Professor Ji Linong: Pay attention to the problem of diabetes and thyroid disease

Introduction Diabetes and thyroid diseases are common diseases of the endocrine system
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What is the connection between the two? Will they affect each other? Recently, at the Merck China Forum, Professor Ji Linong from the Department of Endocrinology, Peking University People's Hospital focused on the incidence of diabetes and thyroid disease, the adverse effects caused by the comorbidity, and the possible comorbidity mechanism, and emphasized that among diabetic patients.
Opportunistic screening for abnormal thyroid function is carried out to achieve early diagnosis and early treatment of thyroid diseases
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The comorbidity of diabetes and thyroid disease is higher than that of the general population.
At the beginning of the report, Professor Ji Linong briefly described the epidemiological status of diabetes and thyroid disease in China
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Diabetes is the No.
1 disease in the field of endocrinology today, and it is widely prevalent all over the world
.

The latest epidemiological data show that the prevalence of diabetes among adults in China is as high as 12.
4%; however, the diagnosis rate of diabetes in China is less than 40%, and the control status is poor
.

At the same time, the epidemic situation of thyroid disease is not optimistic
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According to the survey results of the TIDE project conducted by the Endocrinology Society of the Chinese Medical Association in 31 provinces, municipalities and autonomous regions, the prevalence of thyroid diseases in China is as high as 15.
17%.
What is worrying is that a small survey data shows that the awareness rate of thyroid diseases in China is very low.
Only 28.
7% of residents in Ningbo are aware of thyroid disease, compared with 18% in Guangdong community, suggesting that thyroid disease requires early screening, early diagnosis, and early treatment
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Professor Ji Linong pointed out in the report that both diabetes and thyroid diseases are common diseases in the field of endocrine, which are widespread and have the possibility of co-morbidity
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Multiple epidemiological findings suggest that the prevalence of abnormal thyroid function in diabetic patients exceeds 20%, which may be higher than that in the general population (Figure 1)
.

Figure 1.
Prevalence of thyroid dysfunction in patients with diabetes and the general population A small survey found that patients with Graves disease had a higher prevalence of diabetes than the general population (16.
3% vs.
14.
0%, p<0.
001)
.

A similar trend was observed in patients with hypothyroidism
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The NHANES study found that the prevalence of diabetes and impaired glucose tolerance in patients with hypothyroidism may be higher than that in the general population; logistic regression analysis showed that the risk of diabetes increased by 2.
29 times in the SCH group (Figure 2)
.

Figure 2.
Results of the NHANES Study on the Interaction Between Diabetes and Thyroid Disease Although direct evidence is lacking, the results of multiple epidemiological surveys suggest that the incidence of diabetes and thyroid disease may be higher than in the general population
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If a patient has both diabetes and thyroid disease, will they affect each other? In this regard, Professor Ji Linong combined many retrospective studies to analyze the many adverse effects of diabetes and thyroid disease on the human body in the report
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01 The Graves Eye Disease (GO) study of diabetes mellitus showed that for GO patients with diabetes, the incidence of optic nerve damage was higher than that of GO patients without diabetes; and the proportion of patients with optic nerve damage improved after treatment was lower than that of GO patients with diabetes
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02 Diabetes with hyperthyroidism For diabetic patients with hyperthyroidism, it is more difficult to control blood sugar
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A domestic study showed that compared with type 2 diabetes (T2DM) patients without hyperthyroidism, T2DM patients with hyperthyroidism required more insulin doses to reach the blood sugar target; the time required for blood sugar to reach the target was also longer
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In the past, there have been reports of individual hyperthyroidism complicated with diabetes complicated by diabetic ketosis and hyperthyroid crisis
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In addition, inferred from the mechanism of action, it can also be found that hyperthyroidism combined with diabetes increases the risk of ketosis and hyperthyroid crisis
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On the one hand, increased thyroid hormone secretion can increase hepatic glucose output and inhibit the utilization of peripheral blood sugar, resulting in increased hyperglycemia; on the other hand, increased thyroid hormone secretion can lead to increased secretion of inactive insulin precursors secreted by the pancreas, which can also lead to Increased renal clearance of insulin further reduces insulin levels in the body; both hyperglycemia and insulin deficiency increase the risk of diabetic ketosis (Figure 3)
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Figure 3.
Mechanistic inference of the effect of elevated thyroid hormone on diabetes and hyperthyroidism 03 Diabetes with hypothyroidism The risk of macrovascular and microvascular complications of diabetes increases in diabetic patients with hypothyroidism
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The study found that thyroid-stimulating hormone (TSH) levels in T2DM patients were associated with diabetic cardiac autonomic neuropathy (DCNA), and subclinical hypothyroidism was one of the independent risk factors for DCNA in T2DM patients
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Another study suggested that the risk of diabetic retinopathy and chronic kidney disease was significantly increased when diabetes was combined with hypothyroidism
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Many previous retrospective studies have suggested that the comorbidity of thyroid disease and diabetes is higher than that of the general population, and the comorbidity increases adverse outcomes
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There are also some prospective studies exploring the relationship between thyroid disease and diabetes
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A prospective cohort study abroad suggested that patients with hyperthyroidism had an increased risk of diabetes compared with those with normal thyroid function (Figure 4)
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Figure 4.
Risk of comorbid diseases between hyperthyroid patients and normal thyroid patients.
Professor Ji Linong said that if the condition of comorbid patients is improved, it may help to reduce the interactive effect of diabetes and thyroid disease
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A prospective study found that patients with diabetes receiving metformin treatment may reduce TSH levels; suggesting that metformin in the treatment of diabetes may also help to intervene in hypothyroidism
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Of course, more research is necessary in the future to evaluate the final clinical outcome of metformin affecting TSH levels and the specific mechanism of action
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Re-exploring the comorbidity mechanism of diabetes and thyroid disease If diabetes and thyroid disease comorbid, what are the possible mechanisms? At the forum, Prof.
Ji Linong introduced the possible co-morbidity mechanism of diabetes and thyroid diseases from the aspects of metabolic regulatory pathways, genetics, and inflammatory factors
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01 The intersection of metabolic regulation pathways: diabetes and thyroid disease exist at the intersection of metabolic pathways, for example, insulin and T3 have a synergistic effect in the glucose and lipid metabolism pathway
.

