Insulin And Type 2 Diabetes

Not many people realize it, but the pancreas is one of the most important organs in the body. Without insulin produced in the pancreas, our blood sugar levels could rise or fall to fatal levels. 

Taking insulin for type-II diabetes helps diabetics manage blood sugar levels so they can survive and lead a relatively normal life.

When the pancreas fails to function normally or when you develop insulin resistance, you could be diagnosed with diabetes. Type -II diabetics could require daily supplemental insulin, but what exactly is it and how does it work?

Have you considered clinical trials for Type 2 diabetes?

We make it easy for you to participate in a clinical trial for Type 2 diabetes, and get access to the latest treatments not yet widely available - and be a part of finding a cure.

What is insulin?

In a healthy person, the pancreas creates the hormone we know as insulin. Insulin helps to push glucose from the bloodstream into the cells that use and store it. It also plays a vital role in the liver where it helps regulate metabolism of carbohydrates, proteins, and fats.

Beta cells in the pancreas produce all the insulin used in the body. In a healthy person, a spike in blood sugar triggers these cells to produce more insulin; this is what happens after eating. Increased insulin levels cause more sugar to pass from the bloodstream into the cells.

How insulin works

Insulin works as a type of key. It triggers receptors in the blood vessels that allow sugar molecules to pass through, and it also tells the liver to store blood sugar for later use. The liver stores excess glucose in the form of fat, and as blood sugar decreases, so do insulin levels.

This process of regulating glucose levels in the blood works automatically in a healthy human. In persons with type 2 diabetes,  the insulin receptors become resistant, and eventually r the pancreas fails to produce enough insulin.

In the case of insulin resistance, the pancreas is forced to make more and more of the hormone to maintain balance. This state of overproduction can maintain healthy glucose levels in the blood over the course of months, years, or even decades.

However, at some point, the beta cells will burn out. This is diabetes, and from there you will have to take supplemental insulin to survive. 

But why is it so important to keep blood sugar low? High blood sugar (also called hyperglycaemia) causes many long-term harmful effects in the body, including:

Damaged blood vessels

Sustained hyperglycemia causes blood vessels to narrow and lose their elasticity. This in turn leads to other health problems such as high blood pressure (hypertension), a risk of blood clots, heart attack, and stroke.


High blood sugar also damages blood vessels in the eyes. New abnormal vessels develop in their place and grow at the back of the eye (diabetic retinopathy), and eventually can lead to, increasing eye pressure,  swelling and damage to the optic nerve (glaucoma). Eventually, this can impact vision and cause blindness.

Nerve Damage

Long-term hyperglycemia also damages nerves throughout the body, but more commonly in the hands and feet. Also called diabetic neuropathy, this nerve damage is characterized by tingling in the hands and feet as well as a loss of sensation. 

Kidney failure

The ultra-fine blood vessels in the kidneys that filter blood are highly vulnerable to heightened blood sugar levels. High blood pressure also contributes to this problem, which is why 10–40%¹ of diabetics suffer kidney failure at some point

These and many other problems make it imperative to control blood sugar by taking insulin if you're diabetic.

What are insulins used for?

The various types of insulin available today all have one purpose, and that's to control blood sugar levels in the blood. Called insulin therapy,² taking insulin for diabetics helps them to maintain a normal range of blood sugar and live healthy lives.

Insulin is commonly taken in the form of injections because, as a type of protein, insulin would get digested if eaten or swallowed. There are also insulin inhalants, but we will cover these in greater detail under types of insulin.

Who should take insulin?

Anyone with diagnosed Type 1 or type 2diabetes should take supplemental insulin to help control their blood sugar. However, not all type 2 diabetics have to take insulin, and your doctor will advise on that based on the tests they conduct.

For type 2 diabetics, the best course of action is to try and control blood sugar levels through a regimen of strict nutrition, exercise, and anti-diabetic drugs. If that fails to work, then you will need to start taking insulin. 

When should I take insulin?

If you are a diabetic, your doctor will advise you on when you should take your insulin injection. However, in general, you need to take insulin right before your meals and any time you experience symptoms of high blood sugar. These symptoms include:

  • Increased thirst and hunger, or a very dry mouth

  • Frequent urination

  • Fatigue 

  • Blurred vision and confusion

  • Nausea and vomiting

  • Shortness of breath

  • Fruity breath, a sign of a severe condition called ketoacidosis

  • Abdominal pain

In addition, if you have been taking alternative antidiabetic medication and are still experiencing symptoms such as unexplained weight loss, frequent infections and sores that heal slowly, numbness and areas of darkened skin, talk to your doctor about beginning insulin therapy.

