(P20-033-25) Postprandial Cardiometabolic Parameters in Older Adults With Normal-Weight Obesity

Objectives: Normal-weight obesity (NWO) – or those with a normal body mass index (BMI) yet high body fat percent – is linked to increased risk for cardiovascular disease (CVD). Though ~70% of older adults with a normal BMI are considered NWO, little is known about mechanisms driving CVD in this population. The purpose of this ongoing study is to determine whether older adults with NWO experience adverse changes in cardiometabolic parameters following high-fat meal consumption, which may be implicated in CVD risk.

Methods: Participants (N=25; 8 male/17 female) with a normal BMI (18.5-24.9 kg/m²) were grouped based on age and body fat percent (iDXA): (1) normal-weight lean young adults (NWL-Y; 18-35 years; body fat < 33% [female] or < 23% [male]; n=10), (2) normal-weight lean older adults (NWL-O; ≥60 years; body fat < 33% [female] or < 23% [male]; n=9), or (3) older adults with normal-weight obesity (NWO-O; ≥60 years; body fat ≥33% [female] or ≥23% [male]; n=6). All participants completed an abbreviated fat tolerance test, where a baseline blood sample was obtained, a high-fat meal consumed (75g fat;1102 kcal), and a blood sample collected again 4h later. Fasting and 4h postprandial lipids (i.e., triglycerides, HDL-C) and flow-mediated dilation (FMD) were assessed. Serum indicators of inflammation/endotoxin exposure will be assessed at a later date. Data were analyzed via one-way ANOVA.

Results: Despite similar BMIs (p=0.10), NWO-O had higher body fat percent and lower lean mass percent compared to both NWL-O and NWL-Y (p’s < 0.01). NWO-O had higher fasting triglycerides than NWL-Y, but all groups were below the standard clinical cutoff ( < 150mg/dL), on average (≤ 112mg/dL). However, NWO-O had higher 4h (mean±SD=260±40 mg/dL) and change in triglycerides from baseline than NWL-O and NWL-Y (p’s < 0.01), consistent with an adverse response. Fasting and 4h HDL-C were similar across groups, but HDL-C decreased in NWL-O relative to NWL-Y and NWO-O (p < 0.01). No differences were noted at this point in the study for pre/post high-fat meal FMD (p’s≥0.25).

Conclusions: Despite similar fasting triglycerides with other groups, NWO-O displayed evidence of postprandial dyslipidemia. When completed, this work may further our understanding of the cardiometabolic profile of older adults with NWO.

Funding Sources: Internal funding sources