Reasons for Unstable Blood Glucose Levels: Getting off the Glucose Merry-Go-Round

If you're living with Diabetes, sometimes it can seem as if your blood glucose levels are on a constant white-knuckle ride, one minute rising to dizzying heights before lurching to terrifying lows.

You already know that it's important to eat and exercise sensibly, but what happens when you are following your doctor's advice and are still seeing wild fluctuations?

Here, we explore the reasons behind your unstable blood glucose levels and find out how you can get yourself on a more even keel.

But why does it really matter?

If your blood glucose (sugar) levels are unstable, you are more likely to experience complications.

Complications of diabetes may be managed initially, including bouts of hypoglycaemia (low blood sugar) and hyperglycaemia (high blood sugar), but will usually get worse over time, leading to eye problems (including blindness), kidney problems, nerve pain, and foot problems that may eventually lead to amputation.

The better your blood glucose control, the less likely you are to have these serious complications.

So, how can you keep those levels stable, to prevent those serious problems? And what are the surprising causes of unstable blood glucose levels.

Surprising Reason: Artificial Sweeteners

A 2013 study by Pepino and colleagues found that when seventeen patients with type 2, insulin-resistant Diabetes were given the artificial sweetener Sucralose (Splenda), their blood glucose levels peaked at a higher point than those who drank water.

Registered Nurse, Patty Bonsignore says:

 "If you drink a lot of diet soda then you might want to cut back and see if it has an impact on your blood glucose."

Surprising Reason: Medication

Did you know that there are at least 390 medications known to affect blood glucose control? Some anti-depressants (such as Fluoxetine), painkillers like Oxycodone, and even Progesterone (used in some oral contraceptive pills) can raise blood glucose levels, while NSAIDs (like Aspirin, and ibuprofen), and anti-depressants (like the MAOI Phenelzine) can lower blood glucose levels. Others, such as the anticonvulsant, Topiramate (Topamax) have an unstable effect on blood glucose levels, and may make them rise or fall.

READ Diabetes Symptoms: A Silent Killer Disease

Some drugs, such as alcohol and the beta-blocker medication Propranolol are also known to mask symptoms of hypoglycaemia. This can lead to blood glucose levels going dangerously low. Check your blood glucose levels regularly.

If you feel your medication is causing or masking symptoms, see your doctor.

Surprising Reason: Dehydration

If your blood glucose levels are constantly high, you might want to be sure you're drinking your two litres a day. Dehydration temporarily raises insulin resistance, making your blood glucose levels rise. As your blood glucose levels rise, you start to urinate more as your body tries to dump the excess sugars through your urine. This further increases dehydration and traps you in a vicious circle.

To avoid this cycle, make sure you drink enough daily, especially if you are sick and have a fever.

READ Ten Myths About Staying Hydrated

Surprising Reason: Your Cycle

Different phases of your menstrual cycle do different things to your blood glucose levels. Every woman's menstrual cycle affects her differently. Many women's blood glucose levels go unexpectedly high, but some women's levels drop. The rise experienced by many women is believed to be partly due to changes in the of oestrogen and progesterone causing temporary insulin resistance.

If your cycle does affect your blood glucose levels, closely monitor your blood glucose readings, and talk with your diabetes specialist about the possibility of adjusting either your insulin or your carbohydrate intake.

Surprising Reason: Sleeplessness

It's hard to believe that lack-of-sleep could have such an effect on your blood glucose level, but it's true. In 2010, Dutch researchers (Donga and colleagues) restricted patients with Type 1 Diabetes to four hours of sleep a night. They found that, almost immediately, their insulin resistance increased, causing a rise in blood-glucose levels. This was true, even after only one night.

If you are having trouble sleeping, practice good sleep hygiene and consult your doctor if sleeplessness continues.

More Surprising Causes for Fluctuating Blood Glucose Levels

Surprising Reason: Stress

When we are stressed, our adrenal glands release the emergency glucose stored in our bodies.

In times of stress, our body activates epinephrine and norepinephrine. Norepinephrine prepares us for fight or flight by preventing blood pressure dropping too-low, but epinephrine works to convert the glycogen (the glucose stored in our muscles and liver) into ready fuel, ready to fight or flee. However, when the stress is emotional or long-term, that system doesn't turn off, leading to blood glucose levels remaining high. Additionally, diabetics are famously bad at turning-off this process once the stress has passed.

If you are stressed, look into meditation, or other forms of relaxation.

Surprising Reason: Weather

Both excessive heat and excessive cold can have an impact on your blood glucose control.

Hot Weather

Spending time outside in high temperatures may increase the risk of dehydration which - as we've already discovered - puts a strain on your body. However, Type 1 Diabetics, or Type 2 Diabetics who use insulin, may be more at risk of hypos, as insulin is absorbed more quickly at the injection site.

