Ea Wha Kang

Clinical implications of subclinical hypothyroidism in continuous ambulatory peritoneal dialysis patients.

BACKGROUND Despite the high prevalence of subclinical hypothyroidism in patients with chronic kidney disease, little is known about the clinical features and implications of this disorder in end-stage renal disease patients. This study aimed to investigate the clinical implications of subclinical hypothyroidism in continuous ambulatory peritoneal dialysis (CAPD) patients. METHODS This is a cross-sectional study with 51 stable patients who were maintained on CAPD for more than 3 months. A thyroid function test with blood sampling and echocardiography were conducted. Subclinical hypothyroidism was defined as a thyrotropin (TSH) level over 5 mIU/l and normal free T(4). RESULTS Of the 51 patients, subclinical hypothyroidism was detected in 14 (27.5%). Among those with subclinical hypothyroidism, only 4 (28.6%) patients had autoimmune thyroiditis. Patients with subclinical hypothyroidism had lower left ventricular ejection fractions (LVEF; 61.5 vs. 70.0%, p = 0.002) and lower fractional shortening at endocardial levels (endoFS; 33.9 vs. 40.0%, p = 0.009) compared to those with normal TSH levels. In addition, logTSH was inversely associated with LVEF (r = -0.361, p = 0.009) and endoFS (r = -0.320, p = 0.022). In a multivariate linear regression, adjusted for age, diabetes, previous coronary artery disease and logCRP (C-reactive protein), logTSH was an independent correlate with LVEF (beta = -0.388, p < 0.001). CONCLUSION This study suggests that subclinical hypothyroidism is common and might be implicated in cardiac dysfunction in CAPD patients.

Clinical Features and Outcomes of IgA Nephropathy with Nephrotic Syndrome

BACKGROUND AND OBJECTIVES Nephrotic syndrome (NS) is a rare manifestation of IgA nephropathy (IgAN). Clinical characteristics and long-term outcomes of this condition have not yet been explored. DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS A multicenter observational study was conducted between January 2000 and September 2010 in 1076 patients with biopsy-proven IgAN from four medical centers in Korea. The primary outcome was a doubling of the baseline serum creatinine concentration. RESULTS Of the 1076 patients, 100 (10.2%) presented with NS; complete remission (CR), partial remission (PR), and no response (NR) occurred in 48 (48%), 32 (32%), and 20 (20%) patients, respectively. During the median follow-up of 45.2 months, 24 patients (24%) in the NS group reached the primary endpoint compared with 63 (7.1%) in the non-NS group (P<0.001). The risk of reaching the primary endpoint was significantly higher in the PR (P=0.04) and NR groups (P<0.001) than in the CR group. Among patients with NS, 24 (24%) underwent spontaneous remission (SR). SR occurred more frequently in female patients and in patients with serum creatinine levels ≤1.2 mg/dl and a >50% decrease in proteinuria within 3 months after NS onset. None of the patients with SR reached the primary endpoint and they had fewer relapses during follow-up. CONCLUSIONS This study demonstrated that the prognosis of NS in IgAN was not favorable unless PR or CR was achieved. In addition, SR was more common than expected, particularly in patients with preserved kidney function and spontaneous decrease in proteinuria shortly after NS onset.

Influence of ketoanalogs supplementation on the progression in chronic kidney disease patients who had training on low-protein diet.

Aim:  A low‐protein diet (LPD) is a conservative treatment in patients with chronic kidney disease (CKD) to improve uremic symptoms and slow the progression of renal dysfunction. However, the deleterious effects of protein restriction on nutritional status have raised concern. We investigated whether ketoanalogs supplementation in CKD patients who had training on LPD retards the progression of CKD and maintains nutritional status.

Prognostic value of elevated cardiac troponin I in ESRD patients with sepsis

BACKGROUND Elevated cardiac troponin (cTn) levels have been reported to predict adverse cardiovascular outcomes in asymptomatic ESRD patients. However, the prognostic value of elevated cTn levels associated with sepsis in ESRD patients is unknown. Therefore, this study aimed to elucidate the clinical implications of elevated cTnI levels in ESRD patients with sepsis. METHODS Of the 305 ESRD patients in whom cTnI was measured between January 2003 and December 2005, sepsis developed in 121 patients during follow-up. Based on cTnI levels at the onset of sepsis, patients were classified as elevated cTnI group (ET, n = 50, >0.2 ng/ml) and lower cTnI group (LT, n = 71, < or =0.2 ng/ml). Study endpoints were short- and long-term mortality. Short-term mortality was defined as death occurring within 90 days after sepsis, and patients who survived during this period were followed till death after 90 days. RESULTS Before sepsis, the median concentration of cTnI was 0.05 (0.01-3.59) ng/ml and it was significantly increased to 0.11 (0.01-22.0) ng/ml when sepsis supervened (P < 0.01). Compared to the LT group, the short-term mortality rate was significantly higher in the ET group (P < 0.05). After adjustment for age, diabetes, serum albumin and CRP levels, presence of shock and previous cardiovascular disease history, the ET group had a greater odds ratio of short-term mortality (OR 5.13, P < 0.01). In addition, the Kaplan-Meier plot for long-term survival revealed a significantly higher mortality rate in the ET group. In a multivariate Cox regression analysis, the elevation of cTnI levels was an independent determinant for long-term mortality (HR 5.90, P < 0.01). CONCLUSION This study showed that elevated cTnI levels were significantly associated with short- and long-term mortality in ESRD patients with sepsis. Therefore, elevated cTnI levels in these patients should not be overlooked and be followed for adverse outcomes.

