Tobacco is sweet? Diabetes warning!

Author: Xiao Dan, Director of the Department of Tobacco Control and Respiratory Disease Prevention and Control, China-Japan Friendship Hospital, Researcher

Reviewer: Tang Qin, Deputy Secretary-General of the Science Popularization Expert Committee of the Chinese Medical Association, Researcher

What do you think of when you put the words "smoke" and "sugar" together? Perhaps flavored e-cigarettes. But what you need to know more is that smoking is closely related to the occurrence and development of diabetes and its complications.

Diabetes is a common chronic disease with high disability and mortality rates in modern society. In the past 30 years, the prevalence of diabetes in my country has increased significantly. The "Guidelines for the Prevention and Treatment of Type 2 Diabetes in China (2020 Edition)" published a survey result. From 2015 to 2017, the Endocrinology Branch of the Chinese Medical Association conducted an epidemiological survey on thyroid, iodine nutritional status and diabetes in 31 provinces across the country. The survey showed that the prevalence of diabetes in people aged 18 and above in my country was 11.2%.

The International Diabetes Federation (IDF) released the latest global diabetes map in 2021. Data showed that there are approximately 140 million diabetes patients in my country aged 20 to 79, ranking first in the world.

Smoking and diabetes

Smoking can cause blood sugar to rise

Among the diabetic population in my country, more than 90% suffer from type 2 diabetes. Insulin resistance is an important part of the development of type 2 diabetes. Smoking promotes the secretion of hormones that antagonize insulin, inhibits the production of insulin, and thus increases blood sugar levels. Long-term smoking can also cause the redistribution of adipose tissue, further aggravating insulin resistance.

Smoking increases risk of diabetes

As early as the 1990s, many international scholars began to pay attention to the causal relationship between smoking and diabetes. A study on American men found that those who smoked 15 to 24 cigarettes a day had a 2.38 times higher risk of developing type 2 diabetes than non-smokers.

Figure 1 Comparison of the risk of type 2 diabetes between male smokers and non-smokers in the United States

(Data from Goodbye Smoker: 70 Questions about the Health Harms of Smoking, created by the author)

In 2014, the "Report of the U.S. Surgeon General" widely collected relevant epidemiological research data and pointed out based on a large amount of scientific evidence that smoking increases the risk of diabetes, and that the risk of diabetes in continuous smokers is 30% to 40% higher than that in non-smokers; the more smokers smoke, the longer they smoke, and the younger they start smoking, the higher their risk of developing type 2 diabetes.

Smoking increases risk of diabetes complications

Smoking also increases the risk of various complications of diabetes, especially macrovascular disease. A meta-analysis of 46 prospective studies showed that smoking can increase the risk of all-cause mortality in diabetic patients by 48%, the risk of coronary heart disease by 54%, the risk of stroke by 44%, and the risk of myocardial infarction by 52%. Smoking can also damage the structure and function of the glomeruli and increase the occurrence of urinary protein and diabetic nephropathy.

Secondhand smoke exposure increases diabetes risk

A foreign study found that people who are exposed to secondhand smoke for ≥4 hours a day have nearly 1.4 times the risk of developing type 2 diabetes as those who are not exposed to secondhand smoke, and the longer the daily exposure to secondhand smoke, the higher the risk.

A study in China also reached a similar conclusion. A study on secondhand smoke exposure in women found that compared with those who never smoked and were not exposed to secondhand smoke, women whose spouses smoked had a significantly higher risk of diabetes; the risk of diabetes was positively correlated with the amount of smoking by the spouse, and the more the spouse smoked per day, the higher the risk of diabetes.

Figure 2 (Drawn by the author)

Smoking cessation and diabetes prevention

Quitting smoking reduces risk of diabetes and death

Diabetes guidelines at home and abroad clearly point out that in addition to strengthening physical exercise and maintaining a balanced diet, quitting smoking is also an important and effective means of preventing diabetes. Many studies have shown that long-term smoking cessation can reduce the risk of type 2 diabetes and the risk of death.

A review published in The Lancet in 2015 showed that the longer the smokers quit smoking, the lower their risk of developing diabetes and the greater the health benefits they gain.

Another study in the United States showed that the risk of death from cardiovascular disease in diabetic patients who quit smoking for more than 6 years is reduced by 50% compared with current smokers.

Quitting smoking can help control blood sugar

Timely and effective intervention for smokers who already have diabetes is also the key to controlling blood sugar.

An epidemiological survey among Chinese male patients with type 2 diabetes showed that with the increase in smoking, fasting blood glucose and HbA1c (glycosylated hemoglobin, which can reflect the average blood glucose in a certain period of time before measurement) both showed an upward trend; among smokers who quit smoking, fasting blood glucose and HbA1c gradually decreased with the increase in the number of years since quitting smoking.

Short-term and long-term effects of smoking cessation on diabetic patients

Studies have shown that quitting smoking will cause weight gain and increased blood sugar in patients with type 2 diabetes in the short term. This is because diabetic patients often have symptoms of hunger. After quitting smoking, the appetite suppressant effect of nicotine is lifted, which will cause patients to eat more. However, this effect will gradually weaken over time and basically disappear after 3 to 5 years. At the same time, quitting smoking will also change the intestinal flora, both of which will cause patients to gain weight.

Therefore, the beneficial effects and benefits of smoking cessation on diabetic patients should be viewed in the long term.

Smoking cessation measures and success rates

The "Guidelines for the Prevention and Treatment of Type 2 Diabetes in China (2020 Edition)" recommends that physicians use behavioral intervention and drug intervention for patients who want to quit smoking. Compared with minimal intervention or routine care, combined drug and behavioral intervention can increase the success rate of smoking cessation to 70% to 100%.

For smokers with type 2 diabetes, a 70% to 100% success rate in quitting smoking is an optimistic signal - by taking scientific measures, success in quitting smoking is in sight.

For other smokers, this is also a warning - if you wait until you get sick before regretting it, then no matter how high the success rate is, it will be too late to remedy the situation.

Smoking is harmful in every way and has no benefits. It is always better to quit smoking than not to quit at all, and it is always better to quit early than late.