In diabetes mellitus type 2 (synonyms: Adult-Onset Diabetes Mellitus) or “adult-onset diabetes”; both terms are still widely used but do not reflect the current state of science; other synonyms: Non-primary insulin-dependent diabetes; Type2 diabetes; Type2 diabetes; Diabetes mellitus (type 2 diabetes); Non-primary insulin-dependent diabetes mellitus [type 2 diabetes]; ICD-10-GM E11.-: Diabetes mellitus, type 2) is the so-called “diabetes disease”. There is a glucose metabolism disorder (hyperglycemia/increased blood glucose levels) due to peripheral insulin resistance (decreased or abolished effect of the hormone insulin) and a disorder of insulin secretion (= insulin resistance with relative insulin deficiency). Diagnostic criteria for diabetes mellitus according to WHO criteria are:
- Fasting plasma glucose ≥ 126 mg/dl (7.0 mmol/l).
- Random plasma glucose ≥ 200 mg/dl (11.1 mmol/l) with symptoms typical of diabetes
- HbA1c ≥ 6.5% (48 mmol/mol).
About 90% of all diabetics have type 2 diabetes. First manifestation: > 40 years.
Frequency peak: the maximum incidence of diabetes mellitus type 2 is between the 60th and 70th year of life. Most new cases occur after the age of 30. The prevalence (disease incidence) for diabetes mellitus type 2 is 6-8% (in Germany). 4% of obese Americans have type 2 diabetes mellitus. Of those under 50, 1-2% develop type 2 diabetes mellitus, of those over 60, 10%, and of those over 70, up to 20%. The incidence (frequency of new cases) reaches its highest rate around the age of 85 with 24-29 new cases/1,000 patient-years. Course and prognosis: Type 2 diabetes mellitus may remain undiagnosed for years and is often discovered during a routine examination. Initial manifestation often due to diabetes-specific sequelae (macro- and microangiopathies/disease of large and small vessels: diabetic retinopathy (retinal disease with deterioration of vision up to blindness, due to the high sugar levels), diabetic nephropathy (kidney disease, due to the high sugar levels), diabetic foot syndrome (DFS)) or by the accompanying metabolic syndrome (symptom complex of obesity/overweight, hypertension/high blood pressure hypertriglyceridemia/increased triglycerides in the blood, low HDL cholesterol, increased fasting blood glucose levels). Type 2 diabetes mellitus ranges from insulin resistance with relative insulin deficiency to absolute insulin deficiency later in the course of the disease. It is often associated with other metabolic syndrome problems (see above). Approximately 80% of type 2 diabetics are overweight. Typical coma form is hyperosmolar nonketotic coma (HNKS; synonyms: hyperosmolar diabetic coma; hyperglycemic coma). Note: In normal-weight over 50-year-olds with new-onset diabetes mellitus, consider the possibility of the presence of pancreatic cancer.Therapy consists primarily of weight reduction (diet, exercise) and administration of oral antidiabetic drugs (metformin, first-line drug). If the endogenous insulin reserve is depleted, insulin substitution is required. The life expectancy of a diabetic patient depends mainly on three factors: age at onset of the disease, HbA1c level and renal function. A late age of onset (adult-onset diabetes), a well-controlled HbA1c level, and a healthy kidney (normal buminuria (NORM) or a glomerular filtration rate > 90 ml/min) are associated with high life expectancy. One study showed a partially decreased mortality rate (death rate) of up to 20%. The cardiovascular mortality risk was even almost 30% lower than in the control group (patients without diabetes).According to researchers at the Robert Koch Institute and the German Diabetes Center (DDZ) in Düsseldorf, people with type 2 diabetes in Germany have a 1.8-fold increase in overall mortality compared with the normal population. A British study from 2020 indicates a 1.7-year reduction in life expectancy for type 2 diabetics. Comorbidities (concomitant diseases): Comorbidities are strongly related to age and duration of disease.The most common concomitant disease of type 2 diabetes is hypertension (high blood pressure) (83.8%), followed by hyperlipidemia (lipid metabolism disorders) (65.2%), coronary artery disease (27.1%), arterial occlusive disease (10%), chronic heart failure (8%), myocardial infarction (6.9%), apoplexy (stroke) (5.8%), diabetic neuropathy (20.4%), diabetic retinopathy (10.7%), and diabetic nephropathy (9.9%). Furthermore, 2 out of 3 diabetic patients today have steatosis hepatis (fatty liver).In addition, the risk of tuberculosis is tripled in diabetics. In an Indian study, 25% of tuberculosis patients were also diabetic. Note: If new-onset diabetes mellitus is accompanied by weight loss, the risk of pancreatic cancer is increased: Weight loss of one to eight pounds is associated with about three and a half times the risk of pancreatic cancer (HR 3.47; 0.66%).
