Association of circulating visfatin concentrations with insulin resistance and low-grade inflammation after dietary energy restriction in Spanish obese non-diabetic women: role of body composition changes

Data Independent Acquisition Mass Spectrometry Can Identify Circulating Proteins That Predict Future Weight Loss with a Diet and Exercise Programme

We investigated biological determinants that would associate with the response to a diet and weight loss programme in impaired glucose regulation (IGR) people using sequential window acquisition of all theoretical fragment ion spectra (SWATH) mass spectrometry (MS), a data acquisition method which complement traditional mass spectrometry-based proteomics techniques. Ten women and 10 men with IGR underwent anthropometric measurements and fasting blood tests. SWATH MS was carried out with subsequent immunoassay of specific peptide levels. After a six-month intervention, 40% of participants lost 3% or more in weight, 45% of patients remained within 3% of their starting weight and 15% increased their weight by 3% or more. Hemoglobin A1c (HbA1C) level was reduced with weight loss with improvements in insulin sensitivity. SWATH MS on pre-intervention samples and subsequent principal component analysis identified a cluster of proteins associated with future weight loss, including insulin-like growth factor-II (IGF-II) and Vitamin D binding protein. Individuals who lost 3% in weight had significantly higher baseline IGF-II levels than those who did not lose weight. SWATH MS successfully discriminated between individuals who were more likely to lose weight and potentially improve their sensitivity to insulin. A higher IGF-II baseline was predictive of success with weight reduction, suggesting that biological determinants are important in response to weight loss and exercise regimes. This may permit better targeting of interventions to prevent diabetes in the future.

Effects of dietary restriction on adipose mass and biomarkers of healthy aging in human

In developing countries the rise of obesity and obesity-related metabolic disorders, such as cardiovascular diseases and type 2 diabetes, reflects the changes in lifestyle habits and wrong dietary choices. Dietary restriction (DR) regimens have been shown to extend health span and lifespan in many animal models including primates. Identifying biomarkers predictive of clinical benefits of treatment is one of the primary goals of precision medicine. To monitor the clinical outcomes of DR interventions in humans, several biomarkers are commonly adopted. However, a validated link between the behaviors of such biomarkers and DR effects is lacking at present time. Through a systematic analysis of human intervention studies, we evaluated the effect size of DR (i.e. calorie restriction, very low calorie diet, intermittent fasting, alternate day fasting) on health-related biomarkers. We found that DR is effective in reducing total and visceral adipose mass and improving inflammatory cytokines profile and adiponectin/leptin ratio. By analysing the levels of canonical biomarkers of healthy aging, we also validated the changes of insulin, IGF-1 and IGFBP-1,2 to monitor DR effects. Collectively, we developed a useful platform to evaluate the human responses to dietary regimens low in calories.

Variations in the PBEF1 gene are associated with body mass index: A population-based study in northern China

OBJECTIVE

PBEF1 and its polymorphisms may be important in the physiopathology of obesity. We hypothesized that polymorphisms in PBEF1 gene may modify body mass index (BMI).

METHODS

Thus, we systematically screened 4 tagging polymorphisms (rs4730153, rs2058540, rs3801267 and rs16872158) in PBEF1 gene and evaluated the association between the genetic variants and BMI in a population-based study including 442 subjects in northern China.

RESULTS

We found that the SNP rs3801267 was significantly associated with decreased BMI (P = 0.026 in additive model), while the other 2 SNPs (rs4730153 and rs16872158) showed a borderline significant association with decreased BMI (P = 0.068 and 0.060 in additive models). Combined analysis of these 3 SNPs showed a significant allele-dosage association between the number of variant alleles and decreased BMI (P trend  = 0.007).

CONCLUSIONS

These findings indicate that genetic variants in PBEF1 gene may modify individual BMI in the Chinese population.

Evidence in obese children: contribution of hyperlipidemia, obesity-inflammation, and insulin sensitivity

Background

Evidence shows a high incidence of insulin resistance, inflammation and dyslipidemia in adult obesity. The aim of this study was to assess the relevance of inflammatory markers, circulating lipids, and insulin sensitivity in overweight/obese children.