Your insulin can also become damaged in the heat, making it less effective. If damaged, it may turn grainy, cloudy or brownish. Store insulin in the fridge and do not use damaged insulin.

To keep safe in heat, drink lots of cool water (avoiding alcohol), don't stay in the sun too long, and measure your blood glucose levels more regularly.

Cold Weather

Cold weather also affects blood glucose levels, causing them to rise. As it gets cold and icy, people stay indoors and do less activity which causes a rise in blood sugars. Though some believe it's actually more complex than that.

Some believe diabetes is actually an evolutionary survival mechanism. Sugar is a natural substance that prevents liquid freezing (the scientist Dr. Moalem draws our attention to German ice-wine, a sweet wine made with nearly-frozen grapes; the grapes never fully-freeze, as the sugar content prevents it). But how does this relate to diabetes? Dr. Moalem theorised that, in winter, our prehistoric ancestors produced less insulin so that their blood sugars would rise, preventing them becoming little Neanderthal icicles by the time the thaw set-in.

Fortunately, we're no longer shivering in animal skins every winter. Unfortunately, our pancreas never got the message, and we're still stuck with this little evolutionary quirk.

There's nothing you can do about it, except to wrap-up warm. But it might help to explain why so many diabetics are diagnosed between November and February.

Surprising Reason: Caffeine

The average American consumes 474ml of coffee a day, and 280mg of caffeine. For healthy adults, it appears that drinking up to 400mg of caffeine is safe, and may even prevent diabetes, but the same might not be true for diabetic adults.

READ The Good And Bad Of Coffee

For diabetic adults caffeine has a destabilising effect on blood glucose levels, raising them in some people and lowering them in others. As little as 200mg of caffeine (or just two-and-a-half short Starbucks Cappuccinos per day) can have this effect.

If your blood glucose levels are unstable, try cutting your caffeine consumption.

Surprising Reason: Pain or Illness

Just like stress, when we're in pain or ill our bodies release hormones (such as cortisol, and adrenaline). These hormones fight against insulin, causing your blood glucose levels to rise.

Continue to take all anti-diabetes medications. Even if you don't feel like eating much, take small 15g portions of carbohydrate every hour such as dry toast, rice pudding, fruit juice or regular soda (full-sugar, not diet), and applesauce. Be sure to drink regularly, as dehydration makes hyperglycaemia worse.

If you have a fever, your blood glucose readings are consistently 250mg/dL (13.9mmol/L) while ill, or you have vomiting or diarrhoea for 24 hours or more (sooner if you are becoming dehydrated) seek medical advice.

Go straight to your local emergency department if you have the following signs: abdominal pain, "fruity" breath, nausea and/or vomiting, weakness, rapid breathing, confusion, or unconsciousness. These are signs of ketoacidosis. Ketoacidosis kills.

Surprising Reason: Physical Activity

Okay, not so surprising, because this is where we came in. It's widely known that the amount of physical activity you do will affect your blood glucose levels, but did you know it will effect them for up to 48 hours?

READ Exercise and Physical Activity for Older Adults

However, exercise is not always good for your blood glucose levels. You should not exercise if your blood glucose levels are higher than 250 mg/dL (13.9 mmol/L in the UK) as exercising temporarily raises your blood glucose levels. Blood glucose levels in this range may indicate that your insulin is not controlling your sugars. Test your urine for ketones, if possible. If not possible, seek advice of a doctor before you exercise. Exercising while ketones are present may lead to ketoacidosis, a dangerous complication that must be immediately treated.

Do not exercise, too, if your glucose levels are below 100 mg/dL (5.6 mmol/L). Instead, eat between 15 and 30g of carbohydrate first: oatcakes, 2 rice cakes, or a small banana are all good choices. Once you start, stop immediately and test your blood glucose levels if you feel dizzy, unwell, or develop a headache.

Better blood glucose testing

If your readings are always alarmingly high, make sure they're actually accurate.

Many people forget to wash their hands before taking a reading, and when they get a high reading, it can be quite a jolt. This often happens when people are in a hurry. One Dutch study told participants to touch a piece of fruit before testing their blood glucose levels; 88% of the readings read at least 10% higher than they actually were. So, remember to wash your hands.

Make sure, too, that you clean the machine and use a clean lancet for each blood glucose testing. Modern machines are very sensitive to interference and a smear of old blood may mean that you don't get an accurate reading. You probably do all this, but some people don't.

But the most important thing is to test regularly. Knowing your blood glucose levels can help you keep track of all possible problems , so you can control them as best you can with your support team, helping to prevent complications in the future.

That way, you can go out there, knowing you're in the best shape possible to enjoy life.