1- Blood glucose > 120 mg/dl (6.8 mmol/L) on two repeated measurements. Normal range for blood glucose mg/dl ( mmol/L). boarderline concentrations need Glucose Tolerance Test (GTT).

2- Oral Glucose Tolerance Test (GTT): The patient is asked to come fasting to the lab, and a blood sample is collected. Then, 75 gm of glucose given orally. After this, blood samples are collected after 0.5, 1.0, 1.5, and 2 hours after oral glucose intake. Normally, the blood glucose is not increasing more than 180 mg/dl throughout the test, while in in Diabetic patients, the blood glucose levels might reach above 180 mg/dl and after two hours of start of the test it will not return to normal, and remain to be higher than normal.

3- follow up of Diabetes mellitus: 1.)) measurement of blood glucose level. 2.)) measurement of glycosylation ( HbA1c and Fructoseamine).  Glycated Hb (HbA1c): it represent reaction of Hb unit with glucose molecules.  Glycated plasma proteins (fructoseamine): this is also used for follow up of Diabetic patients.

Complications of Diabetes Mellitus: Diabetic Ketoacidosis in Type I DM due to insulin deficiency. Blood glucose is highly increased but the cells can not use glucose properly -cells started to use lipid for energy production, through lipolysis (by lipoprotein lipase enzyme- Cleaning enzyme).

Lipolysis: Is splitting of triglycerides to monoglyceride and two fatty acids Triglycerids Monoglyceride + two fatty acids Fatty acids are converted to fatty acetyl CoA Excessive formation of acetyl CoA is converted into ketone bodies (ketoacidosis).

Ketoacidosis can occur in starvation. Differentiation between ketoacidosis due to starvation or due to DM is by measuring blood glucose. In starvation there is low blood glucose level, while it is high in DM.

Regulation of glucose metabolism Liver, Pancrease, other endocrim glands are involved in glucose metapolism and therefore the controle of blood glucose level which is normally ranged between 60 – 120 mg/100ml 1- Insulin : Peptide hormone produced by pancrease responsible for decreasing blood glucose by increasing entry of glucose into the cells 2- glucagon : primary hormon responsible for increasing blood glucose by increasing glycogenolisis

And increasing gluconeogensis 3- Epineph, nor Epineph produced by adrenal medulla increasing glycogenolysis and gluconeogensis 4- ACTH, GH increasing blood glucose throgh incresing glycogenolysis and gluconeogensis.

Hypoglycaemia A deacrese of blood glucose to 40 mg% means hypoglycaemia it can be due to : Pancreatic tumour : insulinoma, pancreatitis, other pancreatic tumour Adrenal tumour Glycogen. s. Diseases Reactive hypoglycaemia Drugs Essensial reactive hypoglycaemia,alcohol. Inborn errors of metabolisim, galactosaemia, heridat fructose in tolerance.

Neonatal hypoglycaemia