Research progress of diabetes treatment guided by Traditional Chinese Medicine constitutional types

Yu-Qing Sun,Si-Qing Zhang,Yu-Ling Wang,Sheng Peng,Wen-Rui Wang

1Graduate College,Tianjin University of Traditional Chinese Medicine,Tianjin,China;2Clinical College,Tianjin Nankai Hospital,Tianjin,China.

Abstract Diabetes and its complications seriously affect patients’ life quality, and have a major impact on individuals,families, health systems, and national economies.Traditional Chinese Medicine constitution refers to the inherent characteristics of a relatively comprehensive and stable form, structure, physiological function, and psychological state formed under the combined effects of innate endowments and acquired in the course of an individual’s life.Many studies have shown that the constitution type is closely related to the incidence of diabetes, especially in the process of disease prevention and treatment.This article reviews the correlation of diabetes and its chronic complications with constitution types to provide theoretical basis for the treatment of diabetes based on syndrome differentiation.

Key words:Diabetes,TCM constitution,Pathogenesis,Syndrome differentiation and treatment

Background

Diabetes Mellitus (DM) is one of the most common chronic endocrine diseases in the 21st century [1].In the past decade, the incidence of diabeteshas risen from 4.5%in 2008 to 11.2%in 2018[2−3].The high blood glucose level can lead to serious disorders of carbohydrate, fat and protein metabolism.The medical and economic burden of diabetic patients is not only related to the treatment of hyperglycemia, but also related to the prevention and control of chronic complications of diabetes [4].The current generalized disease judgment and treatment standards cannot meet clinical diagnosis and treatment based on the modern medicine.The differences between populations and individuals are gradually being emphasized.Traditional Chinese Medicine (TCM) constitution theory, which concerns the difference between individuals, maybe provide some new concepts on the treatment of diabetes.TCM constitution is an inherent characteristic of the human body [5].People can be divided into many types on the base of body constitution, which made the treatments different among individuals.Therefore, recognizing the constitution can lead to a precise treatment.The article summarizes the guiding directions for TCM constitution identification in diabetes in order to provide reference in the prevention and treatment of diabetes.

Research progress of TCM constitution

TCM constitution was first embodied in the "Huangdi Neijing", which was classified according to the specificity and unity of individual morphology,physiology, and psychology, and laid the foundation for the study of TCM constitution theory; Physicians of each dynasty then divided the TCM constitution from different perspectives according to the characteristics of the times and treatment experience.For example, in "Lingshu", the TCM constitution is divided into five categories according to the content of Yin and yang: these are Taiyin, Shaoyin, Taiyang,Shaoyang, Yin and Yang balance.Zhang Zhongjing, a famous medical scientist in the Eastern Han Dynasty of China, believed that constitution should be classified from cold and heat, deficiency and excess,dryness and dampness.He believed that there are gaunt men, strong men, slight men, obese people, balanced person, etc.Ancient physicians had many discourses on the classification of TCM constitution, but there were few formed systems.Although they provided a stable cornerstone for the theory of TCM constitution,but did not form a unified classification standard[6].

Modern scholars have further generalization and summarization the TCM constitution based on the current medical clinical background, and put forward the concept of "the theory of traditional Chinese medical constitution", thinking that the TCM constitution is a relatively comprehensive and stable characteristic of morphology, physiology, and psychology formed under the combined action of innate and acquired.Based on TCM syndrome differentiation and treatment, Kuang Tiaoyuan [7]divided the TCM constitution into six categories:obscure, sluggish, dryness, tardive, drowsiness and balanced according to the classification, appearance,pulse and color.Zhao Jinxi [8], guided by the thought of "Shang han lun", believed that the formation of TCM constitution was due to the imbalance of Yin and Yang and the imbalance of Qi and blood.He further divided the TCM constitution into Taiyang,Yangming,Shaoyang, Taiyin, Shaoyin and Jueyin; In addition,there are Tian Daihua's [9] twelve division method.Among them, the most widely accepted in clinical practice is the nine-point method proposed by Wang Qi[10], which is based on the results of physical epidemiological surveys to summarize the body shape,color, head, face, limbs, tongue and pulse, diet, stools,personality, etc.In 2009, the China Association of Traditional Chinese Medicine formulated the"Classification and Judgment of Constitution in Traditional Chinese Medicine" based on Wang Qi's nine-division method of constitution,and used it as the standard of constitution determination to provide research basis for the development of standardization of the theory of TCM constitution.The current TCM constitution research covers a variety of disease syndromes, involving many modern evidences such as blood lipids, hormones, body thermal imaging, tongue picture, etc., bringing the development of TCM constitution to a new stage of sustainable development[10].

