APOB and obesity due to melanocortin 4 receptor deficiency: Meanwhile, the ApoB/ApoA1 ratio also had a strong causality with glucose metabolism indicators (like HbA1c, fasting insulin levels), obesity-related indicators (like BMI, waist-to-hip ratio), and behaviorally relevant indicators (such as smoking, sedentary behavior, (frequent) alcohol consumption, and coffee intake) (specific results are shown in Fig. 7).