Association of high body mass index with development of interstitial fibrosis in patients with IgA nephropathy

Changwei Wu; Amanda Y Wang; Guisen Li; Li Wang

doi:10.1186/s12882-018-1164-2

Association of high body mass index with development of interstitial fibrosis in patients with IgA nephropathy

BMC Nephrol. 2018 Dec 29;19(1):381. doi: 10.1186/s12882-018-1164-2.

Authors

Changwei Wu¹, Amanda Y Wang^{2

3}, Guisen Li⁴, Li Wang¹

Affiliations

¹ Renal Department and Nephrology Institute, Sichuan Provincial People's Hospital, School of Medicine, University of Electronic Science and Technology of China, No. 32 West 2nd Duan, 1st Circle Road, Qingyang District, Chengdu, Sichuan, 610072, People's Republic of China.
² Renal and metabolic division, The George institute for global health, Sydney, Australia.
³ The Faculty of medicine and health sciences, Macquarie University, Sydney, Australia.
⁴ Renal Department and Nephrology Institute, Sichuan Provincial People's Hospital, School of Medicine, University of Electronic Science and Technology of China, No. 32 West 2nd Duan, 1st Circle Road, Qingyang District, Chengdu, Sichuan, 610072, People's Republic of China. guisenli@163.com.

Abstract

Background: The worldwide prevalence of obesity is increasing. Obesity is associated with a variety of chronic diseases, including chronic kidney disease. Several studies suggested that body mass index (BMI) could be an independent risk factor for progression of IgA nephropathy (IgAN). However, whether high BMI is associated with progression of IgAN remains uncertain.

Methods: This retrospective study included patients with biopsy proven IgAN from 2006 to 2017 in Sichuan Provincial People's Hospital. BMI was categorized according to the WHO Asian guideline: underweight (< 18.5 kg/m²), normal weight (18.5-25 kg/m²), overweight (25-28 kg/m²) and obese (≥28 kg/m²). The main outcome was development of end-stage renal disease (ESRD) or a decline in eGFR by at least 30%. The association of BMI and IgAN progression was determined by propensity-score-matched cohort analysis.

Results: Four hundred eighty one patients with IgAN were finally enrolled in this study. The mean age was 37 ± 11 years and 40.3% were men. There was no significant difference in clinical and pathological characteristics among the four-group patients categorized by BMI. After matching with propensity scores, no significant correlation between BMI and renal outcomes was seen. However, compared with the reference group (18.5≦BMI≦25 kg/m²), being overweight (odd ratio [OR], 2.28; 95%CI: 1.06-4.88; P = 0.034) and obese (OR, 3.43; 95%CI: 1.06-11.04; P = 0.039) was associated with a high risk of interstitial fibrosis. In the cross figure demonstrating the association of BMI subgroup and interstitial fibrosis on renal outcomes, ORs of interstitial fibrosis groups were higher than those of no interstitial fibrosis. Compared with other BMI subgroups, patients with 18.5-25 kg/m² had lowest ORs.

Conclusions: High BMI and interstitial fibrosis were associated with progression of IgAN. Interstitial fibrosis appears to be common in IgAN patients with elevated BMI.

Keywords: Body mass index; IgA nephropathy; Interstitial fibrosis; Overweight; Progression; Renal outcomes.

Publication types

Research Support, Non-U.S. Gov't

MeSH terms

Adolescent
Adult
Body Mass Index*
Disease Progression
Female
Fibrosis
Glomerular Filtration Rate
Glomerulonephritis, IGA / complications*
Glomerulonephritis, IGA / pathology*
Glomerulonephritis, IGA / physiopathology
Humans
Ideal Body Weight
Kidney / pathology*
Kidney Failure, Chronic / etiology
Male
Middle Aged
Obesity / complications*
Retrospective Studies
Thinness / complications*
Young Adult