Bone disease in long-term adult kidney transplant patients with normal renal function.

BACKGROUND: In successful renal transplantation, the degree of renal function recovery is usually incomplete and information is scarce about the abnormalities of mineral metabolism in long-term adult renal recipients with normal renal function. This study was designed to investigate bone mineral metabolism in patients with a long-term normal functioning kidney. METHODS: Twenty-nine adult asymptomatic renal transplant (RT) recipients with stable graft function for more than 10 years and serum creatinine <2 mg/dL were studied. They were classified into two groups according to glomerular filtration rate: Group A (N = 12; nine men, three women)>70 mL/min (x: 126 +/- 55 mL/min) and Group B (N = 17; nine men, eight women) <70 mL/min (x: 56 +/- 11 mL/min). Circulating biochemical markers of bone remodelling, bone histomorphometry, and densitometry (lumbar spine and hip) were obtained to investigate bone disease in these patients. RESULTS: Serum PTH was slightly elevated in 10 patients (83%) in group A. Serum PTH levels were positively related to serum calcium, osteocalcin, BAP, telopeptide, OH-proline, and creatinine. There was no histologic data to support overactivity on bone in this group of patients, with only one showing high bone turnover. Mineralization was prolonged in 34% of patients. Twenty-two patients (75%) exhibited normal bone turnover. In the group with GFR>70 mL/min the prevalence of mineralization defect in the presence of normal serum levels of calcitriol suggested vitamin D resistance. Lumbar and femoral neck osteoporosis was present in 25% and 33% of patients in group A, and 23% and 53% in group B, respectively. T-score at lumbar spine was negatively correlated with months since transplantation. Patients under treatment with cyclosporine (CsA) showed increased concentrations of osteocalcin and D-pyr and higher lumbar bone mineral density (BMD), but bone histomorphometry was not influenced by CsA. CONCLUSION: Patients with long-term renal transplantation with normal renal function frequently present with slight increases in PTH, but without an effect on bone histology. CsA did not induce changes in bone histology and delayed mineralization was frequently observed.

Significance of age in the survival of diabetic patients after kidney transplantation.

BACKGROUND: In recent years acceptance of diabetic patients for renal replacement therapy has increased. Renal transplantation for Type I diabetic patients is widely accepted but the appropriate treatment for Type II diabetic patients is still a matter of dispute. Our study was done to determine whether the age of Type II diabetic patients constituted an additional risk factor. METHODS: We analyzed the outcome of renal transplantation in 56 diabetic patients, 31 Type I and 25 Type II diabetics (we excluded any who had combined kidney-pancreas transplants). We compared them with 51 non-diabetic patients who were transplanted because of end-stage renal failure due to nephrosclerosis and age-matched to type II diabetic patients. We assessed the one- and three-year patient and graft survival, the quality of renal function, the main complications and causes of mortality. RESULTS: The overall one- and three-year patient survival was 69% and 60% in Type II patients; 73% and 69% in Type I diabetes patients and 88% and 80% in patients with nephrosclerosis. The overall one- and three-year actuarial graft survival was 50% and 38% in patients with Type II disease and 58% and 50% in Type I diabetes, and 76% and 64% in nephrosclerosis. The main cause of graft loss in all groups was death (with functioning kidney) due to infections and cardiovascular complications. CONCLUSIONS: Diabetes itself is the most important variable in patients who have poor results after kidney transplantation. Increasing age increases slightly the risk for poor graft and patient survival. Both groups of diabetic patients have poorer results than controls but in this comparison age was an independent factor.

Apolipoprotein C-III and E polymorphisms and cardiovascular syndrome, hyperlipidemia, and insulin resistance in renal transplantation.

Hyperlipidemia and insulin resistance frequently develop after renal transplantation, contributing to cardiovascular disease. Individual differences in response based upon genetic variations in proteins regulating lipidic and glucose tolerance metabolism could be expected. In the general population, the S2 allelic variant of the apoprotein (apo) C-III gene has been associated with hypertriglyceridemia and an insulin resistant state, whereas the E4 allele of the apo E has been associated with hypercholesterolemia and atherosclerosis. Its influence in renal transplant patients remains to be seen. In order to assess the impact of apo E and C-III major polymorphisms on atherosclerotic vascular disease, lipid profile and impaired glucose tolerance in renal transplant patients, we studied 110 consecutively examined patients undergoing kidney transplantation (age range 24-73 years). Atherosclerotic complications were detected in 25% of patients, with age, male sex and hypercholesterolemia being significant atherosclerotic risk factors. Among the male patients with E4 allele, the odds ratio for coronary disease and global atherosclerosis were 10.2 (95% CI) and 6.4 (95% CI), respectively. There were no significant differences in the frequency of any of the polymorphisms among patients with dyslipidemia and impaired glucose tolerance. As the number of patients in our sample was small, larger studies are needed to verify these issues. While in the studied population C-III polymorphism appears to have little association with the prevalence of atherosclerotic complications, E4 allele should be considered as a genetic marker of coronary artery disease and global atherosclerosis in renal transplant patients.