CYP7A1 and obesity due to melanocortin 4 receptor deficiency: However, distorted 4βOHC levels could be caused by changes both in production and elimination, and 4βOHC is further metabolized via CYP7A1 and CYP27A1.3 Reduced 4βOHC and elevated plasma 27OHC levels have been reported in an obese mouse model, which could indicate that obesity is associated with increased CYP27A1 activity and therefore increased elimination of 4βOHC.24 However, Ulvestad et al.