There is no reason not to have acupuncture when suffering from diabetes. There are no absolute contraindications of which we are aware, and we have seen no case reports of adverse events where acupuncture treatment has affected someone's diabetic control.
We do, however, issue a couple of cautions to members. The first is that if you see a traditional acupuncturist you are very likely to have treatment for the constitution as well as local treatment for the elbow. There is a small but mentionworthy risk that the treatment may stimulate the residual pancreatic function and cause an increase in body insulin. If this happens and someone has a balanced intake of medications it can force a slight hypo. This is more of a risk with insulin, where the effect is more rapid and a hypo really can cause serious problems. On the meds which people usually have for Type 2 diabetes this is less likely to occur.
The second issue is that long term diabetes can begin to impact on circulation and wound healing, and if the practitioner make a judgement that this is beginning to be the case he or she may well choose to swab all of the points they use to protect against infection from the needle insertion. This is pretty much only a theoretical risk at best - in the UK there are almost no reports of infections from needle insertion - but where a theoretical risk exists modern best practice is to address it by swabbing. Otherwise we follow generally accepted practice in the NHS for not swabbing unless there is an identifiable risk where a patient might be more vulnerable.
We hope that this reassures you and that the treatment of your elbow is successful.