Role of stearoyl-CoA desaturases in obesity and the metabolic syndrome.

The prevalence of obesity and related metabolic disorders increases rapidly in western societies. A proper choice of foods may now prevent or delay many of the health consequences related to these disorders. In this respect, replacing dietary saturated fatty acids (SFAs) by cis-monounsaturated fatty acids (cis-MUFAs) has beneficial effects. In addition to diet-derived cis-MUFAs, the human body can also generate cis-MUFAsfrom SFAs through the action of stearoyl-CoA desaturases (SCDs). SCDs may play an adverse role in obesity and obesity-related insulin resistance. Here, we review the current knowledge on the molecular aspects and the role of SCD1 in obesity and the metabolic syndrome (MS). In mice, many studies have suggested a negative role for SCD1 in the development of obesity and insulin resistance. In humans, however, evidence is less convincing. If anything, increased, rather than decreased, levels of SCD1 mRNA levels are negatively associated with MS-related diseases such as insulin resistance. However, an unequivocal conclusion is currently not possible as the number of human studies is limited. Therefore, more human studies are needed at the molecular as well as at the physiological level to understand the true role of SCD1 during the development of obesity and the MS.