Tze-Wah Kao

Acute-on-chronic kidney injury at hospital discharge is associated with long-term dialysis and mortality

Existing chronic kidney disease (CKD) is among the most potent predictors of postoperative acute kidney injury (AKI). Here we quantified this risk in a multicenter, observational study of 9425 patients who survived to hospital discharge after major surgery. CKD was defined as a baseline estimated glomerular filtration rate <45 ml/min per 1.73 m(2). AKI was stratified according to the maximum simplified RIFLE classification at hospitalization and unresolved AKI defined as a persistent increase in serum creatinine of more than half above the baseline or the need for dialysis at discharge. A Cox proportional hazard model showed that patients with AKI-on-CKD during hospitalization had significantly worse long-term survival over a median follow-up of 4.8 years (hazard ratio, 1.7) [corrected] than patients with AKI but without CKD.The incidence of long-term dialysis was 22.4 and 0.17 per 100 person-years among patients with and without existing CKD, respectively. The adjusted hazard ratio for long-term dialysis in patients with AKI-on-CKD was 19.8 compared to patients who developed AKI without existing CKD. Furthermore, AKI-on-CKD but without kidney recovery at discharge had a worse outcome (hazard ratios of 4.6 and 213, respectively) for mortality and long-term dialysis as compared to patients without CKD or AKI. Thus, in a large cohort of postoperative patients who developed AKI, those with existing CKD were at higher risk for long-term mortality and dialysis after hospital discharge than those without. These outcomes were significantly worse in those with unresolved AKI at discharge.

Rate of decline of residual renal function is associated with all-cause mortality and technique failure in patients on long-term peritoneal dialysis

BACKGROUND Residual renal function (RRF) at the initiation of peritoneal dialysis (PD) therapy can predict patient outcome. However, RRF declines with time at variable rates in different patients. This study was performed to compare the impact of baseline RRF and the rate of RRF decline on patient survival and on death-censored technique survival after initiation of long-term PD. METHODS We enrolled 270 patients with sufficient urine amount (daily urine volume >100 mL) from a medical centre in North Taiwan who began PD between January 1996 and December 2005 and followed them until December 2007. The study population was stratified by the decline rate of RRF into a fast, intermediate and slow decline group. The Kaplan-Meier survival analysis was used to determine patient survival and technique survival. The Cox regression model was used to identify factors associated with patient outcome. The proportional odds polychotomous logistic regression model was used to identify variables associated with rapid decline of RRF. RESULTS During an average follow-up period of 45 months, 50 (18.5%) deaths, 67 (24.8%) death-censored technique failures (transfer to haemodialysis) and 43 (15.9%) renal transplantations occurred. The median rate of RRF decline was 0.885 mL/min/1.73 m(2) per year. Survival analysis showed that patients with fast RRF decline had worse survival and increased risk of technique failure. The multivariate Cox regression model confirmed that the rate of RRF decline was an independent factor associated with patient and technique survival and was a more powerful prognostic factor than basal RRF. Variables associated with a rapid decline of RRF were larger body mass index, presence of diabetes, prior history of congestive heart failure, use of diuretics, peritonitis episodes and hypotensive events. CONCLUSIONS Our data indicate that the rate of decline of RRF is a more powerful prognostic factor than baseline RRF associated with all-cause mortality and technique failure in patients on long-term PD. To prevent accelerated loss of RRF, it is imperative that every effort be made to avoid overdiuresis, peritonitis and hypotensive episodes, especially in those with diabetes, obesity and congestive heart failure.

Sexual dysfunction in female hemodialysis patients: A multicenter study

BACKGROUND Sexual function is one aspect of physical functioning. Sexual dysfunction, no matter the etiology, could cause distress. In female hemodialysis patients, sexual problems have often been neglected in clinical performance and research. METHODS We conducted this study by use of self-reported questionnaires. A total of 578 female hemodialysis patients in northern Taiwan were included in this study. Demographic data, comorbid diseases, medications in use, biochemical, and hematologic parameters were analyzed. All patients were asked to complete by themselves three questionnaires: (1) the Index of Female Sexual Function (IFSF) to assess sexual function; (2) the Beck Depression Inventory (BDI) (Chinese version) to rate the severity of depressive symptoms; and (3) the 36-item Short Form Health Survey Questionnaire (SF-36, Taiwan Standard Version 1.0) to survey their quality of life. RESULTS A total of 138 female patients were enrolled into further analysis. The mean age was 48.7 +/- 11.2 years old. The mean IFSF score was 24.5 +/- 9.3. Age, BDI score, and serum triglyceride levels were the independent factors of dysfunction in each sexual functional dimension. Patients with higher IFSF scores had significantly higher scores in physical functioning and mental health (P= 0.007 and 0.018, respectively). Patients with higher intercourse satisfaction had significantly higher general health scores (P= 0.001). CONCLUSION Sexual dysfunction is frequent in the female hemodialysis population. It is strongly associated with increasing age, dyslipidemia, and depression. The subjects with sexual dysfunction had poorer quality of life. The diagnosis and treatment of sexual dysfunction should be included in the clinical assessment.

