- Diagnosis and Classification of Diabetes
- Initial Assessment and Criteria for Specialist Referral
- Glycaemic Control in Type 2 Diabetes - Oral Hypoglycaemic Agents
- Indications for Insulin in Type 2 Diabetes
- Hypertension
- Dyslipidaemia
- Aspirin Therapy in Diabetes
- Retinopathy
- Nephropathy
- Neuropathy and Foot Ulcers
- Sexual Dysfunction in Men
- Diabetes in Pregnancy and Pre-conception Guidance
4. Indications for Insulin in Type 2 Diabetes
Patients with type 2 diabetes who have persistent hyperglycaemia despite diet, weight reduction, and exercise are typically started on an oral hypoglycaemic drug. Insulin is usually added only if inadequate control persists (eg HbA1c >8%) despite use of these drugs.
However, it is important to remember that, although type 1 diabetes has a peak incidence around the time of puberty, approximately 25 percent of cases present after 35 years of age. There are certain clinical features, which, if present at any age, suggest the necessity for maintenance insulin therapy. Examples include marked and otherwise unexplained recent weight loss (irrespective of the initial weight), a short history with severe symptoms, and the presence of moderate to heavy ketonuria. Diabetic ketoacidosis at first presentation usually indicates that the patient has type 1 diabetes and will require lifelong insulin treatment, although there are exceptions to this general rule.
Insulin is often used to improve metabolic control in patients with type 2 diabetes. The UKPDS highlighted the progressive nature of type 2 diabetes and about 20-25% are estimated to require insulin within 10 years of diagnosis. Insulin therapy should always be accompanied by self-monitoring of blood sugars by the patients where possible.
Insulin can be added or the new long-acting insulin analogue, Glargine (Lantus) (please also refer to NICE Technology Appraisal 53) to oral hypoglycaemic agents with a once daily Insulatard/Humulin I injection at night (usually commencing at 6-10units). If it is clear that adequate control is not being achieved by monitoring fasting plasma glucose, then adding Insulatard/Humulin I with breakfast or switching to a bd Mixtard 30 or M3 regime is considered. In the overweight patient who will be particularly insulin resistant, Metformin is often continued to improve insulin sensitivity. At present a combination of insulin with a glitazone is not licensed in the UK.
Insulin is also required in women on oral hypoglycaemic drugs who wish to conceive. Other patients who often require insulin temporarily are those receiving high-dose steroid therapy.
The unwanted effects of insulin therapy include weight gain and hypoglycaemia. Most patients gain up to 3-5Kg in the first year after commencing therapy. Combining with Metformin may limit weight gain.