Abstract: SA-PO1116
Fatty Kidney: A Meaningful Diagnosis?
Session Information
- CKD Epidemiology, Risk Factors, Prevention - III
November 04, 2023 | Location: Exhibit Hall, Pennsylvania Convention Center
Abstract Time: 10:00 AM - 12:00 PM
Category: CKD (Non-Dialysis)
- 2301 CKD (Non-Dialysis): Epidemiology, Risk Factors, and Prevention
Authors
- Guntupalli, Sri Vibhavari, Emory University School of Medicine, Atlanta, Georgia, United States
- O'Neill, W. Charles, Emory University School of Medicine, Atlanta, Georgia, United States
Background
Fatty kidney has been proposed as a detrimental metabolic condition akin to fatty liver, related to obesity and metabolic syndrome. It has primarily been recognized as an increase in fat within the renal sinus which purportedly exacerbates hypertension and CKD. Whether this condition truly exists and can be diagnosed based on the amount of sinus fat remains unclear because the parameters that normally determine the amount of sinus fat are unknown. This was explored retrospectively in patients who underwent renal sonography in an outpatient nephrology clinic.
Methods
137 sonograms performed in an outpatient nephrology clinic over a 5 month period were reviewed. Kidneys with cysts or hydronephrosis or that were inadequately visualized were excluded Both kidneys were excluded in 49 studies and one kidney was excluded in 20. Total kidney and sinus fat volumes were estimated by measuring areas on longitudinal images using Image J software. Data are presented as means, standard errors, and ranges.
Results
Patient age was 59 ± 2 (39-89), weight 84 ± 2.3 kg (37-142), height 67 ± 0.5 in (59-76), eGFR 46 ± 2 ml/min/1.73 m2 (5-70), and body mass index (BMI) 29 ± 0.7 kg/m2 (12-45). Diabetes was present in 44%, and 77% had hypertension. Sinus fat area per kidney was 13 ± 0.6 cm2 (4-34), kidney area was 40 ± 1.1 cm2, and ratio of sinus fat to total kidney area was 0.33 ± 0.01 (0.10-0.53). Sinus fat was strongly correlated with total kidney area (r=0.86), weakly with age (r=0.22), height (r=0.40), weight (r=0.44), BMI (r=0.29), serum triglycerides (r=0.24, and high density lipoprotein (r=0.33), but not with diabetes (p=0.30), hypertension (p=0.77), fasting blood sugar (r=0.14), hemoglobin A1C (r=0.12) or eGFR (r=0.07). After normalization to kidney size to provide a measure of excess sinus fat, only age remained as a significant determinant (r=0.45). In a multivariate model including age, diabetes, triglycerides, HDL, and BMI, only age was a significant determinant (p=0.003).
Conclusion
In this cohort comprising mostly patients with CKD, the amount of sinus fat was determined almost entirely by kidney size and did not correlate with the degree of CKD or with any metabolic parameters after adjustment for kidney size. Correlations with sinus fat volume previously reported are likely explained by the renal enlargement that occurs with obesity or hyperglycemia.
Funding
- Clinical Revenue Support