[Clinical laboratory tests in diabetes mellitus]

Area of Science:

• Endocrinology
• Clinical Chemistry
• Nephrology

Background:

• Diabetes mellitus diagnosis often begins with symptoms like polydipsia, polyuria, and weight loss, accompanied by glucosuria.
• Initial diagnostic thresholds include random plasma glucose ≥ 200 mg/dl or fasting plasma glucose ≥ 140 mg/dl.

Purpose of the Study:

• To outline the diagnostic criteria and methods for diabetes mellitus.
• To review various biomarkers for assessing glycemic control and detecting diabetic complications.

Main Methods:

• Clinical assessment of symptoms and laboratory tests including random and fasting plasma glucose.
• Oral glucose tolerance test (OGTT) for uncertain cases, interpreted using Japan Diabetic Society criteria.
• Measurement of Glycated Hemoglobin (HbA1c) for mean blood glucose over 1-2 months.
• Assessment of fructosamine, glycated albumin, and 1.5-Anhydroglucitol for shorter-term glucose monitoring.
• Analysis of microalbuminuria, urinary transferrin, and IgG for early detection of diabetic nephropathy.

Main Results:

• Significant correlations exist between microalbuminuria and other urinary microproteins like transferrin and IgG.
• Various biomarkers provide different timeframes for assessing glycemic control, from weeks to months.
• Diagnostic interpretation of OGTT follows established expert committee guidelines.

Conclusions:

• A combination of clinical evaluation, glucose measurements, and specific biomarkers aids in the diagnosis and management of diabetes.
• Early detection of diabetic nephropathy is facilitated by monitoring microalbuminuria and other urinary proteins.
• Glycated hemoglobin (HbA1c) and other markers are crucial for evaluating long-term glycemic control and treatment effectiveness.