GSTM1 and obesity due to melanocortin 4 receptor deficiency: In addition, we performed a stratified analysis by BMI, alcohol use and smoking status of the association between GSTM1, GSTT1 variants and essential hypertension; The results showed that association between GSTT1-null and essential hypertension seems to be significant especially in alcohol users but independent of obesity and smoking even if some of the comparisons do not have enough samples.