An echocardiography-derived calcium score as a predictor of major adverse cardiovascular events in peritoneal dialysis patients-A prospective cohort study.

BACKGROUND: An echocardiography-derived calcium score (ECS) has been shown to predict cardiovascular (CV) mortality in the general population but has not been utilized in the dialysis population. METHODS: We conducted a prospective cohort study including 125 prevalent PD patients. Two blinded and independent echocardiographers determined the ECS for each subject at baseline. The primary outcome was the three-point major adverse cardiovascular events (MACE) which is a composite outcome comprising CV death, non-fatal myocardial infarction and non-fatal stroke. The secondary outcome was all-cause mortality. RESULTS: The mean age was 61 ± 13 years. The median follow-up duration was 40 months (range 1-50). Seventy six (60.8%) of the subjects had diabetes mellitus (DM). The median duration of dialysis was 32 (IQR 16-54) months. The incidences of MACE and all-cause mortality were 13.0 per 100 patient-years and 18.3 per 100 patient-years. Multivariate Cox regression analysis identified the following three independent predictors of MACE: ECS (HR 1.253/unit increase in ECS, 95% CI 1.014-1.547, p = .036), DM (HR 2.467, 95% CI 1.014-6.005, p = .047) and pre-existing cardiovascular disease (CVD) (HR 2.441, 95% CI 1.261-4.728, p = .008); and the following two predictors of all-cause mortality: pre-existing CVD (HR 2.156, 95% CI 1.251-3.714, p = .006) and serum albumin (HR 0.887/g/L increase in serum albumin, 95% CI 0.839-0.937, p < .001). CONCLUSION: The ECS appears to be a significant predictor of MACE in PD patients independently of DM and pre-existing CVD.

Risk factors and clinical course of hungry bone syndrome after total parathyroidectomy in dialysis patients with secondary hyperparathyroidism.

BACKGROUND: Hungry bone syndrome (HBS) is an important postoperative complication after parathyroidectomy for severe secondary hyperparathyroidism (SHPT). There is, however, little data in the literature on its detailed clinical course, and the associated risk factors remain controversial. METHODS: We did a single-center retrospective study on 62 consecutive dialysis patients who underwent total parathyroidectomy for SHPT to examine the risk factors, clinical course and outcome. Data on demographic characteristics, perioperative laboratory parameters including serum calcium, phosphate, alkaline phosphatase (ALP) and parathyroid hormone (PTH), drug treatment for SHPT and operative details of parathyroidectomy were collected. RESULTS: Seventeen (27.4%) patients developed severe postoperative hypocalcemia with HBS. The serum calcium dropped progressively while serum ALP rose after operation until 2 weeks later when serum calcium reached the trough and serum ALP peaked. Serum phosphate also fell but stabilized between 4 and 14 days. The total postoperative calcium and vitamin D supplementation was significantly larger, and hospital stay was significantly longer in the group with HBS as compared with those without HBS. Young age, high body weight, high preoperative ALP level, and low preoperative calcium level independently predicted the development of HBS while preoperative PTH and use of cinacalcet or paricalcitol did not. CONCLUSION: HBS was common after total parathyroidectomy in patients with SHPT, and it is important to closely monitor the postoperative serum calcium, phosphate and ALP levels in the following 2 weeks, especially for those at risk. The implications of our findings on perioperative management are discussed.

Evaluation of the relationship between cardiac calcification and cardiovascular disease using the echocardiographic calcium score in patients undergoing peritoneal dialysis: a cross-sectional study.

Introduction: An echocardiographic calcium score (ECS) predicts cardiovascular disease (CVD) in the general population. Its utility in peritoneal dialysis (PD) patients is unknown. Methods: This cross-sectional study assessed 125 patients on PD. The ECS (range 0-8) was compared between subjects with CVD and those without. Results: Among the subjects, 54 had CVD and 71 did not. Subjects with CVD were older (69 years vs. 56 years, P < 0.001) and had a higher prevalence of diabetes mellitus (DM) (81.5% vs. 45.1%, P < 0.001). They had lower diastolic blood pressure (72 mmHg vs. 81 mmHg, P < 0.001), lower phosphate (1.6 mmol/L vs. 1.9 mmol/L, P = 0.002), albumin (30 g/L vs. 32 g/L, P = 0.001), parathyroid hormone (34.4 pmol/L vs. 55.8 pmol/L, P = 0.002), total cholesterol (4.5 vs. 4.9, P = 0.047), LDL cholesterol (2.4 mmol/L vs. 2.8 mmol/L, P = 0.019) and HDL cholesterol (0.8 mmol/L vs. 1.1 mmol/L, P = 0.002). The ECS was found to be higher in subjects with CVD than in those without (2 vs. 1, P = 0.001). On multivariate analysis, only DM and age were independently associated with CVD. Conclusion: The ECS was significantly higher in PD patients with CVD than in those without, reflecting a higher vascular calcification burden in the former. It is a potentially useful tool to quantify vascular calcification in PD patients.

