Advanced atherosclerosis in predialysis patients with chronic renal failure

Advanced atherosclerosis in predialysis patients with chronic renal failure.BackgroundAtherosclerosis is advanced in hemodialysis patients as shown by increased intima-media thickness of carotid arteries (CA-IMT), although it is not established whether the advanced atherosclerosis results from hemodialysis treatment or from chronic renal failure. The purpose of this study was to evaluate the effects of hemodialysis and renal failure on CA-IMT in patients with chronic renal failure.MethodsCA-IMT was measured by high-resolution B-mode ultrasonography in 110 patients with chronic renal failure before starting dialysis (CRF group), and compared with CA-IMT of 345 hemodialysis patients (HD group) and 302 healthy control subjects. They were all nondiabetic and the three groups were comparable in age and gender.ResultsAs compared with the healthy control subjects, the CRF and HD groups had greater CA-IMTs, whereas CA-IMTs of the CRF and HD groups were not statistically different. There was no significant correlation between duration of hemodialysis and CA-IMT in the HD group. Multiple regression analysis in the total subjects indicated that presence of renal failure, but not being treated with hemodialysis, was a significant factor associated with increased CA-IMT independent of age, gender, blood pressure, smoking, high-density lipoprotein (HDL) and non-HDL cholesterol levels.ConclusionsThese results demonstrate that thickening of arterial wall is present in patients with chronic renal failure before starting hemodialysis treatment, and support the concept that advanced atherosclerosis in hemodialysis patients is due not to hemodialysis treatment, but to renal failure and/or metabolic abnormalities secondary to renal failure

Serum levels of 1,25-dihydroxyvitamin D, 24,25-dihydroxyvitamin D, and 25-hydroxyvitamin D in nondialyzed patients with chronic renal failure

Serum levels of 1,25-dihydroxyvitamin D, 24,25-dihydroxyvitamin D, and 25-hydroxyvitamin D in nondialyzed patients with chronic renal failure.BackgroundIn patients with chronic renal failure (CRF), abnormalities in vitamin D metabolism are known to be present, and several factors could contribute to the abnormalities.MethodsWe measured serum levels of three vitamin D metabolites, 1,25(OH)2D, 24,25(OH)2D and 25(OH)D, and analyzed factors affecting their levels in 76 nondialyzed patients with CRF (serum creatinine> 1.6 and < 9.0 mg/dl), 37 of whom had diabetes mellitus (DM-CRF) and 39 of whom were nondiabetic (nonDM-CRF).ResultsSerum levels of 1,25(OH)2D were positively correlated with estimated creatinine clearance (CCr; r = 0.429; P < 0.0001), and levels of 24,25(OH)2D were weakly correlated with CCr (r = 0.252, P < 0.05); no correlation was noted for 25(OH)D. Serum levels of all three vitamin D metabolites were significantly and positively correlated with serum albumin. Although there were no significant differences in age, sex, estimated CCr, calcium and phosphate between DM-CRF and nonDM-CRF, all three vitamin D metabolites were significantly lower in DM-CRF than in nonDM-CRF. To analyze factors influencing vitamin D metabolite levels, we performed multiple regression analyses. Serum 25(OH)D levels were significantly and independently associated with serum albumin, presence of DM and serum phosphate (R2 = 0.599; P < 0.0001). 24,25(OH)2D levels were significantly and strongly associated with 25(OH)D (β; = 0.772; R2 = 0.446; P < 0.0001). Serum 1,25(OH)2D levels were significantly associated only with estimated CCr (R2 = 0.409; P < 0.0001).ConclusionsThese results suggest that hypoalbuminemia and the presence of DM independently affect serum 25(OH)D levels, probably via diabetic nephropathy and poor nutritional status associated with diabetes, and that 25(OH)D is actively catalyzed to 24,25(OH)2D in CRF, probably largely via extrarenal 24-hydroxylase. Serum levels of 1,25(OH)2D were significantly affected by the degree of renal failure. Thus, this study indicates that patients with CRF, particularly those with DM, should receive supplements containing the active form of vitamin D prior to dialysis

Intrarenal hemodynamic abnormalities in diabetic nephropathy measured by duplex Doppler sonography

Intrarenal hemodynamic abnormalities in diabetic nephropathy measured by duplex Doppler sonography. Intrarenal hemodynamics were studied by duplex Doppler sonography in 112 inpatients with type II diabetes mellitus (DM; 65 males, 47 females, 58 ± 13 years old). The resistive index (RI) and pulsatility index (PI) of the interlobar arteries were calculated. The patients were divided into four groups: group I consisted of patients with urinary albumin excretion (UAE) < 20 µg/min (N = 42), group II with 20 ≦ UAE < 200 (N = 28), group III with UAE ≧ 200 (N = 25), and group IV with serum creatinine ≧ 1.5 mg/dl (N = 17). Both RI and PI values in groups II, III, and IV were significantly higher than those in the controls (age- and sex-matched healthy persons, N = 37; P < 0.001), and those in group IV were significantly higher than those in groups I, II, and III (P < 0.0001). Multiple regression analysis revealed that RI values in DM patients were significantly affected by creatinine clearance, age, and duration of diabetes (R2 = 0.554, P < 0.0001). When intima-medial thickness (IMT) of the femoral and carotid arteries were measured by B-mode ultrasonography, RI values were significantly correlated with both the femoral and carotid arterial IMT. These results demonstrate that intrarenal hemodynamic abnormalities are present in type II DM patients with nephropathy, and that intrarenal hemodynamics are affected by decreased glomerular function and also probably by advanced arteriosclerosis