Serum erythropoietin levels and hematocrit in end-stage renal disease: influence of the mode of dialysis

Serum erythropoietin (Ep) levels were measured by radioimmunoassay in 70 patients with end-stage renal disease (ESRD) to evaluate the influence of the mode of dialysis on the relationship between serum Ep levels and the severity of anemia. Thirty-five patients were on hemodialysis (HD), seven were on intermittent peritoneal dialysis (IPD), and 28 were on continuous ambulatory peritoneal dialysis (CAPD). Compared to HD, CAPD patients had higher serum Ep (CAPD), 46.1 +/- 13.4 v HD, 16.9 +/- 2.2 mU/mL) and hematocrit (CAPD, 33.9 +/- 2.5 v HD, 24.8 +/- 1.4%; P less than 0.05). The Ep and Hct values for IPD patients were intermediate between the other two groups. Serum Ep levels were higher in CAPD patients in the first 4 weeks of initiation of CAPD (144 +/- 35 mU/mL, n = 6) than later (39 +/- 6.4 mU/mL, n = 24). A significant fluctuation in serum Ep and Hct values was noted in patients on all three modes of dialysis, when multiple samples were obtained at different time intervals. There was a weak correlation between serum Ep and Hct in the three groups of dialysis patients; r = 0.36, P less than 0.005. The data suggest that CAPD provides a better biochemical milieu for Ep production and responsiveness than HD treatment of ESRD.     

Total and regional bone densities in dialysis patients.

Total and regional bone mineral densities (BMD) of ten male haemodialysis (HD) patients and ten male patients on continuous ambulatory peritoneal dialysis (CAPD) were measured using dual-energy X-ray absorptiometry (DEXA), and compared with that of age- and sex-matched controls. Our data showed that patients with renal failure on dialysis had reduced bone densities as manifested by a reduction in total body BMD, femoral neck BMD, and Ward's triangle BMD. In addition, head BMD and femoral trochanter BMD were also reduced in HD patients. Among HD patients, the length of the period of dialysis correlated with serum level of parathyroid hormone and the reductions in total body BMD and head BMD. Furthermore, there was a strong negative correlation between bone density of the skull and serum parathyroid hormone. Our results demonstrated regional variations in the reduction of bone density in patients with asymptomatic renal bone disease. DEXA bone scan is a useful adjunct in the early assessment of renal osteodystrophy and bone density of the skull can be used as a monitor in hyperparathyroid bone disease.     

Concentrations of thyroxine-binding globulin in sera and peritoneal dialysates in patients on chronic peritoneal ambulatory dialysis

Losses in thyroxine-binding globulin (TBG) in peritoneal dialysate and thyroid function were evaluated in patients undergoing continuous ambulatory peritoneal dialysis (CAPD), in comparison to patients on hemodialysis (HD) without TBG loss in the dialysate. The TBG concentration in the peritoneal dialysate was 0.26 +/- 0.09 microgram/ml (mean +/- SD, n = 24), with a daily loss of 2.47 +/- 0.94 mg. The serum TBG level in CAPD patients was 21.0 +/- 4.71 micrograms/ml (n = 24), which was not significantly different from that in HD patients (20.0 +/- 5.72 micrograms/ml, n = 24) or in healthy Japanese subjects. The serum TBG level correlated positively with the TBG loss and TBG level in the peritoneal dialysate (p less than 0.001). The serum T4 level in CAPD patients (4.93 +/- 1.38 microgram/dl, n = 24) was significantly greater than in HD patients (4.08 +/- 1.30 microgram/dl, n = 24, p less than 0.05).     

