The purpose of this study was to investigate the effect of exercise training and diet-induced weight loss alone or in combination on inflammatory markers in circulation, in adipose tissue (AT) and in skeletal muscle (SM) in obese subjects. Seventy-nine obese subjects were randomized into a 12-wk intervention: 1) exercise only (EXO), 2) diet-induced weight loss using a very low energy diet (DIO), and 3) exercise and diet-induced weight-loss combined (DEX). Blood samples (metabolic and inflammatory markers) and AT and SM biopsies (mRNA expression) were collected at baseline and after 12 wk. In the EXO group the weight loss was 3.5 kg and in the DIO and DEX groups it was 12 kg in both. Vo(2max) was increased by 14-18% in the EXO and DEX groups with no changes in the DIO group. In the DIO and DEX groups, circulating levels of MCP-1, MIP-1alpha, IL-15, and IL-18 were decreased, and adiponectin was increased (P < 0.05 for all). In the EXO group, MCP-1 was decreased with 10% (P = 0.06). By combining the weight loss in all three groups, we found a correlation between the degree of weight loss and improvement in several of the inflammatory markers (P < 0.05). In AT biopsies, subjects in the DIO and DEX groups achieved a general beneficial but nonsignificant effect on the gene expression of inflammatory markers. In the EXO group, no changes in AT adipokine mRNA were found except for an increment of adiponectin (P < 0.05). In SM, the only observed change was that the gene expression of IL-6 was increased in all three groups (P < 0.05). In conclusion, rather large weight losses (>5-7%) were found to have beneficial effects on circulating inflammatory markers in these obese subjects. Aerobic exercise for 12 wk, which increased Vo(2max), was found to have no effects on circulating inflammatory markers in these obese patients. It is suggested that more intensive exercise may be necessary to affect systemic inflammation.

OBJECTIVE: Low vitamin D (VD) levels are common in obesity. We hypothesized that this may be due to metabolism of VD in adipose tissue (AT). Thus, we studied (1) whether the VD-metabolizing enzymes were expressed differently in AT of lean and obese individuals and in visceral adipose tissue (VAT) and subcutaneous adipose tissue (SAT), and (2) whether their expression was influenced by weight loss. METHODS: Samples of SAT and VAT were analyzed for expression of the vitamin-D-25-hydroxylases CYP2R1, CYP2J2, CYP27A1 and CYP3A4, the 25-vitamin-D-1a-hydroxylase CYP27B1, the catabolic vitamin-D-24-hydroxylase CYP24A1, and the vitamin D receptor, using reverse transcriptase-PCR. Moreover, plasma 25-hydroxy-vitamin D (25OHD) level was measured and related to the expression of these enzymes. Samples of SAT and VAT from 20 lean women and 20 obese women, and samples of SAT from 17 obese subjects before and after a 10% weight loss were analyzed. RESULTS: A plasma 25OHD level o50 nmol l À 1 was highly prevalent in both lean (45%) and obese (90%) women (Po0.01). Plasma 25OHD increased by 27% after weight loss in the obese individuals (Po0.05). Expression levels of the 25-hydroxylase CYP2J2 and the 1a-hydroxylase CYP27B1 were decreased by 71% (Po0.0001) and 49% (Po0.05), respectively, in SAT of the obese. CYP24A1 did not differ between lean and obese women, but the expression was increased by 79% (Po0.05) after weight loss. CONCLUSION: Obesity is characterized by a decreased expression of the 25-hydroxylase CYP2J2 and the 1a-hydroxylase CYP27B1 in SAT, whereas the catabolic CYP24A1 does not differ between lean and obese women. However, the expression of CYP24A1 is increased after weight loss. Accordingly, AT has the capacity to metabolize VD locally, and this can be dynamically altered during obesity and weight loss. INTRODUCTIONLow levels of circulating 25-hydroxy-vitamin D (25OHD) are associated with increased fat mass and body mass index, 1-5 but the underlying mechanism for this association is not fully elucidated. 6 Vitamin D (VD) is stored in adipose tissue (AT), and release of VD from AT is proposed to serve as an endogenous source of VD during the winter, when cutaneous production is low or absent in several parts of the world. 7 As low circulating levels of 25OHD are common in association with the obese state, 8 several studies have examined the effect of weight loss on circulating levels of 25OHD. However, results are inconsistent. After diet-and exercise-induced weight loss, both increased 9-11 and unaltered 12,13 circulating levels of 25OHD have been reported. Likewise, after major weight loss by bariatric surgery, both temporary 14-16 and long-term increases [16][17][18] in circulating levels of 25OHD have been reported, along with reports of no changes one year after surgery. 13,19 Taken together, these findings indicate that body weight is an important factor for circulating 25OHD levels. Several other explanations for the low levels of 25OHD in obesity have been proposed: a decreased exposure to sun light, 20 ...

