Bettina,

Thanks for your question. 

Blood sugar, or glucose level, is usually done when fasting (nothing by mouth for at least 6 to 8 hours).  Normal fasting glucose ranges between 70 and 99.  Levels between 100 and 125 are mildly elevated and are considered pre-diabetic.  Sugar levels of 126 or greater indicate diabetes. 

Another test used to evaluate sugars is the Hemoglobin A1C level.  This test gives the doctor an idea of how the sugars have been over the prior ten weeks.  This test does not have to be done fasting and is usually done to gauge sugar levels in patients that are pre-diabetic.  It also very useful in monitory diabetic patients on therapy, because it provides broader information about a patients glucose control, than just a single blood sugar level.

I noted that you asked your question in the "high triglycerides" category.  Triglyceride levels are closely linked to sugar levels.  If sugars are high, the triglycerides level frequently rises also.  In patients with high values should be checked for diabetes.  In these individuals, not only should the triglycerides be addressed, but the elevated sugars/diabetes needs to be treated.

I hope this has been helpful.

Martin Cane, M.D.