Stratégies actuelles de prise en charge du diabète de type 2

Abstract

Current Management Strategies in Type 2 Diabetes

Since between 2 and 5% of the population aged less than 70 years and up to 15% of elderly individuals are affected by type 2 diabetes, this disease is responsible for an unacceptably high rate of premature morbidity and mortality. One of the main aims of the treatment of type 2 diabetes is to reduce the incidence of specific and macrovascular complications. The lessons learned from the Diabetes Control and Complications Trial (DCCT) can be applied to type 2 diabetes in order to prevent specific complications, including diabetic retinopathy, nephropathy and neuropathy. Various observational studies have suggested that good control of plasma glucose levels is equally important for preventing macrovascular complications; the correction of common cardiovascular risk factors, such as lipid abnormalities, high blood pressure and smoking, is undeniably necessary.

The natural history of type 2 diabetes is one of a progressive disorder resulting from both insulin resistance and a decline in pancreatic β-cell function, which lead to defective insulin secretion. Diet and exercise are effective in many patients at the onset of the disease. Generally speaking, the treatment of type 2 diabetes begins with a non-drug approach, without which the disease will progress rapidly. However, when these nonpharmacological measures fail, treatment with different oral drugs can be initiated: a single pharmacological class can be used in the first stage and 2 classes combined in the second stage. The choice of one or another oral hypoglycaemic agent will depend upon the different and complementary mechanism of action of each class. Sulphonylureas stimulate residual insulin secretion. Metformin inhibits overproduction of glucose by the liver. Acarbose delays the intestinal absorption of polysaccharides. Thiazolidinediones reduce insulin resistance. When the ‘maximal’ oral treatment fails, the final therapeutic step is to start insulin treatment, initially according to the ‘bed-time’ regimen, followed by a regimen of multi-injections.

Two approaches exist regarding the treatment of type 2 diabetes. The first recommends strict glucose control achieved by intensive insulin therapy, even at the risk of frequent weight gain, contrasted with a more liberal approach to glycaemia levels, which allows less aggressive insulin therapy. Our arguments favour the former attitude.

Résumé

La prévalence du diabète de type 2 se situe à environ 2 à 5% chez les moins de 70 ans et atteint 15% chez les personnes plus âgées. Cette maladie est ainsi à l’origine d’un excès considérable de morbidité et de mortalité prématurées. La prise en charge du diabète de type 2 a pour objectif de réduire les complications spécifiques et macrovasculaires de la maladie. Les leçons du DCCT (Diabetes Control and Complications Trial) peuvent s’appliquer au diabète de type 2 pour la prévention des complications spécifiques liées, notamment, à la microangiopathie. Différentes études d’intervention suggèrent qu’une normalisation glycémique est également importante vis-à-vis du risque macrovasculaire, en plus de la nécessaire prise en charge des facteurs de risque classiques. L’histoire naturelle du diabète de type 2 est celle d’une aggravation progressive par déficit de l’insulinosécrétion associé à un certain degré d’insulinorésistance. Lorsque régime et exercice physique ne sont plus suffisants, différents agents oraux peuvent être proposés, d’abord en monothérapie puis en bithérapie. Les sulfamides stimulent l’insulinosécrétion résiduelle, la metformine inhibe l’hyperproduction hépatique du glucose, l’acarbose retarde l’absorption intestinale des sucres complexes, les thiazolidinediones diminuent l’insulinorésistance. Lorsque le traitement oral “maximal” est insuffisant, l’insuline peut être proposée, d’abord dans sa modalité “bed-time” (au coucher), puis en multi-injections.