Net urate handling by renal tubules in maturity onset diabetics

An oral glucose tolerance test [OGTT] was performed and the serum levels of urate and creatinine were determined in 36 maturity-onset diabetics [MOD] and 10 normal controls. The rate of urine flow, the concentration of urate and creatinine were determined on 24 hours collected urine. From these determinations, creatinine clearance [C.C.], urate clearance [U.C.], urate load, final urate excretion per minute and net tubular urate reabsorption were calculated. When the diabetic patients, as a whole, were compared with normal controls, there is significant decrease in the C.C. and nonsignificant increase in U.C.; but when the nonproteinuric diabetics were compared with the controls, a significant elevation in U.C. was noticed. Both proteinuric and nonproteinuric diabetic patients showed a significant decrease in both the filtered urate load to renal tubules and tubular urate reabsorption, but the urate excretion is not significantly changed in the proteinuric 01 nonproteinuric diabetic patients. It is suggested that the increased urate clearance, reported in diabetics in the present investigation, is due to the presence of increased amounts of glucose in the tubular filtrate

Nature of proteinuria in diabetic nephropathy. I- evaluation of albuminuria in various types of diabetes mellitus

By use of a radial immunodiffusion technique for determination of urinary albumin, it was noted that the diabetic patients studied excrete albumin in urine as much as 9 times the normal control values, although the majority of the diabetics have negative results for albumin as tested by the classical procedures for detecting urinary albumin. The juvenile onset diabetics [JOD] have a higher degree of albuminuria than that observed in maturity-onset diabetes [MOD] and maturity.onset diabetes of the young [MODY]. Moreover it has been noted that the extent of urinary albumin excretion is proportionatl to the degree of glucose intolerance. These results implies that the biochemical derrangernent in diabetes particularly hyperglycemia have a direct influence in promoting transglomerular passage of albumin. The higher level of albuminuria in JOD denotes greater detonation of glomerular function. This has been ascribed to result from the consequences of poor metabolic control notably ketosis and ketonuria which has been observed in most of these patients. In diabetics of more than 5 years duration, albuminuria is significantly greater than in diabetics of shorter duration, denoting the progressive nature of the underlying mechanism responsible for albuminuria

Nature of proteinuria in diabetic nephropathy. II- significance of different types of proteinuria in diabetes mellitus

The urinary excretion of albumin, alpha 1 acid glycoprotein [1 Ag], IgA and alpha 2 macroglobulin [alpha 2 MG] was determined in 27 diabetics and 8 normal controls using an immunodiffusion technique. Although alpha 1 AG has a molecular weight [40.000] less than that of albumin [69.000], it was detected in the urine of only one third of the diabetics having albuminuria. Its presence in urine of these patients was accounted for by impaired tubular reabsorption. Urinary excretion of IgA was noted at a greater frequency in diabetics with longer duration of diabetes or with a greater impairment of glucose tolerance. This may suggest that the appearance of IgA in urine of diabetics is a refletion of the greater strain imposed on the kidneys by metabolic derrange-ment, or it can be a sign of diabetic nephropathy. alpha 2 MG was detected only in urine of one patient having end stage renal failure. Thus, it is obvious that in diabetic nephropathy, the increased glomerular permeability did not progress readily to allow for the passage of huge macromolecules, such as alpha 2 MG, but remains limited for the passage of relatively smaller proteins such as albumin, though albuminuria is progressive in nature

Correlation between antithrombin III and glucose intolerance, type of diabetes, diabetic nephropathy and serum triglyceride level

Oral glucose tolerance test OGTT] and the serum levels of Tiglycerides [TG] and antithrombin III [AT III] were determined in 33 diabetic and 8 normal subjects. AT III was determined by radial immunodiffusion technique. The present results denote that the level of AT III in diabetics is not significantly different from the normal controls. Also, it shows that the level of AT III in diabetics is not affected by elevation of the serum TG or by increased impairement of glucose tolerance. Moreover, AT III in diabetics with mild proteinuria was not significantly different from that in patients without proteinuria, nor patients with diabetes of longer than 5 years duration have a different level of AT III than those with diabetes of shorter duration. Juvenile-onset diabetics [JOD] tend to have a higher AT III level as compared with the maturity-onset diabetics [MOD], though the difference was statistically nonsignificant. These results were discussed in relation to the possible role of AT III in the pathogenesis of diabetic vascular disease