Abstract: SA-PO068

Complex Relationship Among Obesity, AKI, and Long-Term Mortality in Coronary Artery Bypass Grafting

Session Information

Category: Acute Kidney Injury

  • 003 AKI: Clinical and Translational

Authors

  • Moon, Hongran, Seoul National University College of Medicine, Seoul, Korea (the Republic of)
  • Lee, Yeonhee, Seoul National University College of Medicine, Seoul, Korea (the Republic of)
  • Kim, Sejoong, Seoul National University Bundang Hospital, Seongnam, GYEONGGI-DO, Korea (the Republic of)
  • Kim, Dong Ki, Seoul National University College of Medicine, Seoul, Korea (the Republic of)
  • Chin, Ho Jun, Seoul National University Bundang Hospital, Seongnam, GYEONGGI-DO, Korea (the Republic of)
  • Kim, Yon Su, Seoul National University College of Medicine, Seoul, Korea (the Republic of)
  • Na, Ki Young, Seoul National University Bundang Hospital, Seongnam, GYEONGGI-DO, Korea (the Republic of)
  • Han, Seung Seok, Seoul National University College of Medicine, Seoul, Korea (the Republic of)
Background

Obesity is an important health concern and related with several comorbidities and mortality. However, its relationship with acute kidney injury (AKI) and long-term mortality remains unresolved, particularly in Korean patients undergoing coronary artery bypass grafting (CABG).

Methods

A total of 3018 patients (aged ≥18 years) were retrospectively reviewed from two tertiary referral centers between 2004 and 2017. Obesity was defined using body mass index (BMI), according to the World Health Organization recommendation. The odds ratios (ORs) and hazard ratios (HRs) for post-surgical AKI and all-cause mortality were calculated after adjusting for multiple covariates. Patients were followed for 90 ± 40.9 months (maximum 13 years).

Results

The proportions of normal weight, underweight, overweight at risk, obese I, and obese II status were 31.7%, 2.4%, 27.8%, 35.1%, and 4.0%, respectively. Post-surgical AKI developed in 799 patients (26.5%). The obese group had a higher OR of AKI [1.72 (1.149-2.560)] than the normal weight group (P=0.008), whereas other groups with abnormal weight status did not confer the higher risk of AKI than the normal weight group. This result suggest that obesity was an indicator of the AKI risk in the CABG subset. However, the relationship trend with mortality was different from the above one. During the follow-up period, 787 patients (26.1%) died. The group with underweight status had a higher HR of mortality [2.69 (1.957-3.687)] than the normal weight group, whereas the groups with overweight at risk, obese I, and obese II status had lower HRs than the normal weight group, as follows: 0.59 (0.486-0.706) , 0.61 (0.512-0.720) and 0.62 (0.410-0.926), respectively. These results suggest that normal weight status did not guarantee the lowest mortality in the CABG subset.

Conclusion

Obesity is related with the high risk of AKI, but not with the high mortality in Korean patients undergoing CABG. Rather, the patients with overweight at risk, obese I status showed better survival rates than the patients with normal weight. These results should be monitored in clinical practice, based on the consideration for several confounding factors, such as inflammation and malnutrition.