hi
first thing this has nothing todo with your diabetes or cholesterol or its treatment . what you say looks like intentional tremor. that is when you try to do a work you get tremor. or ist that the tremor is there always . the first one usually is due to cerebellar lesion second is due to basal ganglia prob ( both parts of brain ) the reason for this may be aging process ( atherosclerosis ) that is reduces blood supply to that part. so check for other symprtoms and confirm it . but nothing to worry .

Hello,
Tremor in one hand doesn't look to be a specific condition due to diabetes and there may be other reasons for it like it could be...
...benign essential tremor
...some side effect of some medication 
....over active thyroid.
....early sign of parkinsonism
The way you are describing your symptoms,it looks to be benign essential tremor.
The only symptom in essential tremor is tremor. If you have other symptoms, then you may have a different condition.

In essential tremor, the tremor usually begins in one arm or hand. Within 1-2 years, the other arm is likely to be affected. Very occasionally, it may also spread to involve the legs. 

There is no test to diagnose essential tremor. Your doctor can usually diagnose essential tremor based on your explanation of the tremor and an examination. It is important for the doctor to make sure that there are no other conditions present that are causing tremor. 
You must consult a neurologist and get blood tests and MRI BRAIN,to rule out other conditions.
Once the cause is found,treatment can be planned.
Thanks