Year-end physical examination, @diabetics: don’t forget these 3 screenings

In November this year, the top medical journal The Lancet published a major study: By 2022, there will be approximately 148 million people with diabetes in China. [1] On average, one in 10 people has been diagnosed with diabetes.

So, once you are diagnosed with type 2 diabetes, what should you pay attention to? In addition to the often mentioned blood sugar control and lifestyle improvement, special attention should also be paid to the screening of chronic complications.

01What are the chronic complications of diabetes?

Diabetes complications can be understood as the troubles caused by diabetes - the existence and development of diabetes leads to further damage to the body. According to the speed of occurrence, they can be divided into acute and chronic.

The former, such as diabetic ketoacidosis, has abnormal blood sugar metabolism, which interferes with the utilization of fat and causes toxic substances to accumulate in the body. In severe cases, coma may occur within a few days.

Complications of diabetes (Image source: self-made by the author)

The latter often takes several years. Chronic complications can be roughly divided into two types based on the tissues affected: vascular diseases, such as myocardial infarction, stroke, nephropathy, and retinopathy; and neurological diseases, such as diffuse neuropathy and cognitive dysfunction. [2]

02Why is it necessary to screen for chronic complications of diabetes?

At this point, some readers may think that since these diseases are caused by diabetes, it is fine to control blood sugar. Why is screening necessary?

The good news is that controlling blood sugar can indeed reduce chronic complications of diabetes. A prospective diabetes study in the UK followed up more than 5,000 patients for 10 years. The results showed that for every 1% decrease in glycated hemoglobin (HbA1c, one of the blood sugar indicators), the risk of myocardial infarction decreased by 14% and retinopathy decreased by 37%. [3]

Unfortunately, there is some bad news too.

First, in reality, not many people can control their blood sugar levels. A large-scale study in China showed that only 30% to 35% of patients with type 2 diabetes can control their blood sugar levels within the ideal range. [4]

Secondly, the mechanism of chronic complications of diabetes is very complex. Traditionally, the focus has been on the harm of high blood sugar to the body. For example, HbA1c mentioned above is formed by the combination of glucose in the blood and hemoglobin in red blood cells. Ideally, it should be controlled within 7%; if it exceeds 7%, it means that blood sugar is too high for a long time and a large number of red blood cells are affected. Red blood cells are equivalent to the couriers of the human body. Once they are affected, blood vessels and nerves may be affected.

Glycated hemoglobin (Source: Polymorphism of aldose reductase gene and susceptibility for developing diabetic retinopathy among type 2 diabetes mellitus patients)

In recent years, many scholars have pointed out that high blood sugar cannot explain all complications. For example, patients with type 2 diabetes often have dyslipidemia. Abnormal blood lipids can also harm body tissues. [5] Another example is individual differences. When faced with disease, each tissue will try to defend itself. However, the protective factors that the body can provide are unpredictable. So there is a strange phenomenon: with the same blood sugar level, some people may develop complications, while others are safe and sound. [6]

Finally, the incidence of chronic complications of diabetes is very high and the consequences are extremely serious.

In terms of morbidity, a domestic study investigated more than 60,000 patients with type 2 diabetes, targeting seven complications, including cardiovascular and cerebrovascular disease, nephropathy, retinopathy, and neuropathy. The results showed that 66.8% of the patients had some chronic complications, and each patient had an average of more than two complications. [7]

In terms of consequences, cardiovascular and cerebrovascular diseases and kidney disease are important causes of death in diabetic patients. [8] Diabetic retinopathy can affect vision and is the most common cause of blindness among working-age people. [9] Cognitive dysfunction not only affects the patient's quality of life, but also places a heavy burden on the family. [10] As for peripheral neuropathy, which may not be familiar to everyone, it can cause foot ulcers and, in severe cases, requires amputation. [11]

Therefore, in addition to controlling blood sugar, patients with type 2 diabetes should also undergo chronic complications screening as soon as possible and regularly.

03How to screen for chronic complications of diabetes?

The answer is simple: get regular physical exams.

According to the examination method, complication screening can be divided into two categories: one is included in routine physical examinations, such as cardiovascular and kidney examinations; the other category requires extra attention.

Additional physical examination items that diabetic patients should pay attention to (Image source: self-made by the author)

Domestic experts recommend that newly diagnosed patients with type 2 diabetes should undergo fundus examination as soon as possible, followed by annual follow-up. If retinopathy is present, the frequency of examinations should be increased. [9] Five years after diagnosis, peripheral nervous system examinations should be performed, and screening should be performed at least once a year thereafter. [11] For patients with type 2 diabetes over 65 years of age, in addition to the above examinations, cognitive function screening should also be performed annually. [10]

Conclusion

The prevention and treatment of type 2 diabetes is divided into three levels: primary prevention, improving lifestyle to avoid the occurrence of type 2 diabetes; secondary prevention, if type 2 diabetes has already occurred, actively control blood sugar and screen for complications in a timely manner; tertiary prevention, if complications have also occurred, then find ways to treat and control them.