QT dispersion in hemodialysis and CAPD patients

Prolongation of repolarization dispersion (QT interval dispersion) measured from the 12-lead surface ECG has been associated with sudden cardiac death and ventricular tachyarrhythmias in a variety of cardiac disorders. The aim of our study was to assess the effects of hemodialysis (HD) and continuous ambulatory peritoneal dialysis (CAPD) on QT dispersion in end-stage renal disease patients. 20 chronic HD patients (mean age 57.75 +/- 13.79 years) and 20 CAPD patients (mean age 50.79 +/- 14.94 years) who had no complaints and symptoms of cardiac arrhythmias as well as 20 healthy volunteers (mean age 48.74 +/- 10.88 years) underwent ECG testing. All HD patients were on bicarbonate three times weekly with cuprophane capillaries. 12-lead ECGs were recorded on the day after HD. The CAPD patients were on a standard CAPD program (four times daily with 2,000 cm(3) peritoneal fluid). ECGs were recorded when the patients were receiving their regular standard CAPD program. All ECGs were analyzed manually by one observer. There were no statistically significant differences in dialysis duration, blood urea nitrogen, creatinine, sodium, calcium, and parathormone values between the HD and CAPD patients. The serum potassium values were significantly higher in HD patients when compared to CAPD patients. There was no difference in the mean of maximal QT among all three groups. The rate of QT interval dispersions was significantly higher in HD and CAPD patients as compared with healthy controls (p < 0.05). There was no statistically significant difference in the QT dispersion rates between HD and CAPD patients. In conclusion, there is a tendency to cardiac arrhythmias in HD patients during the postdialysis period. Although CAPD patients are receiving dialysis daily, they also have higher rates of QT dispersions and accordingly a tendency to arrhythmias.     

Platelet activity and serum homocysteine levels in patients with end-stage renal failure with regard to dialysis modality

BACKGROUND: Recent evidence suggests that the activation of platelets and their interaction with circulating cells are important independent risk factors for atherosclerosis. In non-uremic patients with symptomatic peripheral vascular disease, a relationship between serum homocysteine (Hcy) levels and platelet activity had been reported. The purposes of this study were to evaluate of effects of dialysis modality on platelet activity in patients with end-stage renal failure and to investigate the relationship between platelet activity, Hcy, and left ventricular hypertrophy (LVH). MATERIAL AND METHODS: In age and sex matched 19 healthy subjects, 20 hemodialysis (HD) patients, and 18 continuous ambulatory peritoneal dialysis (CAPD) patients, the expression of platelet surface receptors CD41, CD61, CD42a, and CD62P were investigated. CD62P expression was statistically significantly increased in HD patients compared with CAPD patients and controls (34.4 +/- 22.5%; 17.3 +/- 19.6%, 12.0 +/- 15.6%, respectively, p < 0.05), but not in CAPD patients compared with controls. There was a positive correlation between CD62 expression and duration of dialysis in HD patients (r = 0.498, p = 0.026). Mean plasma Hcy levels in dialysis patients were higher than reference levels. However, we could not find any relationship between CD62 expression, Hcy, and LVH in both groups (p > 0.05). CONCLUSIONS: Hemodialysis and peritoneal dialysis (PD) have a different impact on the expression of CD62: peritoneal dialysis seems to have a more favorable effect. It may be possible that the differences in biocompatibility between PD and HD potentially contribute to differences in CD62 expression.     

Malnutrition-inflammation-atherosclerosis (MIA) syndrome components in hemodialysis and peritoneal dialysis patients

BACKGROUND: Malnutrition, inflammation, and atherosclerosis (MIA syndrome) are common in end-stage renal disease (ESRD) patients. Each component of MIA syndrome is the predictor of outcomes in ESRD patients. In this cross-sectional study, we aimed to compare both dialysis modalities for MIA syndrome components. MATERIAL AND METHODS: Thirty hemodialysis (HD) (mean age 44 +/- 11 years, 14 male and 16 female, mean time on dialysis: 31.0 +/- 19.0 months) and 30 continuous ambulatory peritoneal dialysis (CAPD) patients (41 +/- 9 years, 12 male and 18 female, mean time on dialysis: 25.5 +/- 21.5 months) were included. In order to determine malnutrition in ESRD patients, serum albumin level and anthropometric measurements were used. For inflammation, serum C-reactive protein level, erythrocyte sedimentation rate, and fibrinogen levels were measured. Mean-carotid artery intima media thickness (m-CIMT), presence of carotid plaque and serum homocysteine level were used to determine atherosclerosis. RESULTS: Five CAPD patients (16%) and one HD patient (3%) was hypoalbuminemic. HD and CAPD groups were similar for inflammation. Mean-CIMT and serum homocysteine level were higher in HD patients than CAPD patients. There was a positive correlation between homocysteine and m-CIMT. CONCLUSION: Before choosing renal replacement therapy, malnutrition, inflammation, and atherosclerosis parameters must be investigated in ESRD patients. Hemodialysis seems to be more advantageous for malnutrition components than CAPD. Both dialysis modalities seem to be similar for inflammation, and CAPD modality has superiority for atherosclerosis. Before choosing the type of renal replacement therapy, assessment of MIA syndrome components could be useful for individualization of the decision on which dialytic modality is appropriate in ESRD patients.     

