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Background: Renal transplant recipients have an increased incidence of cardiovascular disease. These patients present abnormalities of lipoprotein profile which are persistent and involve an increasing number of individuals, suggesting the opportunity of an early therapeutic intervention., Methods: We evaluated the effects of a 10- to 12-week diet based on the American Heart Association step-one diet criteria, modified with an increased intake of monounsaturated fats and alimentary fibers, on lipid profile and lipid-related cardiovascular risk in 78 normolipidemic and hyperlipidemic renal transplant recipients., Results: Diet led to a significant reduction in total cholesterol levels by 10%, triglycerides by 6.5%, low-density lipoprotein (LDL)-cholesterol by 10.4% and LDL-cholesterol/high-density lipoprotein (HDL)-cholesterol ratio by 10%, whereas HDL-cholesterol levels remained unchanged. Dividing renal transplant recipients into risk classes according to the National Cholesterol Expert Program guidelines and LDL-cholesterol levels, we observed a progressively increasing reduction in total cholesterol and LDL-cholesterol levels among 'desirable LDL-cholesterol', 'borderline high-risk LDL-cholesterol' and 'high-risk LDL-cholesterol' patients, while HDL-cholesterol levels did not change in any group and the LDL-cholesterol/HDL-cholesterol ratio significantly decreased in 'borderline high-risk LDL-cholesterol' and in 'high-risk LDL-cholesterol' patients (respectively by 6.8%, p < 0.05, and by 21.1%, p < 0.0001). Reduction in triglyceride levels was statistically significant only in subjects with 'desirable LDL-cholesterol' (by 12.3%, p < 0.01). Patients in the 'desirable LDL-cholesterol' class increased from 28 (35.9% of total patients) before diet to 45 (57.7% of total patients, p < 0.01), while subjects in the 'high-risk LDL-cholesterol' class reduced from 24 (30.8% of total patients) to 8 (10.2% of total patients, p < 0.005)., Conclusion: These data suggest the possibility of a nutritional hypolipidemic approach in renal transplant recipients, even if normolipidemic. Dietetic treatment determined an inversion in the typical trend of renal transplant recipients, reducing instead of increasing the number of subjects with hypercholesterolemia, permitting the selection of individual candidates for further pharmacological treatment by carefully evaluating risk/benefit costs.

In order to assess the role of HDL on longevity, we studied HDL subfraction distribution in centenarian women compared with a group of weight- and gender-matched healthy normolipidemic controls. We did not find any significant difference in the mean plasma lipid, apolipoprotein, and Lp(a) levels. On the contrary, in spite of similar HDL-cholesterol concentrations (1.32 +/- 0.41 mmol/l in centenarians vs. 1.32 +/- 0.25 mmol/l in controls, p = not significant), HDL2b and HDL3a levels were, respectively, significantly increased and significantly reduced in centenarians in comparison with controls (HDL2b 32.4 +/- 9.2% in centenarians vs. 23.4 +/- 7.7% in controls, p < 0.002, and HDL3a 26.3 +/- 9.8% in centenarians vs. 34.1 +/- 7.3% in controls, p < 0.01). Moreover, HDL2b levels were significantly raised and HDL3a levels were significantly reduced in centenarians in comparison with both 'middle-aged' and 'elderly' subjects, whereas no difference for any HDL subfraction was found between the two groups of controls of different ages. Age was significantly correlated with HDL2b and HDL3a (respectively, +0.452, p < 0.001, and -0.370, p < 0.01) in all subjects, but not with all the other lipid, lipoprotein and apolipoprotein parameters, but we observed a large overlapping of individual values of HDL2b between centenarians and controls. Since HDL2b levels were found to be inversely correlated with coronary heart disease risk, we could speculate that, in some cases, this may probably favor a healthy ageing, but long-term longitudinal studies are necessary to define the relative importance of HDL subfractions distribution as a marker of longevity. Probably other factors or clinical characteristics play a major role in the ageing process.