What are the types of insulins?

In general, insulin is categorized into fast-acting, intermediate-acting, and slow-acting insulin. This speed of acting depends on the time it takes for the insulin to peak in the bloodstream and how long its effect lasts. 

Within these categories, there are different types of insulin. Here in the US, for example, the most common types of insulin include:

  • Humulin R or human insulin—this is high-strength, ultra-fast acting insulin designated U500. U500 means that 100 milliliters of this solution contains 500 parts of insulin, whereas "normal" strength insulin is U100 or 100 parts of insulin in the same volume of solution. It starts acting within 30 minutes and lasts for up to 8 hours.

  • Humalog or insulin lispro—another fast-acting insulin with a strength of U200. It takes effect up to 30 minutes after eating and lasts for about 5 hours.

  • Lyumjev or insulin lispro-aabc—this insulin is almost the same as Humalog but contains additional ingredients. It works even faster, within 20 minutes of eating and has 3 times the effect of Humalog, but it lasts for only 1-3 hours.

  • Toujeo Solostar, or Lantus—usually made of U300 insulin glargine, a long-acting insulin that works over 24 hours. Due to this, it can be taken as a once-a-day injection.

  • Tresiba or insulin degludec—this is a long-acting version of human insulin. It replaces natural insulin in the body and is also taken once a day as an injection.

In most cases, the insulin you take will be a combination of fast-acting and slow-acting insulin. This makes it easy for you as you only need to buy and draw from one bottle. 

Depending on the mix recommended by your doctor, rapid-acting insulin covers glucose spikes after eating, while long-acting insulin is absorbed and peaks slowly over a longer period. 

More recently, a different type of insulin called Afrezza also became available. Afrezza is an inhalable insulin that works within 12–15 minutes, making it an ultra-fast acting type of insulin. However, it is out of your system in three hours and must be used with injectable insulin.

What is the best type of insulin for type 2 diabetes?

All the different types of insulin are extremely effective at controlling type 2 diabetes. However, each individual will react differently to each type depending on the severity of their insulin resistance, amount of naturally produced insulin, diet, activity levels, among other factors.

Your doctor will work with you to determine which type of insulin, in what strength, and what dosage will work best for you. In many cases, they will prescribe more than one type of insulin and explain how to space your dosages throughout the day.

You may have to:

  • Take multiple injections per day

  • Monitor your blood sugar levels throughout the day to see how your body reacts to the insulin. This helps the doctor to fine-tune your insulin therapy

  • Be more proactive about your lifestyle choices, including cutting out sugars, carbs, and counting the calories you eat

  • Have a sick day plan, as sugars become more volatile when you are unwell

The type of insulin you take will depend on three factors. Onset is the time it takes the insulin  to begin acting in your bloodstream. Peak is the time when that insulin reaches maximum effectiveness, while duration is how long it continues to lower your blood glucose levels.

How to take insulin?

For most people, the most practical way to take insulin is through self-administered injections taken once or several times a day. Others who require more careful blood sugar regulation might have insulin pumps.

Insulin pumps are electronic devices that monitor blood sugar levels and administer the corresponding amount of insulin required. The pump administers insulin through a thin tube inserted just below the skin, which is changed every 2-3 days.

In addition to monitoring glucose levels and administering a continuous amount of insulin, most modern pumps can also administer a higher amount (bolus) to deal with glucose spikes after eating.

If you're taking injectable insulin, your doctor will teach you on how to select the right size of syringe, how to draw the right amount of insulin, how to inject it, and how to vary the injection sites to minimize the risk of reactions. 

If you don't want to inject insulin, there are several other options your doctor can consider:

  • Insulin pens—these look just like a large pen. They contain preloaded insulin cartridges and don't require pre-measuring or mixing.

  • Jet injections—instead of using needles, you simply hold the device against the skin, press a button, and a jet of insulin is pushed under pressure into the body.

  • Inhalable insulin, which is more expensive and is usually not covered by insurance.

How much insulin should I take if I have type 2 diabetes?

