Severe Acute Kidney Disease Is Associated With Worse Kidney Outcome Among Acute Kidney Injury Patients Ⅲ

Results 

Demographics and AKD incidence among patients with AKI. 

We identified 8718 patients with AKI between January 1, 2015, and December 31, 2018. However, 15 patients who underwent dialysis before AKI occurrence, 3781 patients without SCr data between 7 and 90 days after AKI, and 181 patients with incomplete laboratory data or ambiguous comorbidity status were excluded (Fig. 2). The remaining 4741 patients with AKI were all considered AKD patients, according to the KDIGO consensus15. These post-AKI AKD patients were then further categorized according to their baseline eGFR classification. Of these patients, 2050 had baseline eGFR<60 mL/min/1.73 m2 before AKI (lower baseline eGFR group) and 2691 had baseline eGFR ≥60 mL/ min/1.73 m2 before AKI (higher baseline eGFR group). The patient demographics for each group are listed in Table 1. The lower baseline eGFR group included 1093 patients who had AKD stage 1–3 after AKI (53.3%) and 957 patients who had AKD stage 0 after AKI. Nevertheless, no signifcant diferences were noted between the AKD stage 1–3 and AKD stage 0 groups regarding age, sex, or percentages of patients with comorbidities. The higher baseline eGFR group included 1361 patients who had AKD stage 1–3 after AKI (50.5%) and 1330 patients who had AKD stage 0 after AKI. Compared with the AKD stage 0 group, the AKD stage 1–3 group had a significantly higher proportion of patients with anemia (7.9% versus 5.3%, P=0.0070) and malignancy (41.0% versus 31.2%, P<0.0001), but a lower proportion of patients with hypertension or cerebrovascular disease. The proportions of patients with different AKD stages within the lower baseline eGFR and the higher baseline eGFR groups are presented in Table 1, Table S1, and Table S2. 

A NEW HERB FOR CURE KIDNEY DISEASE

Severe AKD was associated with adverse kidney outcomes among the lower baseline eGFR and higher baseline eGFR populations. 

Among the patients with lower baseline eGFR, a year after AKI, those who had AKD stage 1–3 were noted to have a higher risk of MAKEs (a composite outcome containing rapid eGFR decline, initiation of dialysis, and in-hospital mortality; see the "Follow-up and study outcomes" subsection of the "Methods" section) after adjustment for age, sex, and comorbidities (odds ratio [OR] 3.79; CI 3.4–4.58) compared with those who had AKD stage 0 (Fig. 3). Similarly, among the higher baseline eGFR patients, those who had AKD stage 1–3 were more likely to develop MAKEs a year after AKI (OR 4.63, CI 3.88– 5.52) (Fig. 4). Regarding the individual components of MAKE, AKD stage 1–3 was significantly associated with rapid eGFR decline at 1 year among the lower baseline eGFR population (OR 2.53, CI 1.91–3.35) and the higher baseline eGFR population (OR 2.55, CI 1.92–3.37) (Table S3 and Table S4). As to the initiation of kidney replacement therapy (KRT), among the lower baseline eGFR population, AKD stage 1–3 was positively associated with KRT commencement (OR 3.29, CI 2.63–4.11). Similarly, in the higher baseline eGFR group, AKD stage 1–3 was significantly associated with KRT initiation (OR 10.47, CI 5.97–18.36). AKD stage 1–3 was associated with a higher 1-year in-hospital mortality rate in the lower baseline eGFR group (OR 2.64, CI 2.14–3.27) and the higher baseline eGFR group (OR 4.04, CI 3.33–4.89).

events. AKI acute kidney injury, SCr serum creatinine, eGFR estimated glomerular fltration rate, AKD acute kidney disease.

More advanced AKD stages correspond to worse kidney outcomes.

The association between different AKD stages and adverse kidney outcomes was analyzed to determine the clinical significance of the AKD stage. At the 1-year follow-up, compared with patients in the AKD stage 0 group, those with all other AKD stages were associated with a higher risk of MAKEs (AKD stage 1: OR 1.85, CI 1.56–2.19; AKD stage 2: OR 3.45, CI 2.85–4.12; AKD stage 3: OR 10.41, CI 8.68–12.49) (Table 2). Notably, all AKD stages were associated with MAKEs at 1 year for both the lower baseline eGFR group and the higher baseline eGFR group (Figs. 3 and 4). In addition, rapid eGFR decline was associated with different AKD stages, both in the lower and higher baseline eGFR groups. AKD stages 2 and 3 were associated with KRT initiation, whereas AKD stage 1 was not (AKD stage 1: OR 1.01, CI 0.74–1.39; AKD stage 2: OR 1.88, CI 1.39–2.53; AKD stage 3: OR 8.72, CI 7.07–10.76) (Table 2). Furthermore, in both the lower baseline eGFR group and the higher baseline eGFR group, only AKD stages 2 and 3 were associated with KRT initiation (Table S3 and Table S4). Compared with the AKD stage 0 group, all other AKD stages were associated with a higher risk of in-hospital mortality in both the lower baseline eGFR group and the higher baseline eGFR group (Table S3 and Table S4). 

Severe AKD is associated with an increased risk of prolonged dialysis. 

Persistent kidney function impairment can cause irreversible kidney damage and long-term dialysis dependency among patients with lower baseline eGFR. Notably, in patients with lower baseline eGFR, hypertension, and diabetes were risk factors for chronic dialysis at the 1-year follow-up. However, old age and cerebrovascular disease were associated with a lower risk of prolonged dialysis. After adjustment, AKD stage 1–3 was noted to be associated with a higher risk of prolonged dialysis (OR 2.16, CI 1.45–3.23), in comparison with the AKD stage 0 group. However, not all AKD stages were noted to be risk factors, and only AKD stage 3 was significantly associated with prolonged dialysis (Table S3).

Table 1. Characteristics of AKI patients with different baseline eGFR classification and AKD status. *P<0.05. SD standard deviation, eGFR estimated glomerular filtration rate, AKI acute kidney injury, AKD acute kidney disease, COPD chronic obstructive pulmonary disease.