GSTM1 and diabetes mellitus: A significant association was detected between S and serum Hcy per 1-μmol/L increase after adjustment for age, gender, education, smoking, body mass index (BMI), Mini Nutritional Assessment Short Form (MNA-SF), alanine aminotransferase (ALT), C-reactive protein (CRP), hemoglobin (Hb), albumin (ALB), diabetes, kidney disease, and statin use (OR = 1.07, 95% CI = 1.03–1.12, P = 0.002).