GSTM1 and metabolic syndrome: In both genders, elderly participants with ALT levels in the second and third tertile were more likely to have central obesity, hyperglycemia, hypertension, hypertriglyceridemia and MetS (p < 0.05 for all comparisons) compared to those who were in first tertile after adjusting for age, sex, education, married status, current smoking, current drinking, physical activity, and diet habit, and similar associations were also found between Hb and MetS and its components.