Rate of forearm bone loss is associated with an increased risk of fracture independently of bone mass in postmenopausal women: the OFELY study.

BMD is a major determinant of the risk of fragility fractures, but the role of the rate of postmenopausal bone loss is still unclear. In 671 postmenopausal women from the OFELY cohort, we found that the rate of bone loss was significantly associated with fracture risk independently of other well-known predictors including BMD and previous fractures. INTRODUCTION: The level of BMD is a major determinant of the risk of fragility fractures, but the role of the rate of postmenopausal bone loss is still unclear. MATERIALS AND METHODS: In the OFELY study, we analyzed the risk of fracture in 671 postmenopausal women (mean age, 62.2 +/- 9 years), according to the rate of bone loss. BMD was measured annually by DXA at the forearm, with a mean number of measurements of 10.3 +/- 2.6. Peripheral fractures, all confirmed by radiographs, were prospectively registered, and vertebral fractures were evaluated with spine radiographs every 4 years. RESULTS: During a median (interquartile range [IQ]) of 11.2 years (11-12.3 years) of follow-up, 183 incident fragility fractures including 53 vertebral and 130 nonvertebral fractures were recorded in 134 women. The annual median +/- IQ rate of bone loss, calculated from the slope, was -0.30 +/- 0.76% at the mid-radius, -0.55 +/- 0.79% at the distal radius, and -0.40 +/- 0.96% at the ultradistal radius. Women with incident fracture had a rate of bone loss (before fracture) higher by 38-53% than those without fracture (p = 0.0003-0.016). Using multivariate Cox regression models, we found that bone loss in the highest tertile at the mid-radius, distal radius, and ultradistal radius was associated with a significant increased risk of all fractures with an hazard ratio from 1.45 to 1.70 (p = 0.02 to p = 0.009 after adjusting for age, previous fractures, maternal history of fracture, physical activity, grip strength, falls, and baseline BMD). CONCLUSIONS: The rate of bone loss in postmenopausal women is significantly associated with fracture risk independently of other well-known predictors such as BMD and history of fractures.     

Association between a functional interleukin-6 gene polymorphism and peak bone mineral density and postmenopausal bone loss in women: the OFELY study

Genetic factors play an important role in determining bone mass and several genes are involved in this process. Interleukin-6 (IL-6) is a candidate gene for regulation of bone mineral density (BMD) and it has been suggested recently that novel IL-6 -174 G/C allelic variants may be associated with peak BMD in young men and with bone resorption in elderly women. In this study, we assessed the relationships between IL-6 gene polymorphism, peak BMD, rate of postmenopausal BMD loss, and bone turnover in women. BMD was measured by dual-energy X-ray absorptiometry in 255 healthy premenopausal women, aged 31-57 years. BMD loss at the forearm was measured over 4 years in 298 healthy untreated postmenopausal women, 50-88 years (mean 64 years). We also measured levels of serum osteocalcin, bone alkaline phosphatase, and N-propeptide of type I collagen for bone formation and three markers of bone resorption, including urinary and serum C-terminal cross-linking telopeptide of type I collagen and urinary N-terminal telopeptide of type I collagen, in both pre- and postmenopausal women at baseline. In premenopausal women we found a significant association between IL-6 genotypes and BMD at the whole body (analysis of variance [ANOVA], p = 0.03), femoral neck (p = 0.03), trochanter (p = 0.014), Ward's triangle (p = 0.03), and total hip (p = 0.006), with subjects having the CC genotype showing 3%-7% higher BMD levels than their GG counterparts. However, after matching women with CC and GG genotypes for body height the differences decreased (2%-4%), and were no longer significant (p = 0.10-0.23). In postmenopausal women the mean rate of loss at the ultradistal radius was significantly associated with IL-6 genotypes (ANOVA, p = 0.049), with women having the CC genotype showing a significantly greater rate of bone loss (p < 0.05) compared with their GC and GG counterparts. After adjustment for weight changes, the difference in the rate of ultradistal radius bone loss between genotypes decreased and was not significant (p = 0.06 for CC vs. GG). A similar trend was observed for distal radius bone loss (p = 0.10, ANOVA), but not for the middle radius. We found no significant association between genotypes, bone turnover markers in premenopausal women, and either bone turnover or BMD in postmenopausal women. We conclude that this new functional IL-6 polymorphism was weakly associated with level of peak BMD and the rate of forearm trabecular postmenopausal bone loss in this cohort of healthy French women. IL-6 genotypes accounted only for a small proportion of the interindividual variation of both peak BMD and rate of bone loss and were not significant after adjustment for height and changes in body weight, respectively, suggesting that part of the effect may have been due to the differences in body size. Larger long-term studies are necessary to assess adequately the relationships between IL-6 genotype, rate of bone loss, and risk of fracture.     

