Secondary data analysis investigating effects of marine omega-3 fatty acids on circulating levels of leptin and adiponectin in older adults

Abstract

Background: Higher leptin and lower adiponectin levels have been linked to progressing systemic inflammation and diseases of aging. Among older adults with obesity and an inflammatory conditions, we quantified effects of eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) supplementation on leptin, adiponectin, and the leptin-to-adiponectin ratio (LAR). We also examined associations among adipokine and cytokine levels. Methods: Using a randomized, double-blind, placebo-controlled design, participants (mean age 61.3 ± 2.1) received 1.5 g EPA + 1.0 g DHA (n = 14) or mineral oil (n = 18) daily. Plasma adipokine and cytokine levels were quantified by electrochemiluminescence at all study intervals. Results: While no between-group differences were detected, there was a reduction in the LAR (by 23%, p=.065) between weeks 4 and 8 among the EPA+DHA group. Adiponectin levels were negatively associated with IL-1β levels at week 4 (p=.02) and TNF-α levels at week 8 (p=.03). Conclusion: Potential benefits of EPA+DHA supplementation among aging populations warrant further study.

The Leptin-to-Adiponectin Ratio in Inflammation

“…Using LAR, instead of ALR, would allow for the natural association of values being indicative of a higher pro-inflammatory status. When the LAR is reported, it is often calculated by dividing leptin (ng/ml) by adiponectin (mcg/ml) [24,31]. We recommend continuing this practice in future studies.…”

“…Given that it is still unclear if all methods for quantifying leptin and adiponectin yield similar results, additional studies are needed to make this determination. Finally, various previous human studies have measured leptin and adiponectin in plasma/serum, saliva, hair, and/or urine [30,31,[64][65][66][67][68][69][70][71][72][73][74]. There may be methods that would allow the comparison of levels of leptin and adiponectin across sample types, but additional studies are needed to explore this possibility.…”

“…Leptin and adiponectin are hormones made and released by adipocytes in adipose tissue that current literature describes as being mediators of inflammation and influencers of chronic diseases [25][26][27][28][29]. Leptin and adiponectin can be detected in tissue samples [30] however, they are most frequently measured in blood samples for clinical studies [29,31]. The proinflammatory actions of leptin are varied and include 1) inducing monocytes and macrophages to synthesize eicosanoids, 2) triggering of natural killer cell cytotoxicity, 3) stimulating chemotaxis in neutrophils, 4) activating proinflammatory cytokine production in B cells, and 5) promoting Th1-cell immune responses (Th1 cells secrete tumor necrosis factor (TNF)-α, lymphotoxin, and interleukin (IL)-2) [19,[32][33][34][35].…”

Nutritional and lifestyle management of the aging journey: A narrative review

“…Polyunsaturated fatty acids, and especially n-3 PUFAS have since then been extensively researched and shown beneficial across different aspects of health. Marine n-3 PUFAs eicosapentanoic acid (EPA) and docosahexanoic acid (DHA) ( 177 , 178 ), found in the Mediterranean diet through an adequate intake of fish, have consistently shown an inverse relationship with plasma pro-inflammatory markers such as IL-6, CRP, and TNF-a and a positive association with anti-inflammatory markers such as IL-10 and TGF-b in young and older adults. Their mechanism of action is mainly through displacing arachidonic acid, the main substrate for the production of eicosanoids, thus reducing the production of pro-inflammatory cytokines ( 179 ).…”