Aims: This study aimed to investigate the effects of diabetes on cardiac contractile proteins and assess the potential reversibility of these effects through insulin therapy, with a specific focus on the interconnectedness of cardiovascular and pulmonary health. Methods: A prospective 9-month study involving 150 adults categorized into three groups, including diabetic individuals without insulin treatment, those with insulin treatment, and a control group. Comprehensive baseline assessments were conducted, and various measurements, including cardiac contractile proteins, glycemic control, heart function, and pulmonary health, were analyzed at regular intervals. Statistical analyses encompassed paired and independent t-tests, ANOVA, and regression analysis, utilizing SPSS software (version 23) with a significance threshold of p < 0.05. Results: Both diabetic groups demonstrated improved glycemic control, with the Diabetic Insulin Group (DIG) experiencing a reduction in HbA1c levels from 8.3% to 7.9% and the Diabetic Group (DG) displaying a decrease in fasting blood glucose levels from 166.2 mg/dL to 158.4 mg/dL. DG showed enhanced ejection fraction, suggesting improved cardiac function, and a minor shortening of the QTc interval, indicating better electrical cardiac stability, potentially linked to enhanced pulmonary function. A noteworthy increase in actin levels was observed in DIG, signifying a potential reversal of cardiac protein changes with potential implications for pulmonary health. Conclusion: This study underscores the significance of effective glycemic control and the potential of insulin therapy in preserving or restoring heart function in individuals with diabetes, emphasizing the need for comprehensive diabetes management in addressing and preventing cardiac issues. Pulmonary function tests indicated minimal changes in pulmonary health within the study's timeframe, suggesting limited impact during this period.