Effects of genistein and hormone-replacement therapy on bone loss in early postmenopausal women: a randomized double-blind placebo-controlled study.

The natural isoflavone phytoestrogen genistein has been shown to stimulate osteoblastic bone formation, inhibit osteoclastic bone resorption, and prevent bone loss in ovariectomized rats. However, no controlled clinical trial has been performed so far to evaluate the effects of the phytoestrogen on bone loss in postmenopausal women. We performed a randomized double-blind placebo-controlled study to evaluate and compare with hormone-replacement therapy (HRT) the effect of the phytoestrogen genistein on bone metabolism and bone mineral density (BMD) in postmenopausal women. Participants were 90 healthy ambulatory women who were 47-57 years of age, with a BMD at the femoral neck of <0.795 g/cm2. After a 4-week stabilization on a standard fat-reduced diet, participants of the study were randomly assigned to receive continuous HRT for 1 year (n = 30; 1 mg of 17beta-estradiol [E2] combined with 0.5 mg of norethisterone acetate), the phytoestrogen genistein (n = 30; 54 mg/day), or placebo (n = 30). Urinary excretion of pyridinoline (PYR) and deoxypyridinoline (DPYR) was not significantly modified by placebo administration either at 6 months or at 12 months. Genistein treatment significantly reduced the excretion of pyridinium cross-links at 6 months (PYR = -54 +/- 10%; DPYR = -55 +/- 13%; p < 0.001) and 12 months (PYR = -42 +/- 12%; DPYR = -44 +/- 16%; p < 0.001). A similar and not statistically different decrease in excretion of pyridinium cross-links was also observed in the postmenopausal women randomized to receive HRT. Placebo administration did not change the serum levels of the bone-specific ALP (B-ALP) and osteocalcin (bone Gla protein [BGP]). In contrast, administration of genistein markedly increased serum B-ALP and BGP either at 6 months (B-ALP = 23 +/- 4%; BGP = 29 +/- 11%; p < 0.005) or at 12 months (B-ALP = 25 +/- 7%; BGP = 37 +/- 16%; p < 0.05). Postmenopausal women treated with HRT had, in contrast, decreased serum B-ALP and BGP levels either at 6 months (B-ALP = -17 +/- 6%; BGP = -20 +/- 9%; p < 0.001) or 12 months (B-ALP = -20 +/- 5%; BGP = -22 +/- 10%; p < 0.001). Furthermore, at the end of the experimental period, genistein and HRT significantly increased BMD in the femur (femoral neck: genistein = 3.6 +/- 3%, HRT = 2.4 +/- 2%, placebo = -0.65 +/- 0.1%, and p < 0.001) and lumbar spine (genistein = 3 +/- 2%, HRT = 3.8 +/- 2.7%, placebo = -1.6 +/- 0.3%, and p < 0.001). This study confirms the genistein-positive effects on bone loss already observed in the experimental models of osteoporosis and indicates that the phytoestrogen reduces bone resorption and increases bone formation in postmenopausal women.     

Impact of dialysis therapy on insulin resistance in end-stage renal disease: comparison of haemodialysis and continuous ambulatory peritoneal dialysis.

