continuous glucose monitoring (CGM) is widely used in diabetes research but is now gaining more attention for its application in healthy individuals. In this study, we explored how everyday lifestyle factors—diet, exercise, and stress—affect glucose levels in healthy young adults. Over two weeks, ten participants wore CGM devices while completing controlled challenges, including consuming specific foods, performing aerobic and anaerobic exercise, and undergoing a stress-inducing task. We observed that anaerobic exercise caused greater glucose spikes than aerobic exercise, while carbohydrate-rich foods triggered the highest glucose increases. Psychological stress also led to significant glucose changes, underscoring its impact on metabolic health. To analyse individual responses, we introduced the Glucose Recovery Time to Baseline (GRTB) metric, which measures the time for glucose levels to normalize after a challenge. Our findings provide valuable reference data on glucose responses to lifestyle factors in healthy adults. This research highlights CGM’s potential for tracking glucose dynamics in non-diabetic populations and offers new insights into how lifestyle influences metabolic health, paving the way for personalized strategies to prevent metabolic and cardiovascular diseases.