Endothelial dysfunction and the risk of atherosclerosis in diabetic patients with microalbuminuria

Endothelial dysfunction is an important pathogenetic factor in both micro- and macrovascular complications of diabetes mellitus [DM]. The significance of microalbuminuria [MAU] and diabetic retinopathy [DR] as early indicators of endothelial dysfunction in the disease remains controversial. We studied 40 patients with type 2 diabetes and microalbuminuria and 20 age and sex matched control subjects. They were subjected to detailed clinical examination, fundus examination and laboratory investigations including measurement of fasting blood glucose, serum lipid profile, blood urea, serum creatinine, plasma endothelin-l [ET-1] and 24 hours urinary albumin excretion [UAE], besides ultrasonographic assessment of post- obstructive flow-mediated endothelium- dependent increase in brachial artery diameter and blood flow and measurement of carotid artery intima- media thickness [IMT]. Features suggestive of endothelial dysfunction [DR, increased ET-1 and impaired vascular reactivity] were prevalent in the diabetic patients. They had, as well, a statistically significant increase in carotid IMT compared to controls [P = 0.000]. Endothelium- dependent dilatation [EDD] of the brachial artery showed statistically significant negative correlations with urinary albumin excretion [UAE] rate, plasma ET-1 and carotid IMT. We conclude that endothelial dysfunction is common in diabetic patients with MAU. ET-1 is a sensitive marker of endothelial activation/dysfunction but it is affected by many variables. Ultrasonographic studies of superficial arteries, if properly performed, can help in delineating both early functional and pathological alterations of atherosclerosis

Some biochemical aspects associated with accelerated atherosclerosis in chronic renal failure

This study included fifteen patients diagnosed as chronic non-nephrotic renal failure to whom dialysis had never been done and thirty patients diagnosed as chronic non-nephrotic renal failure who were under maintenance hemodialysis for at least one year. In addition a control group of 10 healthy subjects of matched age, sex and socioeconomic status was included in the study. To all subjects the following was done: serum Lp[a], apolipoprotein-B, Thiobarbituric acid reactive substances [TBARS] and lipid profile. Serum Lp[a] was found to be higher in both chronic renal failure groups, either dialyzed or un-dialyzed, when compared to controls. TBARS levels were significantly elevated in both dialyzed and undialyzed group of patients than the control group. The prevalence of cardiovascular diseases was 20% in the non-dialyzed group of patients and 40% in the dialyzed group in-spite of the normal or subnormal serum total cholesterol. This point out to the possibility that other lipoprotein abnormalities such as the increased Lp[a] and increased lipid peroxidation are probably incriminated in the prevalence of accelerated atherosclerosis. It could be concluded that Lp[a] is an independent risk factor for atherosclerosis in chronic renal failure patients. This risk increases with the process of hemodialysis. Increased lipid peroxidation in these patients is an additional factor for the accelerated atherosclerosis

Some cardiopulmonary functions in type I diabetes mellitus with incipient nephropathy

We studied some cardiopulmonary functions in relation to metabolic control and procollagen III in 35 patients with type I diabetes mellitus; 15 normoalbuminuric [Gl] and 20 microalbuminuric [GIl]. Fifteen subjects of comparable age and sex were studied as controls [GIII]. Patients suffering from cardiac, pulmonary or renal diseases other than diabetic nephropathy were excluded. Non of our patients had hypertension, hyperuricaemia or autonomic neuropathy. Echodoppler study showed that E/A ratio, PFR, NPFR and TPF were significantly lower in GIl than GIll [P<0.05 in all parameters except Ei/Ai ratio where P<0,01]. The IRT was significantly prolonged in GIl than Gill [P< 0.01]. There were insignificant difference of all LV diastolic parameters between Gl and GIII [P>0.05] and there were weak-ve correlation between E/A and HbA[1c] [P=0.07] and significant -ve correlation between E/A and procollagen III [P< 0.01]. Although the anthropometric variables did not differ significantly among diabetics and controls, yet the lung functions did between GIl and GIII. The mean values of DLCO and its percent predicted were significantly reduced in GIl than GIll [P<0.01]. Significant -ve correlations were observed between DLCO and both HbA[1c] [p< 0.01] and procollagen III [P<0.05]. Except a significantly lower MVV [P<0.05], there were no significant differences between Gl and GIII in all pulmonary functions [P>0.05]. It could be concluded that type I diabetic patients with microalbuminuria may have LV diastolic dysfunction as well as combined restrictive and obstructive pulmonary defects with significant reduction in the diffusing capacity. These cardiopulmonary changes increase with poor glycaemic control and could be attributed to deposition of collagen in the myocardium and lung paranchyma