Cause of Blood Sugar Variations in Diabetics

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Control of Blood Sugar Levels

Diabetes mellitus is a chronic disease where there is an abnormality in the body’s ability to maintain blood glucose levels. The cause of blood sugar variations in diabetic patients is their inability to absorb and utilize sugar or carbohydrates inf foods. In patients diagnosed with type 1 diabetes there is a complete absence of insulin since the pancreas fails to produce it in response to carbohydrate intake. This is the primary reason why patients have an uncontrolled high blood sugar level, or hyperglycemia. Biosynthetically produced insulin is given to type I diabetics to maintain normal blood sugar levels.

Type 2 diabetics, on the other hand, can produce insulin but often have an increased resistance to the effects of insulin or an inability of cells to respond to insulin whenever blood glucose levels increase. Since the pancreas is triggered to produce more insulin, whenever there is food intake there may be an unusually high insulin levels which does not effectively cause glucose absorption into the cells. Thus, hyperglycemia results even in the presence of insulin. Oral hypoglycemic agents are usually given to type 2 diabetics to maintain blood glucose levels although some may need insulin.

Causes of Blood Glucose Variations

As with normal individuals, various factors can be the cause of blood sugar variations in diabetics. The problem lies, however in their ability to control these responses and maintain normal levels.

Causes of increased blood sugar levels or hyperglycemia include:

  • Stress causes the release of epinephrine, a stress-response hormone, that leads to increased breakdown of glycogen to glucose and release of fatty acids from fatty tissues. Stress can also bring about a release of cortisol, another hormone that causes release of glucose in the blood and which antagonizes the effects of insulin. Stress can be brought about by different factors like emotional problems, diseases, infections, trauma and surgery.

  • Increased food intake – The most immediate cause of hyperglycemia is an increase in sugar intake which is not controlled by internal metabolism.

  • Lack of exercise – Since excess sugars, fat and proteins are stored as glycogen which are then converted to glucose, a lack of exercise coupled with increased food intake can increase blood glucose levels. This is more common in type II diabetics, and they are usually advised to watch their diet and participate in more physical activity and exercise.

  • Failure to take prescribed medications is most dangerous especially in type I diabetics

  • Failure to adjust dosages or timing of drug administration causes blood glucose levels to rise in response to food intake

Causes of decreased blood sugar levels or hypoglycemia are:

  • Fasting, starvation or malnutrition may be due to skipping meals, restricted diet, lack of appetite or any reason to prolong intervals of food intake

  • Strenuous activities – if completed without enough food intake before exercise, the body may use up all available blood glucose and suffer from hypoglycemia before the body has a chance to respond to glucagon breakdown of glycogen

  • Overdosing of insulin and other hypoglycemic drugs

  • Wrong timing and dosage of insulin which may cause inadvertent decrease of blood sugar

  • Excessive alcohol consumption – Without sufficient food intake, the liver fails to release glucose from to the blood as needed

  • Other diseases like liver disease, kidney disease and pancreatic tumors like insulinoma

  • Reactive postprandial hypoglycemia – In patients who have had gastric bypass surgery the body reacts to food intake by releasing too much insulin compared to normal and results in blood sugar levels that are too low.

These show that the inability of a diabetic to properly handle glucose load and the many factors contributing to the cause of blood sugar variations necessitate medical treatment and modifications in lifestyle. Diabetes mellitus is a chronic disease and it is therefore important maintain adequate of control of blood sugar levels to avoid its many complications.

References, “Hypoglycemia”,

WebMD, “Hyperglycemia and Diabetes”,