Although abdominal obesity plays a fundamental role in the onset of immune and inflammatory reactions leading to cardiac abnormalities and premature mortality, the potential association between periumbilical fat and longevity mediated by the antibody-complement system and/or cardiac structure and function remains unclear. To address this issue, we collected biochemical and morphological data from 419 centenarians and 491 non-centenarian oldest-old individuals from the China Hainan Centenarian Cohort Study. Centenarians had lower waist circumference (WC), periumbilical fat thickness (PFT), serum complement C3 level, right atrium end-systolic diameter (RAESD), left atrium end-systolic diameter (LAESD), and left ventricular end-diastolic diameter (LVEDD) than non-centenarians (P<0.05 for all comparisons). WC, PFT, complement C3 levels, RAESD, LAESD, and LVEDD were inversely associated with centenarians (P<0.05 for all variables). Complement C3 level, LAESD, and LVEDD were positively associated with PFT and WC (P<0.05 for all variables). RAESD was positively associated with WC and complement C3 level (P<0.05 for both variables). Centenarians had less periumbilical fat, a weaker complement system, and smaller cardiac structure than non-centenarians. Importantly, periumbilical fat was inversely associated with longevity mediated by complement C3 and cardiac structure. This study suggests that successful aging can be promoted by increased efforts to prevent abdominal obesity.
Keywords: abdominal obesity; cardiac structure; complement C3; longevity; periumbilical fat.