Since the high rate of cardiovascular disease in renal transplant recipients, alterations of lipoprotein profile in such patients were extensively evaluated, but the HDL subclass profile was not completely clarified. Renal transplant recipients usually show normal to high plasma levels of HDL cholesterol, even if some investigations suggested a persistence of low HDL2 levels: this was not useful in terms of cardiovascular protection. We designed this study in order to evaluate HDL subfractions distribution in renal transplant recipients. We studied 55 renal transplant recipients, treated with prednisone, azathioprine and/or cyclosporine, and 34 healthy normolipidemics as controls. In all subjects cholesterol, triglycerides, LDL cholesterol, HDL cholesterol, apolipoproteins A-I and B levels and HDL subfractions, as determined by nondenaturing polyacrylamide gradient gel electrophoresis, were assayed. Renal transplant recipients had cholesterol, triglycerides, LDL cholesterol and apolipoproteins A-I and B levels significantly higher than controls; HDL cholesterol levels were slightly, but not significantly, increased in comparison with controls (respectively 51.1 +/- 15.5 and 46.1 +/- 10.8 mg/dl). Multivariate analysis showed that only the time since transplantation was significantly associated with HDL cholesterol levels. When HDL subfractions were analyzed, renal transplant recipients presented significantly lower levels of HDL3a and HDL3b and, in males, higher levels of HDL2b than controls. HDL cholesterol levels were positively correlated with HDL2b levels in both renal transplant recipients and controls, and negatively correlated with HDL3b in controls. In conclusion, in renal transplant recipients, we failed to demonstrate any decrease of HDL2 particles. On the basis of a nonatherogenic HDL profile, we suggest that the increased cardiovascular risk in renal transplant recipients might be accounted for by other risk factors.

The relation between plasma lipids and coronary heart disease (CHD) in the elderly is still debated, as well as the proposed role of lipoproteins as markers of longevity. In this study both normolipidemic elderly and middle-aged women with CHD showed higher triglycerides and apolipoprotein B levels and lower high-density lipoprotein (HDL)-cholesterol and apolipoprotein A-I levels in comparison with age-matched subjects without CHD. In the middle-aged group, hypertension and HDL-cholesterol levels and, in the elderly group, only HDL-cholesterol levels were independently associated with CHD. No significant difference was found between a group of healthy centenarians and elderly and middle-aged subjects without CHD. These data suggest that plasma lipids are also related to CHD in the elderly and that, even if at present we are not able to consider them as predictors of longevity, some lipoprotein features may contribute to select subgroups of subjects in which other factors play a further role in life expectancy.

Some previous studies have documented an increase in lipoprotein (a) [Lp(a)] levels in renal diseases. Here, we report data in subjects with end-stage renal failure treated with hemodialysis (HD) or with continuous ambulatory peritoneal dialysis (CAPD) and in renal transplant recipients (RTR), compared with a group of normolipidemic controls (C). Lp(a) levels were significantly increased in HD and CAPD patients in comparison with C, while they were only slightly increased in RTR. Both HD and CAPD patients showed Lp(a) levels higher than in RTR, but no difference was found between the subjects of the two dialysis procedures. The prevalence of Lp(a) levels > 25 mg/dl was significantly higher in HD and CAPD patients, but not in RTR, in comparison with C. Moreover, Lp(a) levels did not change after HD. When patients were divided according to their fasting lipid levels in normolipidemics and hyperlipoproteinemics, no difference was found for Lp(a) levels in any group. Mechanisms underlying the increase in Lp(a) levels in these patients are not known. It is possible to suggest an active role of the kidney in the Lp(a) metabolism or that uremic plasma contains some factors affecting Lp(a) metabolism.

In this study lipid and apolipoprotein patterns were investigated at birth and compared with those of adults. In cord sera, cholesterol, triglycerides, low-density lipoprotein (LDL) cholesterol and high-density lipoprotein (HDL) cholesterol were 38.2, 46.2, 50.5, and 31.9%, respectively, of adult values. Apolipoprotein AII, B and CIII were 48.6, 30.6 and 44.5% of adult values, while apo AI, apo CII and apo E showed values approaching those of adults (63.4, 73.3 and 89.7%, respectively). Also cholesterol/HDL cholesterol and LDL cholesterol/HDL cholesterol ratios were lower in newborns. In cord sera, lipids were correlated with various apolipoproteins in a surprisingly different way from adult sera. HDL cholesterol was not inversely correlated with triglycerides, and showed a highly positive correlation with apo E, apo CII and apo CIII, which did not correlate with HDL cholesterol in adults. These data supported the presence of significant differences in plasma concentrations and composition of lipoproteins at birth. Therefore HDL, apo CII, and apo E seem to play a different and more important metabolic role in neonatal lipid metabolism.