BACKGROUND: Insulin resistance contributes to the pathogenesis of atherosclerotic cardiovascular disease and, thus, has an important impact on the mortality of uraemic patients. Haemodialysis (HD) is known to improve insulin resistance observed in uraemia. However, it is not known whether continuous ambulatory peritoneal dialysis (CAPD) alleviates insulin resistance in adult uraemic patients. The objective of this study was to compare the effect of two different dialysis modalities, HD and CAPD, on insulin resistance in adult uraemic patients and to identify the possible predictive factors for changes in insulin resistance. METHODS: Insulin resistance was examined in 19 non-diabetic patients with end-stage renal disease (ESRD) before and after dialysis therapy (HD, n=10; CAPD, n=9), as well as in 10 healthy controls using the hyperinsulinaemic euglycaemic glucose clamp technique. The glucose disposal rate (GDR mg/kg/min) was used as an index of insulin sensitivity during the clamp technique. We also determined which of various biochemical parameters might be associated with change in insulin resistance by carrying out multiple logistic regression analysis. RESULTS: GDR was significantly lower (6.44+/-1.76) in ESRD subjects than in normal subjects (9.90+/-2.01). HD and CAPD therapies significantly normalized GDR from 6.53+/-1.84 to 9.74+/-2.88 and from 6.35+/-1.65 to 8.18+/-1.76 respectively. Multiple logistic regression analysis showed that changes in BUN, haematocrit and plasma bicarbonate were significant predictive factors for the change in insulin resistance. CONCLUSION: CAPD therapy, in spite of its possible adverse effects in patients with atherosclerotic disease, has been shown to improve insulin resistance in adult uraemic patients, similarly to HD therapy.     

Serum beta 2-microglobulin concentration and its removal in patients treated with continuous ambulatory peritoneal dialysis

This study was performed to clarify serum beta-2 microglobulin (beta 2-M) level and its change in 50 CAPD and 56 HD patients. There was significant correlation between duration of dialysis and serum beta 2-M level in CAPD and HD patients treated under 12 months, but no correlation in those treated over 12 months. Serum beta 2-M level was 33.5 +/- 9.1 mg/l in 45 CAPD patients treated over 12 months, and 46.2 +/- 21.1 mg/l in 35 HD patients. In 26 CAPD patients treated over 12 months, clearance and removal of beta 2-M were 1.0 +/- 0.3 ml/min and 43.0 +/- 17.8 mg/day. There was significant correlation between dwell time and beta 2-M removal (p less than 0.01), and these results suggested beta 2-M was removed by diffusion. Because CAPD treatment can lower serum beta 2-M level compared to HD, there is possibility that CAPD is useful at prevention of dialysis associated amyloidosis.     

Posttransplant bone disease: evidence for a high bone resorption state

Loss of bone is a significant problem after renal transplant. Although bone loss in the first post transplant year has been well documented, conflicting data exist concerning bone loss after this time. It is equally unclear whether bone loss in long-term renal transplant recipients correlates with bone turnover as it does in postmenapausal osteoporosis. To examine these issues, we conducted a cross-sectional study to define the prevalence of osteoporosis in long-term (> 1 year) renal transplant recipients with preserved renal function (mean creatinine clearance 73 +/- 23 ml/min). Bone mineral density (BMD) was measured at the hip, spine and wrist by DEXA in 69 patients. Markers for bone formation (serum osteocalcin) and bone resorption [urinary levels of pyridinoline (PYD) and deoxypyridinoline (DPD)] were also measured as well as parameters of calcium metabolism. Correlations were made between these parameters and BMD at the various sites. The mean age of the patients was 45 +/- 11 years. Eighty eight percent of patients were on cyclosporine (12% on tacrolimus) and all but 2 were on prednisone [mean dose 9 +/- 2 mg/day)]. Osteoporosis (BMD more than 2.5 SD below peak adult BMD) at the spine or hip was diagnosed in 44% of patients and osteopenia was present in an additional 44%. Elevated levels of intact parathyroid hormone (i PTH) were observed in 81% of patients. Elevated urinary levels of PYD or DPD were present in 73% of patients and 38% had elevated serum levels of osteocalcin. Levels of calcium, and of 25(OH) and 1,25(OH)2 vitamin D were normal. In a stepwise multiple regression model that included osteocalcin, PYD, DPD, intact PTH, age, years posttransplant, duration of dialysis, cumulative prednisone dose, smoking, and diabetes: urinary PYD was the strongest predictor of bone mass. These results demonstrate that osteoporosis is common in long-term renal transplant recipients. The data also suggest that elevated rates of bone resorption contribute importantly to this process.     

