Objective:To study the association of serum thyroid stimulating hormone(TSH),free thyroxine(FT4)levels with blood pressure variability(BPV)and renal injury in elderly patients with hypertension.Methods:A total of 110 elderly patients with hypertension treated in Dongtai People's Hospital between February 2019 and January 2021 were retrospectively enrolled as hypertension group,while another 105 healthy subjects with corresponding baseline data undergo-ing physical examination simultaneously in our hospital were regarded as control group.Serum TSH and FT4 levels,BPV indexes[24h systolic blood pressure coefficient of variant(24hSCV),24h diastolic blood pressure coefficient of variant(24hDCV),daytime systolic blood pressure coefficient of variant(dSCV),daytime diastolic blood pressure coefficient of variant(dDCV),nighttime systolic blood pressure coefficient of variant(nSCV)and nighttime diastolic blood pressure co-efficient of variant(nDCV)]and renal injury indexes[urinary albumin/creatinine ratio(UACR),estimated glomerular filtration rate(eGFR)and β2-microglobulin(β2-MG)]were compared between two groups.Pearson method was used to analyze the association of TSH and FT4 levels with BPV and renal injury indexes;according to renal injury condition,hypertension group was divided into renal injury group(n=38)and normal group(n=72),then serum TSH and FT4 levels were compared between two groups.Results:Compared with control group,hypertension group showed a significant rise in TSH level,24hSCV,24hDCV,dSCV,dDCV,nSCV,nDCV,UACR and β2-MG levels,and significant reductions in FT4 level and eGFR(P<0.001 all).Pearson correlation analysis indicated that TSH level was positively correlated with all BPV indexes(r=0.457~0.621,P<0.001 all),while FT4 level was inversely correlated with all BPV indexes(r=-0.535~-0.402,P<0.001 all);TSH was positively correlated with UACR and β2-MG(r=0.594,0.644,P<0.001 both),and inversely correlated with eGFR(r=-0.420,P<0.001);FT4 level was inversely correlated with UACR andβ2-MG(r=-0.561,-0.622,P<0.001 both)and positively correlated with eGFR(r=0.409,P<0.001).Com-pared with those in normal group,patients in renal injury group had significant higher TSH level,and significant lower FT4 level(P<0.001 both).Conclusion:Serum TSH level significant rises,and FT4 level significantly decreases in elderly patients with hypertension.They have significant association with blood pressure variability and renal injury.