Which factor increases the risk of a surgical site infection (SSI) in a 65-year-old diabetic man with a penetrating stomach wound?

High blood sugar levels significantly increase the risk of a surgical site infection (SSI), especially in a diabetic patient. Elevated glucose levels can impair immune function, hinder wound healing, and increase the likelihood of bacterial growth, all of which contribute to the development of infections post-surgery.

Factors such as alcohol abuse, while they can impact overall health and recovery, do not have the same direct and pronounced effect on SSI risk in the context of surgical procedures as hyperglycemia does. Similarly, lack of proper medication might contribute to other health issues but is not as directly associated with increasing the risk of infections specifically at the surgical site. Obesity can also contribute to SSIs, as it may lead to technical difficulties during surgery and increased tension on sutures, but again, its impact does not match the critical role high blood sugar plays in this scenario.

In essence, for a diabetic patient, controlling blood sugar levels is crucial in reducing the risk of SSIs, making it the most pertinent factor in this case.