Exercise alone and in combination with a diet-induced weight loss enhance the mRNA expression of adiponectin receptors in AT and in SM but only a pronounced hypocaloric-induced weight-loss increases circulating adiponectin in obese subjects.

Obesity. 2007;15:1954 -1960. Objective: Pre-receptor amplification of glucocorticoids is, in part, determined by the isoenzymes 11␤-hydroxysteroid dehydrogenase (11␤-HSD) type 1 and type 2, interconverting inert cortisone and active cortisol. Increased tissue activity of cortisol may play a part in features of the metabolic syndrome. Our objective was to compare 11␤-HSD1 gene expression in different fat depots (visceral, subcutaneous abdominal, and subcutaneous gluteal) in lean and obese men and women. Research Methods and Procedures: A cross-sectional study design was used for healthy patients undergoing minor abdominal surgery (lean men, 10), minor gynecological surgery (lean woman, 10), or gastric banding operations (obese men, 10; and obese women, 10). Gene expressions of 11␤-HSD1 in adipose tissue samples were determined by real-time reverse transcriptase polymerase chain reaction (RT-PCR). Results: Lean women had lower 11␤-HSD1 gene expression in subcutaneous adipose tissue compared with men (62% lower, p Ͻ 0.01), whereas no significant difference was found between obese men and women. 11␤-HSD1 mRNA in human adipose tissue was higher in obese subjects compared with lean subjects in both women and men and in both subcutaneous and visceral adipose tissue. No difference in mRNA expression of 11␤-HSD1 between visceral and subcutaneous adipose tissue or between subcutaneous adipose tissue from different depots was found. Conclusions: 11␤-HSD1 in adipose tissue is increased in obesity in both women and men, and may contribute to the associated metabolic syndrome. As 11␤-HSD1 expression in lean women was found to be significantly lower than in lean males, the up-regulation associated with obesity may be relatively more devastating in women than in men, and may help explain the higher relative risk of cardiovascular disease in women suffering from the metabolic syndrome.

Objective: Human obesity is closely associated with a state of chronic low-grade inflammation, which also involves the adipose tissue with enhanced production of bioactive substances (adipokines). Calorie restriction (CR) reduces adipocytokine production and improves metabolic profile in rodents. Some of these effects are mediated through activation of the sirtuin 1 (Sirt1) enzyme, and in this study, we investigate whether the natural phytoalexin, resveratrol (RSV), which is a potent Sirt1 activator, has anti-inflammatory effects in human adipose tissue explants. Design: The effect of RSV on interleukin 1b (IL1b)-induced change of adipokine mRNA gene expression and secretion were measured in human adipose tissue explants. Results: Exposure of human adipose tissue in vitro to IL1b for 24 h increased secretion of the proinflammatory adipokines IL6, IL8 and monocyte chemoattractant protein 1 (MCP-1) 3-7.7-fold (Po0.05) and increased IL6, IL8, MCP-1, IL1b and PAI-1 mRNA expression 1.3-7.2-fold (Po0.05) accordingly. Concomitant incubations with RSV reversed the IL1b-stimulated secretion (16-36%) and gene expression (25-48%) of these adipokines. IL1b reduced adiponectin mRNA expression (40%), a decrement that was reversed by RSV treatment. Similar effects were observed in differentiated human preadipocytes in primary culture, indicating that human adipocytes are a potential target for RSV effects. Finally, the effects were neutralized by sirtinol, a Sirt1 inhibitor. Conclusion: This study is the first to show anti-inflammatory effects of RSV on adipokine expression and secretion in human adipose tissue in vitro through the SIRT1 pathway. Thus, RSV is hypothesized to possess beneficial effects and might improve the metabolic profile in human obesity.

