Determinants of Postprandial Triglycerides Across the Spectrum of Aging

Abstract Objectives Elevated postprandial triglycerides (TG) are a risk factor for cardiovascular disease, and older adults exhibit greater postprandial lipemia (PPL) compared to younger adults. However, determinants of PPL, especially in older populations, remain poorly defined. This cross-sectional study examined the influence of body composition, lifestyle behaviors, and metabolic risk factors for PPL across the aging spectrum. Methods We recruited individuals evenly distributed between the ages of 50–89 years (50% male; 50% female). Participants completed diet and physical activity questionnaires and wore an accelerometer for 5 days. Body composition was measured via bioelectrical impedance. Following an overnight fast, participants also completed an abbreviated fat tolerance test: a blood draw was performed before and 4 hours after consumption of a high-fat meal (9 kcal/kg; 73% fat) to determine fasting and peak postprandial metabolic responses. Results 56 participants (age groups: 50s, n = 15; 60s, n = 15; 70s, n = 15; 80s, n = 11) completed the study. Fasting TG did not differ across age groups (50s: 99.7 ± 50.1 mg/dL; 60s: 114.3 ± 71.1 mg/dL; 70s: 102.9 ± 45.0 mg/dL; 80s: 86.9 ± 39.5 mg/dL; P = 0.63). There was also no difference in 4-hour TG across age groups (50s: 162.9 ± 76.9 mg/dL; 60s: 181.9 ± 99.9 mg/dL; 70s: 130.8 ± 82.0 mg/dL; 80s: 130.8 ± 60.6 mg/dL; P = 0.40). Across age groups, variables significantly correlated (p's < 0.05) with 4-hour TG included BMI (r = 0.29), visceral adiposity (r = 0.31), ALT (r = 0.37), fasting glucose (r = 0.27), 4-hour glucose (r = 0.34) and alcohol intake (r = 0.33). In a backward elimination regression (R2 = 0.31), the most predictive variables of 4-hour TG were 4-hour glucose (β = 0.31; P = 0.01), ALT (β = 0.33; P = 0.007), and alcohol intake (β = 0.25; P = 0.04). Conclusions In older adults aged 50–89, we identified ALT, postprandial glucose, and alcohol intake as key determinants of postprandial TG. Future studies should aim to explore the relationship between liver health, insulin resistance, alcohol intake, and PPL across the aging spectrum. Funding Sources Donna Cadwalader Research and Development Grant, College of Education and Human Sciences and Oklahoma State University Foundation.