Lipemia pós-prandial: influência do envelhecimento

Abstract

MethodsTriglyceride levels were measured in 3 conditions: after a 12-hour fast, and 2 and 6 hours after a standard meal containing 40 g of fat. Results The repeated-measures analysis of triglyceride levels showed a distinct behavior of the age groups throughout the 6 hours. The younger participants (GI) had a reduction in the triglyceride levels in the sixth hour; the elderly (GIII) had increasing values in the sixth hour; and those in the intermediate age group (GII)maintained their triglyceride levels, when comparing the second and sixth hours of blood collection. The differences in behavior were significant (P=0.01). ConclusionIn a healthy adult population sample, aging influences the postprandial lipemia behavior.

Postprandial lipemia in the elderly involves increased incorporation of ingested fat in plasma free fatty acids and small (Sf20–400) triglyceride-rich lipoproteins

“…Fasting plasma TG concentrations correlate with PPL (5) because chylomicrons compete with lipoproteins secreted by the liver for hydrolysis/clearance of their TG load by the enzyme lipoprotein lipase. Therefore, the observed increased PPL in the elderly in previous studies (4,5,9) can be explained, at least in part, by increased plasma TG concentrations in the fasting state. Furthermore, fat-free mass is a major determinant of energy expenditure, with skeletal muscle representing the tissue with the largest fractional removal of circulating TG (21) and being a major player in fat oxidation and the removal of ingested lipid (23).…”

“…The magnitude of postprandial lipemia (PPL) is positively associated with the risk of cardiovascular disease (19,20). It has been documented previously that the magnitude of PPL is increased with aging (4,5,9), a phenomenon that places elderly individuals at greater risk for cardiovascular disease compared with their young counterparts.…”

Clinical Considerations and Mechanistic Determinants of Postprandial Lipemia in Older Adults

“…In addition, a single report found lower plasma TG concentrations during the postprandial period in older individuals (18), a finding that may be skewed by the fact that the younger control group was composed of middle-aged individuals rather than young participants. The overwhelming amount of evidence, however, clearly demonstrates that PPL is greater in older individuals (8)(9)(10)(11)(12)(13)20). The response of plasma TGs during the postprandial period in older individuals is characterized by a higher peak (observed typically 3-4 h after ingesting high-fat meal) and a more prolonged presence of these TGs in plasma compared with that in young individuals (8,10).…”

“…Glucose intolerance with aging (21) can also confound the interpretation of postprandial TG responses in older individuals. Furthermore, because increased basal (i.e., fasting state) plasma TG concentrations can increase the magnitude of PPL (24), increased fasting plasma TG concentrations, a typical observation in older individuals, may by itself contribute to the increased PPL in some of these individuals (10). However, and because when older individuals have basal plasma TG concentrations comparable to those of young controls, they still demonstrate increased PPL (20), there are factors beyond the increase in fasting plasma TG concentrations that mediate the increase in PPL in older adults.…”

“…It has been known for some time that older individuals have exaggerated PPL compared with young controls (8)(9)(10)(11)(12)(13). This increase in PPL as individuals age may explain the increased incidence of CVD observed in the older segment of the population (1,14).…”