Methods

We enrolled 45 male children (aged 6 to 13 years, lean control = 16, obese = 19, overweight = 10) in this study. The plasma total cholesterol, HDL cholesterol, triglyceride, glucose and insulin levels, the circulating levels of inflammatory factors, such as TNF-α, IL-6, and MCP-1, and the high-sensitive CRP level were determined using quantitative colorimetric sandwich ELISA kits.

Results

Compared with the lean control subjects, the obese subjects had obvious insulin resistance, abnormal lipid profiles, and low-grade inflammation. The overweight subjects only exhibited significant insulin resistance and low-grade inflammation. Both TNF-α and leptin levels were higher in the overweight/obese subjects. A concurrent correlation analysis showed that body mass index (BMI) percentile and fasting insulin were positively correlated with insulin resistance, lipid profiles, and inflammatory markers but negatively correlated with adiponectin. A factor analysis identified three domains that explained 74.08% of the total variance among the obese children (factor 1: lipid, 46.05%; factor 2: obesity-inflammation, 15.38%; factor 3: insulin sensitivity domains, 12.65%).

Conclusions

Our findings suggest that lipid, obesity-inflammation, and insulin sensitivity domains predominantly exist among obese children. These factors might be applied to predict the outcomes of cardiovascular diseases in the future.

Visfatin concentrations in patients with endometrial cancer

OBJECTIVE

Visfatin is one of the most recent proteins shown to be highly expressed in adipose tissue. The purpose of this study was to determine visfatin levels in patients with endometrial cancer (EC).

METHODS

A total of 90 patients (46 EC patients and 44 healthy controls) were included in the study. Fasting venous blood samples were collected from all patients. Serum visfatin levels were measured by an enzyme-linked immunosorbent assay (ELISA). The correlation between serum visfatin levels and clinicopathologic variables were determined.

RESULTS

Serum visfatin levels were found to be higher in patients with EC (p < 0.001). Visfatin concentrations were positively correlated with age (p = 0.002, r = 0.323), body mass index (BMI) (p = 0.001, r = 0.354), fasting insulin (p = 0.002, r = 0.326), total cholesterol (TC) (p = 0.006, r = 0.285), triglyceride (TG) (p < 0.001, r = 0.364) levels and homeostasis model-resistance index (HOMA-IR) (p = 0.007, r = 0.281) of patients. By using classification and regression trees (C&RT) method, we found that visfatin predicted patients with EC 100% and controls 81.8%.

CONCLUSION

Visfatin was the most important risk factor for occurrence of EC other than, age, BMI, Diabetes Mellitus and other biochemical factors like HDL, LDL, TG, TC. Clearly, there are largely unknown aspects of visfatin pathophysiology in EC and require further study.

Intermittent fasting vs daily calorie restriction for type 2 diabetes prevention: a review of human findings

Intermittent fasting (IF) regimens have gained considerable popularity in recent years, as some people find these diets easier to follow than traditional calorie restriction (CR) approaches. IF involves restricting energy intake on 1-3 d/wk, and eating freely on the nonrestriction days. Alternate day fasting (ADF) is a subclass of IF, which consists of a "fast day" (75% energy restriction) alternating with a "feed day" (ad libitum food consumption). Recent findings suggest that IF and ADF are equally as effective as CR for weight loss and cardioprotection. What remains unclear, however, is whether IF/ADF elicits comparable improvements in diabetes risk indicators, when compared with CR. Accordingly, the goal of this review was to compare the effects of IF and ADF with daily CR on body weight, fasting glucose, fasting insulin, and insulin sensitivity in overweight and obese adults. Results reveal superior decreases in body weight by CR vs IF/ADF regimens, yet comparable reductions in visceral fat mass, fasting insulin, and insulin resistance. None of the interventions produced clinically meaningful reductions in glucose concentrations. Taken together, these preliminary findings show promise for the use of IF and ADF as alternatives to CR for weight loss and type 2 diabetes risk reduction in overweight and obese populations, but more research is required before solid conclusions can be reached.

