Bin Zhu1,2, Wen-Hua Liu3, Dong-Rong Yu4,5, Yi Lin4,5, Qiang Li6, Meng-Li Tong4,5, Ya-Yu Li4,5, Ru-Chun Yang4,5, Yuan-Yuan Du4,5, Xuan-Li Tang4,5, Fei Jiang4,5, Dan Fei4, Xin-Yi Wei4, Fei-Fei Zhang4, Jia-Zhen Yin4,5, Wen-Rong Wang4,5, Xian-Fa Li4,5, Yue Sun4,5, Yong-Zhong Zhong4,5, Mei-Juan Zhang4,5, Xiao-Xia Cheng4,5, Cai-Feng Zhu4,5, Hong-Yu Chen4,5. 1. Department of Nephrology, Hangzhou Hospital of Chinese Medicine (Guangxing Hospital), Affiliated to Zhejiang University of Chinese Medicine, Hangzhou, China, zhubing@hotmail.com. 2. Key laboratory of Zhejiang Province, Hangzhou Hospital of Chinese Medicine (Guangxing Hospital), Affiliated to Zhejiang University of Chinese Medicine, Hangzhou, China, zhubing@hotmail.com. 3. Department of Nephrology, Qinghai Provincial People's Hospital, Xining, China. 4. Department of Nephrology, Hangzhou Hospital of Chinese Medicine (Guangxing Hospital), Affiliated to Zhejiang University of Chinese Medicine, Hangzhou, China. 5. Key laboratory of Zhejiang Province, Hangzhou Hospital of Chinese Medicine (Guangxing Hospital), Affiliated to Zhejiang University of Chinese Medicine, Hangzhou, China. 6. Department of Statistics, the George Institute for Global Health, University of New South Wales, Sydney, New South Wales, Australia.
Abstract
AIM: To investigate the relationship between hemoglobin levels and the progression of IgA nephropathy (IgAN). METHODS: In a two-center cohort of 1,828 cases with biopsy-proven IgAN, we examined the association of hemoglobin levels with the primary outcome of a composite of all-cause mortality or kidney failure defined as a 40% decline in eGFR, or ESKD (defined as eGFR <15 mL/min/1.73 m2 or need for kidney replacement therapy including hemodialysis, peritoneal dialysis, or kidney transplantation), or the outcome of kidney failure, assessed using Cox and logistic regression models, respectively, with adjustment for confounders. RESULTS: At baseline, mean age, eGFR, and hemoglobin levels were 33.75 ± 11.03 years, 99.70 ± 30.40 mL/min/1.73 m2, and 123.47 ± 18.36 g/L, respectively. During a median of approximately 7-year follow-up, 183 cases reached the composite outcome. After adjustment for demographic and IgAN-specific covariates and treatments, a lower quartile of hemoglobin was nonlinearly associated with an increased risk of the primary outcome or kidney failure in the Cox proportional hazards models (primary outcome: HR for quartile 3 vs. 4, 1.37; 95% CI, 0.83-2.25; HR for quartile 2 vs. 4, 1.18; 95% CI, 0.68-2.07; HR for quartile 1 vs. 4, 1.91; 95% CI, 1.15-3.17; kidney failure: HR for quartile 3 vs. 4, 1.39; 95% CI, 0.84-2.31; HR for quartile 2 vs. 4, 1.20; 95% CI, 0.68-2.11; HR for quartile 1 vs. 4, 1.83; 95% CI, 1.09-3.07) in the fully adjusted model. Then, hemoglobin levels were transformed to a binary variable for fitting the model according to the criteria for anemia of 110 g/L in the women and 120 g/L in men in China. The participants in the anemia group had an increased risk of developing outcomes compared with the nonanemia group in both genders (primary outcome: male: HR, 1.64; 95% CI, 1.01-2.68; female: HR, 1.68; 95% CI, 1.02-2.76; kidney failure: male: HR, 1.60; 95% CI, 0.97-2.64; female: HR, 1.58; 95% CI, 0.95-2.61) in the fully adjusted model. CONCLUSIONS: A low level of hemoglobin was nonlinearly associated with IgAN progression. The anemic IgAN patients presented a higher risk of developing poor outcomes compared with the nonanemic patients.
AIM: To investigate the relationship between hemoglobin levels and the progression of IgAnephropathy (IgAN). METHODS: In a two-center cohort of 1,828 cases with biopsy-proven IgAN, we examined the association of hemoglobin levels with the primary outcome of a composite of all-cause mortality or kidney failure defined as a 40% decline in eGFR, or ESKD (defined as eGFR <15 mL/min/1.73 m2 or need for kidney replacement therapy including hemodialysis, peritoneal dialysis, or kidney transplantation), or the outcome of kidney failure, assessed using Cox and logistic regression models, respectively, with adjustment for confounders. RESULTS: At baseline, mean age, eGFR, and hemoglobin levels were 33.75 ± 11.03 years, 99.70 ± 30.40 mL/min/1.73 m2, and 123.47 ± 18.36 g/L, respectively. During a median of approximately 7-year follow-up, 183 cases reached the composite outcome. After adjustment for demographic and IgAN-specific covariates and treatments, a lower quartile of hemoglobin was nonlinearly associated with an increased risk of the primary outcome or kidney failure in the Cox proportional hazards models (primary outcome: HR for quartile 3 vs. 4, 1.37; 95% CI, 0.83-2.25; HR for quartile 2 vs. 4, 1.18; 95% CI, 0.68-2.07; HR for quartile 1 vs. 4, 1.91; 95% CI, 1.15-3.17; kidney failure: HR for quartile 3 vs. 4, 1.39; 95% CI, 0.84-2.31; HR for quartile 2 vs. 4, 1.20; 95% CI, 0.68-2.11; HR for quartile 1 vs. 4, 1.83; 95% CI, 1.09-3.07) in the fully adjusted model. Then, hemoglobin levels were transformed to a binary variable for fitting the model according to the criteria for anemia of 110 g/L in the women and 120 g/L in men in China. The participants in the anemia group had an increased risk of developing outcomes compared with the nonanemia group in both genders (primary outcome: male: HR, 1.64; 95% CI, 1.01-2.68; female: HR, 1.68; 95% CI, 1.02-2.76; kidney failure: male: HR, 1.60; 95% CI, 0.97-2.64; female: HR, 1.58; 95% CI, 0.95-2.61) in the fully adjusted model. CONCLUSIONS: A low level of hemoglobin was nonlinearly associated with IgAN progression. The anemic IgANpatients presented a higher risk of developing poor outcomes compared with the nonanemic patients.