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Updated: Mar 28, 2026
Modeling and Evaluation of Murine Diabetic Cardiomyopathy Model
Published on: November 29, 2024
Differential impact of type-1 and type-2 diabetes on control of heart rate in mice
Catherine L Stables1, David S Auerbach2, Steven E Whitesall3
1Department of Neurology, University of Michigan, Ann Arbor, MI, USA.
Insights
Diabetic mice exhibit altered heart rate (HR) and heart rate variability (HRV) patterns. Factors like time of day and stress significantly impact these measurements, crucial for understanding cardiac autonomic dysfunction in diabetes.
Area of Science:
- Cardiovascular Physiology
- Diabetology
- Animal Models
Background:
- Cardiac autonomic dysfunction is a significant diabetes complication, affecting heart rate (HR) and heart rate variability (HRV).
- Previous animal studies show inconsistent HR/HRV data, potentially due to measurement methods, time of day, and stress levels.
- Systematic assessment is needed to clarify HR and HRV changes in diabetic models.
Purpose of the Study:
- To systematically evaluate heart rate (HR) and heart rate variability (HRV) in two common diabetic mouse models.
- To investigate the influence of time of day and stress on HR and HRV measurements in diabetic mice.
Main Methods:
- ECG radiotelemetry devices implanted in db/db (type-2 diabetic), STZ-treated db/+ (type-1 diabetic), and control db/+ mice.
- Analysis of HR and HRV over 24 hours and during treadmill stress testing.
- Comparison of HR and HRV parameters between diabetic and control groups.
Main Results:
- Diabetic mice (db/db and STZ-treated) displayed altered circadian HR patterns and blunted HR response to stress.
- Reduced HRV associated with sympathetic control was observed in db/db mice and partially in STZ-treated mice.
- Significant differences in HR and HRV were noted depending on the time of day.
Conclusions:
- Time of day and stress level are critical factors when assessing HR and HRV in diabetic mouse models.
- db/db mice show altered circadian sympathetic control, while STZ-treated mice exhibit a relative reduction.
- This study provides essential baseline data and a framework for future research on cardiac autonomic function in diabetes.
Aims:
Cardiac autonomic dysfunction is a serious complication of diabetes. One consequence is disruption of the normal beat-to-beat regulation of heart rate (HR), i.e. HR variability (HRV). However, our understanding of the disease process has been limited by inconsistent HR/HRV data from previous animal studies. We hypothesized that differences in the method of measurement, time of day, and level of stress account for the differing results across studies. Thus, our aim was to systematically assess HR and HRV in two common diabetic mouse models.
Methods:
ECG radiotelemetry devices were implanted into db/db (type-2 diabetic), STZ-treated db/+ (type-1 diabetic), and control db/+ mice (n=4 per group). HR and HRV were analyzed over 24 h and during treadmill testing.
Results:
24 h analysis revealed that db/db mice had an altered pattern of circadian HR changes, and STZ-treated mice had reduced HR throughout. HRV measures linked to sympathetic control were reduced in db/db mice in the early morning and early afternoon, and partially reduced in STZ-treated mice. HR response to treadmill testing was blunted in both models.
Conclusions:
It is important to consider both time of day and level of stress when assessing HR and HRV in diabetic mice. db/db mice may have altered circadian rhythm of sympathetic control of HR, whereas STZ-treated mice have a relative reduction. This study provides baseline data and a framework for HR analysis that may guide future investigations.
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