Long-term risk of coronary events after AKI.

The incidence rate of AKI in hospitalized patients is increasing. However, relatively little attention has been paid to the association of AKI with long-term risk of adverse coronary events. Our study investigated hospitalized patients who recovered from de novo dialysis-requiring AKI between 1999 and 2008 using patient data collected from inpatient claims from Taiwan National Health Insurance. We used Cox regression with time-varying covariates to adjust for subsequent CKD and ESRD after discharge. Results were further validated by analysis of a prospectively constructed database. Among 17,106 acute dialysis patients who were discharged, 4869 patients recovered from dialysis-requiring AKI (AKI recovery group) and were matched with 4869 patients without AKI (non-AKI group). The incidence rates of coronary events were 19.8 and 10.3 per 1000 person-years in the AKI recovery and non-AKI groups, respectively. AKI recovery associated with higher risk of coronary events (hazard ratio [HR], 1.67; 95% confidence interval [95% CI], 1.36 to 2.04) and all-cause mortality (HR, 1.67; 95% CI, 1.57 to 1.79) independent of the effects of subsequent progression to CKD and ESRD. The risk levels of de novo coronary events after hospital discharge were similar in patients with diabetes alone and patients with AKI alone (P=0.23). Our results reveal that AKI with recovery associated with higher long-term risks of coronary events and death in this cohort, suggesting that AKI may identify patients with high risk of future coronary events. Enhanced postdischarge follow-up of renal function of patients who have recovered from temporary dialysis may be warranted.

Dialysis-requiring acute kidney injury increases risk of long-term malignancy: a population-based study.

BACKGROUND: Acute kidney injury (AKI) is gaining worldwide attention recently, emerging as a major public health threat. However, the association between the development of AKI and subsequent malignancy has not been studied before. METHODS: We conducted a population study based on the Taiwan National Health Insurance database, using 1,000,000 representative database during 2000-2008. All patients' survival to discharge from index hospitalization with recovery from dialysis-requiring AKI were identified (recovery group), and matched with those without recovery and those without AKI, at a 1:1:1 ratio. RESULTS: We identified 625 individuals more than 18 years old [352 male (56.5%); mean age, 63.3 years] in recovery group and matched 625 individuals in each group. During a mean followed-up of 3.7 years, the incidences of new-onset malignancy were 4.2, 2.9, and 2.6 per 100 person-year among the non-recovery, the recovery, and the non-AKI group, respectively. After adjustment, the recovery group was more likely to develop long-term de novo malignancy than those without AKI [hazard ratio (HR) 1.44, 95% confidence interval (CI) 1.02-2.03; p = 0.04], while less likely than those who did not recover (HR 0.66, 95% CI 0.45-0.98; p = 0.04). CONCLUSIONS: Dialysis-requiring AKI can post a long-term risk of de novo malignancy for those who survive from the initial insult. Even patients who have recovered from dialysis still carry a significantly higher possibility of developing malignancy than those without AKI episode.

The impact of acute kidney injury with temporary dialysis on the risk of fracture.

Acute kidney injury (AKI) has a negative impact on long-term renal function and prognosis. However, the association between acute renal dysfunction and long-term effects on bone disorders has not yet been characterized. Using a population-based cohort study, we aimed to evaluate associations between AKI and long-term effects on bone fractures. We identified relevant data of all hospitalized patients aged >18 years with histories of dialysis-requiring AKI, with subsequent recovery and discharge, from the claim records of the Taiwan National Health Insurance database between 2000 and 2008. We determined long-term de novo bone fracture and all-cause mortality after patients' index-hospitalization discharge using propensity score-adjusted Cox proportional hazard model. Varying-time models were used to adjust for long-term effects of end-stage renal disease (ESRD) on main outcomes. Among 448 AKI patients who had dialysis and survived 90 days after index-hospitalization discharge without reentering dialysis, 273 were male (60.9%) with a mean age of 61.4 ± 16.6 years. Controls included 1792 hospitalized patients without AKI, dialysis, or bone fracture history. In the AKI recovery group, bone fracture incidence was 320 per 10,000 person-years and hazard ratio (HR) of long-term bone fracture was 1.25 (p = 0.049) compared with the control group, independent of subsequent ESRD status (HR = 1.55; p = 0.01). Both AKI recovery status (HR = 2.31; p < 0.001) and time varying factor of bone fracture (HR = 1.43; p < 0.001) were independent predictors of mortality compared with controls. In conclusion, AKI requiring temporary dialysis independently increases long-term risk of bone fracture, regardless of subsequent progression to ESRD. Long-term bone fractures may negatively impact patient mortality.

Increased risk of active tuberculosis following acute kidney injury: a nationwide, population-based study.

BACKGROUND: Profound alterations in immune responses associated with uremia and exacerbated by dialysis increase the risk of active tuberculosis (TB). Evidence of the long-term risk and outcome of active TB after acute kidney injury (AKI) is limited. METHODS: This population-based-cohort study used claim records retrieved from the Taiwan National Health Insurance database. We retrieved records of all hospitalized patients, more than 18 years, who underwent dialysis for acute kidney injury (AKI) during 1999-2008 and validated using the NSARF data. Time-dependent Cox proportional hazards model to adjust for the ongoing effect of end-stage renal disease (ESRD) was conducted to predict long-term de novo active TB after discharge from index hospitalization. RESULTS: Out of 2,909 AKI dialysis patients surviving 90 days after index discharge, 686 did not require dialysis after hospital discharge. The control group included 11,636 hospital patients without AKI, dialysis, or history of TB. The relative risk of active TB in AKI dialysis patients, relative to the general population, after a mean follow-up period of 3.6 years was 7.71. Patients who did (hazard ratio [HR], 3.84; p<0.001) and did not (HR, 6.39; p<0.001) recover from AKI requiring dialysis had significantly higher incidence of TB than patients without AKI. The external validated data also showed nonrecovery subgroup (HR = 4.37; p = 0.049) had high risk of developing active TB compared with non-AKI. Additionally, active TB was associated with long-term all-cause mortality after AKI requiring dialysis (HR, 1.34; p = 0.032). CONCLUSIONS: AKI requiring dialysis seems to independently increase the long-term risk of active TB, even among those who weaned from dialysis at discharge. These results raise concerns that the increasing global burden of AKI will in turn increase the incidence of active TB.