Reduced Residual Renal Function is Associated with Endothelial Dysfunction in Patients Receiving Peritoneal Dialysis

♦ Background: Endothelial dysfunction, which contributes to atherosclerosis and arteriosclerosis, commonly accompanies end-stage renal disease (ESRD). However, little is known about the role of residual renal function (RRF) in endothelial protection in ESRD patients. This study aimed to investigate the relationship between endothelial function and RRF in patients undergoing peritoneal dialysis (PD). ♦ Methods: This was a cross-sectional study involving 72 prevalent PD patients. Demographic and clinical data were recorded and residual glomerular filtration rate (GFR), Kt/V urea, and serum concentrations of inflammatory markers were measured. Endothelial function was assessed by brachial artery endothelium-dependent vasodilation [flow-mediated dilation (FMD)] to reactive hyperemia following 5 minutes of forearm ischemia. ♦ Results: In patients with FMD% above the median value (FMD > 2.41%), residual GFR was significantly higher compared to that in patients with FMD% below the median [1.50 (0 – 9.64) vs 0.48 (0 – 3.89) mL/min/1.73 m2, P = 0.026]. Correlation analyses revealed that residual GFR (ρ = 0.381, P = 0.001) and total Kt/V urea (γ = 0.408, P < 0.001) were positively correlated with FMD%, whereas PD duration (γ = –0.351, P = 0.003), high-sensitivity C-reactive protein (ρ = –0.345, P = 0.003), pulse pressure (γ = –0.341, P = 0.003), and age (γ = –0.403, P < 0.001) were inversely correlated with FMD%. In contrast, there was no correlation between peritoneal Kt/V urea and FMD%. In multivariate linear regression analysis adjusted for these factors, residual GFR was found to be an independent determinant of FMD% (β = 0.317, P = 0.017). ♦ Conclusion: This study shows that RRF is independently associated with endothelial dysfunction in ESRD patients on PD, suggesting that RRF may contribute to endothelial protection in these patients.

Hyponatremia as a Predictor of Mortality in Peritoneal Dialysis Patients

Background and Aim Hyponatremia is common in patients with chronic kidney disease and is associated with increased mortality in hemodialysis patients. However, few studies have addressed this issue in peritoneal dialysis (PD) patients. Methods This prospective observational study included a total of 441 incident patients who started PD between January 2000 and December 2005. Using time-averaged serum sodium (TA-Na) levels, we aimed to investigate whether hyponatremia can predict mortality in these patients. Results Among the baseline parameters, serum sodium level was positively associated with serum albumin (β = 0.145; p = 0.003) and residual renal function (RRF) (β = 0.130; p = 0.018) and inversely associated with PD ultrafiltration (β = −0.114; p = 0.024) in a multivariable linear regression analysis. During a median follow-up of 34.8 months, 149 deaths were recorded. All-cause death occurred in 81 (55.9%) patients in the lowest tertile compared to 37 (25.0%) and 31 (20.9%) patients in the middle and highest tertiles, respectively. After adjusting for multiple potentially confounding covariates, increased TA-Na level was associated with a significantly decreased risk of all-cause (HR per 1 mEq/L increase, 0.79; 95% CI, 0.73–0.86; p<0.001) and infection-related (HR per 1 mEq/L increase, 0.77; 95% CI, 0.70–0.85; p<0.001) deaths. Conclusions This study showed that hyponatremia is an independent predictor of mortality in PD patients. Nevertheless, whether correcting hyponatremia improves patient survival is unknown. Future interventional studies should address this question more appropriately.

Spontaneous remission of nephrotic syndrome in patients with IgA nephropathy

BACKGROUND IgA nephropathy (IgAN) can be complicated by nephrotic syndrome. Because the spontaneous resolution of heavy proteinuria is rare, corticosteroid therapy should be considered in such cases, particularly when IgAN is combined with minimal-change disease. Here, we report our experience of spontaneous remission of nephrotic syndrome in patients with IgAN and the long-term outcomes of these patients. METHODS Two hundred and thirty-three patients with biopsy-proven IgAN were enrolled between January 2001 and March 2009. Demographic, clinical and laboratory data were collected retrospectively based on medical records. In addition, pathologic findings were reviewed for glomerular and tubulointerstitial lesions. Outcome data for complete or partial remission, spontaneous remission, relapse, deterioration of renal function, and end-stage renal disease were recorded. RESULTS Twenty-four patients (10.3%) presented nephrotic syndrome. Among them, five patients underwent spontaneous remission within 6 months after the presentation of nephrotic syndrome. Interestingly, spontaneous remission occurred even in two patients who had elevated serum creatinine levels and advanced renal damage. During follow-up, neither recurrence nor relapse occurred, and no patients showed progressive deterioration of kidney function. Conclusions. This study suggests that spontaneous remission of nephrotic syndrome may occur in any stage of IgAN and carries a favourable long-term outcome without relapse. Given the possibility of under-reported cases, large-scale studies are required, and careful attention should be paid to such complicated cases.