Treatment of Severe Tumoral Calcinosis with Teriparatide in a Dialysis Patient after Total Parathyroidectomy.

Tumoral calcinosis is a rare but debilitating condition that can affect dialysis patients. Optimal management is largely unknown. We report the clinical course, treatment, and outcome of a peritoneal dialysis (PD) patient who developed tumoral calcinosis refractory to conventional treatment but improved with teriparatide therapy. A 26-year-old lady on PD for 2 years presented to us with tumoral calcinosis involving bilateral hands. Response to surgical excision, parathyroidectomy, and conversion to hemodialysis failed to result in sustained remission, and tumoral calcinosis progressed. After total parathyroidectomy, the patient had transient but partial remission in which her calcinosis deposits remained but were asymptomatic without pain or clinical signs of inflammation. However, she later experienced a relapse with involvement of the left elbow, right shoulder, right hip, and right thigh. Tumoral calcinosis remained uncontrolled resulting in debilitation, likely attributable to poor calcium and phosphate control because of adynamic bone disease after parathyroidectomy despite treatment of superimposed tuberculosis and therapy with sodium thiosulphate and pamidronic acid. Clinical improvement was however evident after the use of teriparatide. Asymptomatic hypocalcemia occurred after teriparatide therapy but resolved after 2 months. In conclusion, teriparatide appears to be useful for treating tumoral calcinosis in the presence of adynamic bone disease. Hypocalcemia can occur in the initial months of therapy.

Increased utilization of peritoneal dialysis to cope with mounting demand for renal replacement therapy--perspectives from Asian countries.

With the number of end-stage renal disease (ESRD) patients growing, one of the crucial questions facing health care professionals and funding agencies in Asia is whether funding for dialysis will be sufficient to keep up with demand. During the ISPD's 2006 Congress, academic nephrologists and government officials from China, Hong Kong, India, Indonesia, Japan, Macau, Malaysia, Philippines, Singapore, Taiwan, Thailand, and Vietnam participated in a roundtable discussion on dialysis economics in Asia. The focus was policy and health care financing. The roundtable addressed ESRD growth in Asia and how to obtain enough funding to keep up with the growth in patient numbers. Various models were presented: the "peritoneal dialysis (PD) first" policy model, incentive programs, nongovernmental organizations providing PD, and PD reimbursement in a developing economy. This article summarizes the views of the participant nephrologists on how to increase the utilization of PD to improve on clinical and financial management of patients with ESRD.

Prevalence and associated factors of reduced bone mineral density in patients with idiopathic inflammatory myopathies.

AIM: To determine the prevalence and identify the associated factors of reduced bone mineral density (BMD) in patients with idiopathic inflammatory myopathies (IIMs). METHOD: Existing patients diagnosed to have IIMs were recruited for measurement of BMD by dual energy X-ray absorptiometry. Demographic, clinical and treatment variables of these patients were recorded. The prevalence of osteopenia and osteoporosis were calculated. Using multivariate analysis, the independent associated factors for reduced BMD were evaluated. RESULTS: Thirty-eight patients with IIMs completed the study with 32 (84.2%) being female. The mean age of the patients was 52.8 ± 13.0 years. Nine (23.7%) patients had osteoporosis and 18 (47.4%) had osteopenia. Multivariate analysis revealed female gender and low serum albumin levels at onset were associated with lower spinal BMD. For femoral neck, the factors associated with lower BMD were high Myositis Disease Activity Assessment Visual Analogue Scales (MYOACT) score and high cumulative prednisolone dose. CONCLUSIONS: Reduced BMD is prevalent in patients with IIMs. Female gender, low serum albumin level at onset, high disease activity and high cumulative corticosteroid dose appeared to be the independent associated factors. Regular assessment of BMD is advisable. The use of anti-osteoporotic and steroid-sparing agents should be encouraged.

