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 view of the results in rats and humans showing the FFA dependency of GSIS in the prolonged fasting state (18, 19, 42, 43) plus the very low fasting FFA levels caused by glucoseinduced hyperinsulinemia in the control group in Boden’s study, it is possible that this condition favored a maintenance of the difference between their heparinIntralipid study vs.
Category: