Blood Sugar Check

Blood sugar can be checked by patients at home. This is called SMBG (self-monitoring blood glucose) or in the laboratory. Small portable hand held battery operated devices are in common use. The accuracy has about 10% variability as compared to laboratory testing.

Indications :

All cases of Type I Diabetes mellitus should frequently check blood sugars. This should be done multiple times daily in most cases as fluctuations are more common in Type I DM

  • by those on multiple insulin injections daily,
  • while adjusting insulin doses,
  • when hypoglycemia is suspected,
  • before exercise /games etc
  • before driving.
  • During travel

It is required less frequently in Type II Diabetes. It is checked for patients on insulin and those having hypoglycemic episodes. Once a week check may be enough for most patients. Those who are on a tight control of sugars require more frequent checks.

It is also recommended during treatment of hypoglycemia to ensure that blood levels of glucose have improved and remain improved.

Time of Testing :

For type II cases and those suspected to have hypoglycemia often, morning and before dinner levels are useful. However, treatment should not be delayed in serious hypoglycemia suspicions as delay in correcting glucose levels may cause permanent injury to some organs especially nervous system.

Methods :

Venous or capillary blood is used for measurement of blood sugar. It can be measured in plasma or serum. Capillary and plasma levels are 10% lower and higher compared to venous and serum levels due to glucose utilization by tissues and RBCs.

Glucometers use strips impregnated with glucose oxidase. Most show plasma glucose rather than whole blood levels.

Calibration is required before using a fresh set of strips.

Best results are obtained if a lancet is used for puncture of the skin. Blood should come out easily rather than being squeezed from the fingertip. Sides of terminal digits should be used as punctures in front areas would be painful when hands are used. Hands should be washed and dried before a sample is taken.

Higher values may not be measured precisely and are often shown as High levels.

Test strips should be fresh and manufacturers guidelines should be adhered to.

Units of Measurement :

Old methods report sugar level in mg/deciliter while the newer methods are in mmol/liter. To convert from mg/dl to mmol /l the former values are divided by 18.

HbA1C or glycated Hb measures level over previous 12 weeks or so. The test, however, should be done in a fasting stage and is a good guide for overall diabetic control.

Diabetes mellitus

Diabetes Mellitus

Diabetes is a condition where a person either does not produce required amounts of insulin or is unable to utilise insulin appropriately. It is a common (about 10% of the population), complex disease. It can cause complications if not treated and controlled well.

Types of Diabetes:

There are 2 common types of diabetes Type I and Type II. There are other rare varieties due to pancreatic diseases, hormonal disorders, in pregnancy, after drugs and even rarer genetic disorders.

Type I is the cause in about 10 % of cases, onset is in childhood or young age and insulin is required for treatment.

Type II is the common variety, onset is usually around 50 Yrs of age, often associated with overweight and the risk is high if one parent is diabetic (30 %) and if both parents are diabetic (50 %). During initial stages, diet modification and oral drugs may control sugars but later insulin may be required.

Symptoms:

Classically symptoms in diabetes are polyuria (more urine), polydypsia (more thirst ) and polyphagia ( more eating). In children very high sugars may develop suddenly and patient may become unconscious at the onset (DKA etc). Infections both recurrent and difficult to treat may occur. However in a large no the disease remains without many symptoms and found out accidentally or when complecations arise.

Signs are seen only in advanced and long standing diseases. These are few and may include eye, heart, nerve changes, dehydration and very rapid breathing due to acid accumulation in the body.

Diagnosis of diabetes:

Diabetes is diagnosed by blood glucose testing or glycated hemoglobin levels.

Normal Plasma glucose level after 8 hrs of fasting is < 100 mg/dl. Normal 2 hrs after breakfast (called PP) or after 75 gms of glucose orally is <140 mg.   Diabetes is diagnosed if either fasting plasma glucose is >126 or PP or oral GTT (after 75 gms of glucose is >200 mg/dl.

If fasting value is 100 -125 it is called impaired fasting glucose and if PP or Oral GTT is between 140 and 199 mg/dl it is called impaired glucose tolerance( IGT).

In a person with symptoms of diabetes a random value of plasma sugar >200 mg /dl or fasing plasma sugar >126 mg/dl qualifies for diagnosis of diabetes.

Lab tests for diabetes  

For common types of diabetes the following tests may be required at the time of initial diagnosis.

Complete blood counts, Blood sugar, kidney and liver function tests, urine routine and urine for microalbumin, lipid profile, Chest X Ray, ECG. Ultrasonography of abdomen, fundus examination, foot examination and blood pressure is noted.

In Type I cases or where genetic, pancreatic or hormonal disorders are suspected, tests for these are carried out as appropriate.

This is a chronic disease and lifelong follow up and treatment are required.

 

 

Coming next ~

Complications of diabetes

Treatment of diabetes.