Impact of timing of renal replacement therapy initiation on outcome of septic acute kidney injury

IntroductionSepsis is the leading cause of acute kidney injury (AKI) in critical patients. The optimal timing of initiating renal replacement therapy (RRT) in septic AKI patients remains controversial. The objective of this study is to determine the impact of early or late initiation of RRT, as defined using the simplified RIFLE (risk, injury, failure, loss of kidney function, and end-stage renal failure) classification (sRIFLE), on hospital mortality among septic AKI patients.MethodsPatient with sepsis and AKI requiring RRT in surgical intensive care units were enrolled between January 2002 and October 2009. The patients were divided into early (sRIFLE-0 or -Risk) or late (sRIFLE-Injury or -Failure) initiation of RRT by sRIFLE criteria. Cox proportional hazard ratios for in hospital mortality were determined to assess the impact of timing of RRT.ResultsAmong the 370 patients, 192 (51.9%) underwent early RRT and 259 (70.0%) died during hospitalization. The mortality rate in early and late RRT groups were 70.8% and 69.7% respectively (P > 0.05). Early dialysis did not relate to hospital mortality by Cox proportional hazard model (P > 0.05). Patients with heart failure, male gender, higher admission creatinine, and operation were more likely to be in the late RRT group. Cox proportional hazard model, after adjustment with propensity score including all patients based on the probability of late RRT, showed early dialysis was not related to hospital mortality. Further model matched patients by 1:1 fashion according to each patients propensity to late RRT showed no differences in hospital mortality according to head-to-head comparison of demographic data (P > 0.05).ConclusionsUse of sRIFLE classification as a marker poorly predicted the benefits of early or late RRT in the context of septic AKI. In the future, more physiologically meaningful markers with which to determine the optimal timing of RRT initiation should be identified.

Association of Kidney Function With Residual Hypertension After Treatment of Aldosterone-Producing Adenoma

BACKGROUND Autonomous secretion of aldosterone in patients with primary aldosteronism increases glomerular filtration rate and causes kidney damage. The influence of a mild decrease in kidney function on residual hypertension after adrenalectomy is unexplored. STUDY DESIGN Nonconcurrent prospective study. SETTING & PARTICIPANTS The study was based on the Taiwan Primary Aldosteronism Investigation (TAIPAI) database. 150 patients (61 men; overall mean age, 47.2 +/- 11.6 years) with a diagnosis of aldosterone-producing adenoma had undergone unilateral adrenalectomy at National Taiwan University Hospital from July 1999 to January 2007. PREDICTOR Presurgery estimated glomerular filtration rate (eGFR). OUTCOMES & MEASUREMENTS Residual hypertension after adrenalectomy, defined either as less than 75% of recorded blood pressure measurements with systolic blood pressure less than 140 mm Hg and diastolic blood pressure less than 90 mm Hg or requiring antihypertensive medications during the first year after surgery. RESULTS Before surgery, 27 (18%), 72 (48%), and 51 (34%) patients had moderately to severely decreased (<60 mL/min/1.73 m(2)), mildly decreased (60 <or= eGFR < 90 mL/min/1.73 m(2)), or nondecreased eGFR (>or=90 mL/min/1.73 m(2)), respectively. After surgery, 16 (59.3%), 29 (40.3%), and 10 (19.3%) patients in each category had postsurgery residual hypertension. Compared with patients without decreased eGFR before surgery, adjusted odds ratios for postsurgery residual hypertension were 2.7 (95% confidence interval, 1.03 to 7.0; P = 0.04) and 2.8 (95% confidence interval, 1.05 to 9.3) for mildly and moderately to severely decreased eGFR, respectively. LIMITATIONS Arbitrary definition for residual hypertension. CONCLUSIONS Two-thirds of patients with aldosterone-producing adenoma were cured of hypertension by means of unilateral adrenalectomy. Kidney function impairment, even mild, appears to be associated with a high incidence of postsurgery residual hypertension.

