Does asthma affect Cystatin C ?? In one of my reports, the Cystatin C level was 1.32 ,and five days later ,in the Dr .Lal Path report ,it was 1.08. Creatinine was .74 and .83 respectively in that report. Protein was negative in all reports . So I had done UACR but that was less than 30 .I am an asthma patient . I have stone history in one kidney . But ultrasound is Okay . Is this a problem related to my kidneys or it is just asthma issue.