Abstract: PO1566
Obesity at Time of Diagnosis Is Associated with Proteinuria in Glomerular Disease
Session Information
- Glomerular Diseases: Clinical Features and Outcomes in Nephrotic Syndromes and Complement-Mediated Diseases
November 04, 2021 | Location: On-Demand, Virtual Only
Abstract Time: 10:00 AM - 12:00 PM
Category: Glomerular Diseases
- 1203 Glomerular Diseases: Clinical, Outcomes, and Trials
Authors
- Zeitler, Evan, UNC Kidney Center, Chapel Hill, North Carolina, United States
- Hu, Yichun, UNC Kidney Center, Chapel Hill, North Carolina, United States
- Poulton, Caroline J., UNC Kidney Center, Chapel Hill, North Carolina, United States
- Blazek, Lauren N., UNC Kidney Center, Chapel Hill, North Carolina, United States
- Mottl, Amy K., UNC Kidney Center, Chapel Hill, North Carolina, United States
- Flythe, Jennifer E., UNC Kidney Center, Chapel Hill, North Carolina, United States
- Hogan, Susan L., UNC Kidney Center, Chapel Hill, North Carolina, United States
Background
Obesity is an established risk factor for chronic kidney disease (CKD). The relationship between obesity and glomerular disease outcomes is not well studied.
Methods
We evaluated a cohort of adult patients with biopsy-proven IgA nephropathy, focal segmental glomerulosclerosis (FSGS), ANCA-associated vasculitis (ANCA), or membranous nephropathy (MN) between January 2014 and June 2020, with follow up through April 2021. We categorized body mass index (BMI) at time of biopsy as <25 kg/m2, 25 kg/m2≥BMI<30 kg/m2 or ≥30 kg/m2. We used Fisher's exact and Kruskal-Wallis tests to compare baseline characteristics between groups and a proportional hazards model to evaluate factors associated with CKD progression to kidney replacement therapy (KRT). We used the sign rank test to compare Kaplan-Meier curves of KRT-free survival.
Results
The cohort included 153 patients: 77 (50%) male with median age 50 (IQR 38-65) years and median BMI 28 (IQR 24-34) kg/m2. Compared to patients with lower BMIs, patients with BMI >25 kg/m2 had higher median urine protein to creatinine ratios (uPCR) (p=0.02, Table 1). In univariate analyses, factors associated with progression to KRT were: blood pressure (p = 0.01), uPCR (p <0.01), and lower eGFR (p<0.001). BMI at biopsy was not associated with CKD progression, adjusted HRs (95% CIs): BMI 25≥BMI<30 kg/m2 - 1.09 (0.42-2.83); BMI ≥30 kg/m2- 1.54 (0.68-3.52). Logrank p-value for KM curves was 0.004, with paired uPCR values imparting the greatest distinction between curves (data not shown).
Conclusion
Among glomerular disease patients, BMI was associated with proteinuria, but not with progression to KRT.
Baseline Characteristics Across BMI Groups
Baseline characteristic: median [IQR] or n (%) | All (N = 153) | BMI < 25 (n = 43) | BMI 25-30 (n = 42) | BMI ≥ 30 (n = 68) | p |
Age (years) | 50 (38, 65) | 50 (30, 72) | 54 (42, 62) | 49 (40, 62) | 0.95 |
Male | 77 (50) | 18 (42) | 27 (64) | 32 (47) | 0.10 |
Race (self-reported) Black White Other | - 39(26) 88(58 ) 24(15) (N = 151) | - 6 (14 ) 29 (69) 7 (16 ) | - 10 (23) 25(59) 7(16) (n = 41) | - 23(34) 34 (50) 10 (14) (n = 67) | 0.22 |
Primary disease ANCA FSGS IgAN Membranous | - 54(35) 36(23) 42(27) 21(13) | - 21 (48) 7 (16) 13 (30) 2 (4) | - 14 (33) 11 (26) 8 (19) 9 (21) | - 19 (27) 18 (26) 21 (30) 10 (14) | 0.10 |
Systolic BP (mmHg) | 134 (120, 145) (N = 152) | 131 (118, 142) | 130 (122, 145) | 138 (127, 149) (n = 67) | 0.14 |
Diastolic BP (mmHg) | 76.00 (70, 84) (N = 152) | 74.00 (68, 82) | 75.00 (70, 82) | 78.00 (72, 88) (n = 67) | 0.35 |
eGFR (ml/min/1.73m2) | 43 (19, 83) | 46 (20, 82) | 56 (21, 87) | 38 (18, 75) | 0.35 |
uPCR (g/g Cr) | 2.33 (1.0, 5.6) (N = 151) | 1.50 (0.6, 3.4) (n = 42) | 2.90 (1.1, 5.7) | 3.40 (1.3, 7.9) (n = 67) | 0.02 |
uPCR (g/g Cr) < 2 >= 2 | - 67 (44) 84 (56) (N = 151) | - 27 (65) 15 (35) (n = 42) | - 16 (38) 26 (62) | - 24(36) 43(64) (n = 67) | 0.01 |
KRT during follow up | 42 (27) | 11 (26) | 11 (26) | 20 (29) | 0.92 |
Death during follow up | 11 (7) | 4 (9) | 1 (2) | 6 (9) | 0.41 |
Funding
- NIDDK Support