Chronic kidney disease (CKD) is a significant and critical comorbidity in diabetic patients. However, in Japan and other countries, the "terms" used to describe CKD complicated with diabetes have been confused. These terms include diabetic nephropathy, diabetic kidney disease (DKD), CKD with diabetes, and diabetes and CKD. To make it clear, the Japanese Diabetes Society and the Japanese Society of Nephrology updated the corresponding Japanese nomenclature for DKD and clearly defined the concept of DKD. We herein review the brief history of kidney complications in diabetic patients and the definition of the concept of DKD.

The present study aimed to determine whether the 30-second chair-stand test (CS-30) can be used to predict and evaluate Peak VO₂ <5 METs in 166 older adult patients with type 2 diabetes mellitus (mean age: 74.7±5.2 years). The survey items included the motor function (CS-30, grip strength), comorbidity history, exercise tolerance, and patient background factors. We divided the subjects into the Peak VO₂ >5 METs and Peak less VO₂ <2 METs groups, and compared their survey items. A logistic regression analysis was performed, and the presence or absence of Peak VO₂ <5 METs was set as the dependent variable, and the survey items for which significant differences were identified between the two groups were set as independent variables. The CS-30 results were then extracted. The receiver operating characteristic (ROC) curve for the CS-30 was 0.791 and the cut-off value was 20 (sensitivity, 75 %; specificity, 69 %). The CS-30 is a useful diagnostic tool for predicting Peak VO₂ <5 METs in older adult males with type 2 diabetes mellitus.

The patient was a 29-year-old female. Her first child had had postnatal hyperglycemia, and at 1 month old, genetic testing had revealed a polymorphism in the ABCC8 gene in both the mother and child. A 75-g oral glucose tolerance test (OGTT) performed at 17 weeks' gestation for the second child was positive at 3 points, so the patient was diagnosed with gestational diabetes mellitus. Insulin therapy was initiated at 21 weeks' gestation. Postpartum insulin therapy was discontinued; however, the plasma glucose levels were 159 mg/dL at 0 min, 315 mg/dL at 60 min, and 338 mg/dL at 120 min. The HbA1c level was 6.6 % during the 75-g OGTT at 2 months postpartum, leading to a diagnosis of diabetes, and insulin therapy was started. Considering that diabetes mellitus was caused by the ABCC8 gene variant and that glycemic control was poor despite insulin therapy, glycemic control rapidly improved when glibenclamide 1.25 mg/day was initiated. Diabetes due to ABCC8 genetic disease has a varied age of onset and onset patterns; however, sulfonylureas have been reported to be effective, and an accurate diagnosis is important.

A 65-year-old man with type 2 diabetes complicated by lactic acidosis was admitted to our hospital. Initially, his insulin secretion was almost completely non-existent; however, he gradually recovered. Two other cases of type 2 diabetes, one with extreme hyperglycemia and the other with ketosis-prone type 2 diabetes, also presented with almost non-existent insulin secretion. Both patients recovered. As these three cases showed different onset symptoms, different mechanisms need to be considered to explain the extreme reduction in insulin secretion. It has been suggested that although pancreatic beta cells are susceptible to various metabolic and inflammatory stresses, which can almost completely suppress their insulin secretion, they can subsequently regain their function.

The principal causes of death among 68,555 patients with diabetes and 164,621 patients without diabetes who died in 208 hospitals throughout Japan between 2011-2020 were determined based on a survey of hospital records. 1. The most frequent cause of death in patients with diabetes was malignant neoplasia (38.9 %) (lung 7.8 %, pancreas 6.5 %, liver 4.1 %), followed, in order of descending frequency, by infectious diseases (17.0 %) and then vascular diseases (10.9 %) (cerebrovascular diseases 5.2 %, ischemic heart diseases 3.5 %, renal failure 2.3 %). The proportion of deaths from malignant neoplasia and vascular diseases has trended upward and downward, respectively. Almost all deaths from ischemic heart diseases were due to myocardial infarction, and the proportion of deaths from heart diseases other than ischemic heart diseases was relatively high (9.0 %), with most cases due to heart failure. Diabetic coma associated with hyperglycemia accounted for only 0.3 % of deaths. 2. The proportion of deaths from malignant neoplasia, infectious diseases, renal failure, ischemic heart diseases, and heart failure was significantly higher in patients with diabetes than in those without diabetes, and the proportion of deaths from cerebrovascular diseases was significantly lower in patients with diabetes. 3. In regard to the relationship between the age and cause of death in patients with diabetes, malignant neoplasia was the most frequent cause of death in all age groups, and the incidence was around 50 % for those in their 50s and 60s. The incidence of death due to infectious diseases was highest in patients older than their 70s. The incidence of death due to vascular diseases for patients in their 40s and 50s was higher than that due to infectious diseases. The highest incidence of death due to ischemic heart diseases was observed for patients in their 40s, and that due to renal failure and heart failure in patients older than their 70s. 4. Compared to patients without diabetes, patients with diabetes demonstrated a higher incidence of death due to pancreas cancer, infectious diseases, renal failure, ischemic heart diseases and heart failure and lower incidence of death due to cerebrovascular diseases in all age groups. 5. The average age at death of patients with diabetes was 74.4 years old in men and 77.3 years old in women, which were lower than the average lifespan of the Japanese general population in 2020 by 7.2 and 10.4 years, respectively. However, these differences were smaller than in previous surveys. 6. The average age at death due to all causes, especially due to ischemic heart diseases, cerebrovascular diseases, heart failure, infectious diseases, and diabetic coma, was lower in patients with "poorer" glycemic control than in those with "better" glycemic control. 7. In the total survey population, the average age at death of patients with diabetes was significantly higher than that of patients without diabetes. The average age at death due to malignant neoplasia and cerebrovascular diseases was higher in patients with diabetes than in those without diabetes and that due to renal failure, ischemic heart diseases, and infectious diseases was lower in patients with diabetes than in those without diabetes.