Q. My postprandial sugar levels are high even after taking Metformin. Do I need Insulin injection?

Answered by
Dr. Zulfiqar Ahmed
and medically reviewed by Dr. Vinodhini. J
This is a premium question & answer published on Dec 22, 2020 and last reviewed on: Jan 22, 2021

Hello doctor,

I have developed type-2 diabetes in the past three years. However, in the last year, I did not require insulin as my sugar levels were normal. I live abroad, and I am on Metformin. Due to COVID-19 and various lockdowns in the country, my sugar levels were out of control. I am now back to my strict diet, exercise and still taking Metformin 500 mg twice a day. My morning sugar levels are normal, anywhere between 90 and 133. A test again before lunch very rarely shows high sugar levels. I may need to use my Novolin N injection. If not during lunch, I may have to use 30 minutes before my evening meal. I noticed my eyes are going blurry, and hard to see if my sugar levels rise above 150. A few months back, the retina in my right eye ripped, and I had to do a laser repaired. Then the same thing occurred in my left eye. The doctors here did not know to look at the correlation between that, and diabetes neither did I. When testing my blood sugar from Monday through Sunday before each meal, I usually have an average between 90 to 150. I say if it goes above that, then I take 3 to 5 units of insulin. However, last week before dinner, it pushed up to 248, and I had to take 10 units to get it down. I eat no sugar. I watch my carbs, primarily fruits and vegetables, doing everything I can. The doctor here in this country says that he would like to switch me over to the insulin pen, which is considered a 70/30 distribution.

My question is, do you recommend this insulin pen, even though I have days that my sugar may otherwise in the morning be acceptable? Right now, this doctor here in this country is asking me not to take any Metformin or insulin for one week. He wants to see all of my sugar numbers every morning and afternoon so that he can see the pattern of my sugar. Would you follow the same treatment?



Welcome to

Diabetes has many complications, so it is not just to bring down the numbers but to monitor and treat complications associated with diabetes. Check your eyes for retinopathy, kidneys with urine albumin creatinine ratio, and check your feet.

Lifestyle modifications are the best treatment for diabetes. Take a low carbohydrates diet and no added sugar. No sugary juices, bread, rice, pasta, and potatoes. If you cannot stop, at least take as little as possible. Take more vegetables, salads, and fibers. Consume fruits only as a sweet dish. Do not take mango, grapes, and banana. Do not take apple not more than one piece. Strawberries and other berries are fine to take along with peach, apricot, and small amounts of plums.

Intermittent fasting will also help you to control your diabetes. You can fast for 16 hours, like taking your dinner at 7 pm and not eating anything after that. Next, you can take breakfast at 11 am. During fasting, drink water and green tea without sugar. You can extend fasting to 24 hours then 36 hours as your body adopts. You can do fasting two times a week, or as you feel comfortable, it will control your sugar.

Drink more water. Sleep well. Do exercise at least walk 30-40 minutes daily. The more you practice these things, the better will be your control. Check your sugar frequently. Your fasting target should be 90-130. Two hours after eating, it should be 150-160. HbA1c should be less than 7. These targets can vary in individual patient depending upon his diabetes duration and other relevant issues.

In my opinion, it is not a good idea to take insulin after you find out that your sugar is high and then bring it down fast. It creates big fluctuations in your sugar levels, meaning one time it is high, and after a few minutes it is down. This is not good. Actually you should check your sugar more frequently one in the morning before breakfast if it is in the range as I above mentioned no need to take any insulin. Then check your sugar before lunch, and the same rule applies and check it after eating as well. I mean that if your sugars are higher after eating only, you should start taking insulin just before meals, like 15-20 minutes before eating, so there should not be a surge in level. How much should you take? That depends on two things: one how much is your sugar before eating and how much carbohydrates are you going to eat. But before considering to bring down your sugars after eating, first bring in control the fasting sugars. Better is to take basal insulin-like Glargine, which comes in the trade name of Lantus at night. You can start it like six units and then increase every day 1-2 units if your fasting sugars are higher than 120-130.

If your fasting is in range, then no need. If it goes less than 70, then decrease about 3/4 units the next day. Once your fasting sugar is in range, then we concentrate on after eating sugar. That should be near 150. You can start to take Novo rapid only at your main meal and take it just before meal if you find after eating sugars are higher than range. Your HbA1c should be less than 7. Another important issue is if you have any of the diabetes complications other than eyes as you mentioned.

You should check urine albumin creatinine ration at least one a year to check how your kidneys are doing. Do you have any heart issues? How about ur blood pressure and cholesterol levels? It is not just to bring sugar number down but to keep the whole body healthy, as I mentioned above. Check your diet and lifestyle modifications as above. Low carbohydrate diet and intermittent fasting, as I mentioned above, will help you a lot. If you could practice it well, I hope you may not even need insulin, and your Metformin will be enough.

Thank you doctor,

I want to know about my lab results and the current treatment plan in place, and I asked you if you would follow the same treatment plan. Or is there something else I should be doing? Please go back and read my initial questions.



Welcome back to

I will give you the details about how to use insulin. In my opinion, it is better first you should check your sugars regularly (fasting and before and after meal). Do it for at least three to four days. Then we will be in a better position to see what time your sugars are really high and how much.

First option can be to increase the Metformin to its maximum dose of 2 gram daily. Then we can add either another oral medication or go to insulin. Depending upon your sugar levels your preference and feasibility.

If insulin to be started I think you can use Glargine as a basal insulin and Novorapid as a bolus insulin and it is better than insulin pen 30/70. And I have already explained how to use Lantus and Novorapid.

Our body continuously produces insulin in small amounts. This is called basal insulin. Then the time we eat there is increased surge of insulin which is a bolus insulin. So when we give insulin in patients who have diabetes we try to make it same way. Lantus or Glargine is basal insulin and it remains in the body all the time and it is called basal insulin. It is long acting. Where as insulin like Novorapid is bolus insulin which is given just before the meals to stop the surge of glucose or sugar levels after eating. It is short acting and starts its work in 15-20 minutes reaches at peak at about 90 minutes and stays in body for four to five hours only. Where is 30/70 is mixture of intermediate acting and short acting insulin and the ratio is fixed and it cannot be changed. It is harder to control sugar with this mixed insulin and you need to be strict in your diet. Basal bolus insulin gives you more flexibility in terms of your diet and you can modify the insulin according to your levels of sugar and content of your meal.

I hope this helps.

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