Relationship Between Serum Homocysteine Level And Renal Function Injury In Male Physical Examination

Objective With the increasing studies on homocysteine(Hcy),more and more researchers have found that elevated serum Hcy levels are associated with renal function injury.Serum Hcy levels are 3 to 5 times higher than normal in the end-stage renal disease(ESRD)patients.Current studies on the relationship between Hcy levels and renal function injury have focused on patients with a primary disease that clearly causes kidney damage,such as hypertensive nephropathy and diabetic nephropathy.We questioned that whether elevated Hcy level also affect renal function in patients without a primary disease that clearly causes kidney damage.At present,there are few studies on these issues.To address this issue,we had studied the relationship between serum Hcy levels and renal function injury in elderly healthy men,and we found that high level of serum Hcy and elderly are risk factors for renal function injury that should not be ignored in elderly people.Then whether elevated Hcy level also affect renal function in middle-aged men without disease that clearly causes kidney damage? The aim of this study was to investigate the relationship between serum Hcy and renal function when excluding the effects of diseases and age.Methods We conducted a cross sectional study based on the data collected from medical center in 2014.1 to 2015.12 in Tianjin medical university general hospital.We selected 974 men aged 44 to 90 randomly with no smoking and alcohol history.Some of them were excluded,if they had history of hypertension,diabetes,cerebrovascular disease,hyperlipidemia,chronic kidney disease,taking antihypertensive,hypoglycemic,lipid-lowering drugs and drugs with renal toxicity recently.Finally total 752 subjects were enrolled in the study.We measured serum Hcy concentration with enzymatic method,and measured cystatin C(Cys C)concentration with latex immunoturbidimetric method.We calculated GFR with Hoek?s formula or Cockcroft-Gault(CG)formula.Subjects whose age were 44-64 were middle-aged group(403 cases),and whose age were 65-90 were elderly group(349 cases).The average GFR level and serum Hcy level were analyzed from these two groups.According to the chronic kidney disease stages from American kidney foundation,GFR less than 90 ml?(min·1.73m~2)is used as criterion for early renal function injury,and GFR less than 60 ml?(min·1.73m~2)is used as criterion for moderate renal function injury.If serum Hcy concentration was above 15?mol/L,we defined it as hyperhomocysteinemia(HHcy).All middle-aged men were divided into HHcy group(130 cases)and control group(273 cases).In middle-aged men we compared the serum Hcy concentration,age,height,weight,BMI,blood pressure,blood sugar,blood fat,uric acid,urea,creatinine,Cys C,GFR,and the prevalence of early renal function injury between these two groups.We analyzed the correlation between GFR and Hcy,blood pressure with Pearson correlation analysis..All middle-aged men were divided into four groups according to the serum Hcy level quarterback spacing.Risk factors for renal function injury were analyzed in Logistic regression analysis.Results In elderly group,the mean serum Hcy concentration was 15.66?mol/L.The prevalence of HHcy was 45.27%(158/349).The mean GFR was 67.83 ml ?(min·1.73m~2)and the prevalence of moderate renal function injury was 36.67%(128/349).In middle-aged group,the mean serum Hcy concentration was 14.30?mol/L.The prevalence of HHcy was 32.26%(130/403).The mean Cys C concentration was 0.79mg/L.The mean GFR was 99.99 ml?(min·1.73m~2),and the prevalence of early renal function injury was 24.07%(97/403).In middle-aged group,we found serum Hcy [(20.60±6.55)vs(11.30±2.16)?mol/L],creatinine [(85±11)vs(80±9)?mol/L)],Cys C [(0.83±0.13)vs(0.77±0.10)mg/L],the prevalence of early renal function injury(36.15% vs 18.31%)and the GFR levels [(94.96±15.00)vs(102.38±14.19)ml/(min·1.73m~2)] were significantly different between HHcy group and control group.In addition,there were non-significant differences in the levels of systolic blood pressure(P=0.070)and diastolic blood pressure(P=0.055)between two groups.Correlation analysis showed that glomerular filtration rate was negatively correlated with serum Hcy level(r=-0.247,P<0.001)and systolic blood pressure(r=-0.098,P=0.049),but not correlated with diastolic blood pressure(r=-0.078,P=0.118).Logistic analysis demonstrated that elevated serum homocysteine concentration enhanced the risk of early renal function injury obviously.Compared with the first group as reference,the odd ratio from the second to the forth group was 2.512(95%CI:1.076-5.863),5.456(95%CI:2.460-12.103),5.380(95%CI:2.419-11.966) respectively(P<0.05).One-Way ANOVA demonstrated that Hcy(F=269.556,P<0.001)and blood sugar(F=3.948,P=0.009)were risk factors for early renal function injury in middle-aged men.Backward stepwise regression method showed that Hcy(P<0.001)but not blood sugar(P=0.146)had a significant impact on the risk of early renal function injury.Conclusion In the research,we surveyed the serum Hcy concentration and kidney function in some men from 44 to 90 years in Tianjin cadre physical examination.We find the prevalence of HHcy as high as one-third among the middle-aged men and half among the elderly men.The prevalence of early renal function injury close to a quarter among the middle-aged group and fifty percent among the elderly group.In addiition,among the elderly men the prevalence of moderate renal function injury as high as one-third.Glomerular filtration rate was lower and prevalence of early renal function injury was higher in HHcy subjects compared with no-HHcy ones among the middle-aged men.With serum Hcy concentration increasing,glomerular filtration rate declined obviously and the risk of early renal function injury increased obviously.Therefore,We suggest that high level of serum Hcy concentration is a risk factor for renal function injury.