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Modifying influence of dietary sugar in the relationship between cortisol and visceral adipose tissue in minority youth.
Gyllenhammer, LE, Weigensberg, MJ, Spruijt-Metz, D, Allayee, H, Goran, MI, Davis, JN
Obesity (Silver Spring, Md.). 2014;22(2):474-81
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Plain language summary
Visceral adipose tissue (VAT) is one of the strongest risk factors associated with obesity and related co-morbidities. A potential mechanism for this association involves cortisol and cortisol receptors, however the specific interaction of cortisol and diet upon fat deposition has not yet been explored in humans. The purpose of this cross-sectional study was to assess the impact of a high-fat, high-sugar diet on the association between stress and visceral fat in 165 overweight minority youth. The results of this study showed that cortisol was significantly associated with elevated VAT under conditions of high sugar intake in this population. Based on these findings, the authors conclude that dietary sugar may play a crucial role in moderating the adverse effects of cortisol.
Abstract
OBJECTIVE Cortisol has been associated with preferential visceral adipose tissue (VAT) deposition; however, findings in humans are mixed, which may be clarified when diet is considered. DESIGN AND METHODS Participants included 165 African-American and Latino, overweight adolescents (BMI% 97.2±3.2%, ages 13-18, 67% Latino, 66% female). Body composition was determined by dual energy X-ray absorptiometry, abdominal fat depots [VAT, subcutaneous (SAT)] by multiple-slice MRI, time-controlled serum sample to measure cortisol, and 2-day multi-pass 24-hour dietary recall. Linear regression analysis examined the cross-sectional relationship between cortisol, and the interaction of diet and cortisol on adiposity measures. Sex, race, age, and total body fat were a priori covariates. RESULTS There was a significant interaction between cortisol and sugar (total and added) in the prediction of VAT (P(interaction) ≤ 0.05). Amongst participants with high total or added-sugar intake, cortisol was significantly associated with VAT (ß = 0.031 P < 0.001; ß = 0.026 P < 0.001), with no relationship in low consumers of total or added-sugar. CONCLUSION Dietary sugar may play an important role in modifying the relationship between cortisol and VAT, such that cortisol is significantly associated with elevated VAT under conditions of high sugar intake.
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Long-chain n-3 PUFAs reduce adipose tissue and systemic inflammation in severely obese nondiabetic patients: a randomized controlled trial.
Itariu, BK, Zeyda, M, Hochbrugger, EE, Neuhofer, A, Prager, G, Schindler, K, Bohdjalian, A, Mascher, D, Vangala, S, Schranz, M, et al
The American journal of clinical nutrition. 2012;96(5):1137-49
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Adipose tissue inflammation is the basis of obesity-related systemic inflammation, which predisposes patients to the development of metabolic and cardiovascular disease. Previous studies show that long-chain omega-3 polyunsaturated fatty acids (n-3 PUFAs) reduce cardiovascular events and exert anti-inflammatory effects but their effects on human adipose tissue inflammation have so far been unknown. This randomized open-label controlled clinical trial evaluated the effect of an 8-week treatment with n-3 PUFAs eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) on adipose tissue and systemic inflammation and on metabolic control. Fifty-five severely obese non-diabetic patients, scheduled for bariatric surgery, were allocated to receive either n-3 PUFAs (n=27) or an equivalent amount of butterfat as control (n=28). Systemic inflammatory markers and metabolic variables were measured at baseline and at the end of the intervention before the participants underwent bariatric surgery. Adipose tissue samples were collected during surgery for the assessment of inflammatory gene expression and lipid mediator production. Treatment with n-3 PUFAs for 8 weeks favourably affected adipose tissue and systemic inflammation. In adipose tissue, the expression of most inflammatory genes was reduced and the concentrations of lipid mediators, responsible for the resolution of inflammation (resolving lipid mediators), were increased. Systemically, the results showed a shift to a more anti-inflammatory plasma fatty acid profile and a decrease in circulating triglyceride levels. The authors concluded that the observed beneficial effects of n-3 PUFAs may be useful in the long-term treatment of obesity.
Abstract
BACKGROUND Chronic adipose tissue inflammation is a hallmark of obesity, triggering the development of associated pathologies, particularly type 2 diabetes. Long-chain n-3 PUFAs reduce cardiovascular events and exert well-established antiinflammatory effects, but their effects on human adipose tissue inflammation are unknown. OBJECTIVE We investigated whether n-3 PUFAs reduce adipose tissue inflammation in severely obese nondiabetic patients. DESIGN We treated 55 severely obese nondiabetic patients, scheduled to undergo elective bariatric surgery, with 3.36 g long-chain n-3 PUFAs/d (EPA, DHA) or an equivalent amount of butterfat as control, for 8 wk, in a randomized open-label controlled clinical trial. The primary efficacy measure was inflammatory gene expression in visceral and subcutaneous adipose tissue samples (subcutaneous adipose tissue and visceral adipose tissue), collected during surgery after the intervention. Secondary efficacy variables were adipose tissue production of antiinflammatory n-3 PUFA-derived eicosanoids, plasma concentrations of inflammatory markers, metabolic control, and the effect of the Pro12Ala PPARG polymorphism on the treatment response. RESULTS Treatment with n-3 PUFAs, which was well tolerated, decreased the gene expression of most analyzed inflammatory genes in subcutaneous adipose tissue (P < 0.05) and increased production of antiinflammatory eicosanoids in visceral adipose tissue and subcutaneous adipose tissue (P < 0.05). In comparison with control subjects who received butterfat, circulating interleukin-6 and triglyceride concentrations decreased significantly in the n-3 PUFA group (P = 0.04 and P = 0.03, respectively). The Pro12Ala polymorphism affected the serum cholesterol response to n-3 PUFA treatment. CONCLUSIONS Treatment with long-chain n-3 PUFAs favorably modulated adipose tissue and systemic inflammation in severely obese nondiabetic patients and improved lipid metabolism. These effects may be beneficial in the long-term treatment of obesity. This trial was registered at clinicaltrials.gov as NCT00760760.