Perhaps your son feels "different" because of his diabetes, and it may be especially important for him to feel accepted like every other boy. Finding naturalistic opportunities for friendship at your son's age should not be too challenging. Is there a Boy Scout troop in your town? How about Little League, soccer, tennis, or a swim team? All of these can be good opportunities for solid starting encounters.

If your son does not enjoy outside activities, perhaps a chess club, trading cards club or drama/chorus group might suit him. Many of these opportunities require solid adult leadership, so you might consider becoming a manager or assistant of the team or club -- not to interfere, but to provide adult scaffolding to help your son be successful.