Vibrio vulnificus peritonitis after handling of seafood in a patient receiving CAPD.

Vibrio vulnificus is a marine bacterium and opportunistic human pathogen. Associated infections have contributed to the majority of seafood-related deaths in the United States. In patients with such predisposed clinical conditions as chronic liver disease, immunocompromised state, and end-stage renal disease, this organism has been associated with the development of life-threatening primary septicemia and severe wound infection. However, continuous ambulatory peritonitis dialysis (CAPD)-related peritonitis caused by V vulnificus has not been reported. We describe a patient receiving CAPD who developed peritonitis caused by V vulnificus after handling seafood. This case highlights the importance of strict aseptic technique during CAPD exchanges and calls for an effort in educating our dialysis patients on precautions about seafood handling.

Novel mutations of the AGXT gene causing primary hyperoxaluria type 1.

BACKGROUND: Primary hyperoxaluria type 1 (PH1), an inherited cause of nephrolithiasis, is due to a functional defect of the liver-specific peroxisomal enzyme alanine:glyoxylate aminotransferase (AGT). A definitive PH1 diagnosis can be established by analyzing AGT activity in liver tissue or mutation analysis of the AGXT gene. METHODS: The molecular basis of PH1 in three Chinese patients, two with adult-onset and one with childhood-onset recurrent nephrolithiasis, was established by analyzing the entire AGXT gene. RESULTS: Three novel mutations (c2T>C, c817insAG and c844C>T) and two previously reported mutations (c33insC and 679-IVS6+2delAAgt) were identified. c2T>C converts the initiation codon from ATG to ACG, which predicts significant reduction, if not complete abolition, of protein translation. c817insAG leads to a frameshift and changes the amino acid sequence after codon 274. c844C>T changes glutamine at codon 282 to a termination codon, resulting in protein truncation. CONCLUSIONS: This is the first report describing AGXT gene mutations in Chinese patients with PH1. AGXT genotypes cannot fully explain the clinical heterogeneity of PH1, and other factors involved in disease pathogenesis remain to be identified. Our experience emphasizes the importance of excluding PH1 in patients with recurrent nephrolithiasis to avoid delay or inappropriate management.

Persistent sterile peritoneal inflammation after catheter removal for refractory bacterial peritonitis predicts full-blown encapsulating peritoneal sclerosis.

BACKGROUND: Encapsulating peritoneal sclerosis (EPS) is the most serious complication of peritoneal dialysis, having high morbidity and mortality. To improve outcomes, early diagnosis is needed to direct treatment during the early inflammatory phase. However, in the early inflammatory phase, clinical features are nonspecific, and no reliable diagnostic criteria have been established. Because bacterial peritonitis and termination of dialysis are two important risk factors triggering the progression of EPS, patients with refractory bacterial peritonitis necessitating dialysis catheter removal are at particularly high risk of developing EPS. Many of these patients might indeed experience non-resolving sterile peritonitis (probably the inflammatory phase of EPS) before progression to full-blown disease (that is, the presence of intestinal obstruction). We undertook a retrospective study to compare, in this particular situation, the clinical characteristics of patients with or without sterile peritoneal inflammation, assessing their clinical outcomes in terms of short-term mortality and the chance of developing full-blown EPS. METHODS: Our retrospective review included 62 patients whose dialysis catheter was removed because of refractory peritonitis between January 2005 and December 2010. RESULTS: Of the 62 patients identified, 39 (63%) had persistent sterile peritoneal inflammation ("high-risk" group, n = 39), and 23 (37%) had resolution of inflammation without significant intra-abdominal collection after catheter withdrawal ("control" group, n = 23). Compared with the control group, the high-risk group had a significantly longer PD duration (71.6 ± 43.3 months vs 42.3 ± 29.9 months, p = 0.003), a higher dialysate-to-plasma ratio (D/P) of creatinine (0.768 ± 0.141 vs 0.616 ± 0.091, p = 0.004), and a higher computed tomography score for EPS (7.69 ± 2.98 vs 1.00 ± 1.00, p < 0.001). During the 6-month study period, the high-risk group had a higher chance of developing full-blown EPS (31% vs 0%, p = 0.002) and a higher 6-month all-cause mortality (36% vs 4.3%, p = 0.004). CONCLUSIONS: Persistent sterile peritoneal inflammation was common after dialysis catheter removal for refractory bacterial peritonitis, and the patients with such inflammation were at high risk of progression to full-blown EPS.