C4A and hypertensive disorder: The T ≥ 1 group was older, had a higher proportion of male and had hypertension, which was also characterized by a significantly lower level of serum albumin, eGFRcr-cys, serum IgG, and serum IgM, with a higher level of urinary protein excretion (UPE), serum creatinine, serum cystatin C, Hs-CRP and serum C4.