Hyperleptinemia is associated with parameters of low-grade systemic inflammation and metabolic dysfunction in obese human beings

Leptin is an adipose tissue-derived hormone that has been involved in hypothalamic and systemic inflammation, altered food-intake patterns, and metabolic dysfunction in obese mice. However, it remains unclear whether leptin has a relationship with parameters of systemic inflammation and metabolic dysfunction in humans. We thus evaluated in a cross-sectional study the circulating levels of leptin in 40 non-obese and 41 obese Mexican individuals, examining their relationship with tumor necrosis factor alpha (TNF-α), interleukin (IL) 12, IL-10, central obesity, serum glucose and insulin levels, and serum triglyceride and cholesterol concentrations. Circulating levels of leptin, TNF-α, IL-12, IL-10, and insulin were measured by ELISA, while concentrations of glucose, triglyceride, and cholesterol were determined by enzymatic assays. As expected, serum levels of leptin exhibited a significant elevation in obese individuals as compared to non-obese subjects, showing a clear association with increased body mass index (r = 0.4173), central obesity (r = 0.4678), and body fat percentage (r = 0.3583). Furthermore, leptin also showed a strong relationship with serum TNF-α (r = 0.6989), IL-12 (r = 0.3093), and IL-10 (r = −0.5691). Interestingly, leptin was also significantly related with high concentrations of fasting glucose (r = 0.5227) and insulin (r = 0.2229), as well as elevated levels of insulin resistance (r = 0.3611) and circulating triglyceride (r = 0.4135). These results suggest that hyperleptinemia is strongly associated with the occurrence of low-grade systemic inflammation and metabolic alteration in obese subjects. Further clinical research is still needed to determine whether hyperleptinemia may be a potential marker for recognizing the advent of obesity-related metabolic disorders in human beings.

A weight loss diet intervention has a similar beneficial effect on both metabolically abnormal obese and metabolically healthy but obese premenopausal women

BACKGROUND/AIMS

We studied the effect of a 12-week energy-restricted diet intervention on cardiometabolic risk in two groups of nonmorbid obese premenopausal Caucasian women, i.e. a metabolically abnormal obese (MAO) and a metabolically healthy but obese (MHO) group.

METHODS

The participants were 53 MAO and 25 MHO women (age range 19-49 years; body mass index inclusion criterion: 30-39.9). We assessed changes in body weight and composition, blood lipids, insulin resistance, hepatic enzymes, inflammatory markers and adipocytokines.

RESULTS

Overall, many of the study outcomes improved with the intervention in both MAO and MHO participants, but there was no difference in the magnitude of change between the groups. Body weight, waist circumference and total fat mass decreased significantly in response to the intervention in both MAO and MHO women (all p < 0.001). Fasting insulin, insulin resistance (homeostasis model assessment), hepatic enzymes (alanine aminotransferase and γ-glutamyltransferase), fatty liver index and leptin levels also decreased in both groups after the intervention (all p < 0.001), whereas total cholesterol, triglycerides and C-reactive protein decreased significantly only in MAO women (all p < 0.001).

CONCLUSION

These findings reinforce the idea that MHO women would also benefit from a lifestyle weight reduction intervention.

Adipokines and the cardiovascular system: mechanisms mediating health and disease

This review focuses on the role of adipokines in the maintenance of a healthy cardiovascular system, and the mechanisms by which these factors mediate the development of cardiovascular disease in obesity. Adipocytes are the major cell type comprising the adipose tissue. These cells secrete numerous factors, termed adipokines, into the blood, including adiponectin, leptin, resistin, chemerin, omentin, vaspin, and visfatin. Adipose tissue is a highly vascularised endocrine organ, and different adipose depots have distinct adipokine secretion profiles, which are altered with obesity. The ability of many adipokines to stimulate angiogenesis is crucial for adipose tissue expansion; however, excessive blood vessel growth is deleterious. As well, some adipokines induce inflammation, which promotes cardiovascular disease progression. We discuss how these 7 aforementioned adipokines act upon the various cardiovascular cell types (endothelial progenitor cells, endothelial cells, vascular smooth muscle cells, pericytes, cardiomyocytes, and cardiac fibroblasts), the direct effects of these actions, and their overall impact on the cardiovascular system. These were chosen, as these adipokines are secreted predominantly from adipocytes and have known effects on cardiovascular cells.