Haemorrheological changes in diabetic neuropathies - abstract

ABSTRACT

Chronic hyperglycaemia leads to disturbances in metabolic pathways in nerves. However, the underlying mechanisms are still not fully understood. One of the theories of diabetic neuropathy has implicated a vascular factor, which we believe may be associated with abnormal haemorrheological changes. Persistent hyperglycaemia creates a "stressful" conditions which triggers increased production of the acute-phase-reactant protein, fibrinogen, causing the development of a hyperfibrinogenaemic state. Apart from the red cell concentration, fibrinogen is the next most important determinant of whole blood viscosity. Therefore, an hyper-viscosity syndrome is commonly seen in diabetic patients. The increased viscosity could be an important factor in the development of endothelial damage in the vaso nervorum, hence contributing to the pathogenesis of diabetic neuropathy. The present study examined changes in haemorrheological parameters, with particular emphasis on plasma fibrinogen concentration in diabetics with and without peripheral neuropathy. Forty-seven (47) diabetics, 39 females and 8 males, were selected randomly during routine attendance at the Diabetic Clinic at the Unversity Hospital of the West Indies. Patients underwent a comprehensive medical check and were screened for peripheral neuropathy. Twenty-one patients were classified as insulin-treated and 26 as non-insulin-treated. For the diabetic patients, the mean (ñ SD) Age = 53.71 ñ 15.22 years, duration of diabetes mellitus = 12.96 ñ 7.97 years, B.M.I. = 30.00 ñ 10.00, blood pressue = 162.58 ñ 33.91/91.78 ñ 11.65 mm Hg; HbA1 = 13.99 ñ 4.83 percent. Only 2 (4.35) of the patients smoked or drank alcohol. A sex and age-matched non-diabetic control group consisting of 30 subjects were also studied. Venous blood was analysed for plasma fibrinogen concentration (PFC), packed-cell volume (PCV), haemoglobin concentration (HB) and glycosylated haemoglobin (HbA1) levels. The prevalence of peripheral neuropathy in the diabetic patients was 73.87 percent. PFC was significantly (p < 0.001) elevated in diabetic group, 5.06 ñ 1.26 g/l, compared with non diabetic groups, 3.19 ñ 0.65 g/l. However there was no significant difference in PFC betwen diabetics with (4.19 ñ 1.36 g/l) and without (5.14 ñ 1.14 g/l) neuropathy. Both PCV and Hb values were significantly less (p<0.05) in diabetics than in non-diabetics. Neither PCV nor Hb showed any significant variation between deabetics with and without neuropathy (AU)