Total and regional bone mineral density by dual photon absorptiometry in patients on maintenance hemodialysis.

To evaluate bone loss in renal osteodystrophy, we measured total and regional (head, trunk, pelvis, leg and arm) bone mineral density (BMD) by dual photon absorptiometry in 72 patients on maintenance hemodialysis (HD). We also examined the validity of serum carboxy-terminal parathyroid hormone (C-PTH) and intact-PTH as an indicator of secondary hyperparathyroidism. Total BMD correlated inversely with age in female patients (r = -0.57, p less than 0.01), but not in male patients. Female patients older than 50 years were omitted from analysis to exclude the effect of menopause on bone. Among clinical and biochemical parameters, only trunk BMD correlated inversely with the duration of HD (r = -0.26, p less than 0.05). Head, trunk and total BMD correlated inversely with serum alkaline phosphatase, C-PTH and intact-PTH, while pelvis BMD did not. Leg and arm BMD also correlated inversely with serum intact-PTH, but not with serum C-PTH. The serum level of C-PTH correlated positively with the duration of HD (r = 0.40, p less than 0.005), while intact-PTH did not. As compared with 18 control male volunteers aged 25-42 years, trunk, pelvis, leg, arm and total BMD were significantly lower in male patients on HD aged 22-49 years, whereas head BMD did not differ significantly between the two groups. The percent decrease of BMD was most prominent in the trunk (-19.6%, p less than 0.001).(ABSTRACT TRUNCATED AT 250 WORDS)     

The effect of alendronate on bone mass after distal forearm fracture.

Fracture and immobilization of an extremity lead to bone loss at the fracture and at adjacent sites. We conducted a 1-year, single-center, prospective, randomized, double-blind study to determine whether bone loss would occur in the distal radius after a Colles' fracture and whether this loss could be prevented using an antiresorptive drug (alendronate). Thirty-seven women with a recent fracture of the distal forearm and low bone mineral density (BMD) of the lumbar spine were randomized to receive either 10 mg alendronate daily or placebo. BMD of both forearms was measured at baseline and after 3, 6, and 12 months. The results of four women who developed reflex sympathetic dystrophy were not included in the analysis. In the placebo group, there was a significant reduction at 3 months and 6 months in BMD of total radius (p < 0.01), one-third distal radius (p < 0.01), middistal radius (p < 0.05), and ultradistal radius (p < 0.01) on the fractured side. The loss in BMD at one-third distal radius remained significant at month 12 (p < or = 0.001). In the alendronate group BMD of total distal radius, one-third distal radius, and middistal radius at the fractured side remained unchanged. BMD of ultradistal radius increased significantly at months 3, 6, and 12, compared with baseline (p < 0.05). The difference between the two treatment groups was significant at 3 months and 6 months and borderline significant (p = 0.054) after 1 year in total distal radius. In ultradistal radius the differences were significant at all time points. We conclude that BMD of the distal radius of a recently fractured forearm decreases significantly in the 6 months after fracture and the resulting deficit remains evident at least 1 year after fracture. This bone loss can be prevented by alendronate.     

Relationships between brain natriuretic peptide, troponin I and QT dispersion in asymptomatic dialysis patients

OBJECTIVES: The relationships between increased wall stress, myocyte death, and ventricular repolarization instability in patients with heart failure were reported. DESIGN AND METHODS: The relationships between brain natriuretic peptide (BNP), a predictor of increased wall stress of hearth; troponin I (cTnI), a predictor of myocyte death; and QT dispersion (QTd), a reflection of ventricular repolarization instability were evaluated in age- and sex-matched asymptomatic 29 hemodialysis (HD) patients and 26 peritoneal dialysis (PD) patients, and the finding were compared. RESULTS: Serum BNP and cTnI levels in HD patients (722.9 +/- 907.9 pg/mL, 0.05 +/- 0.07 microg/L, respectively), just before HD, were significantly higher than those of PD patients (255.4 +/- 463.7 pg/mL, 0.02 +/- 0.02 microg/L, respectively; p < 0.05). There was no significant difference between groups with regard to corrected QTd and maximum and minimum QT intervals (p > 0.05). Serum cTnI levels were significantly and positively correlated with serum BNP levels in both dialysis groups (r = 0.447, p = 0.048). No relationship was found between plasma BNP and ECG parameters studied in both groups (p > 0.05). CONCLUSION: Increased serum cTnI levels were associated with elevated BNP levels in both dialysis groups. The increases in BNP and troponin I are more likely to reflect hypervolemia. Although CAPD patients were receiving dialysis daily and HD patients were more hypervolemic, CAPD patients have similar QTdc and accordingly a similar tendency toward arrhythmias. This suggests that factors other than electromechanical interaction may be important in determining the QT interval length in patients on dialysis.     

