Effect of insulin resistance on CAC scores in cancer survivors

Background: Many ca. survivors exhibit signs of IR, an important risk factor for the development of CAD. CAC scans offer a risk assessment of CV disease before cardiac damage has occurred. We investigated how IR affects CAC scores in cancer survivors. Objectives: The aim of this study was to show that CAC scores differ significantly between insulin-sensitive- and -resistant cancer survivors. Methods: We enrolled 90 cancer survivors of a large community hospital from March 2021 to January 2022 into this pilot study. Patients were subdivided into three groups: insulin-sensitive (IS), insulin-resistant/prediabetic and insulin-resistant/diabetic. All patients received a CAC scan. Results: 70% of asymptomatic survivors overall and 81% of asymptomatic IR patients show CAD on CAC scans. 17 CAC scans in the IS group, 6 CAC scans in the IR/prediabetic group and 5 CAC scans in the IR/diabetic group showed an Agatston score of 0. The p-value between the three groups was statistically significant (p = 0.005) whereas the IR/prediabetic- and the IR/diabetic group did not differ statistically from each other. The mean MESA 10-year CHD risk with CAC was 7.8. There was a highly significant difference between the 3 groups (p < 0.001). The two IR groups did not differ statistically (p = 0.076). Conclusions: Survivors with IR including prediabetes have less frequent zero CAC scores than insulin-sensitive survivors. Our study also showed that IR including prediabetes significantly increases the MESA 10-yr. CHD Risk with CAC in cancer survivors. This trial highlights the importance of screening survivors for IR and draws attention to the association of IR to CAC not only in diabetes but also in prediabetes. The high fraction of asymptomatic survivors with CAD is concerning and calls for further investigation. CAC scans are an inexpensive and efficient way of screening asymptomatic cancer survivors for CAD.