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Understanding Your Blood Sugar
If you have diabetes then it is important to understand and regulate your blood sugars. Being too high or too low can lead to problems. Blood sugars are best within the range of 4 to 7mmol/l. Many doctors will accept blood sugars under 10mmol/l. Maintaining tight control can minimize damage to kidneys, heart, eyes and circulation.
Normal blood sugars
The NHMRC (National Health Medical Research Council) of Australia says that blood sugars should be in range of 3.5-to 7.8mmol/l.
Impaired Glucose Tolerance
People are diagnosed with Impaired Glucose Tolerance if their fasting blood glucose levels are between 6.1 and 6.9mmol/l or 2 hours after a meal or glucose load they are between 7.8 and 11.1mmol/l.
This means there is impairment in the body's ability to control blood glucose levels. If diet and exercise are maintained and an ideal weight is achieved then often Diabetes Mellitus can be prevented or delayed.
Diabetes Mellitus
Once levels are greater than or equal to 7mmol/l fasting or 11.0mmol/l two hours after a glucose tolerance test or meal then Diabetes is diagnosed. Even if you lose weight and blood sugars return to normal, you will still have diabetes, as so far there is no cure. If weight is regained, you are ill or stressed; blood sugars can still climb.
Guidelines for Testing Blood Sugars
Self - blood glucose testing is a method of measuring how much sugar is in your blood. It is done by using a drop of blood from a finger. The blood is applied to a test strip, which is read by a blood glucose machine.
It is always wise advice to test blood sugar with a blood glucose monitor at least 4 times a week, two fasting (first thing in the morning) and two, two hours after the evening meal or the main meal of the day. If you have a meal out, are unwell or have suspicions of blood sugars being too high or too low then an extra test should be done.
With type 1 Diabetes on regular insulin injections, tests are done much more frequently. Your doctor, dietitian and nurse educator will help to set up a routine that will be suitable for you.
Testing allows you to be responsible and in control of your own health. You will learn to understand when certain foods and situations give glucose readings out of the best practice range and be able to improve them in the future.
Common Reasons For Blood Glucose Readings That Are Too High or Too Low
To further assist in understanding blood sugars, the following looks at some of the situations where blood sugars may vary.
Explaining the Highs Known as hyperglycaemia.
Repeated high blood sugars, particularly in the elderly can lead to reduction in cognitive function.
Food and Alcohol
Too much carbohydrate food or alcohol - alcohol requires glucose to break it down and then is used as energy.
Poor spacing of meals and food - a late lunch, larger than normal afternoon tea and then dinner can give a high two hours after the evening meal.
Over correcting a low blood sugar giving a rebound high - you felt unwell, your blood sugar was close to 3mmol/l and you ate some lollies and a slice of bread and jam. This results in a big swing and blood sugars are then too high. It is better to regulate eating and exercise to prevent low blood sugars.
Fatty meal - This will delay absorption leading to a high blood glucose level later.
High GI foods cause rapid absorption - Meals of rice or mashed potato that are high GI foods can give high readings if quantities are not strictly controlled.
Therapies
Insulin
The type - Sometimes the type and regime of insulin needs to be adjusted. If you are taking too much insulin and having lows, you then overeat and have highs. Reducing the dose of insulin under medical supervision can solve the problem.
The quantity - dial up error or too much insulin for spacing, quantity of food and exercise.
Medications - sulphonylureas in the elderly can cause lows and lead to highs later as too much food is consumed.
Monitoring
If monitoring is not carried out properly, blood sugars may be out of control without your knowledge- Using the wrong strip for the machine.
- Using strips that have expired or stored incorrectly.
- Using the machine incorrectly.
- Not washing hands before testing (handling sweet foods such as jam or fruit can give higher results).
- Incorrect calibration/set up.
- Improper care of Blood Glucose strips such as - when using strips in vial make sure lid is on tightly and fingers are dry.
- Some medications may react with the strip and give false readings.
Stress - Physical and Emotional
- Illness
- Back pain
- Physically inactive in comparison to normal
- Adrenaline raising activities e.g. fright- blocks insulin production
- Pregnancy - greater insulin resistance as pregnancy progresses
- Menstrual cycle- ovulation or premenstrual tension
- Anxiety or other worries- e.g. relationships, work, environment
Others
Insulin resistance - fat around the middleHigh blood sugars fasting in the morning
Dawn phenomena - insensitivity to insulin between approximately 4.00 am and 8.00 am due to the sleep-induced surge of growth hormone secretion.
Smogyi phenomenon - unrecognized nocturnal low blood sugars cause counter regulator hormones to be released. Check blood sugars at 2.00 or 3.00 am.
Inadequate insulin dose at night - Dose to cover the overnight period. Need to increase insulin.
Gastro paresis -This can be caused by autonomic neuropathy leading to a delay in the emptying of the stomach contents, and therefore leading to unpredictable absorption of food and thus giving poor diabetic control. A high fat meal also delays emptying.
Travelling - inactive and changing eating routines.
Over production of glucose in the liver - Due to inactivity or sleeping at night. Blood sugars in the morning are high.
Dehydration
Understanding the Low Blood Sugars or Hypoglycaemia
The brain uses glucose (sugar) as its main fuel. If blood sugars drop then protective neurohormonal responses are triggered. These switch off endogenous (pancreatic) insulin production and release hyperglycaemic hormones such as glucagons, growth hormone, cortisol and adrenaline. These responses are associated with the hypoglycaemic adrenergic symptoms of sweatiness, hunger, and shakiness. If correction does not occur by introducing glycogen or sugar then cloudy consciousness and possible coma and death could result. This would only occur in poorly controlled type 1 diabetes.
Situations Where Food and Alcohol Can be at Fault
Insufficient carbohydrate food.
A high GI meal giving rapid absorption. Blood sugars drop before the next meal or snack.
Blood sugars already low - not enough carbohydrate food or low GI foods are consumed that take too long to return blood sugars to normal.
Too long between carbohydrate foods - Food intake is not spaced correctly throughout the day. Try and ensure that some quantity of low GI foods are consumed every 2½ to 3 hours. A longer time is possible when very inactive. A shorter time is sometimes necessary in times of stress, physical activity and tiredness.
A meal or snack is missed.
Insufficient carbohydrate for energy requirements at that time. It may be just low joule vegetables as a source of carbohydrate.
Insulin or medication is taken when food is delayed or inadequate.
Excess alcohol is consumed without sufficient carbohydrate. This is more common with Type 1 diabetes.
Monitoring
- Tests may have been performed later than 2 hours after a meal.
- Strips may be out of date and therefore inaccurate.
- There may be incorrect storage of strips or machine - too cold < 5°C or too hot > 30°C
- Not enough blood has been put on the strip or too long has been taken in getting sufficient blood on the strip for the reading.
- An error message is given.
Other factors
A higher level of exercise than normal - blood glucose levels will stay lower for the next 24 hours.
Excessive tiredness - Blood sugars drop more rapidly when tired.
Stress - Stress can drop blood sugars.
Added to site on : Thursday, 13 May 2004