Serum free carnitine, carnitine esters and lipids in patients on peritoneal dialysis and hemodialysis

Serum free and esterified carnitine levels as well as lipids were investigated in patients undergoing regular hemodialysis (HD) treatment before and during 12 weeks of treatment with L-carnitine (1 g i.v.) at the end of each HD. The results were compared with those obtained in patients on continuous ambulatory peritoneal dialysis (CAPD; n = 15) or intermittent peritoneal dialysis (IPD; n = 3) and healthy controls (CO; n = 20). In HD patients (n = 23) total carnitine (TC) was 49.9 +/- 3.9 (CO: 46.0 +/- 2.5; NS), free carnitine (FC) was 31.6 +/- 2.8 (CO: 37.4 +/- 1.3; p less than 0.05), short-chain acylcarnitine (SCC) was 17.0 +/- 1.8 (CO: 7.2 +/- 0.9; p less than 0.0001) and long-chain acylcarnitine (LCC) was 1.2 +/- 0.2 mumol/l (CO: 0.6 +/- 0.1; p less than 0.05). FC was in the normal range in CAPD (35.6 +/- 3.2) and IPD (44.5 +/- 8.0 mumol/l) patients, whereas SCC (30.1 +/- 3.5) and LCC (2.9 +/- 0.2) levels were maximal elevated in IPD patients (11.8 +/- 0.8 and 1.5 +/- 0.2 on CAPD). Therefore, TC was higher in IPD than in CAPD patients (77.5 +/- 5.0 vs. 49.0 +/- 3.5 mumol/l). 12 weeks after L-carnitine supplementation in HD patients, TC was 313.9 +/- 22.6, FC was 207.7 +/- 12.4, SCC was 99.6 +/- 12.1 and LCC was 7.1 +/- 0.6 mumol/l. TC and FC were significantly lower in females compared with males. Total cholesterol and ketone bodies were normal, HDL cholesterol was significantly decreased before and after L-carnitine supplementation.(ABSTRACT TRUNCATED AT 250 WORDS)     

Dual-energy x-ray absorptiometry of the forearm: reproducibility and correlation with single-photon absorptiometry.

Although single-photon absorptiometry (SPA) has been the predominant tool used to assess bone mineral density (BMD) in the forearm, the development of dual-energy x-ray absorptiometry (DEXA) provides the benefits of greater source stability, reduced scanning time, and improved image resolution compared to SPA. In the present study we used the DEXA bone densitometer (Hologic, Inc., Waltham, MA) to (1) measure BMD in the one-third radius and ultradistal radius; (2) examine the reproducibility of these BMD measurements; and (3) compare the BMD at the one-third radius with SPA (SP2, Lunar Corp., Madison, WI). In 65 normal women (ages 22-74 years) we examined changes in the forearm DEXA BMD with age, revealing significant quadratic regression equations. The reproducibility of DEXA BMD (mean +/- SEM) in 7 normal subjects aged 22-50 years is 0.85 +/- 0.16% for the predominantly cortical one-third radius site and 0.97 +/- 0.15% for the more trabecular ultradistal site. The regression relationship between DEXA and SPA of the one-third radius in 26 subjects (ages 22-68 years) is DEXA BMD = 0.105 + 0.826 (SPA BMD); R = 0.97, R2 = 0.94, p less than 0.0001. Bone densitometry of the forearm using DEXA may be performed relatively rapidly, providing reproducibility and image resolution that are generally superior to those observed with SPA.     

