by Faisal
Hi,
My blood sugar is about 120–130 mg/dL in the morning. In the evening it comes down to 80–90 mg/dL and sometimes reaches 100 mg/dL.
I take Diamicron 30 mg in the morning and Glucophage 2,000 mg at night. Why does my blood sugar fluctuate like this, and what should I do?
Answer by Dr. Albana Greca, MD, MMedSc
Hi Faisal,
The difference you describe is modest. Blood glucose changes during the day with meals, medicines, activity, sleep, stress and hormones. The most important details are when the evening test was taken, whether you have symptoms and what your HbA1c shows.
For many nonpregnant adults with diabetes, a common before-meal target is 80–130 mg/dL. Fasting readings of 120–130 are therefore within or at the upper edge of that target, while evening readings of 80–100 are also within target if measured before dinner or at bedtime.
These treatment targets differ from diagnostic ranges for people without diabetes, as explained in our guide to diabetes blood sugar levels and targets.
A common explanation is the dawn phenomenon. Early-morning hormones signal the liver to release glucose before waking. With type 2 diabetes, insulin action may not fully control this rise.
Other causes include a late or high-carbohydrate dinner, bedtime snacks, poor sleep, sleep apnea, stress, illness, steroid medicines or treatment not matching overnight needs. These are discussed in our article on why blood sugar can be higher in the morning.
The original explanation that dinner carbohydrate simply remains circulating because metabolism slows during sleep is inaccurate. Digestion, liver glucose output, hormones and medication timing all contribute.
Diamicron contains gliclazide, a sulfonylurea that stimulates insulin release. Daytime activity, meal size and the medicine’s effect may make an evening reading lower than the morning value.
A result of 80–100 mg/dL is not hypoglycemia. However, gliclazide can cause a low, especially with skipped meals, strenuous exercise, alcohol, kidney or liver problems or interacting medicines. Because hypoglycemia begins below 70 mg/dL, test promptly if you develop sweating, shaking, hunger, dizziness, confusion or unusual weakness.
Do not increase, reduce or stop either medicine from these readings alone. Metformin rarely causes hypoglycemia by itself, but the combination with gliclazide still requires attention to low readings.
Treatment depends on HbA1c, kidney and liver function, meal timing, other conditions and hypoglycemia history. The differences between common tablets are summarized in our diabetes medication guide.
For several days, record:
If morning readings remain higher, ask whether an overnight check or short CGM assessment would help distinguish dawn phenomenon from an overnight low or medication-timing problem.
Cinnamon, bitter melon and gymnema have not been proven to provide predictable glucose control or replace prescribed treatment. Adding them to gliclazide may make glucose harder to predict and could increase low-glucose risk.
Arrange a review if fasting glucose is repeatedly above your target, HbA1c remains high, readings fall below 70 mg/dL or you have symptoms of lows. HbA1c gives a broader picture than isolated readings, as explained in our article on HbA1c and average glucose.
Seek urgent help for severe confusion, seizure, fainting, inability to swallow, persistent vomiting, deep or rapid breathing, severe dehydration or very high glucose with ketones.
Your readings may represent reasonable control rather than harmful fluctuation. Confirm the medicine formulations, record test timing and review the pattern and HbA1c with your clinician.
Do not increase Diamicron on your own, because the lower evening readings show that hypoglycemia risk must also be considered.
Hope this helps.
Dr. Albana Greca
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