What are the possible negative side effects of taking Ultralente insulin? Could it aggravate problems with the tendons in the hands?

Tenosynovitis in the hands is a recognised accompaniment to diabetes which is thought to have an autoimmune basis and has nothing to do with Ultralente insulin.

DOB
Additional comments from Dr. Stuart Brink:

There are no additional known side effects of Ultralente insulin compared to other types of insulin. It is a longer acting insulin, and so peaks and valleys must be counterbalanced with food, activity and blood glucose monitoring (as with all insulins). It is often used as a basal insulin coupled with premeal boluses of Humalog, Novolog, or Regular insulin as part of a multi-dose intensified insulin regimen. Some diabetologists believe that Ultralente insulin is more unpredictable and varied in its effects, others use it as a substitute for an insulin pump, and still others use Ultralente insulin to gain a longer duration of effect compared to NPH or Lente insulin. As with all insulin programs, its use should be individualized based upon treatment goals and blood glucose readings.

SB