Diabetes Mellitus:- Part 8 – Diagnostic Criteria, Management, and Microalbumin/creatinine ratio

October 26, 2022Chemical pathologyLab Tests

Diabetes Mellitus Diagnostic Criteria

Diabetes Mellitus diagnostic criteria:

Any one of the following is needed to diagnose the diabetes mellitus:

1. When there are classical signs and symptoms like polyphagia, polydipsia, and polyuria.
   1. With a glucose level of ≥200 mg/dL.
2. Fasting glucose level is ≥126 mg/dL.
3. 2-hour glucose level with overload is ≥200 mg/dL during the Oral glucose tolerance test.

Impaired fasting glucose (IFG) diagnostic criteria:

• When the fasting glucose level is  110 to 125 mg/dL.

Impaired glucose tolerance(IGT) diagnostic criteria:

1. When Fasting glucose level <126 mg/dL.
2. When 2-hour oral glucose tolerance is between 140 to 199 mg/dL.

Management role in diabetes mellitus:

1. The role of the lab is in the preclinical and for the management of diabetes mellitus.
2. Regular check-ups of the glucose level and the urine.
3. It will prevent complications from diabetes mellitus.

The preclinical workup includes:

1. This is advised in patients with a strong family history of diabetes mellitus.
2. This will delay or may even prevent the onset of type 1 diabetes mellitus.
3. American diabetes association recommends immune-related markers in the first-degree relatives of diabetics.
4. Islet cell antibodies (ICA).
5. Insulin autoantibodies.
6. Glutamic acid decarboxylase antibodies.
7. Protein tyrosine phosphatase antibodies.
8. Genetic markers like HLA typing.
9. Insulin secretion like:
   1. Fasting level.
   2. Pulses level.
   3. Response to a glucose challenge.

Clinical markers for the diagnosis of diabetes mellitus are:

1. This mainly depends upon the presence of hyperglycemia.
2. OGTT may help to classify diabetes mellitus.
3. Insulin and C-peptide levels also help and assist in the classification of diabetes mellitus.

The clinical factors are:

1. Blood glucose level.
2. Oral glucose tolerance test.
3. Presence of urine ketone bodies.
4. Insulin level.
5. Estimation of C-peptide level.

Management of the diabetes mellitus:

The biochemical testing of the patient will help diagnose and monitor the therapy.

Management in the acute stage for:

1. Diabetic ketoacidosis.
2. Hypoglycemia.
3. Hyperosmolar nonketotic coma.

Management in the chronic stage is:

1. This is to control blood glucose concentration to decrease chronic complications like:
   1. Nephropathy.
   2. Retinopathy.
   3. Vascular diseases.
2. These complications can be controlled by:
   1. HbA1c.
   2. Urea.
   3. Creatinine.
   4. Urinary albumin excretion (microalbuminuria).
   5. Blood lipids level.
3. Recommendations for the control of glycemic control are:
   1. HbA1c
      1. Normal  = <6%
      2. The goal for diabetics = <7%
   2. Medical advise:
      1. If diabetes is unstable, then advise HbA1c quarterly.
      2. If diabetes is controlled, then advise HbA1c twice a year.
4. Microalbumin in the urine every year.
   1. This is the persistent microalbuminuria that is below the detection by the routine reagent methods.
5. A lipid profile is advised yearly.

Microalbumin/creatinine ratio:

Indication for microalbumin/creatinine ratio:

1. In the case of diabetes Mellitus.
2. Patient with hypertension.
3. Patients with heart disease.
4. People over the age of 50 years.
5. H/O smoking.
6. In the case of obesity.
7. A person with family H/O kidney diseases, hypertension, and diabetes mellitus.
8. >200 µg/min excretion in the urine indicates severe kidney disease (Nephropathy).
9. Once diabetic nephropathy is diagnosed, then renal function deteriorates quickly.
10. 30 to 300 mg/24 hours (20 to 200 µg/min) of urinary albumin is called microalbuminuria.

Urinary albumin excretion:

1. Patients with diabetes mellitus are more prone to develop kidney diseases.
2. Renal transplantation is needed in 1/3 of the patients with type 1 diabetes mellitus.
3. Diabetes is the most common cause of end-stage kidney disease in the USA and Europe.
4. Nephropathy is less common in type 2 diabetes.
5. Early detection of diabetic kidney disease depends upon the detection of urinary albumin.

Diabetes Mellitus: Albumin urinary excretion

Urinary albumin excretion:

Microalbumin/creatinine ratio facts:

1. Patients with diabetes mellitus are tested yearly to check their kidney disease status.
2. Albuminuria ≤0.3 g/day was detected only by the sensitive method.
3. This is the random urine sample (spot urine) where albumin concentration in mg is divided by the creatinine in gram (mg/g).
   1. Albumin/creatinine ratio (mg/g) predicts overnight excretion rate >30 µg/minute.
4. OR this is the ratio of albumin µg/L to creatinine mg/L, <30 is normal.
   1. A ratio of 30 to 300 indicates microalbuminuria.
   2. If this ratio is >300, it indicates macroalbuminuria
5. No doubt, 24 hours sampling is the gold standard method.

American diabetes association recommendations: