Dipeptidyl Peptidase-4 Inhibitor Reduces the Risk of Developing Hypertrophic Scars and Keloids following Median Sternotomy in Diabetic Patients: A Nationwide Retrospective Cohort Study Using the National Database of Health Insurance Claims of Japan.

Background: Hypertrophic scars and keloids, which are abnormalities of fibrosis, often occur in surgical wounds; however, their exact cause and preventive measures are unknown. The administration of dipeptidyl peptidase-4 inhibitors to humans is expected to suppress fibrosis in wounds and minimize hypertrophic scar and keloid formation.
Methods: This study aimed to verify the suppressive effect of dipeptidyl peptidase-4 inhibitors on the formation of hypertrophic scars or keloids using real world data from the National Database of Health Insurance Claims and Specific Health Checkups of Japan. It is a retrospective cohort study, and data were extracted from the National Database between April of 2013 and March of 2015. Patients who underwent median sternotomy were included in the study based on their claimed surgical codes. Subjects who were prescribed dipeptidyl peptidase-4 inhibitors constituted the treatment group; subjects who were not prescribed or administered dipeptidyl peptidase-4 inhibitors during that period constituted the nontreatment group.
Results: Subjects included 5430 patients throughout Japan (3509 men and 1921 women). Of the 446 subjects who were treated with dipeptidyl peptidase-4 inhibitors within 1 year before the procedure, fewer than 10 (<2 percent) developed either hypertrophic scars or keloids. Of the 4984 subjects who were not treated, 152 (3.05 percent) were at significantly lower risk for hypertrophic scars and keloids (p = 0.04). A logistic regression analysis was performed to adjust for confounding factors, with history of hypertrophic scar formation as the explained variable.
Conclusion: This study revealed that dipeptidyl peptidase-4 inhibitors suppress the onset of hypertrophic scars or keloids after surgery in humans.
Clinical Question/level of Evidence: Therapeutic, III.