Metabolic Syndrome, Prediabetes
Conditions
Keywords
Continuous glucose monitoring, Postprandial glucose, Exercise snack, Resistance exercise, Heart rate variability, Prediabetes, Metabolic syndrome
Brief summary
This study will examine whether light physical activity after meals can improve 24-hour glucose responses in adults with metabolic syndrome and prediabetes. Participants will complete three experimental conditions in a randomized crossover order: prolonged sitting, 15 minutes of postprandial walking, and brief resistance exercise snacks consisting of squats and calf raises performed every 20 minutes during the postprandial period. Continuous glucose monitoring will be used to assess 24-hour glucose responses, and heart rate variability will be measured during the 2-hour postprandial period to evaluate acute autonomic responses. The main outcome is 24-hour mean glucose derived from continuous glucose monitoring.
Detailed description
Metabolic syndrome and prediabetes are associated with impaired glucose regulation and increased cardiometabolic risk. Light physical activity after meals may help reduce postprandial glucose excursions and improve overall daily glucose control. However, it remains unclear whether brief resistance exercise snacks can provide glucose benefits comparable to postprandial walking under standardized meal conditions. This study is a randomized crossover trial in adults aged 40 to 65 years with metabolic syndrome and prediabetes. Each participant will complete three experimental conditions in a randomized order: prolonged sitting, 15 minutes of walking after a standardized meal, and brief resistance exercise snacks performed every 20 minutes during the postprandial period. The resistance exercise snacks will consist of simple body-weight exercises, including squats and calf raises. Glucose responses will be assessed using continuous glucose monitoring. The primary outcome will be 24-hour mean glucose after each experimental condition. Key secondary glycemic outcomes will include 2-hour postprandial glucose incremental area under the curve, 2-hour mean glucose, peak glucose, time to peak glucose, nocturnal mean glucose, and glycemic variability indices. Heart rate variability will be assessed during the 2-hour postprandial period using RR interval data collected with a chest strap heart rate monitor to evaluate acute autonomic responses to each condition. The purpose of this study is to determine whether brief resistance exercise snacks can improve 24-hour glucose regulation and postprandial glucose responses compared with uninterrupted sitting, and whether these responses are comparable to postprandial walking.
Interventions
BEHAVIORALPostprandial walking
Participants will perform 15 minutes of light-to-moderate walking after consuming a standardized meal. Walking intensity will be monitored using heart rate and rating of perceived exertion.
BEHAVIORALBrief resistance exercise snacks
Participants will perform 3-minute bouts of body-weight resistance exercises every 20 minutes during the postprandial period after consuming a standardized meal. The exercise bouts will include squats and calf raises.
Sponsors
Seoul National University
Study design
Allocation
RANDOMIZED
Intervention model
CROSSOVER
Primary purpose
PREVENTION
Masking
DOUBLE (Investigator, Outcomes Assessor)
Masking description
Masking is not feasible because participants and investigators will be aware of the assigned exercise condition.
Intervention model description
Participants will complete three experimental conditions in a randomized crossover order: prolonged sitting, 15 minutes of postprandial walking, and brief resistance exercise snacks performed every 20 minutes during the postprandial period. Each participant will serve as his or her own control.
Eligibility
Sex/Gender
ALL
Age
40 Years to 65 Years
Healthy volunteers
No
Inclusion criteria
* Inclusion Criteria: * Adults aged 40 to 65 years * Presence of metabolic syndrome * Fasting glucose of 100 mg/dL or higher or HbA1c of 5.7% or higher * Not regularly engaged in structured exercise training, defined as less than 150 minutes per week during the past year * Able to consume the standardized study meals * Able to wear a continuous glucose monitor and a chest strap heart rate monitor * Able to provide written informed consent
Exclusion criteria
* History of major cardiovascular, cerebrovascular, respiratory, renal, hepatic, neurological, or other severe medical conditions that may affect study participation. * Uncontrolled hypertension, defined as systolic blood pressure ≥160 mmHg or diastolic blood pressure ≥100 mmHg. * Current use of medications associated with a high risk of hypoglycemia, such as insulin or sulfonylureas. * Initiation or dose change of insulin or oral glucose-lowering medications within the past 3 months. * Initiation or dose change of medications for hypertension, dyslipidemia, or diabetes within the past 3 months. * Musculoskeletal, neurological, or orthopedic conditions that limit safe participation in walking or body-weight resistance exercise, including severe knee, hip, back, or ankle pain. * Regular participation in moderate-to-vigorous exercise of 150 minutes or more per week during the past year. * Difficulty consuming the standardized study meals, including food allergy, dietary restrictions, or severe gastrointestinal symptoms. * Difficulty wearing a continuous glucose monitor or history of severe skin irritation or allergy to adhesive sensors. * Difficulty wearing a chest strap heart rate monitor or skin problems at the chest strap site. * Pregnancy or planned pregnancy. * Acute illness, infection, surgery, or hospitalization within the past month. * Current participation in another interventional study. * Any condition judged by the investigator to make participation unsafe or inappropriate.
Design outcomes
Primary
| Measure | Time frame | Description |
|---|---|---|
| 24-hour mean glucose | 24 hours after each experimental condition | Mean glucose over 24 hours after each experimental condition, derived from continuous glucose monitoring. |
Secondary
| Measure | Time frame | Description |
|---|---|---|
| 2-hour postprandial glucose incremental area under the curve | 0 to 120 minutes after the standardized meal | The 2-hour postprandial glucose incremental area under the curve will be calculated from continuous glucose monitoring data after the standardized meal. |
| Change in RMSSD | 0 to 120 minutes after the standardized meal | Change in the root mean square of successive differences from the pre-meal resting baseline during the 2-hour postprandial period. RMSSD will be calculated from RR interval data collected with a chest strap heart rate monitor. |
Contacts
CONTACTYunmin Han
Outcome results
None listed