In management of diabetes, glucose lowering is the basic target of treatment. Insulin is essential to type 1 diabetes. Non-insulin therapy in type 2 diabetes is very diverse and continuously developing to improve glucose control and prevent diabetes-related complications. In the recent 30 years, recommended specifications of anti-diabetic drugs are high glucose-lowering efficacy, low risk of hypoglycemia, less burden of weight gain, and cardiovascular safety. With development of SGLT2 inhibitors (sodium glucose cotransporter 2 inhibitors) and GLP-1RA (glucagon-like peptide-1 receptor agonist), the clinical benefits also include risk reduction of diabetes-related complications (hospitalization for heart failure, chronic kidney disease, atherosclerotic cardiovascular disease), even in non-diabetic patients. Anti-diabetic medication can have a role in holistic management for prevention and treatment of diabetes and diabetes-related complications, as well as an improvement of mortality.

앞으로 정밀의료는 개인별 특성에 맞게 당뇨병의 진단, 분류, 치료를 보다 구체화시키는 데 일조할 것이다. 단일유전자 당뇨병에 있어서는 이러한 변화가 이미 두드러지게 나타나고 있다. MODY 아형은 MODY의 원인 유전자에 따라 HNF1α-, GCK-, HNF4α-, HNF1β-MODY 등으로 구분되고 있으며 MODY 진단에 있어서도 원인 유전변이를 ACMG-AMP 지침을 통해 검증하는 것이 일반화되고 있다. 정확한 진단이 이루어지면 MODY 아형에 따라 설포닐유레아, GLP-1수용체 작용제, 인슐린, 혹은 치료 없이 경과 관찰 등 개별화된 치료 방법을 적용할 수 있다. MODY에서 적용되고 있는 이러한 정밀의료로의 변화는 단일유전자당뇨병뿐 아니라 전체 당뇨병의 분류, 진단, 치료에 있어서도 큰 변화를 가져올 수 있는 계기가 될 것으로 기대된다. 아직 국내에서는 MODY에 대한 진단 검사 및 발견이 적은 편이다. 이를 높이기 위해서는 임상에 널리 적용 가능한 분자유전학적 검사의 확대 및 보험 적용이 바탕이 되어야 하며 임상의를 대상으로 임상유전체의학에 대한 교육이 확대될 필요가 있다.

Precision medicine, which optimizes diagnosis and treatment of diseases according to individualized characteristics, is becoming a reality in the field of diabetes, especially for monogenic diabetes. Maturity-onset diabetes of the young (MODY) is a type of monogenic diabetes characterized by early onset, relative non-obesity, non-insulin dependence, and autosomal dominant inheritance. With the trend toward precision medicine and improvement in genetic testing, there have been advances in the classification, diagnosis, and treatment of MODY. MODY accounts for about 1% of diabetes in Korea, with GCK (glucokinase)-MODY, HNF1α (hepatocyte nuclear factor-1 alpha)-MODY, and HNF4α (hepatocyte nuclear factor-4 alpha)-MODY being most common. In the diagnosis of MODY, applying guidelines for interpretation of variant pathogenicity is important. For the treatment of MODY, individualized treatment strategies according to the causative gene of MODY should be applied when available. Still, the majority of MODY is misdiagnosed and more genetic testing is required in Korea. We review updates regarding the classification, diagnosis, and treatment of MODY.

Diabetes mellitus and cognitive dysfunction are highly prevalent in the aging population. In the aging society, clinicians will be increasingly tasked with managing elderly patients who have both cognitive dysfunction and diabetes. A growing number of epidemiological and clinical studies confirmed that diabetes is associated with an increase in the risk of cognitive dysfunction and dementia. Cognitive dysfunction is of particular importance because it is associated with poor self-management ability, poor diabetes management with more frequent severe hypoglycemic episodes, and increased risk of cardiovascular morbidity and mortality. Current diabetes guidelines recommend screening for cognitive dysfunction in older and high-risk patients and providing individualized guidance for patients with cognitive dysfunction. Nonetheless, there is limited awareness among clinicians regarding this subject compared to other diabetic micro- and macrovascular complications. Recently, there has been increasing understanding in this field through multimodal neuroimaging and biomarkers for early detection of cognitive dysfunction in diabetes. In addition, new agents such as glucagon-like peptide 1 receptor agonists showed promising protective effects against cognitive dysfunction and dementia in patients with type 2 diabetes. In this review, we summarize the relationship between diabetes and cognitive dysfunction, especially dementia, and some contributing factors and pathogenesis of dementia in diabetes. We also review how anti-diabetic medications may influence cognitive dysfunction and clinical management guidance.