TCM constitution assessment scale

The TCM constitution Assessment Scale was first compiled by Wang Qi [11] et al.The test-retest reliability of the subscales is between 0.77 and 0.90,and the Cronbach's coefficient is between 0.72 and 0.80; In order to shorten the number of items on the scale and improve the efficiency of questionnaire filling.Zhu Yanbo et al made deletions on the basis of the original scale, and formed two versions of the TCM constitution Assessment Scale with 41 items[12]and 30 items [13].Then, in order to facilitate researchers to choose the scales, 1295 healthy people verified the reliability, structure validity, and discrimination validity of the three scales[14].

Correlation between diabetes and TCM constitution

TCM constitution determines the predisposition of diabetes

Diabetes belongs to the category of "Xiaoke" in the field of traditional Chinese medicine.The "Lingshu"pointed out that "the lack of Qi will change the situation";"Su Wen"pointed out that"person who love eating sweet food and fat, maybe turn to Xiaoke".It can be seen that TCM constitution is an inherent factor in the onset of diabetes, and it plays a decisive role in the formation,occurrence and development of diabetes.The TCM constitution theory believes that the human constitution is changing, and has a certain degree of openness and tolerance.Therefore, during the life, the constitution will change to a certain extent and even produce qualitative changes;That is to say,constitution is not fixed,but a relatively stable form of performance formed in the change of movement [15−16], and it is closely related to disease.

The TCM constitution theory believes that whether cause damage when factors such as external or internal injuries invade the human body,it depends on personal TCM constitution factors.People of different constitutions have different susceptibility to diseases[17].Balanced constitution is the health state, and the Yin and Yang is balance in the body.When this balance is broken, a biased constitution will be formed, which is vulnerable to some pathogenic factors.

A large number of studies have shown that biased constitution is a risk factor for many chronic diseases[18−19].The main internal cause is the weakness and hot of internal organs.Yu Lei [20] et al.conducted a survey of 486 patients with abnormal glucose tolerance to explore the distribution of TCM constitution.The results showed that balanced constitution,phlegm-dampness constitution, Yin-deficiency constitution, Qi-deficiency constitution, and Yang-deficiency constitution accounted for 42.54%,16.71%, 11.14%, 10.69%, and 9.13% respectively.In addition, the BMI and abdominal circumference of dampness-heat constitution and phlegm-dampness constitution were significantly higher than other constitutions.Gao Hong [21] et al.conducted a 1-year follow-up of 134 pre-diabetic patients and found that patients with dampness-heat constitution and phlegm-dampness constitution are more likely to develop diabetes.Meng Xianghe [22] et al.summarized the characteristics of pre-diabetes and found that the risk factors for pre-diabetes are similar to the living habits of patients with phlegm-dampness constitution; In addition to the effects of innate endowment, the main factors for the formation of phlegm-dampness constitution are excessively greasy diet, irregular life, lack of exercise, and obesity.It can be seen that TCM constitution has a mutual influence on the physiological functions and psychological state of patients with pre-diabetes,and can predict and judge the occurrence of diabetes.Therefore, TCM constitution identification is helpful for disease prevention and body conditioning.

Characteristics of TCM constitution distribution of diabetic patients

Based on traditional Chinese medicine theory,diabetes disease has three stages, namely the spleen-warm syndrome stage, the Xiaoke stage and the Xiaodan stage.The main TCM constitutions are different in these stages.

In the spleen-warm syndrome stage, the main feature of this stage is"Yin deficiency transforms heat",which caused by Yin deficiency and internal fire.For overeating, pungent and hot, overworked, the heat are intensified and further leads to the endogenous Yin and Qi deficiency.In this stage, there are many signs of Qi and Yin deficiency.Patients will have symptoms of dry mouth and fatigue.

