Assessment of cognitive functions in middle aged patients suffering from type I and II diabetes mellites

Abstract

Diabetes mellitus describes a metabolic disorder of multiple aetiology characterized by chronic hyperglycaemia with disturbances of carbohydrate, fat and protein metabolism resulting from defects in insulin secretion, insulin action, or both. The effects of diabetes mellitus include long-term damage, dysfunction and failure of various organs. Expert Committee proposed two major classes of diabetes mellitus and named them, IDDM or Type 1 (beta-cell destruction, usually leading to absolute insulin deficiency), and NIDDM or Type 2. (may range from predominantly insulin resistance with relative insulin deficiency to a predominantly secretory defect with or without insulin resistance). The diagnosis of diabetes is based on one of three methods of blood glucose measurement .Diabetes can be diagnosed if the patient has a fasting blood glucose level of 126 mg per dL (7.0 mmol per L) or greater on two separate occasions. The limitations of this test include the need for an eight-hour fast before the blood draw, a 12 to 15 percent day-to-day variance in fasting blood glucose values, and a slightly lower sensitivity for predicting microvascular complications. An HbA1c of 48 mmol/mol (6.5%) is recommended as the cut point for diagnosing diabetes. A value of less than 48 mmol/mol (6.5%) does not exclude diabetes diagnosed using glucose tests. The complications of diabetes mellitus are far less common and less severe in people who have well-controlled blood sugar levels, which are acute and chronic complications affecting most body systems. A less addressed and not as well recognized complication of diabetes is cognitive dysfunction. Patients with type 1 and type 2 diabetes mellitus have been found to have cognitive deficits that can be attributed to their disease. Both hypoglycemia and hyperglycemia have been implicated as causes of cognitive dysfunction, and many patients fear that recurrent hypoglycemia will impair their memory over time. Although much research has been done, the pathophysiology underlying this complication is not well understood, and the most appropriate methods to diagnose, treat, and prevent cognitive dysfunction in diabetes have not yet been defined. In this study a comprehensive review of the literature regarding the subject of cognitive dysfunction was presented.It must be remembered that although there have been many significant contributions regarding the association of diabetes and cognitive dysfunction and many hypotheses based on this association, the causative mechanisms of diabetes on cognitive dysfunction are still undergoing development. Glycaemic control appears to play a role in determining the degree of cognitive dysfunction detected in patients with type 2 diabetes, although this has not uniformly been observed. In patients with type 1 diabetes mellitus, deficits in speed of information processing, psychomotor efficiency, attention, mental flexibility, and visual perception seem to be present, whereas in patients with type 2 diabetes, an increase in memory deficits, a reduction in psychomotor speed, and reduced frontal lobe/executive function have been identified. Severe hypoglycemic episodes may contribute to cognitive dysfunction in the young; however, as patients age episodes seem to have less of an influence.