Mouse F2 cross study dissects genetic architecture of the obesity paradox in carotid atherosclerosis

A preprint from bioRxiv describes a quantitative genetic study examining the so-called obesity paradox — the counterintuitive observation that overweight or obese individuals sometimes show lower mortality or better outcomes than leaner individuals with certain cardiovascular conditions.

Using an F2 intercross of 299 mice derived from BALB/cJ and LP/J strains on an Apoe knockout (Apoe−/−) background, and fed a Western diet for 12 weeks, the investigators measured carotid atherosclerotic lesion size alongside body weight. The study applied quantitative trait locus (QTL) mapping to identify genomic regions associated with both traits and to characterise the phenotypic and genetic relationships between them.

The experimental design — using an inbred mouse cross to isolate genetic contributors in a controlled dietary context — allows the authors to move beyond epidemiological correlation and begin to interrogate the underlying genetic architecture. The Apoe−/− model is well established in atherosclerosis research as a way of accelerating plaque formation under high-fat feeding.

The work is primarily of interest to researchers in cardiovascular genetics, mouse genetics, and quantitative genetics. Body weight in this context is described as a surrogate for adiposity in the mouse model. This preprint has not yet been peer-reviewed, and findings in mouse models do not translate directly to human biology.