Impact Of Moderate-to-vigorous Physical Activity And Visceral Adiposity On Postprandial Triglycerides In Metabolically At-risk Adults

Abstract

Postprandial lipemia occurs early in chronic disease progression. The degree of postprandial triglyceride (ppTG) is influenced by physiological and lifestyle factors such as diet, central obesity, and physical activity (PA). However, it is unclear how habitual dietary factors and PA impact ppTG in healthy adults with high central adiposity. PURPOSE: To examine the impact of habitual moderate-to-vigorous PA (MVPA), saturated fat (SF) in the habitual diet, and central adiposity on ppTG in metabolically at-risk adults. METHODS: Non-diabetic adults (n = 21) with a high waist circumference (> 35” women, >40” men) completed a high-fat meal challenge (50 g FAT, 54 g CHO, 12 g PRO), with blood collected at fasting and hourly after meal ingestion for 5 h. TG (mmol/L) was determined by lipid panels and summarized as iAUC and the change from fasting (TGmax). Habitual dietary data was collected through the online DHQ-III, with SF percentage (SF / total fat) used for analysis. Visceral adipose tissue (VAT) was determined through bioelectrical impedance analysis. Participants wore an accelerometer for 7 days (>10 h/day) and average number of MVPA bouts/day (≥ 2690 counts/min) was derived. Separate linear models for TG iAUC and TG magnitude were used to test the impact of an interaction between average MVPA bouts and VAT, accounting for habitual dietary SF. RESULTS: MVPA, VAT, and habitual dietary SF explain ~36% of variation in TG iAUC and TGmax. Average MVPA bouts and VAT jointly impacted TG iAUC (p < 0.01), with a ppTG-lowering effect observed with lower VAT and more frequent MVPA bouts and a pronounced ppTG-raising effect observed with greater VAT with frequent MVPA bouts (β = 1.1). Habitual SF did not predict TG iAUC (p = 0.68). Likewise, average MVPA bouts and VAT impacted TGmax (p = 0.03), with a TG-raising effect observed with greater VAT despite more MVPA bouts (β = 0.31). Interestingly, an inverse relationship was observed between habitual SF intake and TGmax (β = - 0.04, p = 0.02). CONCLUSION: Frequent MVPA promotes lower ppTG, a benefit that is reversed with increased VAT. These findings suggest that increased VAT promotes ppTG even with regular MVPA, stressing the importance of strategies to decrease VAT in improving regulation of postprandial lipemia in at-risk adults. Supported by USDA-ARS Pulse Crop Health Initiative 58-3060-9-040.