Hemoglobin A1c or HbA1c is a protein on the surface of red blood cells. The HbA1c test is used to monitor blood sugar levels in people with type 1 and type 2 diabetes over time. Normal HbA1c levels are 6% or less. HbA1c levels can be affected by insulin use, fasting, glucose intake (oral or IV), or a combination of these and other factors. High hemoglobin A1c levels in the blood increases the risk of microvascular complications, for example, diabetic neuropathy, eye, and kidney disease.

Diet. Your diet should include lots of complex carbohydrates (such as whole grains), fruits, and vegetables. It’s important to eat at least 3 meals per day and never skip a meal. Eat at about the same time every day. This helps keep your insulin or medicine and sugar levels steady. Avoid empty calories, such as foods high in sugar and fat, or alcohol.
^ Imperatore G, Boyle JP, Thompson TJ, Case D, Dabelea D, Hamman RF, Lawrence JM, Liese AD, Liu LL, Mayer-Davis EJ, Rodriguez BL, Standiford D (December 2012). "Projections of type 1 and type 2 diabetes burden in the U.S. population aged <20 years through 2050: dynamic modeling of incidence, mortality, and population growth". Diabetes Care. 35 (12): 2515–20. doi:10.2337/dc12-0669. PMC 3507562. PMID 23173134. Archived from the original on 2016-08-14.

Diabetes mellitus type 2 is characterized by high blood glucose in the context of insulin resistance and relative insulin deficiency.[52] This is in contrast to diabetes mellitus type 1 in which there is an absolute insulin deficiency due to destruction of islet cells in the pancreas and gestational diabetes mellitus that is a new onset of high blood sugars associated with pregnancy.[13] Type 1 and type 2 diabetes can typically be distinguished based on the presenting circumstances.[49] If the diagnosis is in doubt antibody testing may be useful to confirm type 1 diabetes and C-peptide levels may be useful to confirm type 2 diabetes,[53] with C-peptide levels normal or high in type 2 diabetes, but low in type 1 diabetes.[54]

Diabetes is a number of diseases that involve problems with the hormone insulin. Normally, the pancreas (an organ behind the stomach) releases insulin to help your body store and use the sugar and fat from the food you eat. Diabetes can occur when the pancreas produces very little or no insulin, or when the body does not respond appropriately to insulin. As yet, there is no cure. People with diabetes need to manage their disease to stay healthy.