I have low thyroid. I don't know if it is related to diabetes, though. I got it before I got diabetes, and the treatment is completely separate. I just want to warn you that it is important to take the right level of thyroid hormone. More than once I have over-dosed on thyroid hormone and ended up with disabling heart palpitations (which come in episodes, and which last 3 to 6 hours or so). My experience is that the brand Synthroid is more likely to cause palpitations than Levoxyl (but I don't think Levoxyl is sold outside the U.S.). Two thyroid medications can have the same strength but have different effects on the body. Our thyroids produce more than one hormone, and the proportion of these hormones can be different from one medication to the next. Thus, this is one instance in which it is important to take a brand-name medication. If you take the generic, the drug store may give you medications from different drug companies, and the effect on the body may not be the same from one to the next.