As a result of their increasing prevalence, diabetes and depression, together with population growth and aging, are growing public health concerns. Diabetes and depressive disorder may occur on the basis of a common pathophysiology and interact with each other. Complex environmental, social, behavioral, and emotional factors influence diabetes care. In particular, maintaining psychological well-being for people with diabetes is the foundation for achieving diabetes treatment goals and satisfactory quality of life. An improved understanding of depressive disorder and diabetes may potentially lead to early detection, and timely treatment planning may simultaneously prevent the onset of depression. Ultimately, this can build positive health behaviors and optimizing medical outcomes for living with diabetes.

Sleep problems and diabetes mellitus are increasing in prevalence. Although it is unclear if they are related, a number of related studies implicate such a relationship. A number of related studies implicate such a relationship. In this review, the significance of sleep in diabetes mellitus will be reviewed by summarizing the relationships between sleep, circadian rhythm, sleep disorders, and diabetes mellitus. Also, the mechanisms of influence will be reviewed. In addition, although the relationship between sleep and diabetes mellitus mainly has focused on type 2 diabetes mellitus, this review also summarizes the relationship between type 1 diabetes mellitus and sleep. In clinical practice, sleep problems have not been emphasized in management or prevention of diabetes mellitus. Considering their close relationship and impact on prognosis, mental health and physical health study will need to be integrated for treatment and prevention of diabetes mellitus.

Many patients with diabetes continue smoking and high-risk drinking during diabetes treatment. Some patients try and fail to stop alcohol drinking and smoking because of the addictive and habitual effects. Considering the high lifetime prevalence of alcohol and nicotine use disorders, the percentage of people who actively use treatment services is low. Smoking is related to increased vascular complications and mortality as well as development of diabetes. A small amount of alcohol is allowed in the diabetes treatment guidelines, but the limit can be difficult to maintain in reality. Therefore, it is necessary for a medical doctor to evaluate the alcohol and smoking problems of diabetic patients, and it may be helpful to use screening and evaluation tools such as AUDIT (alcohol use disorders identification test) for alcohol drinking and FTND (Fagerstrom Test for Nicotine Dependence) for smoking. It is important that patients are provided necessary information and a brief intervention and that they are recommended a professional treatment such as active treatment with anti-craving medications and structural psychosocial treatment programs. Many patients are worried about the harmful effects of alcohol drinking and smoking and think they should quit it, but at the same time, they may have their own reasons for not being able to quit drinking and smoking, and may be suffering from ambivalent ideas about alcohol drinking and smoking. Therefore, rather than criticizing the patient's alcohol drinking and smoking behavior, it is important to show understanding of patient difficulties and to encourage the patient to stop drinking and smoking.

The number of elderly diabetes patients continues to increase. These patients experience decline in physical functions related to aging and various accompanying disease. These interrupt insulin self-injection and self-management of diabetes. Therefore, it is necessary to understand the characteristics of elderly diabetes patients in order to provide proper insulin injection education.

Clinical Practice Guidelines for Diabetes recommend that overweight or obese adults lose more than 5% of their body weight and reduce their total caloric intake to maintain the reduced body weight. In diabetic patients, the goal of weight control is not simply to lose weight, but to achieve health benefits by controlling blood sugar well and reducing the risk of complications and other comorbidities. An extremely calorie-restricted diet, whose long-term effectiveness has not been verified, is not recommended as it may increase the risk of hypoglycemia and ketoacidosis. For weight control in obese diabetic patients, it is important to follow diabetic diet guidelines while setting actionable energy goals that prevent hypoglycemia and do not increase health risks. The energy target should be adjusted in consideration of individual conditions such as daily intake, body size, and activity level.