02 Genetic susceptibility: Studies have found that type 1 diabetes (T1DM) and autoimmune thyroid disease share common genetic susceptibility genes.
At least 5 genes (CTLA-4, PTPN22, IL2Ra, VDR, TNF) have been identified as T1DM.
and co-inherited predisposition genes for autoimmune thyroid disease
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In addition, studies have also shown that the polymorphism of the gene encoding type 2 deiodinase may be associated with the risk of T2DM
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Not only that, the study found that the positive rate of thyroid antibodies in patients with type 1 diabetes mellitus (T1DM) was significantly increased; and the positive rate of diabetes-related antibodies in patients with autoimmune thyroiditis was also increased, and the higher the number, the higher the risk of T1DM (Figure 5)
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Figure 5.
The number of positive diabetes-related antibodies and the risk of T1DM in specific autoimmune diseases The levels of the factors were significantly increased, and high levels of TNF-α could affect the growth and differentiation of rat thyroid cells
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In addition, some studies have shown that the level of TNF-α in human tissue and circulation can be increased when thyroid function is abnormal.
TNF-α is correlated with insulin resistance and fasting blood glucose, which may be involved in the pathogenesis of diabetes
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Other interaction mechanisms: Studies have shown that in the state of hyperthyroidism or hypothyroidism, the glucose transport capacity of monocytes is decreased, and diabetes and abnormal thyroid function may interact through insulin resistance
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Prof.
Ji Linong emphasized that existing clinical evidence supports a correlation between diabetes and thyroid disease
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Based on this, various authoritative guidelines in the field of diabetes and thyroid have proposed opportunistic screening recommendations for diabetic patients with abnormal thyroid function (Figure 6).
, early diagnosis and early treatment; at the same time, in patients with thyroid disease also need to pay attention to the screening of diabetes
.

Figure 6.
Recommendations for opportunistic screening of patients with diabetes mellitus for thyroid dysfunction according to various authoritative guidelines in the field of diabetes and thyroid The general population, and comorbidities may increase adverse patient outcomes
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The exact mechanism of the coexistence of diabetes and thyroid dysfunction is still unclear, and it may be related to the intersection of metabolic regulatory pathways, genetic susceptibility, and the role of inflammatory factors
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In clinical work, attention should be paid to opportunistic screening in patients with diabetes mellitus and thyroid disease to improve the diagnosis rate and early control rate of these two diseases
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Expert Profile Ji Linong Peking University People's Hospital ✫ Director of Endocrinology Department of Peking University People's Hospital, Director of Peking University Diabetes Center, doctoral tutor Chairman of Research Professional Committee ✫ Editor-in-chief of Chinese Journal of Diabetes ✫ Vice President of Chinese Stroke Association ✫ Vice President of Endocrinology and Metabolism Branch of Chinese Medical Doctor Association ✫ Director of Chinese Medical Association President of the Perioperative Medical Research Association ✫ Chairman of the Endocrinology Professional Committee of Beijing Medical Association, consultant to the World Health Organization ✫ Member of the Diabetes Policy Group of the International Diabetes Federation Asia West Pacific Region (IDF-WPR) Source of this article: Thyroid Academy