Antithrombin III Deficiency in Maturity Onset Diabetes Mellitus and Atherosclerosis

A Review on Cellular and Molecular Mechanisms Linked to the Development of Diabetes Complications

Modern lifestyle, changing eating habits and reduced physical work have been known to culminate into making diabetes a global pandemic. Hyperglycemia during the course of diabetes is an important causative factor for the development of both microvascular (retinopathy, nephropathy and neuropathy) and macrovascular (coronary artery disease, stroke and peripheral artery disease) complications. In this article, we summarize several mechanisms accountable for the development of both microvascular and macrovascular complications of diabetes. Several metabolic and cellular events are linked to the augmentation of oxidative stress like the activation of advanced glycation end products (AGE) pathway, polyol pathway, Protein Kinase C (PKC) pathway, Poly-ADP Ribose Polymerase (PARP) and hexosamine pathway. Oxidative stress also leads to the production of reactive oxygen species (ROS) like hydroxyl radical, superoxide anion and peroxides. Enhanced levels of ROS rescind the anti-oxidant defence mechanisms associated with superoxide dismutase, glutathione and ascorbic acid. Moreover, ROS triggers oxidative damages at the level of DNA, protein and lipids, which eventually cause cell necrosis or apoptosis. These physiological insults may be related to the microvascular complications of diabetes by negatively impacting the eyes, kidneys and the brain. While underlying pathomechanism of the macrovascular complications is quite complex, hyperglycemia associated atherosclerotic abnormalities like changes in the coagulation system, thrombin formation, fibrinolysis, platelet and endothelial function and vascular smooth muscle are well proven. Since hyperglycemia also modulates the vascular inflammation, cytokines, macrophage activation and gene expression of growth factors, elevated blood glucose level may play a central role in the development of macrovascular complications of diabetes. Taken collectively, chronic hyperglycemia and increased production of ROS are the miscreants for the development of microvascular and macrovascular complications of diabetes.

Hemostatic variables in Arab diabetics

Blood coagulation studies showed that patients with non-insulin-dependent diabetes mellitus (NIDDM) had significantly higher fibrinogen, FVIII:C, ristocetin co-factor, FV, FIX, lower ATIII, and PCV than those with insulin-dependent diabetes mellitus (IDDM). Diabetics with IDDM had a significantly higher ATIII, ristocetin co-factor, lower plasminogen and alpa-2-antiplasmin, and more enhanced platelet aggregation responses to ristocetin than age-matched controls. Patients with NIDDM as compared with controls, exhibited higher levels of fibrinogen, ristocetin co-factor, FVIII:C, FIX, and platelet count, but lower plasminogen, alpha-2-antiplasmin and PCV, reduced platelet aggragability to collage, ADP, and ristocetin. Diabetics with retinopathy and nephropathy had still higher levels of fibrinogen, FVIII:C, ATIII and ristocetin co-factor than those without complications. These results are in accord with many similar studies in Caucasians. It is concluded that the pattern of the changes in hemostatic variables noted in Saudi diabetic do not confirm the existence of racial and/or geographical variations in the hemostatic changes associated with diabetes mellitus.

Parenteral nutrition in patients with diabetes mellitus: theoretical and practical considerations

It is estimated that there are 11 million diabetics in the United States. Increasing recognition of the importance of nutrition in clinical medicine coupled with the frequent hospitalizations of the diabetic patient has heightened interest in their nutritional therapy. Patients with diabetes mellitus exhibit many abnormalities in the regulation of carbohydrate metabolism which may be accentuated during illness as part of the metabolic response to injury. An understanding of the effect of injury/illness, parenteral nutrition, and diabetes mellitus on carbohydrate metabolism is essential for the development of a rational approach to the initiation and maintenance of nutritional support in the diabetic patient.

Prognostic indicators of success and failure in vitrectomy for diabetic retinopathy

Results of pars plana vitrectomy for complications of diabetic retinopathy were analyzed by logistic regression analysis in 1007 eyes to determine the preoperative and intraoperative factors associated with visual success or failure. Preoperative factors associated with a poorer visual outcome (final visual acuity less than 5/200) include preoperative iris neovascularization, cataract, visual acuity less than 5/200 and traction or rhegmatogenous retinal detachment. Intraoperative factors associated with a greater chance of a poor visual result include use of intravitreal gas or air and creation of an iatrogenic retinal break or detachment. The presence of any one of these factors resulted in a 1.5 to 3.9 times greater risk of a poor final visual result. The regression coefficients may be combined to predict the likelihood of obtaining final acuity greater than or equal to 5/200 in eyes with various preoperative characteristics.

Plasma antithrombin III activity: an aid in the diagnosis of preeclampsia-eclampsia

Plasma antithrombin III (AT III) activity was examined retrospectively in patients with preeclampsia-eclampsia, chronic hypertension, and chronic hypertension with superimposed preeclampsia-eclampsia. Levels of AT III were greater than 1 SD below normal pregnant control in each case of preeclampsia-eclampsia syndrome. The degree of reduction in plasma AT III activity was correlated with the severity of disease. AT III activity was within normal limits in patients with chronic hypertension. AT III activity dropped prior to the appearance of clinically evident disease in three patients who were followed from an early gestational age. In no instance was low plasma AT III activity associated with normal pregnancy. Coincidental disease, including pyelonephritis and a viral syndrome, were associated with markedly decreased levels of plasma AT III activity in otherwise normal pregnancies. Plasma AT III activity may be valuable as a tool in diagnosing preeclampsia-eclampsia, as a screening test for preclinical preeclampsia-eclampsia, and as an indicator of severity of disease.