Does Nicotine Raise Blood Sugar? Understanding the Link Between Smoking and Diabetes

Does nicotine affect blood sugar and lead to diabetes?

Yes, smoking can increase blood sugar levels. In fact, it’s a known risk factor for Type 2 diabetes and prediabetes. Smoking increases the risk of getting diabetes by 30% to 40%. 

A 2016 study of people with diabetes looked at blood sugar levels in smokers versus nonsmokers. It found that smokers generally had higher hemoglobin A1C levels (a measure of how much sugar is in your blood). And this appears to be a dose-dependent response. In other words, the longer people had smoked, the greater their A1C.

How does this happen? Research suggests that smoking leads to insulin resistance via a few different pathways. With insulin resistance, the body doesn’t respond to insulin as well and therefore can’t use glucose as it should. This leads to high blood glucose levels and eventually diabetes. The culprit is likely nicotine. But it’s possible that other components of tobacco smoke, like heavy metals, can also play a part.

Studies have also found a link between smoking and decreased function of beta cells, which are the cells in the pancreas that make insulin.

What’s the risk of smoking cigarettes if you have diabetes?

Smoking and Type 2 diabetes individually increase the risk for several diseases and complications. This is because both conditions damage your blood vessels. When you combine the two, the risk is even greater. 

Smoking and diabetes increase your risk of:

• Coronary artery disease and heart attacks

• High blood pressure

• Heart failure

• Stroke

• Peripheral artery disease

• Kidney disease

• Nerve damage

• Leg and foot pain

• Foot ulcers

One study found that among people with diabetes, smoking was the greatest predictor of death.

Is it bad to vape if you have diabetes?

Many people have switched from cigarettes to vaping or e-cigarettes thinking that they’re less harmful. Some think that it may even help them quit smoking altogether. But it’s important to know that vaping isn’t better than smoking. Here’s why:

• Vapes also contain nicotine, as well as harmful chemicals.

• Vaping might actually prolong your nicotine dependence.

• It’s also bad for your teeth and gums.

• There’s a potential for long-term health effects, including lung cancer.

• Vaping is very addictive, especially for young people.

What are the benefits of quitting smoking with diabetes?

Quitting smoking provides many health benefits — and not just for people with diabetes. Studies show that people without diabetes who quit smoking decrease their risk of developing Type 2 diabetes.

As it relates to diabetes, there’s good news here as well. All of the complications listed above are much less likely when you quit smoking and manage your blood sugar levels. This includes heart attack, stroke, and diabetes-related kidney disease — even death.

It’s important to note that the benefits of quitting smoking on your blood sugar might take longer to see. That’s because quitting smoking could lead to a small increase (0.1% to 0.2%) in A1C for maybe a year or more. But, over time, A1C levels tend to lower. They can even be similar to those of never-smokers after about 10 years. Experts agree that the benefits of quitting far outweigh the risk of an initial A1C increase.

How can I quit smoking?

There’s no doubt that quitting smoking or vaping is difficult. It can take many attempts and a lot of self-motivation. That is why it’s important to work with your healthcare team and experienced counselors if needed. What works will also depend on your own individual situation.

Some ways that have been shown to work include: 

• Going “cold turkey” and quitting all at once

• Smoking less over time by setting a limit on how many cigarettes you smoke per day and per week

• Using mobile apps or social media that give you tips, inspiration, and tools to help you practice cessation habits each day

• Asking your primary care provider or endocrinologist about whether a smoking cessation medication might be good for you

• Finding a counselor or support group that focuses on helping people who want to quit smoking or vaping

• Participating in a smoking cessation program

Using nicotine replacement products like nicotine gum, lozenges, or patches can also help you quit. They can replace the urge to smoke or vape. But they might not be the best choice for people with diabetes due to the effects of nicotine on insulin resistance (as noted above).

For more resources and help, visit smokefree.gov. The site lists specific resources that are tailored to people of different ages, genders, and backgrounds. It’s possible to get symptoms of nicotine withdrawal (such as headaches, irritability, and cravings) when you try to quit. So it’s good to be prepared and have a support person or team on standby.

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Written by:

Timothy Aungst, PharmD

Timothy Aungst, PharmD, has worked in pharmacy practice for a decade. He has served as an associate professor of pharmacy practice, a clinical pharmacist in outpatient cardiology management, and now in home healthcare.

Edited by:

Sophie Vergnaud, MD

Sophie Vergnaud, MD, is the Senior Medical Director for GoodRx Health. A pulmonologist and hospitalist, she practiced and taught clinical medicine at hospitals in London for a decade before entering a career in health education and technology.

Reviewed by:

Mandy Armitage, MD

Mandy Armitage, MD, has combined clinical medicine with her passion for education and content development for many years. She served as medical director for the health technology companies HealthLoop (now Get Well) and Doximity.

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