Abstract

Objectives

The increase in insulin resistance and its impact on cardiac insulin metabolic signaling is becoming a significant contributor to heart failure, especially given the escalating rates of obesity, cardiorenal metabolic syndrome, and our aging population. Our study aims to comparatively evaluate the development of insulin resistance and the occurrence of QT lengthening depending on gender.

Materials and Methods

In our study, 8-week-old Balb/c female and male mice were used. An insulin resistant model was induced by feeding mice with standard rodent chow and tap water containing high sucrose (32%; w/v) for 14 weeks. Animals in the control groups were fed with standard rodent chow and tap water. Body weights, fasting blood glucose levels, insulin resistance using oral glucose tolerance test, food and water consumption, and electrocardiographic (ECG) parameters were measured in control and metabolic syndrome group male and female mice.

Results

The present study showed that fasting blood glucose levels were increased and insulin resistance was developed in male mice consuming 32% sucrose solution for 14 weeks, while no change was observed in female mice. According to the results, chow consumption was decreased both in male and female mice, while their body weight was not changed. Water consumption was not changed in males, while it increased in females. It was also observed that caloric intake increased significantly as a result of high-sucrose diet compared to control in both genders. No change was observed in ECG parameters of male mice, while QT was lengthened in female mice with insulin resistance, which did not show any metabolic deterioration.

Conclusion

Our results showed that no change in ECG parameters was observed in male mice with insulin resistance, while QT lengthening observed in female mice with sucrose feeding without metabolic deterioration, suggesting that female mice are more sensitive to QT lengthening induced by sugar independent of metabolic changes.