Xiaodan stage is the complication stage of diabetes."Lingshu " pointed out "those who are weak in the viscera will eliminate the ailments of the disease".It can be seen that the complications of Xiaodan stage are related to the fragility of the various organs caused by the deficiency of Yin and Yang.In this period, the patient has dark and gloomy complexions, cold appearance,coldness,weakness in the waist and knees,combined with various acute and chronic diseases such as skin, muscles and bones, blood vessels, nerves, and internal organs [23−24].The TCM constitution is corrected with the life quality of diabetic patients.Li Kang [25] et al.conducted TCM constitution identification of patients with newly diagnosed type 2 diabetes, and observed the function of pancreatic islet β cells in patients with different TCM constitutions.It was found that patients with Yang-deficiency constitution had the worst pancreatic β-cell function,and patients with dampness-heat constitution and phlegm-dampness constitution had the most severe insulin resistance.Luo Jiali [26] et al.conducted a survey of 1,600 elderly people in the community.The results found that approximately 21.49% of the elderly in the community suffer from diabetes, and the TCM constitution of patients with type 2 diabetes are mostly concentrated in dampness-heat constitution (42.47%),Yang-deficiency constitution (34.9%) and Yin-deficiency constitution (30.0%).The possible reason is that the subject of the study is elderly diabetic patients.In summary, diabetes has a high correlation with TCM constitution types, and the disease stage is different, the demographic data of the patient is different, and the constitution distribution is different.Therefore,through TCM constitution identification,we can provide targeted treatment methods and conditioning programs for diabetic patients with different characteristics at different periods.

TCM constitution determines the occurrence and development of diabetes complications

Professor Wang discussed Qi elaborated on the correlation with TCM constitution and disease, put forward the "constitution disease correlation theory",and pointed out that TCM constitution can affect the development and outcome of diseases.It can also be said that TCM constitution determines disease transmission and tendency.Therefore, identification based on physical fitness can provide a reliable basis for early detection and early treatment of diabetes complications.

TCM constitution and diabetic nephropathy.Diabetic nephropathy is diabetic glomerulosclerosis.Since there are no obvious clinical symptoms in the early stage of diabetic nephropathy,most patients have reached the middle stage of diabetic nephropathy when are diagnosed.Han Liyan [27] found that in patients with diabetes mellitus and chronic complications, the types of TCM constitutions are mostly concentrated in Qi-deficiency constitution (22.6%), Yin-deficiency constitution (19.0%), Yang-deficiency constitution(13.9%), and with diabetic nephropathy are mostly dampness-heat constitution and Yin-deficiency constitution.Zhang Rongdong [28] et al.conducted a TCM constitution survey on 286 patients with diabetic nephropathy stage III.Among them, the distribution of medical constitution from high to low is Qi-deficiency constitution (26.5%), phlegm-dampness constitution(20.15%), Yin-deficiency constitution (16.04%), blood stasis constitution (13.43%), Yang-deficiency constitution (12.31%), dampness-heat constitution(8.96%) and others (2.61%).In stage III diabetic nephropathy, the pathogenesis is mostly due to heat accumulation in viscera,draining body fluid,leading to the production of phlegm and blood stasis [29].Therefore,the TCM constitution mainly focuses on the deficiency and phlegm stasis constitution.

TCM constitution and diabetic retinopathy.Diabetic retinopathy is a common complication of diabetes and one of the important causes of blindness.Lei Chunyan [30] et al.performed TCM constitution identification of 300 diabetic retinopathy patients, of which the highest distribution was Yin-deficiency constitution (24.3%), followed by phlegm-dampness constitution (21%) and Yang deficiency constitution(17.7%).The results of Li Jing [31] et al.showed that the TCM constitution classification of patients with DR mostly focused on balanced constitution (28.1%),Qi-deficiency constitution (21.5%), Yang-deficiency constitution (18.5%), dampness-heat constitution(14.1%).As the pathogenesis of diabetic retinopathy is characterized by "deficiency-based", the transmission and change laws are mostly Yin deficiency - Qi and Yin deficiency - Yin and Yang deficiency.This study reflects that the characteristics of diabetic retinopathy lesions are similar to the physical distribution law to a certain extent, indicating that the type of physique is inherently related to the occurrence of diabetic retinopathy.

