Lipid metabolism in the elderly

Abstract

Adiposity increases with age. The size of the adipose tissue mass is determined by the balance between the recruitment of lipid substrates (ie free fatty acids) from adipose tissue and their subsequent oxidation by respiring tissues. Thus, change in the liberation of free fatty acids from adipocytes, the capacity of respiring tissue to oxidize free fatty acids or a combination of both may contribute to the age-related increase in body fat. This review focuses on studies that have examined the effect of age on free fatty acid release and the capacity of respiring tissues to oxidize fat. In vitro studies have shown that hormonal and pharmacological stimulation of lipolysis diminished with age. Despite this cellular defect, however, in vivo studies suggest that fatty acids are recruited from adipose tissue in excess of the energy demands of the body in older individuals. The capacity of respiring tissues, in particular skeletal muscle, to oxidize fat declines with age. The age-related decrease in fat oxidation is related to a reduction in both the quantity and oxidative capacity of respiring tissue. Taken together, these results suggest that an age-related decrease in the capacity of respiring tissues to oxidize fat, rather than decreased free fatty acid release, is a more likely determinant of lipid imbalance and the age-related increase in adiposity. Interventions designed to increase the mass or oxidative capacity of respiring tissue, therefore, may be effective in counteracting the age-related reduction in fat oxidation. Descriptors: aging; lipid metabolism; free fatty acids; adipose tissue; fat-free mass

Factors influencing energy intake and body weight loss after gastric bypass

“…Of course, this does not exclude the possibility that insulin or leptin have different effects on energy intake according to age. It has been reported that, in normal body weight subjects, aging is associated with a lower lipolytic capacity (Toth & Tcherof, 2000), in particular after sympathetic stimulation (Blaak, 2000), and this could explain the increased adipose tissue deposition of older subjects. Furthermore, a blunted lipolytic activity has been described in obese, post-menopausal women submitted to hypocaloric diet (Nickals et al, 1997).…”

Nutrition, sirtuins and aging

“…In the most simplistic way it appears that reproductive function and insulin resistance, both of which are associated with accelerated aging, are also closely related to body fat mass and are both affected by hormones produced by adipocytes (Mora and Pessin, 2002). Moreover, free fatty acids released constantly into the circulation, especially from visceral WAT by its relative high number of β-adrenoceptors, induce insulin resistance when not oxidized immediately as is the case in the elderly (Toth and Tchernof, 2000;Möller and Kaufmann, 2005. Interestingly, human adipocytes show an increased expression of SIRT1 when they are incubated in serum from calorie-restricted rats, whereas both insulin and IGF-1 are to suppress SIRT1 up-regulation when added to the serum .…”

Overview of the physiological changes and optimal diet in the golden age generation over 50

“…Figure 1 shows the age-related changes in free fatty acid metabolism in older humans. Until now, few animal or human studies have shown that ageing affects the stimulation, release and activity of fat metabolism-relevant hormones with a serious negative impact on the rate of lipolysis, as well as whole body composition [38]. One reason for this occurrence might be the age-related reduced insulin release from pancreatic tissue.…”