The expression levels of serum ALB (31.91 ± 7.52 vs. 35.73 ± 5.72), PA (31.52 ± 9.05 vs. 36.44 ± 6.58) and Hb (91.20 ± 23.90 vs. 98.17 ± 27.69) in the malnutrition group were significantly lower than those in the normal group, and the difference was statistically significant (P < 0.05). Here, GSTM1 is linked to malnutrition.