Evaluation of urine deoxypyridinoline and bone mineral density in 861 Chinese during routine health examination.

The aim of this study was to investigate the interrelation among urine deoxypyridinoline (DPD), age, sex, and bone mineral density (BMD) and to clarify whether DPD can be used to screen for low bone mass (T-score <-1) of the lumbar spine and proximal femur in the Chinese population. We reviewed medical records over a 1-yr period of all subjects who completed an annual health examination. A total of 302 men (age: 48.20 +/- 10.86 yr) and 559 women (age: 46.45 +/- 11.16 yr) who lived in the Taipei area, had no major systemic disorders, and underwent urine DPD test and BMD examination of both the lumbar spine (L-BMD) and proximal femur (F-BMD) were recruited. The urine DPD was weakly correlated with middle age in men (r = 0.154, p < 0.01). There was no correlation between DPD and age in women. The DPD and L-BMD were weakly correlated in both middle-aged men (r = -0.165, p < 0.05) and women (r = -0.171, p < 0.01), and moderately correlated in elderly women (r = -0.315, p < 0.01). There was a higher correlation between DPD and F-BMD in men than in women, especially in the middle-aged groups (men: r = -0.258, p < 0.01; women: r = -0.170, p < 0.01). Women in the highest tertile of DPD had 2.40 times the risk (95% confidence interval: 1.49-3.85) of those in the lowest tertile after age adjustment. There was poor agreement or none between DPD and BMD measurements in patients with low bone mass at either site in either sex. Urine DPD tests to substitute for BMD measurements in routine health examination for Chinese is not recommended.     

Markers of bone metabolism in hemodialyses and hemodiafiltration

Renal osteodystrophy is a common complication of chronic renal failure and renal replacement therapy. The purpose of the study was to assess whether hemodialysis (HD) or hemodiafiltration (HDF) affects bone turnover. In all, 45 HD and 17 HDF patients were evaluated with respect to bone metabolism markers. We assessed PTH; markers of bone formation-alkaline phosphatase and its bone isoform, osteocalcin; markers of bone resorption- PICP, ICTP; Ctx; beta2-microglobulin; and urinary DPD. BMD were determined for femoral neck and lumbar spine (L2-L4) using DEXA. Hemodialyzed patients had lower calcidiol, calcitriol, and BMD in the femur neck, and higher phosphate, Kt/V, residual renal function, venous pH, osteocalcin, ALP, bALP, DPD, beta2-microglobulin, ICTP, Ctx, osteoprotegerin, and RANKL than patients on HDF. HDF seems to ameliorate bone metabolism in comparison with HD. Bone turnover in end-stage renal failure might be affected to some extent by the choice of renal replacement therapy.     

Osteocalcin levels in uremic patients: influence of calcitriol treatment through two different routes and type of dialysis.

Osteocalcin, the most abundant non-collagen protein of bone, is synthesized by the osteoblast. Serum osteocalcin concentration depends primarily on new cellular synthesis, and is a sensitive marker of bone turnover reflecting osteoblastic function. In uremic and hemodialysis (HD) patients, a direct relationship between serum osteocalcin and histological parameters of bone formation has been observed. The modality of dialysis may influence serum osteocalcin levels though the available data are controversial. The aim of this study is to assess the acute and chronic effects of calcitriol and the influence of modality of dialysis on serum osteocalcin levels. Twelve patients on continuous ambulatory peritoneal dialysis (CAPD) were treated with calcitriol. For control purposes, 24 patients, 12 on CAPD and 12 on HD, not treated with calcitriol serum osteocalcin levels were included. In CAPD patients previously treated with calcitriol, serum osteocalcin levels were higher than in nontreated patients. The higher levels occur independent of serum levels of parathyroid hormone (PTH), Ca and P. Hemodialysis patients had osteocalcin levels similar to those of CAPD patients under calcitriol treatment. However, the levels of HD patients were higher than CAPD nontreated patients. Serum ionized Ca was similar in CAPD and HD nontreated patients; however, total Ca was significantly higher in HD than in CAPD patients, both with and without calcitriol. After the intravenous administration of calcitriol, serum osteocalcin levels increased from 9.2 + 2.5 to 13.5 + 5.4 ng/ml (p less than 0.01).(ABSTRACT TRUNCATED AT 250 WORDS)