Smoking and Diabetes

According to the International Diabetes Federation (IDF), there is sustained global growth in diabetes prevalence, with 537 million individuals between the ages of 20-79 years living with diabetes in 2021. By 2030, this number is expected to reach 643 million, and by 2045, it will surpass 783 million. 

It is crucial that the general population is aware of diabetes, given the rising number of cases being diagnosed. 850,000 people in the United Kingdom now have type 2 diabetes but have not yet received a diagnosis. Having a thorough understanding of this disease will help the general population to asses their lifestyle choices and decrease their risk of developing diabetes. 

What is diabetes?

Diabetes mellitus is a long-term glucose metabolism condition that can lead to clinical consequences – someone with diabetes is 20 times more likely to have an amputation than someone who does not have the illness. 

The American Diabetes Association defines diabetes mellitus as a condition where the body’s blood sugar levels, primarily known as blood glucose levels, are higher than usual due to the body’s inability to utilise or store blood sugar for energy. High blood glucose levels are referred to as hyperglycaemia. So, how does the body transport sugar from the blood into your cells to be stored as energy?

When you ingest carbs, your saliva produces an enzyme called amylase, which initiates the breakdown of the sugars (glucose) in the carbohydrates. Glucose delivers energy to your cells. As the glucose enters the bloodstream, your blood sugar levels rise. The pancreas releases the hormone insulin, which then helps to carry sugar from the bloodstream into your cells. Once this has been done, the sugar is immediately used as fuel for energy or stored for later use. With a diabetic, there is an insulin imbalance and not all diabetics have the same symptoms.

Types of Diabetes 

Type 1, type 2 and gestational diabetes are the three types of diabetes classified. Type 1 and type 2 diabetes are the two most common kinds of diabetes, with type 2 responsible for the vast majority  of total incidence rates (>85%).1

Type 1 diabetes is characterised by beta cell loss in the pancreas. Beta cells secrete insulin. In type 1 diabetes mellitus, as the pancreas will eventually stop producing insulin altogether. When there is insufficient insulin, a person becomes hyperglycaemic. Symptoms include increased thirst, weight loss and impaired vision.

Genetics is one of the most important risk factors for type 1 diabetes mellitus (T1DM). If a parent has T1DM, your risk increases. There are various geographic and environmental aspects to consider. Exposure to a viral disease, for example, is likely to play a role in T1DM. This type of diabetes accounts for 5-10% of all diabetes cases.It presents itself during childhood or adolescence.

People with type 2 diabetes mellitus (T2DM) have reduced insulin sensitivity (insulin resistance). To compensate, the beta cells produce additional insulin. However, your pancreas eventually stops producing sufficient insulin to keep your blood sugar levels normal. Obesity is the single most important risk factor for T2DM, followed by smoking, genetics and PCOS. T2DM is more closely linked to genetics than type 1 and is more commonly found in older individuals. 

Gestational diabetes develops in pregnant women as a result of a reduction in insulin secretion. If you are overweight, have PCOS, or are of Middle Eastern, African-Caribbean, Black or South Asian descent, you are at higher risk of developing gestational diabetes. Symptoms include frequent urination and fatigue. Gestational diabetes normally goes away once the baby is born. Unfortunately, those who have experienced it are more likely to acquire gestational diabetes or type 2 diabetes in later pregnancies.

Occasionally, diabetes can be medically and chemically induced.3 Corticosteroids at high dosages, such as those used to treat lupus, are a common cause of diabetes during therapeutic usage. Corticosteroids are anti-inflammatory drugs that inhibit your immune system.

Smoking and diabetes

How does smoking affect patients with diabetes?

Diabetes puts you at a risk for cardiovascular illness, such as a heart attack or stroke. When you combine this with smoking, your chances of having these diseases increase. People with diabetes who smoke often require higher insulin doses to maintain blood sugar levels near the target.4 Cigarette chemicals, like nicotine, cause cells to become resistant to insulin, causing blood sugar levels to rise. Diabetes-related elevated blood sugar levels can damage blood vessels around the heart over time. Cigarette smoking can also harm blood arteries by causing plaque formation.

Type 2 diabetes

A meta-analysis found that smoking is an independent factor for type 2 diabetes. Heavy smokers saw a 66% increase in risk, whereas light smokers faced a 29% increase. Overall, the study indicated that active smoking was associated with a 44% increase in diabetes risk. 5 Additionally, those who smoke have a higher chance of accumulating belly fat, which raises their risk of type 2 diabetes.

Risks of smoking

Cigarette smokers are more prone to develop cardiovascular disease. When you smoke, your blood vessels stiffen and constrict. This causes your heart to beat faster and your blood pressure to increase, resulting in the formation of clots. A stroke can develop when a clot prevents blood flow to a part of your brain. Smoking-related blockages can also impair blood flow. Smoking harms your lungs' airways, which can lead to lung disease. Many cancer cases are caused by cigarette smoking. Furthermore, tobacco smoking has been linked to stroke and coronary heart disease.6

While smoking has long been recognised to cause heart disease and lung cancer, many people are unaware that it can also cause eyesight loss.

Diabetic retinopathy is a frequent diabetic condition. It damages the retina's small blood vessels in the eye. The retina is the rear of the eye's light-sensitive layer of cells that turns light into electrical impulses. The impulses are delivered to the brain, where they are translated into the pictures you see. A network of tiny blood capillaries provides the retina with the consistent blood flow it needs. Retinal blood vessels can deteriorate, leak, or get clogged, affecting vision over time. Serious eye damage can occur in certain diabetic retinopathy patients.


Diabetes can be treated in a variety of ways to mitigate its effects. 

