Insulin therapy and quality of life. A review

Three central goals in the treatment of diabetes mellitus are (1) the avoidance of hyperglycaemia to prevent the development or progression of diabetes complications over time, (2) the avoidance of hypoglycaemia and (3) the maintenance or achievement of good quality of life. Insulin is the most powerful agent that can be used to control blood glucose levels. This article reviews the studies that have investigated the effects of different types of insulin and insulin delivery techniques on quality of life of patients with type 1 or type 2 diabetes. First, the concept of 'quality of life' (QoL) is defined and different ways of measuring QoL are explained. Secondly, the effects of different aspects of insulin therapy on QoL are reviewed: (1) the phenomenon of 'psychological insulin resistance'; (2) the effects of different types of insulin: regular insulin versus short-acting insulin analogues, long-acting insulin analogues or biphasic mixtures; (3) multiple daily injections versus pump therapy. Having multiple complications of diabetes is clearly associated with decreased QoL. Results from large studies such as the Diabetes Control and Complications Trial (DCCT) and United Kingdom Prospective Diabetes Study (UKPDS) suggest that intensive treatment itself does not impair QoL. Recent findings further suggest that pump therapy, compared to multiple daily injections, has beneficial effects on QoL. The fact that multiple tools are used to assess QoL makes it difficult to draw conclusions regarding the effects of different types of insulin on QoL. More work on the standardization of the assessment of QoL in diabetes is urgently needed.