Overview of type 2 diabetes in adults
Type 2 diabetes is associated with a progressive loss of pancreatic beta-cell insulin secretion on a background of insulin resistance, causing relative insulin deficiency. Although the incidence increases with age, type 2 diabetes can occur in childhood (see Type 2 diabetes in children and adolescents).
Patients with type 2 diabetes are usually asymptomatic initially, and diabetes may be undiagnosed for many years. Type 2 diabetes is not typically associated with ketoacidosis, and insulin treatment is not essential unless other antihyperglycaemic drugs do not achieve or no longer maintain glycaemic targets, or when the presentation is of severe hyperglycaemia (see Management of first presentation of severe hyperglycaemia in adults).
Management of type 2 diabetes should always focus on dietary intake and regular exercise. This lifestyle modification can facilitate weight loss, significantly improve the patient’s glycaemic profile, and reduce cardiovascular disease risk (see Lifestyle management for adults with type 2 diabetes). Lifestyle modification can often significantly improve the glycated haemoglobin (HbA1c). Significant weight loss within the first few years after diagnosis may even lead to remission of diabetes.
For adults with type 2 diabetes, individualised glycaemic targets should be determined and antihyperglycaemic treatment optimised to achieve and maintain targets. Antihyperglycaemic treatment with metformin is now recommended for all adults with type 2 diabetes, regardless of their initial HbA1c, unless contraindicated or not tolerated. Additional antihyperglycaemic treatment may be required at diagnosis to achieve glycaemic targets and will be required over time to maintain targets (see Approach to antihyperglycaemic treatment for adults with type 2 diabetes). Monitoring the glycaemic profile in adults with type 2 diabetes is important to ensure glycaemic targets are being maintained.
In addition to treating hyperglycaemia, it is also important to minimise other risk factors for microvascular and macrovascular complications associated with diabetes. In particular, diabetes is a major risk factor for cardiovascular disease, so managing the patient’s cardiovascular disease risk is an important component of diabetes management (see Cardiovascular disease in patients with diabetes). Screening for and monitoring of chronic complications of type 2 diabetes is discussed here.
Some antihyperglycaemic drugs also have proven cardiovascular and renal benefits. These drugs should be considered in patients with atherosclerotic cardiovascular disease (established or a high risk of1), heart failure or chronic kidney disease2, even if not indicated for glycaemic benefit (see Use of antihyperglycaemic drugs for cardiovascular and renal benefits in adults with type 2 diabetes).
Practical aspects of managing a patient with type 2 diabetes (eg alcohol intake, driving, travel) are discussed here.