Body fat distribution and obesity:a comparison of upper and lower body adipose tissue biology in humans

Obesity increases the risk of developing cardiometabolic diseases due to adipose tissue (AT) dysfunction and body fat distribution, with abdominal fat accumulation increasing the risk of complications. This thesis investigated the differences between upper and lower body AT biology, focusing on AT blood flow (ATBF), inflammatory signatures, and the oxidative machinery of abdominal (upper body) and femoral (lower body) subcutaneous AT in humans with normal weight or obesity. It also investigated the influence of prolonged exposure to various oxygen levels on the inflammatory phenotype of abdominal and femoral adipocytes. From this research, it was found that it is technically feasible to measure abdominal and femoral intravascular ATBF using percutaneous Doppler ultrasound. Furthermore, we demonstrated distinct inflammatory signatures between abdominal and femoral AT and adipocytes. Moreover, AT oxygen extraction and adipocyte oxygen consumption were lower in abdominal than femoral AT in women with normal weight or obesity. Finally, low physiological oxygen levels decreased gene expression and secretion of pro-inflammatory factors in both abdominal and femoral adipocytes derived from individuals with obesity but not normal weight

Distinct inflammatory signatures of upper and lower body adipose tissue and adipocytes in women with normal weight or obesity

IntroductionUpper and lower body fat accumulation poses an opposing obesity-related cardiometabolic disease risk. Depot-differences in subcutaneous adipose tissue (SAT) function may underlie these associations. We aimed to investigate the inflammatory signatures of abdominal (ABD) and femoral (FEM) SAT in postmenopausal women with normal weight or obesity.MethodsWe included 23 postmenopausal women with normal weight (n = 13) or obesity (n = 10). In vivo secretion of adipokines from ABD and FEM SAT was measured using the arterio-venous balance technique. Adipokine gene expression and adipocyte morphology were examined in ABD and FEM SAT. Furthermore, adipokine expression and secretion were investigated in vitro using differentiated human primary ABD and FEM subcutaneous adipocytes derived from the study participants.ResultsPlasma leptin and plasminogen activator inhibitor (PAI)-1 concentrations were higher, and ABD and FEM adipocytes were larger in women with obesity than normal weight. No differences in adipocyte size and blood flow were apparent between ABD and FEM SAT. We found significant release of leptin and monocyte chemoattractant protein (MCP)-1 from ABD and FEM SAT, with higher fractional release of MCP-1 from ABD than FEM SAT. Gene expression of leptin, PAI-1, and tumor necrosis factor-α was lower in ABD than FEM SAT and higher in women with obesity than normal weight. In ABD adipocytes, interleukin-6, PAI-1, and leptin gene expression were higher, while adiponectin and dipeptidyl-peptidase-4 gene expression were lower than in FEM adipocytes. Finally, ABD adipocytes secreted less MCP-1 compared to FEM adipocytes.DiscussionThese findings demonstrate that upper and lower body SAT and adipocytes are characterized by distinct inflammatory signatures in postmenopausal women, which seem independent of adipocyte size

Effects of vitamin D supplementation in endometriosis: a systematic review

Background: There is a growing body of human, animal and in vitro studies on vitamin D (vit D) substitution in endometriosis. The aim of this systematic review is to critically appraise and qualitatively synthesize the results of the available studies that examine the supplementation of vit D for endometriosis treatment. Methods: A systematic search of the literature was conducted in four electronic databases (Medline, Cochrane, Scopus, Embase) and grey literature for original research articles on humans, animals and in vitro models published in any language. Results: Four human studies, four animal studies and four in vitro studies were included. Quantitative synthesis of human studies showed no significant effect of vit D intake for dysmenorrhea (2 studies, 44 vit D vs 44 placebo, mean -0.71, 95% CI -1.94, 0.51) and non-cyclic pelvic pain (2 studies, 42 vit D vs 38 placebo, mean 0.34, 95% CI -0.02, 0.71). Regarding reproductive outcomes in women with endometriosis after in vitro fertilization, the only available study showed no differences between women taking vit D and women taking placebo. Three of the four included animal studies showed regression of endometriotic implants when treated with vit D. The in vitro studies demonstrated that vit D decreases invasion and proliferation of endometriotic lesions without affecting apoptosis. Conclusions: Although in vitro and animal studies suggest regression of the endometriotic implants and decrease of invasion and proliferation after vit D supplementation, this was not reflected in the results of the meta-analysis, which showed no benefit of vit D supplementation in patients with endometriosis and dysmenorrhea or non-cyclic pelvic pain as well as on the outcome of IVF treatment. However, given the heterogeneity and the diversity of the available studies, more research is required to shed light on the role of vit D supplementation in women with endometriosis. Keywords: 1,25(OH)2D; 25(OH)D; 25(ΟΗ)D3; Endometriosis; Supplementation; Vitamin

The catcher in the gut:Tirzepatide, a dual incretin analog for the treatment of type 2 diabetes mellitus and obesity

The ever-increasing burden of obesity, type 2 diabetes mellitus (T2DM) and related comorbidities is demanding a better pathophysiological understanding as well as new treatment options. Incretin based therapies are already available while the recent Food and Drug Administration (FDA) approval of the dual glucagon-like peptide-1 (GLP-1) and glucose-dependent insulinotropic polypeptide (GIP) receptor agonist tirzepatide appears to revolutionize the treatment of T2DM and obesity. GLP-1 and GIP exert pleiotropic physiological actions, including enhancement of insulin secretion, glycemic and appetite control, cardioprotection, and adipose tissue improved function among others. Evidence from recent clinical trials has shown that tirzepatide is at least or more effective compared to classic metabolic therapeutic agents, including insulin, when it comes to glycemic control in T2DM. Of importance, it also exerts remarkable weight-lowering actions, emerging as an alternative to bariatric surgery for obesity treatment. Overall, current data show that tirzepatide is a highly effective therapeutic option for T2DM. Numerous ongoing randomized controlled clinical trials are further examining its potential as a treatment for obesity

Of mice and men:Considerations on adipose tissue physiology in animal models of obesity and human studies

The ever-increasing burden of obesity demands a better pathophysiological understanding, especially regarding adipose tissue pathophysiology. Animal models of obesity are of great importance in investigating potential mechanisms and implications of obesity. Many issues should be considered while interpreting the preclinical results as anatomical and pathophysiological differences exist among species. Importantly, the natural history of obesity development differs considerably. An important example of conflicting results among preclinical models and human physiological studies is that of adipose tissue oxygenation, where rodent models almost unanimously have shown the presence of hypoxia in the adipose tissue of obese animals while human studies have yielded conflicting results to date. Other issues which require further clarification before generalizing preclinical data in humans include adipose tissue browning, endocrine function and fibrosis. The aim of this mini-review is to synopsize similarities and differences between rodent models and humans, which should be taken into consideration in obesity studies

Nutrition, dietary habits, and weight management to prevent and treat patients with peripheral artery disease

Peripheral artery disease (PAD) affects 3%-10% of the Western population and if remains untreated can have devastating consequences to patients and their families. This review article analyzes how healthy dietary habits can decrease PAD rates when applied in the general population. The aim is to focus on dietary, nutritional and weight management interventions in patients with established PAD. Most adults with PAD are overweight or obese, while three out of four patients are characterized by deficiencies in vitamins and minerals. Weight loss interventions when needed and specialized dietary plans should be routinely recommended in patients with PAD. Appropriate nutritional support is of paramount importance in patients with advanced stages of PAD (critical limb ischemia)