Differences Between Kidney Functions And Effects Of Serum ET-1and NO On Them In Early-and Late-onset Severe Preeclampsia

Objectives: According to the criteria of comprehensive crowd, HNP women and NP womenrespectively, our study aimed to evaluate the values of the four markers—serum BUN, UA andCREA and proteinuria in kidney functions of severe preeclampsia (SPE) patients, and toexplore the differences of kidney functions between early-and late-onset SPE (EOSPE andLOSPE), and to investigate the effects of the serum levels of endothelin-1(ET-1) and nitricoxide (NO) on the kidney functions.Materials and Methods: Serum samples were collected for serum BUN, UA and CREAlevels by whole—automatic biochemistry analysis instrument, urine samples were collected forproteinuria by whole—automatic urine analysis instrument, from SPE patients (n=193), includingEOSPE cases (n=100) and LOSPE cases (n=93), NP women (n=201, including101cases ofEOSPE control—EOSPE-C women with matched gestational age and100cases of LOSPE control—LOSPE-C women with matched gestational age) and HNP women (n=110) in the Obstetrics ofthe Jilin University Bethune Second Hospital from January2011to March2013. The serumsamples from EOSPE (n=18), LOSPE (n=16), EOSPE-C (n=17), LOSPE-C (n=16), and HNP(n=16) were detected for serum ET-1levels using enzyme-linked immunosorbent assay (ELISA)and for serum NO level via spectrophotography. SPSS17.0software was used for the statisticalanalysis of date.Results:1. Serum BUN levels in NP women were lower than HNP women (P<0.001). The serum levels ofBUN, UA and CREA in SPE were higher than NP respectively (P<0.001). In SPE, the prevalenceof proteinuria3+was higher than proteinuria <3+. The serum levels of BUN, UA and CREA withproteinuria3+were higher than those with proteinuria <3+in SPE. According to the criteria ofreference range upper limits of serum BUN, UA and CREA levels in comprehensive crowd,> the95centile values of serum BUN, UA and CREA levels in HNP women and NP womenrespectively, the incidences of increased serum BUN, UA and CREA levels in SPE were higher incomparison to HNP and NP(P<0.001). The reference range upper limits of serum BUN, UA andCREA levels in comprehensive crowd were higher (P<0.001) compared with> the95centilevalues of serum BUN, UA and CREA levels in HNP women.2. The serum levels of BUN, UA and CREA in EOSPE and LOSPE were higher than EOSPE-Cand LOSPE-C respectively (P<0.001). Serum BUN and CREA levels in EOSPE were higher thanthose in LOSPE respectively (P<0.001), while no statistical difference was observed in serum CREA levels between EOSPE and LOSPE. The prevalence (90.0%) of proteinuria3+in EOSPEwas higher (P<0.001) than that (66.7%) of proteinuria3+in LOSPE, and no case of proteinuria1+was noted in EOSPE. According to the criteria of reference range upper limits of serum BUN, UAand CREA levels in comprehensive crowd,> the95centile values of serum BUN, UA and CREAlevels in HNP women and NP women respectively, the incidences of increased serum BUN levelswere significantly higher (P<0.001), and the incidences of increased serum CREA levels werestatistically higher (P<0.05) in EOSPE as compared with LOSPE, but the incidences of increasedserum UA levels between EOSPE and LOSPE were found to be similar (P>0.05).3. The serum levels of BUN, UA and CREA were positively correlated (r=0.307, P<0.001;r=0.394, P<0.001; r=0.349, P<0.001) with gestational ages in NP women. The serum levelsof BUN and CREA were but negatively correlated (r=-0.353, P<0.001; r=-0.233, P<0.01)with gestational ages in SPE women.4. There were statistically positive correlations (r=0.236, P<0.05; r=0.279, P<0.001) of serum UAlevels with hematocrit (HCT) in HNP and NP women. There almost were statistically positivecorrelations (r=0.159, P=0.097; r=0.130, P=0.065) of serum CREA levels with HCT in HNP andNP women. There almost was a positive correlation (r=0.120, P=0.096; r=0.172, P=0.099) ofserum UA levels with HCT in SPE and LOSPE patients respectively.5. According to the criteria of> the95centile values of serum BUN and UA levels in HNPwomen, the serum NO and ET-1levels in SPE patients with increased serum BUN and UA levelswere lower than the other SPE patients without increased serum BUN and UA levels. Of them,there was a statistical difference in serum ET-1levels between the SPE patients.6. The serum NO levels and NO/ET-1in LOSPE patients with proteinuria3+were lower than theother LOSPE patients with proteinuria <3+(P<0.05).Conclusions:1．The95centile values of serum BUN, UA and CREA levels in HNP women are more objectivemarkers for evaluating the changes of kidney functions during pregnancy as compared withreference range upper limits of serum BUN, UA and CREA levels in comprehensive crowd. The95centile values of serum BUN, UA and CREA levels in NP women are more objective criteriafor assessing the pathological changes of kidney constructions and functions in SPE women ascompared with reference range upper limits of serum BUN, UA and CREA levels incomprehensive crowd.2. Increased serum BUN and CREA levels may be considered as the markers of severe kidneydamage and kidney dysfunction. Proteinuria levels might be sensitive markers of the damage ofkidney constructions and functions. Only increased serum UA level may not be regarded as themarker for evaluating kidney function.3. The effects of gestational ages on kidney functions in NP women may be associated with HCTchanges and the development of fetus and placenta. The influence of gestational ages on kidneyfunctions in SPE may be associated with HCT changes and the onset time involved placenta.4. The damage of kidney constructions and functions is more severe in EOSPE than in LOSPE.5. Decreased serum NO levels and NO/ET-1are related to kidney dysfunctions in LOSPE,while increased serum NO levels are conducive to inhibit the noxious roles of ET-1forvascular and kidney tissues in LOSPE. 6. Increased levels of proteinuria and serum BUN and UA in SPE without increasedserum ET-1levels may be involved in the mechanisms of kidney paracrine andautocrine ET-1.