Cys-C, as an ideal endogenous marker reflecting GFR, is an early sensitive indicator of impaired renal function in normal serum creatinine, and the impaired renal function itself is a risk factor for CHD.[24] Urinary albumin is an early sensitive indicator of renal insufficiency and is theoretically positively correlated with Cys-C,[25] which was also confirmed in this study. Here, ALB is linked to Renal insufficiency.