Kidney function at 3 months after acute kidney injury is an unreliable indicator of subsequent kidney dysfunction: the NARA-AKI Cohort Study

The use of anti-adrenergic agents as a predictor of acute kidney injury and delayed recovery of kidney function: the NARA-AKI cohort study

Association of preoperative regular use of anti-adrenergic agents with postoperative acute kidney injury (AKI) and with trajectory of kidney function after AKI is still unknown. In a retrospective cohort study, adults undergoing non-cardiac surgery under general anesthesia were included. Obstetric or urological surgery, missing data, or preoperative dialysis was excluded. The exposure of interest was preoperative regular use of anti-adrenergic agents. The outcomes were AKI within 1 week postoperatively and trajectories of kidney function within 2 weeks postoperatively among patients with AKI. Multivariable logistic regression models were used to examine the association of anti-adrenergic agents with AKI. Linear mixed-effects models were used to compare the trajectories of postoperative kidney function after AKI between patients with and without anti-adrenergic agents. Among 5168 patients, 245 had used anti-adrenergic agents. A total of 309 (6.0%) developed AKI, and the use of anti-adrenergic agents was independently associated with postoperative AKI even after adjustment for preoperative and intraoperative potential confounders [odds ratio (95% confidence interval): 1.76 (1.14-2.71)]. The association was similar across preexisting hypertension or cardiovascular disease. Analyses restricted to patients with AKI suggested that the timing and stage of AKI were similar among those with and without anti-adrenergic agents; however, the recovery of kidney function was delayed among those with anti-adrenergic agents (P for interaction = 0.004). The use of anti-adrenergic agents was associated with postoperative AKI and delayed recovery of kidney function after AKI. Temporary withdrawal of anti-adrenergic agents during perioperative periods may contribute to prevent AKI and shorten the duration of AKI.

Age-Based Versus Young-Adult Thresholds for Nephrosclerosis on Kidney Biopsy and Prognostic Implications for CKD

SIGNIFICANCE STATEMENT

Nephrosclerosis (glomerulosclerosis, interstitial fibrosis, and tubular atrophy) is the defining pathology of both kidney aging and CKD. Optimal thresholds for nephrosclerosis that identify persons with a progressive disease are unknown. This study determined a young-age threshold (18-29 years) and age-based 95th percentile thresholds for nephrosclerosis on the basis of morphometry of kidney biopsy sections from normotensive living kidney donors. These thresholds were 7.1-fold to 36-fold higher in older (70 years or older) versus younger (aged 18-29 years) normotensive donors. Age-based thresholds, but not young-age threshold, were prognostic for determining risk of progressive CKD among patients who underwent a radical nephrectomy or a for-cause native kidney biopsy, suggesting that age-based thresholds are more useful than a single young-age threshold for identifying CKD on biopsy.

BACKGROUND

Nephrosclerosis, defined by globally sclerotic glomeruli (GSG) and interstitial fibrosis and tubular atrophy (IFTA), is a pathology of both kidney aging and CKD. A comparison of risk of progressive CKD using aged-based thresholds for nephrosclerosis versus a single young-adult threshold is needed.

METHODS

We conducted morphometric analyses of kidney biopsy images for %GSG, %IFTA, and IFTA foci density among 3020 living kidney donors, 1363 patients with kidney tumor, and 314 patients with native kidney disease. Using normotensive donors, we defined young-age thresholds (18-29 years) and age-based (roughly by decade) 95th percentile thresholds. We compared age-adjusted risk of progressive CKD (kidney failure or 40% decline in eGFR) between nephrosclerosis that was "normal compared with young," "normal for age but abnormal compared with young," and "abnormal for age" in patients with tumor and patients with kidney disease.

RESULTS

The 95th percentiles in the youngest group (18-29 years) to the oldest group (70 years or older) ranged from 1.7% to 16% for %GSG, 0.18% to 6.5% for %IFTA, and 8.2 to 59.3 per cm 2 for IFTA foci density. Risk of progressive CKD did not differ between persons with nephrosclerosis "normal compared with young" versus "normal for age but abnormal compared with young." Risk of progressive CKD was significantly higher with %GSG, %IFTA, or IFTA foci density that was abnormal versus normal for age in both cohorts.

CONCLUSIONS

Given that increased risk of progressive CKD occurs only when nephrosclerosis is abnormal for age, age-based thresholds for nephrosclerosis seem to be better than a single young-age threshold for identifying clinically relevant CKD.

Long-Term Tailor-Made Exercise Intervention Reduces the Risk of Developing Cardiovascular Diseases and All-Cause Mortality in Patients with Diabetic Kidney Disease

This study aimed to determine the effect of long-term exercise on the risk of developing cardiovascular diseases (CVD) and all-cause mortality in patients with diabetic kidney disease (DKD). A single-center, prospective intervention study using propensity score matching was performed over 24 months. The intervention group (n = 67) received six months of individual exercise instruction from a physical therapist, who performed aerobic and muscle-strengthening exercises under unsupervised conditions. New events were defined as the composite endpoint of stroke or CVD requiring hospitalization, initiation of hemodialysis or peritoneal dialysis, or all-cause mortality. The cumulative survival rate without new events at 24 months was significantly higher in the intervention group (0.881, p = 0.016) than in the control group (n = 67, 0.715). Two-way analysis of variance revealed a significant effect of the group factor on high density lipoprotein-cholesterol (HDL-C) which was higher in the intervention group than in the control group (p = 0.004); eGFRcr showed a significant effect of the time factor, which was lower at 24 months than before intervention (p = 0.043). No interactions were observed for all items. In conclusion, aerobic exercises combined with upper and lower limb muscle strengthening for six months reduce the risk of developing CVD and all-cause mortality in patients with DKD.