TCM constitution and laboratory examination of diabetic patients.There are study [32] explored the visceral fat thickness and serum adipokinetic lactone levels in obese type 2 diabetic patients with different TCM constitutions, and compared 231 patients who met the criteria.Among them, patients with phlegm-damp constitution and yin-deficiency constitution have the highest levels of visfatin（P＜0.05），comparing the thickness of visceral fat in patients with different TCM constitutions, patients with phlegm-dampness constitution have the thickest visceral fat, followed by dampness-heat constitution and the lowest is balanced constitution;Because serum lactone is related to the thickness of carotid artery intima, it is also an important factor in the pathogenesis of diabetic nephropathy.Therefore,diabetic patients with phlegm-dampness constitution should pay attention to the occurrence of coronary atherosclerosis and diabetic nephropathy.

In summary,the different TCM constitution types of diabetic patients will have a certain impact on the course of the disease, the types and numbers of complications, and so on.Therefore, correcting the biased constitutions of patients through TCM constitutions identification can help prevent or delay the occurrence and development of diabetes complications.

Application of TCM constitutions identification in diabetes

Based on the "physical and disease-related theory" put forward by Professor Wang Qi, that is, TCM constitutions can affect the occurrence, development and outcome of diseases.It mainly includes the following three arguments: TCM constitutions can determine the onset and tendency of the disease.TCM constitutions can affect the pathogenesis and the nature of syndromes.TCM constitutions can affect the outcome and prognosis of the disease[33−34].In other words, diseases will show different manifestations according to the differences in human Qi and blood,Yin and yang, and viscera [35].Traditional Chinese medicine diagnosis mainly includes the model of syndrome differentiation and disease differentiation,but it is limited to diseases and syndrome types.The diagnosis and treatment process shows a state of"Thousand people rule the same".Although it has certain clinical effects,there are still certain limitations.After the TCM constitutions and related theories were put forward, researchers gradually realized that if you want to be “people-oriented and adapt to individual conditions”, you cannot limit yourself to the exploration of diseases, but must combine the constitutions characteristics of different patients for diagnosis and treatment activities.To the effect of"seeing the micro-knowledge" and "preventing micro-duration"[36].

Formulate diabetes treatment based on TCM Constitution identification

Zhou Kailun [37] et al believed that the precise treatment of patients with diabetes and hyperuricemia should be combined with the TCM constitution.In the early stage, the aim is to maintain or promote Yin and Yang balance; In the mid-term, individualized treatment should be put forward based on the TCM constitution; in the later stage, the complications are the main aims to improve the life quality.

Li Tianxing [38] et al.formulated a three-level diabetes prevention plan based on the TCM constitution.Primary prevention is aimed at people with high-risk TCM constitution types for diabetes,early prevention can be carried out by identifying biased physiques and conditioning them early.Secondary prevention is aimed at people at risk of diabetes, and formulating health regimens with reference to the conventional prevention and control methods of type 2 diabetes to prevent the occurrence of diabetes.Tertiary prevention is a diagnosis and treatment model that combines TCM constitution type differentiation, disease differentiation and syndrome differentiation for patients with type 2 diabetes,that is,on the basis of conventional treatment, combined with biased TCM constitution conditioning and syndrome differentiation to treat diseases, prevent the occurrence of complications or delay the progress of existing complications.

TCM constitution identification can improve clinical treatment effect

Zhao Meng [39] et al.divided 140 patients with diabetes into an intervention group and a control group.The intervention group added TCM constitutions identification management based on the control group,and provided medication, exercise, diet and psychological guidance to the patients based on the constitutions test results.The treatment plan was adjusted in time during the patient's quarterly follow-up visits.After 2 years of follow-up, the intervention group was significantly better than the control group in terms of fasting, postprandial blood glucose, waist-to-hip ratio, BMI, blood lipid level, and quality of life (P＜0.05 for all).Due to the interaction of TCM constitutions, disease, and syndrome types,TCM syndromes change with the transformation of patients' TCM constitution.Zhao Jinxi [40] and Pang Guoming [41] combined the TCM constitution type’s characteristics to treat diabetic patients, and have good effects.

It can be seen that TCM constitutions identification can not only provide guidance for disease prevention,but also provide personalized clinical programs for disease treatment and prognosis.Therefore, in the future treatment and conditioning process, TCM constitutions identification and syndrome identification should be organically combined to make the treatment plan more in line with the patient's treatment needs,reflecting the "individual" diagnosis and treatment thinking.

Summary

Diabetes can occur in any type of TCM constitution,but its distribution still has certain rules to follow, and TCM constitution is closely related to the onset and outcome of diabetes.TCM constitution theory helps clinicians notice the differences between individuals,and provides new ideas for disease prevention and treatment.