Evaluate the collective function of references cited together in a given text segment.
Classify their combined role into one of the following categories: 'method', 'background', or 'result'.

Text:In addition, human Lpin1 polymorphisms have been associated with numerous metabolic traits including insulin and/or glucose levels (Suviolahti et al., 2006; Loos et al., 2007; Wiedmann et al., 2008), resting metabolic rate (Loos et al.
Category: