Clinical Study Of 25（OH）D₃ And Thyroid Hormone Levels In Patients With Idiopathic Membranous Nephropathy

Objective: To study the changes of serum 25（OH）D₃ and thyroid hormone levels in patients with idiopathic membranous nephropathy and its clinical significance.Methods: 175 patients with idiopathic membranous nephropathy were enrolled in this study.Clinical data such as serum 25（OH）D₃,thyroid hormone and urinary protein,albumin,renal function and blood lipids were collected.Analyzed the changes and characteristics of 25（OH）D₃ and thyroid hormone levels and their correlations with clinical indicators.Patients were grouped according to the levels of 24 h urinary protein,albumin,25（OH）D₃,TT₃ and glomerular filtration rate.Patients were divided into urinary protein ≥3.5g/d group and urinary protein <3.5g/d group,albumin <30g/L group and albumin ≥ 30g/L group,25（OH）D₃ <12nmol /L group and 25（OH）D₃> 12nmol/L group,TT₃<1.34nmol/L group and TT₃≥1.34 nmol/L group,eGFR≥90ml/min group and eGFR 60-89ml/min group.Comparison of clinical indicators between the groups was performed.The influencing factors of 24 h urinary protein,albumin,25（OH）D₃ and TT₃ were analyzed by multiple stepwise regression analysis.Result: 1.General information: The mean value of 24 h UP was 4.61±3.33g/d,the mean value of serum albumin was 25.25±6.82g/L,the mean value of eGFR was 92.48±18.21 ml/min,the mean value of serum 25（OH）D₃ was 13.62 [6.79,25.62] nmol/L,76 patients（45.5%）with 25（OH）D₃<12nmol/L,normal level in 1 case.The mean value of TT₃ was 1.47±0.37nmol/L,54 patients（30.9%）with T₃<1.34 nmol/L.The mean value of TT₄ was 88.27 ± 24.33 nmol / L,53 patients（30.28%）with TT₄<78.38 nmol / L.The mean value of FT₃ was 4.30 ± 0.64 pmol / L,19 patients（10.86%）with FT₃<3.60 pmol / L.The mean value of FT₄ was 9.99 ± 2.24 pmol / L,31 patients（17.7%）with FT₄<7.86 pmol / L.2.Analysis of relevance: 25（OH）D₃ was positively correlated with TT₃、TT₄、FT₃、FT₄、eGFR、total protein、albumin and IgG（r = 0.384、0.330、0.277、0.281、0.245、0.568、0.658、0.535,P <0.01）,was negative correlated with 24 h UP、blood phosphorus、TC and LDL-C（r =-0.310、-0.170、-0.467、-0.420,P <0.01）,and was not correlated with TSH,serum calcium,PTH,TG and HDL-C（P> 0.05）.TT₃ was positive correlated with 25（OH）D₃、eGFR、albumin and IgG（r=0.384、0.204、0.417、0.312,P<0.01）,was negative correlated with 24 h UP、fibrinogen、TC and LDL-C（r =-0.179、-0.345、-0.273、-0.275,P<0.05）,and was not correlated with TG and HDL-C（P>0.05）.FT₃ was positive correlated with 25（OH）D₃、eGFR and albumin（r=0.384、0.204、0.417、0.312,P<0.01）,was negative correlated with TC and LDL-C（r =-0.218、-0.195,P<0.05）,and was not correlated with 24 h UP、IgG、fibrinogen、TG and HDL-C（P>0.05）.TT₄ was positive correlated with 25（OH）D₃、albumin and IgG（r=0.330、0.356、0.303,P<0.01）,was negative correlated with FIB、TC and LDL-C（r =-0.230、-0.272、-0.264,P<0.01）,and was not correlated with eGFR、24h UP、TG and HDL-C（P>0.05）.FT₄ was positive correlated with 25（OH）D₃ and albumin（r=0.281、0.268,P<0.01）,was negative correlated with fibrinogen and LDL-C（r =-0.186、-0.172,P<0.05）,and was not correlated with eGFR、24h UP、IgG 、TG and HDL-C（P>0.05）.3.Comparison between groups: The levels of 25（OH）D₃、TT₃、total protein、albumin and IgG were lower and the levels of TC,LDL-C and fibrinogen were higher in the 24 h UP≥3.5g/d group than in the 24 h UP<3.5g /d group（P<0.05）.There was no significant difference in the levels of TT₄、FT₃、FT₄、TSH、 eGFR、HDL-C and LDL-C between the two groups（P>0.05）.The 25（OH）D₃、TT₃、TT₄、FT₃、eGFR and IgG levels were lower and 24 h UP、fibrinogen、TC、TG and LDL-C levels were higher in the albumin <30g/L group than in the albumin >30g/L group（P<0.05）.There was no significant difference of FT₄、TSH and HDL-C levels between the two groups（P>0.05）.The levels of TT₃、TT₄、FT₃、FT₄、eGFR、total protein、albumin and IgG were lower and the levels of 24 h UP、blood phosphorus、fibrinogen、TC、LDL-C were higher in the 25（OH）D₃<12nmol/L group than in the 25（OH）D₃≥12nmol/L group（P<0.05）.There was no significant difference of TSH、blood calcium、PTH、TG and HDL-C levels between the two groups（P>0.05）.The levels of 25（OH）D₃、total protein、albumin、IgG and eGFR were higher and the levels of fibrinogen、TC and LDL-C were lower in the TT₃<1.34nmol/L than in the TT₃≥1.34nmol/L group（P<0.05）.There was no significant difference in the levels of 24 h UP、TSH、TG and HDL-C between the two groups（P>0.05）.The levels of 25（OH）D₃、TT₃、total protein、albumin and IgG were lower and levels of fibrinogen、TC、LDL-C were higher in the eGFR 60-90ml/min group than in the eGFR≥90ml/min group（P<0.05）.There was no significant difference in the levels of TT₄、FT₃、FT₄、TSH、24h UP、serum calcium,phosphorus、PTH、TG and HDL-C between the two groups（P>0.05）.4.Multiple stepwise regression analysis: 25（OH）D₃ was the influencing factor of 24 h urinary protein in IMN patients（B=-0.054,P=0.007）.TT₃、FT₃、25（OH）D₃、24h urinary protein were the influencing factors of albumin in IMN patients（B=4.330、1.714、0.235、-0.367,P<0.05）;albumin was the influencing factor of 25（OH）D₃ in IMN patients（B=0.790,P=0.001）.TT₄、 albumin、eGFR were the influencing factors of TT₃ in IMN patients.25（OH）D₃ was the influencing factor of fibrinogen in IMN patients（B=0.008、0.015、0.003,P<0.05）.Conclutions:1.Reduced levels of serum vitamin D are prevalent in IMN patients.About 45% of patients with severe vitamin D deficiency.The level of serum 25（OH）D₃ in IMN patients was correlated with proteinuria,hypoproteinemia,abnormal lipid metabolism and decreased renal function.2.Lower thyroid hormone levels were seen in IMN patients.About 30% of IMN patients with T₃ levels decreased and about 30% of patients with T₄ levels decreased.Thyroid hormone levels in IMN patients were associated with decreased proteinuria,hypoproteinemia,abnormal lipid metabolism and decreased renal function.3.The level of 25（OH）D₃ in IMN patients was related to the level of thyroid hormone,they were involved in the pathophysiological process of IMN.