A missense mutation in the β3AR gene was associated with hypertension (Tonolo et al., 1999; Ringel et al., 2000; Hao et al., 2004) and other features of the metabolic syndrome such as insulin resistance and in some populations, overweight/obesity and dyslipidemia (Widen et al., 1995; Arner and Hoffstedt, 1999; Thomas et al., 2000). This evidence concerns the gene ADRB3 and metabolic syndrome.