Diabetes mellitus, type 2

Type 2 diabetes mellitus (T2DM) is a metabolic disorder with chronic hyperglycaemia in consequence to disturbed insulin sensitivity/insulin resistance. According to the WHO, the international diabetes federation, and the American diabetes association diagnosis criteria are (American Diabetes Association, 2018, World Health Organization and International Diabetes Federation, 2006):

  • Elevated fasting plasma glucose concentrations ≥ 126 mg/dl (7.0 mmol/l), at least 8h after dietary intake or,
  • Elevated 2h plasma glucose concentrations after a 75 g oral glucose tolerance test ≥ 200 mg/dl (11.1 mmol/l) or,
  • Elevated glycated haemoglobin (HbA1c) ≥ 6.5%.

Type 2 diabetes mellitus accounts for about 90% of all diabetes cases worldwide. Patients have peripheral insulin resistance and insulin release is insufficient to regulate glucose concentrations. It therefore results in relative insulin deficiency and chronic hyperglycaemia (American Diabetes Association, 2018).

Most but not all patients with type 2 diabetes mellitus are overweight or obese. The risk of developing T2DM increases with age, obesity, and physical inactivity. However, T2DM occurs also in lean individuals with a healthy lifestyle. The aetiology and genetic risk factors are poorly understood. Patients with T2DM may first be first started with lifestyle intervention (towards a healthy diet, increase physical activity) if overweight and inactivity are prevalent yet patients may also need drugs to increase insulin sensitivity (e.g. metformin medication). Insulin therapy (i.e. insulin injection) is generally not indicated (American Diabetes Association, 2018).

The prevalence of youth-onset of T2DM rises, especially in countries with high numbers of overweight and obesity. The onset of T2DM rarely occurs before the age of ten years but often occurs after puberty. Above 90% of affected children and adolescents are overweight to obese and have familiar history of diabetes mellitus type 2. The treatment goal is the same as for adult patients, to optimise glycaemic control and weight management. Paediatric guidelines recommend the initial use of Metformin as medication in combination with lifestyle interventions (Shah & Nadeau, 2020).

Synonyms: Diabetes type two, Diabetes type II, Type-2-diabetes, Type-II-diabetes, Type II diabetes, Diabetes mellitus type II, Diabetes mellitus type 2, Non-insulin-dependent diabetes