Microangiopathies

In addition to marked perifascicular atrophy, infarctlike areas are sometimes seen, and are also consistent with a microangiopathy. Muscle fibers which appear normal morphologically may show loss of myofibrillar ATPase activity from the center of the fibers this is also characteristic of muscle subject to ischemia. Such changes may be reversible, but more prolonged ischemia undoubtedly causes irreversible muscle necrosis. 

Diabetes continues to be a major cause of excessive morbidity, severe disability and premature death in Western populations. In developed countries, the cost of diabetes to society may be estimated to be as high as 5% of the total health costs, much of which relates to the chronic vascular complications of this disorder (Williams, 1991). The vascular lesion in diabetes consists of (1) microangiopathy, distinguished by thickening of capillary basement membranes resulting in increased vascular permeability, which is clinically manifested as diabetic retinopathy (Fig. 12.1a) and/or nephropathy (Fig. 12.1b), and (2) macroangiopathy (Fig. 12.2),... 

Figure 12.1 (a) Diabetic microangiopathy pre-proliferative retinopathy, (b) Diabetic microangiopathy glomerular disruption and degeneration In diabetic nephropathy. 

TBA, thiobarbituric acid reactivity DCs, diene conjugates MA, microangiopathy LP, lipid peroxides DM, diabetic patients C, controls HDL, high-density lipoprotein. 

Overall, and contrary to others (Lyons, 1991), we feel that the weight of scientific evidence indicates that lipid peroxidation is increased in diabetes irrespective of whether complications are present or not. The presence of microangiopathy or severe atheroma is likely to increase the degree of peroxidation even further. 

In a recent study, serum ascorbate concentrations were significantly reduced in a group of elderly diabetic patients (w = 40, mean age 69 years) in comparison with an age-matched group of non-diabetic controls ( = 22, mean age 71 years), and this reduction was more pronounced in those patients with microangiopathy (Sinclair et al., 1991). Diabetic patients were shown to have a high serum dehydroascorbate/ascorbate ratio indicative of increased oxidative stress. Ascorbate deficiency was partially corrected by vitamin C supplementation, 1 g daily by mouth, but the obvious disturbance in ascorbate metabolism in the diabetic patients was accentuated, since serum ascorbate concentrations fell (after the initial rise) despite continued vitamin C supplementation (Fig. 12.3). 

Eluorescence of both collagen (Monnier etal., 1986) and IgG (Jones etal., 1988) are associated with diabetic micrOangiopathy. Monnier etal. (1986) found that measured collagen-linked fluorescence in skin biopsies from both patients with type 1 diabetes ( = 41, age range 29-52 years) and controls ( =25, age range 28-41 years) was significantly correlated with the severity of retinopathy as well as arterial and joint stifihess. Jones et al. (1988) found increased fluorescence of serum IgG in diabetic patients with... 

Solerte, S.B., Adamo, S., Viola, C., Schianca, G.P.C., Crippa, A. and Ferrari, E. (1984). Acute-phase protein reactants pattern and macroglubulin in diabetes mellitus. Pathophysiological aspects in diabetic microangiopathy. Ric. Clin. Lab. 14, 575-579. 

Angiopathy of large (macroangiopathy) and small (microangiopathy) vessels is also the result of high blood glucose concentrations. Angiopathy results in ischemia and skin breakdown. 

Patients with both type 1 and type 2 diabetes are prone to complications. The specific chronic diabetic complications are due to microangiopathy and include neuropathy, retinopathy and nephropathy. Recent data stress the vital role of hyperglycaemia and oxidative stress in their pathophysiology. Premature atherosclerosis (which can be considered... 

Unlabeled Uses Prevention of postoperative deep vein thrombosis (DVT), protection of aortocoronary bypass grafts, reduction of graft loss after renal transplant, treatment of intermittent claudication, sickle cell disease, subarachnoid hemorrhage, diabetic microangiopathy, ischemic heart disease... 

Schindl A, Heinze G, Schindl M, Pemerstorfer-Schon H, Schindl L (2002) Systemic effects of low-intensity laser irradiation on skin microcirculation in patients with diabetic microangiopathy. Microvasc Res 64(2) 240-246... 

Stratton J, Warwicker P, Watkins S, Farrington K. Desmopressin may be hazardous in thrombotic microangiopathy. Nephrol Dial Transplant 2001 16(l) 161-2. 

Schmidt, R., Fazekas, F., Hayn, M., Schmidt, H., Kapeller, P., Toob, G., Offenbacher, H., Schumacher, M., Eber, B., Weinrauch, V., Kostner, G.M., and Esterbauer, H. 1997. Risk factors for microangiopathy-related cerebral damage in Aistrian stroke prevention study. J. Neurol. Sci. 152, 15-21. 

Marquie G, Duhault J, Hadjiisky P, Petrov P, Bouissou H. Diabetes mellitus in Sand Rats (Psammomys obesus)-. microangiopathy during development of diabetic syndrome. Cellular and Molecular Biology 1991, 37, 651-667. 

Moake JL, BynesJJ. Thrombotic microangiopathies associated with drugs and bone marrow transplantation. Hematol Oncol Clin North Am 1996 10 485 197. 

Viale P Pagani L, Alberici F Clinical features and prognostic factors of HIV-associated thrombotic microangiopathies. Eur J Haematol 1998 60 262-263. 

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