Primary aldosteronism: changes in cystatin C-based kidney filtration, proteinuria, and renal duplex indices with treatment.

Objectives To obtain information about the effect of prolonged aldosterone excess on kidney function. Methods We determined kidney function changes defined by cystatin C-based estimations of glomerular filtration rate (CysC-GFR). Pretreatment proteinuria and intrarenal Doppler velocimetric indices in primary aldosteronism were examined and followed after adrenalectomy or spironolactone treatment. Results This prospective, multicenter study included 130 primary aldosteronism patients (56 men; age, 49.9 ± 13.4 years: 100 with adenoma and 30 with idiopathic hyperaldosteronism) and 73 essential hypertension patients (36 men; age, 51.4 ± 14.8 years) as controls. Patients with primary aldosteronism had higher CysC-GFR (P < 0.05) and heavier proteinuria (0.042) than those with essential hypertension. With primary aldosteronism, a higher aldosterone–renin ratio (odds ratio, OR = 7.85, P = 0.008) was independently related to pretreatment CysC-GFR. The factors related to pretreatment proteinuria included CysC-GFR (OR, −0.006, P = 0.001), plasma aldosterone concentration (OR, 0.004, P = 0.002), and duration of hypertension (OR, 0.016, P = 0.032). Duration of hypertension was also independently correlated with the pretreatment resistive index among primary aldosteronism patients (OR, 0.004, P = 0.035). CysC-GFR (all, P < 0.05), proteinuria (P < 0.001), and resistive index (P < 0.001) decreased 1 year after adrenalectomy but not with spironolactone treatment. Conclusion Our data suggest that prolonged hyperaldosteronism will cause relative kidney hyperfiltration and reversible intrarenal vascular structural changes, which disguise the consequent renal injury, including declining GFR and proteinuria. Adrenalectomy and spironolactone treatment exert different clinical impacts toward kidney damage even with a similar blood pressure-lowering effect.

Economic, Social, and Psychological Factors Associated With Health-Related Quality of Life of Chronic Hemodialysis Patients in Northern Taiwan: A Multicenter Study

This study evaluated the associations between economic, social, psychological factors, and health-related quality of life of hemodialysis patients. Cross-sectional study design was used. End-stage renal disease patients who had received maintenance hemodialysis for more than 2 months at 14 centers in northern Taiwan were invited to participate. Demographic, economic, and psychosocial data of patients were collected. Depression was assessed by the Beck Depression Inventory. Health-related quality of life was measured by the Medical Outcomes Study Short-Form 36. Multivariable linear regression analyses were performed. Eight hundred sixty-one patients (373 males, mean age 59.4 +/- 13.2 years) completed the study. Higher monthly income was positively associated with role emotional and mental health (P < 0.05), and so was increased frequency of social activities with social functioning (P < 0.05). The more worries, the stronger the inverse associations with social functioning (P < 0.05) and mental health (P < 0.01). Higher depression scores were associated with lower scores of all Short-Form 36 dimensions (P < 0.01). Higher monthly income and increased social activities are associated with better health-related quality of life, whereas more worries and higher depression scores are associated with worse health-related quality of life of hemodialysis patients.

Verification and evaluation of aldosteronism demographics in the Taiwan Primary Aldosteronism Investigation Group (TAIPAI Group)

Objective: Current data on primary aldosteronism (PA) from Asian populations are scarce. This cohort study clarifies the attributes of patients with PA in a typical Chinese population. Design: An observational cohort study. Methods: The records of patients referred to the Hypertension Clinic from a multi-centre registration in Taiwan from January 1995 to December 2007 were reviewed. All patients with PA were classified into two subtypes: aldosterone-producing adenomas (APA) and idiopathic hyperaldosteronism (IHA); their characteristics were compared. Results: Our cohort consisted of 346 patients with PA, 255 with APA and 91 with IHA. The initial hypokalaemia (59% in APA vs. 27.5% in IHA, p < 0.0001) and transtubular potassium gradient (TTKG) (6.30 ± 2.41 in APA vs. 4.91 ± 2.03 in IHA, p = 0.01) were higher in the APA group. Baseline plasma aldosterone concentration (PAC) was also significantly different between the two subgroups (49.96 ± 38.15 ng/dl in APA vs. 34.24 ± 21.47 in IHA, p < 0.0001). Conclusions: In typical Chinese PA patients, the APA subgroup had a higher proportion of hypokalaemia with elevated TTKG and higher PAC as compared with the IHA subgroup. This largest Asian database also demonstrated major differences between the Caucasian and Chinese populations including female predilection, frequent hypokalaemia, and common paralytic myopathy.