Insulin is measured in International Units. For example, U-100 insulin contains 100 units of insulin in 1 mL of solution. Your doctor will likely start you on a low dose of long acting insulin,  such as 10 units a day. This dosage will be based on your body weight, insulin resistance, and other factors.

From there, your daily dosage will go up by two or four units daily with strict monitoring until your blood glucose reaches the recommended fasting level or your recommended blood sugar target.

Another way you can cover your insulin needs is to count your carbohydrates and sugars. One unit of rapid-acting insulin is enough for 10 grams of carbs. This insulin–carb ratio can change, so you need to know how many carbs you're eating with every serving and vary your insulin dosage accordingly.

It is important to stick to the right dose since an insulin overdose can lead to a dangerous condition called hypoglycemia. This is where blood glucose levels are extremely low, resulting in symptoms like:

These symptoms can also occur after strenuous activity, when you skip a meal, or if you mix up short and long-acting insulin in the wrong amounts. 

For that reason, you should always carry a high-sugar snack such as fruit juice, soda, glucose tabs, or honey to take in case you experience hypoglycemia.

What are the possible side effects of insulins?

The most commonly used type of insulin today is human insulin under brand names like Humulin. In addition to the risk of hypoglycemia, human insulin can also cause other side effects such as:

  • Headaches

  • Allergic reactions at the site of injection

  • Weight gain within a very short period

  • Itching and rashes at the site of injection

  • General weakness

  • Muscle cramps

  • Sweating

  • A fast or abnormal heartbeat

  • Swelling in the hands, arms, feet, or legs

  • Difficulty breathing or swallowing

  • Skin changes at the site of injection (lipodystrophy). 

These and other side effects are rare, but you should always let your doctor know if you experience any negative side effects from taking insulin. 

What are the benefits of taking insulin for type 2 diabetes

You may already be managing your type 2diabetes using antidiabetic drugs and lifestyle changes. However, there may be some medical benefits to taking up insulin therapy to help manage your blood sugar:

  • Insulin is much more effective at managing blood sugar and fights symptoms such as fatigue or frequent urination.

  • Taking insulin reduces the risk of diabetes complications.

  • If your pancreas is still producing insulin, taking supplemental insulin reduces pressure on the pancreas and may help it recover with time.

  • If other treatments have failed, insulin therapy is the only viable option left to manage type 2 diabetes

Alternative treatments for type 2 diabetes

In general, some type 2 diabetics—such as those with insulin resistance—might be able to control their blood sugar by taking other types of medication. These alternative forms of medication include:

  • Metformin—a drug that stops the production of sugar in the liver

  • Sulfonylureas and glinides—these are pills that increase insulin production in the pancreas

  • SGLT2-inhibitors—these are drugs that prevent glucose from being reabsorbed by the kidneys back into the bloodstream, which results in excess sugar being eliminated in your urine.

  • Gliptins or DPP-4 inhibitors, help increase insulin production.Incretin therapies and amylin analogs—these pills or injections reduce sugar production in the liver. They also slow down the absorption of food and include piils like Victoza and Januvia.

  • Glitazones—these are pills that help remove sugar from the blood by reducing insulin resistance. Not a first line agent, given side effects. 

When should I see a doctor?

Whether or not you have been diagnosed with type 2diabetes, see a doctor immediately if you experience any of the signs of abnormal blood sugar or insulin side effects listed above.

Most importantly, diabetes can cause life-threatening conditions. If you experience any of the following, visit the ER immediately for emergency care.

  • Nausea, vomiting, and fruity breath, all symptoms of diabetes ketoacidosis

  • Shortness of breath and difficulty breathing

  • Irregular heartbeat

  • Clammy skin and profuse sweating

  • Drowsiness or confusion

  • Blood sugar levels that are consistently above 140 mg/dL (7.8 mmol/L)

The lowdown

If you are a type 2 diabetic, taking insulin may be necessary to keep your blood sugar levels under control. It is important to know all you can about the types of insulin, how to administer it and when, as well as what dosages are right for you. Your doctor will take you through most of this. 

And, if you're supporting a loved one with type 2 diabetes, remember to show them care and affection as they adjust to this condition. Be on the lookout for signs of high or low blood sugar and keep in touch with their doctor so that you can reduce the risk of any diabetic emergencies.

Have you considered clinical trials for Type 2 diabetes?

We make it easy for you to participate in a clinical trial for Type 2 diabetes, and get access to the latest treatments not yet widely available - and be a part of finding a cure.

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