Metabolic influences in experimental thrombosis

Possible metabolic consequences of fermentation in the colon for humans

We postulate that the short chain fatty acids, produced in the large gut by the microbial fermentation of dietary fiber, improve glucose tolerance and inhibit hepatic cholesterol and fibrinogen synthesis, probably by preventing an increase in serum levels of free fatty acids, and by improving insulin sensitivity. Since hypercholesterolemia, hyperfibrinogenemia and glucose intolerance are important risk factors for coronary heart disease, this could serve as a basis for recommendations that Western populations at risk should increase their dietary intake of substrates for short chain fatty acids.

Hematologic alterations in diabetes mellitus

Several hematologic abnormalities have been defined in patients with diabetes mellitus, despite the lack of classic hematologic pathologic findings in this condition. Studies of the erythrocyte and the formation of hemoglobin A1c have provided a means of documenting glycemia and a model reaction for diabetic sequelae through postsynthetic protein modification. Oxygen affinity has been noted to be abnormal in the diabetic erythrocyte, concomitant with a decreased concentration of inorganic phosphorus, glycosylation of the 2,3-diphosphoglycerate binding site or preexisting vascular disease. Red cell membrane viscosity has also been documented to be increased in the hyperglycemic subject. Abnormalities in the polymorphonuclear leukocyte have been described, involving the properties of adherence, random migration, chemotaxis, phagocytosis and killing. Certain metabolic abnormalities are also present in this cell type. The lymphocyte has been shown to have abnormal metabolic properties, mitogen responses and cell surface properties in diabetes both in animals and human subjects. Certain subpopulations of lymphocytes appear to be especially vulnerable to changes concomitant with diabetes mellitus. In vitro abnormalities of platelet behavior have been widely studied, although the in vivo significance of these findings remains controversial. Studies of the fluid phase of coagulation have suggested the existence of a hypercoagulable state in hyperglycemic subjects. The clinical significance of most of these findings remains to be defined. Nevertheless, the observation that many of the abnormalities described are reversible when hyperglycemia is corrected has given impetus to the development of improved systems of glucose "control" for diabetic patients.