Association of serum fetuin A with truncal obesity and dyslipidemia in non-diabetic hemodialysis patients

BACKGROUND Fetuin A, a predictor of cardio-vascular (CV) mortality in dialysis patients has been associated with dyslipidemia in non-diabetic coronary artery disease. Truncal obesity is linked to dyslipidemia and also predicts CV mortality. This study had aimed to investigate the associations among fetuin A, truncal obesity, and dyslipidemia in hemodialysis (HD) patients. METHODS One hundred and nine non-diabetic HD patients were evaluated. Waist circumference, highly sensitive C-reactive protein (hs-CRP), fetuin A, and lipoprotein levels (i.e. total cholesterol (T-CHO), low-density lipoprotein (LDL-C), high-density lipoprotein (HDL-C), non-HDL-C, and triglyceride (TG)) were measured for analysis of correlations. The patients were divided into tertiles by fetuin A concentrations. RESULTS Data from 63 women and 46 men aged 60+/-13 years were analyzed. Patients in the highest tertile of fetuin A (0.33-0.51 g/l) had higher serum creatinine, albumin, T-CHO, LDL-C, non-HDL-C, and TG, more truncal obesity and lower hs-CRP than patients in the lowest tertile (all P<0.05). In multi-variable linear regression analysis, fetuin A was independently associated with TG level and total iron binding capacity after adjustments for age, hemoglobin, albumin, calcium, body mass index, and hs-CRP. Patients in the highest fetuin A tertile had 3.2- and 4.4-fold higher incidence of truncal obesity (P=0.038) and hyper-triglyceridemia (P=0.015) independent of nutritional status and inflammation. CONCLUSION Fetuin A is positively associated with truncal obesity and dyslipidemia, which are independent of malnutrition and inflammation. It may predict visceral adiposity and dyslipidemia, especially TG and TG-rich lipoproteins, in HD patients.

U-curve association between timing of renal replacement therapy initiation and in-hospital mortality in postoperative acute kidney injury.

Background Postoperative acute kidney injury (AKI) is associated with poor outcomes in surgical patients. This study aims to evaluate whether the timing of renal replacement therapy (RRT) initiation affects the in-hospital mortality of patients with postoperative AKI. Methodology This multicenter retrospective observational study, which was conducted in the intensive care units (ICUs) in a tertiary hospital (National Taiwan University Hospital) and its branch hospitals in Taiwan between January, 2002, and April, 2009, included adult patients with postoperative AKI who underwent RRT for predefined indications. The demographic data, comorbid diseases, types of surgery and RRT, and the indications for RRT were documented. Patients were categorized according to the period of time between the ICU admission and RRT initiation as the early (EG, ≦1 day), intermediate (IG, 2–3 days), and late (LG, ≧4 days) groups. The in-hospital mortality rate censored at 180 day was defined as the endpoint. Results Six hundred forty-eight patients (418 men, mean age 63.0±15.9 years) were enrolled, and 379 patients (58.5%) died during the hospitalization. Both the estimated probability of death and the in-hospital mortality rates of the three groups represented U-curves. According to the Cox proportional hazard method, LG (hazard ratio, 1.527; 95% confidence interval, 1.152–2.024; P = 0.003, compared with IG group), age (1.014; 1.006–1.021), diabetes (1.279; 1.022–1.601; P = 0.031), cirrhosis (2.147; 1.421–3.242), extracorporeal membrane oxygenation support (1.811; 1.391–2.359), initial neurological dysfunction (1.448; 1.107–1.894; P = 0.007), pre-RRT mean arterial pressure (0.988; 0.981–0.995), inotropic equivalent (1.006; 1.001–1.012; P = 0.013), APACHE II scores (1.055; 1.037–1.073), and sepsis (1.939; 1.536–2.449) were independent predictors of the in-hospital mortality (All P<0.001 except otherwise stated). Conclusions The current study found a U-curve association between the timing of the RRT initiation after the ICU admission and patients’ in-hospital mortalities, and alerts physicians of certain factors affecting the outcome after the RRT initiation.