Objective:To investigate the correlation between serum growth differentiation factor 15 (GDF15) and the clinicopathological characteristics of patients with IgA nephropathy (IgAN), and further explore the relationship of GDF15 with the cardiac and renal prognosis of IgAN patients.Methods:It was a single-center retrospective cohort study. From January 2018 to December 2022, the relevant data were collected from patients who were diagnosed with primary IgAN at the Department of Nephrology, Beijing Anzhen Hospital Affiliated to Capital Medical University, and regularly followed up for at least 1 year. Serum samples were collected at admission and the baseline level of serum GDF15 was measured. Based on the median GDF15 level, IgAN patients were categorized into high-level GDF15 group and low-level GDF15 group, and their clinicopathological characteristics were compared. A multiple linear regression model was then constructed to identify independent factors associated with serum GDF15 level based on these comparisons. Subsequently, Kaplan-Meier survival analysis was performed to investigate the association between serum GDF15 level and the cardiorenal prognosis of IgAN patients.Results:A total of 104 IgAN patients were included in this study. The serum GDF15 level in these IgAN patients was 825.60 (556.84, 1 428.15) ng/L. Serum GDF15 level was positively correlated with 24 h urinary protein ( r=0.405, P<0.001), negatively correlated with estimated glomerular filtration rate (eGFR)( r=-0.606, P<0.001). The serum levels of GDF15 in patients with tubular atrophy or interstitial fibrosis (overall comparison among T0, T1, and T2, H=21.866, P<0.001), crescentic lesions (overall comparison among C0, C1, and C2, H=13.787, P=0.001), or intrarenal arteriolar lesions (overall comparison among none, mild, and moderate-to-severe, H=9.856, P=0.007) were significantly different. Compared with IgAN patients without tubular atrophy or interstitial fibrosis, those with Oxford classification T1 ( Z=-17.326, P=0.042) or T2 ( Z=-42.933, P<0.001) had higher serum GDF15 levels. Compared with IgAN patients without crescentic lesions, those with Oxford classification C2 had higher serum GDF15 levels ( Z=-45.929, P=0.001). Compared with IgAN patients without intrarenal arteriolar lesions, those with moderate-to-severe arteriolar sclerosis had higher serum GDF15 levels ( Z=-26.686, P=0.005). The median GDF15 was used as the cut-off value to divide IgAN patients into a high-level GDF15 group (≥825.60 ng/L, n=52) and a low-level GDF15 group (<825.60 ng/L, n=52). Compared to low-level GDF15 group, IgAN patients in high-level GDF15 group presented with a higher proportion of diabetes mellitus ( χ 2=9.420, P=0.002) and cardiovascular disease ( χ 2=7.792, P=0.005), a higher level of systolic blood pressure ( Z=-2.266, P=0.023), body mass index ( Z=-2.183, P=0.031), 24 h urinary protein ( Z=-3.485, P<0.001), blood total cholesterol ( Z=-2.002, P=0.045) and left ventricular mass index ( Z=-2.649, P=0.008), and a lower level of blood albumin ( Z=-3.053, P=0.002) and eGFR ( Z=6.480, P<0.001). Multiple linear regression analysis showed that serum GDF15 level was independently associated with systolic blood pressure (regression coefficient B=29.453, 95% CI 14.139–44.767, P<0.001), blood albumin ( B=-81.412, 95% CI -113.084–-49.740, P<0.001) and eGFR ( B=-9.797, 95% CI -17.554–-2.040, P=0.014). Moreover, IgAN patients in high-level GDF15 group exhibited significantly poorer cardiac and renal prognosis compared to low-level GDF15 group ( χ 2=9.955, P=0.002). Conclusion:High serum GDF15 level correlates with disease severity in IgAN, and high serum GDF15 level may suggest a poorer cardiorenal prognosis in IgAN patients.

Objective:To investigate the correlation between serum growth differentiation factor 15 (GDF15) and the clinicopathological characteristics of patients with IgA nephropathy (IgAN), and further explore the relationship of GDF15 with the cardiac and renal prognosis of IgAN patients.Methods:It was a single-center retrospective cohort study. From January 2018 to December 2022, the relevant data were collected from patients who were diagnosed with primary IgAN at the Department of Nephrology, Beijing Anzhen Hospital Affiliated to Capital Medical University, and regularly followed up for at least 1 year. Serum samples were collected at admission and the baseline level of serum GDF15 was measured. Based on the median GDF15 level, IgAN patients were categorized into high-level GDF15 group and low-level GDF15 group, and their clinicopathological characteristics were compared. A multiple linear regression model was then constructed to identify independent factors associated with serum GDF15 level based on these comparisons. Subsequently, Kaplan-Meier survival analysis was performed to investigate the association between serum GDF15 level and the cardiorenal prognosis of IgAN patients.Results:A total of 104 IgAN patients were included in this study. The serum GDF15 level in these IgAN patients was 825.60 (556.84, 1 428.15) ng/L. Serum GDF15 level was positively correlated with 24 h urinary protein ( r=0.405, P<0.001), negatively correlated with estimated glomerular filtration rate (eGFR)( r=-0.606, P<0.001). The serum levels of GDF15 in patients with tubular atrophy or interstitial fibrosis (overall comparison among T0, T1, and T2, H=21.866, P<0.001), crescentic lesions (overall comparison among C0, C1, and C2, H=13.787, P=0.001), or intrarenal arteriolar lesions (overall comparison among none, mild, and moderate-to-severe, H=9.856, P=0.007) were significantly different. Compared with IgAN patients without tubular atrophy or interstitial fibrosis, those with Oxford classification T1 ( Z=-17.326, P=0.042) or T2 ( Z=-42.933, P<0.001) had higher serum GDF15 levels. Compared with IgAN patients without crescentic lesions, those with Oxford classification C2 had higher serum GDF15 levels ( Z=-45.929, P=0.001). Compared with IgAN patients without intrarenal arteriolar lesions, those with moderate-to-severe arteriolar sclerosis had higher serum GDF15 levels ( Z=-26.686, P=0.005). The median GDF15 was used as the cut-off value to divide IgAN patients into a high-level GDF15 group (≥825.60 ng/L, n=52) and a low-level GDF15 group (<825.60 ng/L, n=52). Compared to low-level GDF15 group, IgAN patients in high-level GDF15 group presented with a higher proportion of diabetes mellitus ( χ 2=9.420, P=0.002) and cardiovascular disease ( χ 2=7.792, P=0.005), a higher level of systolic blood pressure ( Z=-2.266, P=0.023), body mass index ( Z=-2.183, P=0.031), 24 h urinary protein ( Z=-3.485, P<0.001), blood total cholesterol ( Z=-2.002, P=0.045) and left ventricular mass index ( Z=-2.649, P=0.008), and a lower level of blood albumin ( Z=-3.053, P=0.002) and eGFR ( Z=6.480, P<0.001). Multiple linear regression analysis showed that serum GDF15 level was independently associated with systolic blood pressure (regression coefficient B=29.453, 95% CI 14.139–44.767, P<0.001), blood albumin ( B=-81.412, 95% CI -113.084–-49.740, P<0.001) and eGFR ( B=-9.797, 95% CI -17.554–-2.040, P=0.014). Moreover, IgAN patients in high-level GDF15 group exhibited significantly poorer cardiac and renal prognosis compared to low-level GDF15 group ( χ 2=9.955, P=0.002). Conclusion:High serum GDF15 level correlates with disease severity in IgAN, and high serum GDF15 level may suggest a poorer cardiorenal prognosis in IgAN patients.