Objective: Weight loss with preferential effect on the visceral adipose tissue (VAT) depot could have important clinical benefits. In this study, we investigated the independent and combined effect of regular exercise and diet induced weight loss on body fat distribution. Design: Randomized control design of i) exercise-only (EXO; 12 weeks of exercise without dietrestriction), ii) hypocaloric-diet (DIO; 8 weeks of very low energy diet (VLED 600 kcal/day) followed by 4-weeks weight maintenance diet) and iii) hypocaloric-diet and exercise (DEX; 8 weeks VLED 800 kcal/dayCa 4-week weight maintenance diet combined with exercise throughout the 12 weeks). Subjects: Seventy-nine obese males and females were included. Measurements: Body fat distribution was quantified by magnetic resonance imaging (MRI)-technology. Results: In the EXO group, the weight loss (3.5 kg) and the relative reduction in VAT (18%) was significantly lower compared with the weight losses in the DIO and DEX groups (12.3 kg; P!0.01) and to the reduction in VAT (30-37%; P!0.01). In all the three groups, the relative reduction of VAT was higher as compared with the reduction in fat mass (FM; combining all fat depots determined by MRI; P!0.01 for all comparisons). The changes in VAT were associated with changes in FM and related to the initial VAT/FM ratio (r 2 Z0.72; P!0.01). Conclusion: Exercise has no additional effects in reduction of the VAT depot, compared with the major effects of hypocaloric diet alone. In addition, the effects of exercise per se on VAT are relatively limited. The effects on the VAT depot are closely associated with changes in total FM.

Objective: Calorie restriction increases the life span in a number of different organisms. This effect is dependent upon activation of the Sirt1 enzyme, and many of the beneficial effects of calorie restriction can be mimicked using resveratrol, which activates the Sirt1 enzyme. Nothing is known about this system in human adipose tissue; therefore, we investigated this system in human adipose tissue. Design: Sirt1 mRNA was measured in adipose tissue biopsies from human volunteers before and after 6 days of total fasting. In addition, adipose tissue from lean and obese individuals was compared and in vitro investigations were performed. Results: Long-term total fasting (6 days) of nine human volunteers increased Sirt1 mRNA expression in subcutaneous adipose tissue more than twofold (0.197-0.454 arbitrary units, Po0.05). Likewise, lean women (n ¼ 12) had more than twofold higher Sirt1 expression in subcutaneous adipose tissue compared to obese women (n ¼ 12; 0.33-0.73 arbitrary units, Po0.05). Sirt1 was equally expressed in the stroma-vascular fraction and the isolated adipocyte fraction. Finally, in vitro, we demonstrated that resveratrol (a Sirt1 activator) significantly enhanced the lipolytic effect of epinephrine in human adipose tissue (Po0.05). Conclusion: Human adipose tissue contains Sirt1 and the expression of Sirt1 can be regulated by calorie restriction as in other species. Furthermore, we demonstrated that resveratrol affects human fat-cell metabolism similar to the effects in rodents (that is, increased epinephrine induced lipolysis). These findings indicated that the beneficial effects of calorie restriction in humans might involve the activation of Sirt1. Thus, based on these findings, we propose that Sirt1 might play important roles for the beneficial effects of calorie restriction in humans.

The primary aim of the present study was to investigate if overweight and obese compared to lean individuals displayed differences in levels of inflammatory markers in circulation, skeletal muscle (SM) and adipose tissue (AT) after acute exercise. Fifteen lean (BMI: 22.4 ± 2 kg/m(2)) and 16 overweight or obese (BMI 31.8 ± 3 kg/m(2)) individuals were included in the study. They completed 120 min of ergometer bicycling at 55-60 % of maximal heart rate. Blood samples were obtained at baseline (T = 0), after 60 (T = 60) and 120 min of exercise (T = 120), and analyzed using an ELISA method. SM and AT biopsies were obtained at T0 and T120, and mRNA expression was investigated using a Real-time RT-PCR method. Circulating IL-6, TNF-α, IL-8, and IL-15 all increased at T = 120 min (p < 0.01). Circulating IL-6 and IL-15 increased in all subjects at T = 120 min (p < 0.01), but only the increase of IL-6 was significantly higher in overweight and obese subjects (p < 0.05), and was positively correlated with body fat percentage (p < 0.01). Circulating IL-8 and TNF-α were increased in overweight and obese (p < 0.05) but not in lean subjects. Acute exercise induced an increase in IL-6 mRNA expression in SM biopsies (p < 0.05). IL-6 as well as adiponectin mRNA expression was increased in AT biopsies (p < 0.05); however, no effect of body weight was found. The findings suggest that the systemic inflammatory response to acute exercise is different in lean compared to overweight and obese subjects, with a more pronounced increase in inflammatory markers (e.g., IL-6, IL-8, and TNF-α) in overweight and obese individuals.