To regulate their blood glucose (sugar) levels, everyone with type 1 diabetes and some people with type 2 diabetes must take insulin. Using an insulin pump instead of an insulin pen can be an excellent option. It may provide you with greater freedom in managing your diabetes.

Metformin is a diabetic medication that is used to treat type 2 diabetes and gestational diabetes. It is also used to help prevent type 2 diabetes if you are at high risk. It is frequently provided to those who smoke and have diabetes. Metformin decreases blood sugar levels by boosting your body's insulin response.

Obesity surgery techniques to the stomach or intestine are available to assist you with weight loss. Numerous studies have shown that this can aid in entering type 2 diabetes individuals into remission.7

You may be eligible to receive an islet cell transplant if you have type 1 diabetes. This may prevent you from developing severe hypoglycaemia.


Type 1 diabetes cannot be prevented; however, T2DM is largely avoidable by lifestyle modifications. 

  • Exercising and eating healthy – Being overweight increases your odds of having T2D, while exercising your muscles improves your ability to absorb glucose and utilise insulin, lowering your risks of developing T2D.
  • Avoid smoking – Smokers are more likely than non-smokers to acquire T2D, thus it's advisable to quit smoking.
  • Alcohol consumption – Alcohol in moderation improves insulin's ability to transport glucose into the cells. Additionally, some research shows that moderate alcohol use lowers the risk of T2D.8


Diabetes can lead to kidney damage developing over time, making it more difficult to eliminate extra fluid and waste from your body. Excessive blood sugar levels and high blood pressure are to blame. Diabetic nephropathy, often known as kidney disease, is the medical term for this condition.

Too much sugar in your blood might cause an increase in sugar in your saliva. This encourages the growth of bacteria, which creates acid, affecting tooth enamel and harming the gums. The blood vessels in your gums can also be compromised, increasing the likelihood of gum infection.

Additionally, damage to blood vessels can reduce the quantity of blood travelling to your genitals, causing you to lose sensation and thus, also causing a loss of libido.

How do you quit smoking?

You can stay motivated by writing down your reasons for quitting. Telling others that you will be quitting smoking will hold you accountable. Another option is to use smoking aids, such as nicotine patches, to help with the transition. Exercising is another way that will also keep you busy and away from your cravings. 

Additionally, the NHS offers some beneficial resources that can be accessed by anyone seeking assistance or additional information on how to stop smoking.


Within weeks of quitting, you will notice reduced coughing and shortness of breath, improved lung function, and a lower chance of sudden death from a heart attack. Also, keep in mind that the typical timeframe for people to quit smoking is approximately 3 months. 

Other advantages include cost savings and the prevention of damage to others caused by second-hand smoking. Each year, second-hand smoke causes around 41,000 fatalities among non-smokers and 400 deaths among babies. In adults, second-hand smoking causes stroke, lung cancer, and coronary heart disease. You can be satisfied that you are no longer hurting others by second-hand smoke and that you are reaping the long-term benefits to your health once you have quit smoking.


Diabetes is a chronic condition that causes an individual's blood sugar level to become excessively high. Diabetes is classified into two types: type 1 and type 2. Type 1 diabetes develops when the immune system attacks and destroys insulin-producing cells in the body. Type 2 diabetes develops when the body does not produce enough insulin and/or becomes insulin resistant. Diabetes already increases the risk of heart disease, lung disease, and diabetic retinopathy, but people with diabetes who smoke are at a further increased risk. It is recommended that individuals who have diabetes minimise their smoking habits, if not come to a complete cessation of smoking, as it will only cause further harm to the body. Quitting smoking can be hard, but there are a lot of resources available to help and encourage you throughout  your journey.


  1. Forouhi NG, Wareham NJ. Epidemiology of diabetes. Medicine. 2010 Nov;38(11):602–6.‌
  2. Mobasseri M, Shirmohammadi M, Amiri T, Vahed N, Hosseini Fard H, Ghojazadeh M. Prevalence and Incidence of Type 1 Diabetes in the world: a Systematic Review and meta-analysis. Health Promotion Perspectives [Internet]. 2020 Mar 30;10(2):98–115. Available from:
  3. Ferner RE. 8 Drug-induced diabetes. Baillière’s Clinical Endocrinology and Metabolism. 1992 Oct;6(4):849–66.‌
  4. Centers for Disease Control and Prevention. Smoking and Diabetes [Internet]. Centers for Disease Control and Prevention. 2019. Available from:
  5. Wang Y, Ji J, Liu Y, Deng X, He Q. Passive Smoking and Risk of Type 2 Diabetes: A Meta-Analysis of Prospective Cohort Studies. Hernandez AV, editor. PLoS ONE. 2013 Jul 26;8(7):e69915.
  6. U.S. Department of Health and Human Services. The Health Consequences of Smoking - 50 Years of Progress: A Report of the Surgeon General [Internet]. 2014. Available from:
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  8. Chiva-Blanch G, Badimon L. Benefits and Risks of Moderate Alcohol Consumption on Cardiovascular Disease: Current Findings and Controversies. Nutrients [Internet]. 2019 Dec 30;12(1):108. Available from:

Ambria Pearce

Bachelor of Science - BSc, Neuroscience, University of Sussex, England

Ambria is currently a BSCs Neuroscience student at the University of Sussex. She has a particular interest in the brain-gut connection; where the brain has a direct influence on the stomach and intestines and the neural processes of mental disorders. She intends to further study neuroscience at a Masters's level. presents all health information in line with our terms and conditions. It is essential to understand that the medical information available on our platform is not intended to substitute the relationship between a patient and their physician or doctor, as well as any medical guidance they offer. Always consult with a healthcare professional before making any decisions based on the information found on our website.
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