Diabetes is one of those insidious conditions that creeps up slowly and you don’t realize you have got it until it is too late. For example, this week I saw one patient who had been checking his blood sugars and they were all around 100 (normal) so he gave up checking his sugar levels at the end of last year. He now reported some suspicious symptoms, but as he had stopped taking his blood sugar levels we repeated the blood test. Sugar levels were now around 550!
Diabetes is a serious ailment, which can arise for many reasons, and can affect many systems in the human body. Diabetes, called “sugar” by patients, is diagnosed and monitored mainly through a simple blood test – the Blood Glucose level.
To stop the sugar levels increasing daily, a balance is achieved through a hormone called Insulin which helps the body use and control the amount of glucose in the blood. Insulin is produced in areas of the pancreas called ‘islets’ and released into the blood when the level of glucose in the blood rises. In simple terms, people who do not produce enough insulin develop Diabetes.
People can also develop diabetes if they do not respond normally to the insulin their bodies produce. This occurs most commonly when a person is overweight, and since obesity is on the rise, so are various types of Diabetes.
Normally, blood glucose levels increase slightly after a person eats a meal. This increase causes the pancreas to release insulin so that blood glucose levels do not get too high. Blood glucose levels that remain high over time can cause damage to the eyes, kidneys, nerves, and blood vessels, which explains why good glucose control is important.
There are many ways to carry out blood glucose tests, including Fasting Blood Sugar (FBS). This is a measurement of blood glucose after fasting for 12 to 14 hours.
The other common test is called the Random Blood Sugar (RBS). A random blood sugar measurement may also be called a casual blood glucose test. This is a measurement of blood glucose that is taken regardless of when the person last ate a meal. Sometimes several random measurements are taken throughout a day. Random testing is useful because glucose levels in healthy people do not vary widely throughout the day, so wild swings may indicate a metabolic problem.
Glucose Tolerance Testing can also be done, usually to confirm a condition known as Gestational Diabetes, which can occur during pregnancy. To monitor the treatment of diabetes, there are another couple of tests which can be carried out. The commonest is Glycated Hemoglobin, otherwise referred to as HbA1c. This test actually is an indicator of the average glucose concentration over the life of the red blood cells (which is taken as over the previous three months).
“Normal” levels may vary from lab to lab, but generally the range taken for FBS is that the level should be less than 110 milligrams per deciliter (mg/dL).
Diagnosis of diabetes needs a fasting blood glucose level higher than 125 mg/dL on two separate days.
A fasting glucose level below 40 mg/dL in women or below 50 mg/dL in men that is accompanied by symptoms of hypoglycemia (low blood sugar) may indicate an insulinoma, a tumor that produces abnormally high amounts of insulin. Lower than expected glucose levels can also indicate Addison’s disease, an underactive thyroid gland or pituitary gland, liver disease (such as cirrhosis), malnutrition, or a problem that prevents the intestines from absorbing the nutrients in food.
So you can see “sugar” is important which is why we have specialist endocrinologists at my hospital.