These three levels are like three lifebuoys for diabetes. Patients newly diagnosed with type 2 diabetes have already missed the first lifebuoy. However, there is no need to be discouraged: as long as scientific methods are adopted, it is possible to avoid complications and delay, reduce or even eliminate the impact of the disease on life expectancy and quality of life.

Author: Zhao Yanchang, Master of Medicine, member of the China Science Writers Association

Reviewer: Tang Qin, Director of the Science Popularization Department of the Chinese Medical Association, National Health Science Popularization Expert

Produced by: Science Popularization China

References

[1]ZHOU B, RAYNER AW, GREGG EW, et al. Worldwide trends in diabetes prevalence and treatment from 1990 to 2022: a pooled analysis of 1108 population-representative studies with 141 million participants[J/OL]. The Lancet, 2024, 0(0)[2024-11-18]. https://www.thelancet.com/journals/lancet/article/PIIS0140-6736(24)02317-1/fulltext. DOI:10.1016/S0140-6736(24)02317-1.

[2] Chinese Diabetes Society. Guidelines for the prevention and treatment of type 2 diabetes in China (2020 edition)[J]. Chinese Journal of Diabetes, 2021, 13(4): 315-409.

[3]STRATTON IM, ADLER AI, NEIL HAW, et al. Association of glycaemia with macrovascular and microvascular complications of type 2 diabetes (UKPDS 35): prospective observational study[J/OL]. BMJ: British Medical Journal, 2000, 321(7258): 405. DOI:10.1136/bmj.321.7258.405.

[4] Gao Leili, Ji Linong, Lu Juming, et al. Investigation of drug treatment and blood sugar control status of patients with type 2 diabetes in my country from 2009 to 2012 [J]. Chinese Journal of Diabetes, 2014(7): 594-598.

[5]EID S, SAS KM, ABCOUWER SF, et al. New insights into the mechanisms of diabetic complications: role of lipids and lipid metabolism[J/OL]. Diabetologia, 2019, 62(9): 1539. DOI:10.1007/s00125-019-4959-1.

[6]YU MG, GORDIN D, FU J, et al. Protective Factors and the Pathogenesis of Complications in Diabetes[J/OL]. Endocrine Reviews, 2024, 45(2): 227-252. DOI:10.1210/endrev/bnad030.

[7] He Xiaoning, Zhang Yawen, Ruan Zhen, et al. Study on the prevalence of chronic complications and average medical expenses per visit in patients with type 2 diabetes in China [J/OL]. Chinese Journal of Endocrinology and Metabolism, 2019, 35(03): 200-205. DOI:10.3760/cma.j.issn.1000-6699.2019.03.004.

[8] Chu Xiaoting, Xiong Jianjing, Zhang Guohui, et al. Analysis of the changing trend of diabetes-related mortality among residents in Jing'an District, Shanghai from 2005 to 2019 [J/OL]. Chinese Journal of Chronic Disease Prevention and Control, 2021(5): 397-401. DOI:10.16386/j.cjpccd.issn.1004-6194.2021.05.018.

[9] Fundus Disease Group of the Ophthalmology Branch of the Chinese Medical Association, Fundus Disease Group of the Ophthalmology Branch of the Chinese Medical Association. Clinical diagnosis and treatment guidelines for diabetic retinopathy in my country (2022) [J/OL]. Chinese Journal of Ophthalmology, 2023, 39(2): 99-124. DOI:10.3760/cma.j.cn511434-20230110-00018.

[10] Endocrinology Branch of the Chinese Medical Association, Research Working Group on Antihypertensive Treatment Targets for Adults with Type 2 Diabetes in China. Chinese Expert Consensus on the Prevention and Treatment of Cognitive Dysfunction in Patients with Type 2 Diabetes [J/OL]. Chinese Journal of Endocrinology and Metabolism, 2022, 38(6): 453-464. DOI:10.3760/cma.j.cn311282-20220518-00320.

[11] Neurological Complications Group of the Diabetes Branch of the Chinese Medical Association, Office of Diabetes Prevention and Control at the Primary Level of the National Basic Public Health Service Project. National Guidelines for the Diagnosis and Treatment of Diabetic Neuropathy at the Primary Level (2024 Edition) [J/OL]. Chinese Journal of Diabetes, 2024, 16(5): 496-511. DOI:10.3760/cma.j.cn115791-20240408-00160.