The impact of dialysis modality on arterial stiffness in patients with end-stage renal disease.

Background: Arterial stiffness determined by brachial–ankle pulse wave velocity (baPWV) has been established as a powerful predictor of cardiovascular mortality in hemodialysis (HD) patients. There are, however, few studies regarding the comparative impact of different renal replacement therapies (RRTs) on PWV. Therefore, we conducted a cross-sectional study to compare arterial wall properties and cardiac function between patients treated with continuous ambulatory peritoneal dialysis (CAPD) and those with HD who were matched for age, dialysis duration, and blood pressure. Methods: baPWV and transthoracic echocardiography (TTE) were performed in HD patients (n = 23) after 1 h of midweek dialysis session and CAPD patients (n = 26) with empty abdomen after drainage of dialysate. The baseline data were retrospectively reviewed. Results: baPWV was significantly higher in HD patients than in CAPD patients (18.1 ± 2.8 vs. 16.1 ± 2.7 m/s, p = 0.015). TTE revealed significantly increased E/E′, left atrial volume index (LAVI), and inferior vena cava (IVC) diameter index in HD patients compared with CAPD patients (p < 0.05). In a multivariate regression analysis adjusted for dialysis modality, age, systolic BP, residual glomerular filtration rate, diabetes, and echocardiographic parameters, HD was independently associated with increased baPWV. Conclusion: This study showed that HD patients had significantly increased arterial stiffness and severe diastolic dysfunction compared with CAPD patients.

Spontaneous Remission of IgA Nephropathy Associated With Resolution of Hepatitis A

Although most cases of immunoglobulin A (IgA) nephropathy are idiopathic, several diseases are associated with IgA nephropathy. Of these, chronic liver disease resulting from hepatitis B or C virus infection has been reported as a secondary cause of IgA nephropathy. Recently, hepatitis A virus (HAV)-associated kidney disease has received attention because acute kidney injury can occur as a complication of HAV infection, generally caused by acute tubular necrosis or interstitial nephritis. However, unlike IgA nephropathy related to hepatitis B or C, HAV-associated IgA nephropathy is extremely rare and long-term outcomes have not been reported yet. We describe a case of spontaneous remission of IgA nephropathy associated with serologically documented HAV infection. The patient presented with microhematuria and moderate proteinuria, but acute kidney injury did not occur during active hepatic injury. Kidney biopsy specimens clearly showed mesangial IgA deposits with intact tubules and interstitium. Serum liver enzyme levels returned to reference values 1 month after the onset of acute hepatitis, but urinary protein excretion remained increased. Approximately 1 year later, urinary abnormalities were resolved and a second biopsy showed no mesangial IgA deposits. These findings suggest that IgA nephropathy can transiently accompany HAV infection, but may not progress to chronic glomerulonephritis after recovery from HAV.

Low Triiodothyronine Syndrome and Long-Term Cardiovascular Outcome in Incident Peritoneal Dialysis Patients

BACKGROUND AND OBJECTIVES A direct association between low triiodothyronine (T3) syndrome and cardiovascular (CV) mortality has been reported in hemodialysis patients. However, the implications of this syndrome in peritoneal dialysis (PD) patients have not been properly investigated. This study examined the association between low T3 syndrome and CV mortality including sudden death in a large cohort of incident PD patients. DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS This prospective observational study included 447 euthyroid patients who started PD between January 2000 and December 2009. Measurement of thyroid hormones was performed at baseline. All-cause and cause-specific deaths were registered during the median 46 months of follow-up. The survival rate was compared among three groups based on tertile of T3 levels. RESULTS In Kaplan-Meyer analysis, patients with the lowest tertile were significantly associated with higher risk of all-cause and CV mortality including sudden death (P<0.001 for trend). In Cox analyses, T3 level was a significant predictor of all-cause mortality (per 10-unit increase, adjusted hazard ratio [HR], 0.86; 95% confidence interval [95% CI], 0.78 to 0.94; P=0.002), CV death (per 10-unit increase, adjusted HR, 0.84; 95% CI, 0.75 to 0.98; P=0.01), and sudden death (per 10-unit increase, adjusted HR, 0.69; 95% CI, 0.56 to 0.86; P=0.001) after adjusting for well known risk factors including inflammation and malnutrition. The higher T3 level was also independently associated with lower risk for sudden death (per 10-unit increase, adjusted HR, 0.71; 95% CI, 0.56 to 0.90; P=0.01) even when accounting for competing risks of death from other causes. CONCLUSIONS T3 level at the initiation of PD was a strong independent predictor of long-term CV mortality, particularly sudden death, even after adjusting well known risk factors. Low T3 syndrome might represent a factor directly implicated in cardiac complications in PD patients.