Metabolic factors in obesity

IL-6 secretion in osteoarthritis patients is mediated by chondrocyte-synovial fibroblast cross-talk and is enhanced by obesity

Increasing evidence suggests that inflammation plays a central role in driving joint pathology in certain patients with osteoarthritis (OA). Since many patients with OA are obese and increased adiposity is associated with chronic inflammation, we investigated whether obese patients with hip OA exhibited differential pro-inflammatory cytokine signalling and peripheral and local lymphocyte populations, compared to normal weight hip OA patients. No differences in either peripheral blood or local lymphocyte populations were found between obese and normal-weight hip OA patients. However, synovial fibroblasts from obese OA patients were found to secrete greater amounts of the pro-inflammatory cytokine IL-6, compared to those from normal-weight patients (p < 0.05), which reflected the greater levels of IL-6 detected in the synovial fluid of the obese OA patients. Investigation into the inflammatory mechanism demonstrated that IL-6 secretion from synovial fibroblasts was induced by chondrocyte-derived IL-6. Furthermore, this IL-6 inflammatory response, mediated by chondrocyte-synovial fibroblast cross-talk, was enhanced by the obesity-related adipokine leptin. This study suggests that obesity enhances the cross-talk between chondrocytes and synovial fibroblasts via raised levels of the pro-inflammatory adipokine leptin, leading to greater production of IL-6 in OA patients.

Evaluating Weight Status and Sex as Moderators of the Association of Serum Leptin with Bone Mineral Density in Children and Adolescents

BACKGROUND/AIMS

Animal studies suggest that leptin may adversely affect bone mineral density (BMD). Clinical studies have yielded conflicting results. We therefore investigated associations between leptin and bone parameters in children.

METHODS

830 healthy children (age = 11.4 ± 3.1 years; 75% female; BMI standard deviation score [BMIz] = 1.5 ± 1.1) had fasting serum leptin measured with ELISA and body composition by dual-energy X-ray absorptiometry. The main effects for leptin and BMIz plus leptin's interactions with sex and BMIz were examined using hierarchical linear regressions for appendicular, pelvis, and lumbar spine BMD as well as bone mineral content (BMC), and bone area (BA).

RESULTS

Accounting for demographic, pubertal development, and anthropometric variables, leptin was negatively and independently associated with lumbar spine BMC and BA, pelvis BA, and leg BA (p < 0.05 for all). Sex, but not BMIz, moderated the associations of leptin with bone parameters. In boys, leptin was negatively correlated with leg and arm BMD, BMC at all bone sites, and BA at the subtotal and lumbar spine (p < 0.01 for all). In girls, leptin was positively correlated with leg and arm BMD (p < 0.05 for both).

CONCLUSION

Independent of body size, leptin is negatively associated with bone measures; however, these associations are moderated by sex: boys, but not girls, have a negative independent association between leptin and BMD.
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Maternal Hyperleptinemia Improves Offspring Insulin Sensitivity in Mice

Maternal obesity and gestational diabetes are prevalent worldwide. Offspring of mothers with these conditions weigh more and are predisposed to metabolic syndrome. A hallmark of both conditions is maternal hyperleptinemia, but the role of elevated leptin levels during pregnancy on developmental programming is largely unknown. We previously found that offspring of hyperleptinemic mothers weighed less and had increased activity. The goal of this study was to determine whether maternal leptin affects offspring insulin sensitivity by investigating offspring glucose metabolism and lipid accumulation. Offspring from two maternal hyperleptinemic models were compared. The first model of hyperleptinemia is the Lepr(db/+) mouse, which has a mutation in one copy of the gene that encodes the leptin receptor, resulting in a truncated long form of the receptor, and hyperleptinemia. Wild-type females served as the control for the Lepr(db/+) females. For the second hyperleptinemic model, wild-type females were implanted with miniosmotic pumps, which released leptin (350 ng/h) or saline (as the control) just prior to mating and throughout gestation. In the offspring of these dams, we measured glucose tolerance; serum leptin, insulin, and triglyceride levels; liver triglycerides; pancreatic α- and β-cell numbers; body composition; incidence of nonalcoholic fatty liver disease; and the expression of key metabolic genes in the liver and adipose tissue. We found that the offspring of hyperleptinemic dams exhibited improved glucose tolerance, reduced insulin and leptin concentrations, reduced liver triglycerides, and a lower incidence of nonalcoholic fatty liver disease. Overall, maternal hyperleptinemia was beneficial for offspring glucose and lipid metabolism.

Influence of obesity on surgical outcomes in type III paediatric supracondylar humeral fractures

INTRODUCTION

Obesity was associated with poor treatment outcome in paediatric supracondylar humeral fractures. It is controversial about the association is related to more severe fractures in obese children or obesity directly affects treatment. The purpose of this study was to evaluate the influence of obesity on surgical outcomes after control of fracture severity.

PATIENTS AND METHODS

This is a retrospective comparative study of 107 children treated for type III supracondylar humeral fractures between January 2009 and December 2013. Children were classified according to sex-specific body mass index (BMI)-for-age growth chart into 4 groups: underweight group (n=10); normal-weight group (n=71); overweight group (n=13); and obese group (n=13). Clinical outcomes were assessed using the Flynn criteria. Radiographic evaluation included the Baumann angle and the lateral humerocapitellar angle. Loss of reduction was defined by Skaggs' criteria.

RESULTS

The mean age, sex, and Flynn criteria were comparable among the four BMI groups. Obese children were more likely to develop a varus change in the Baumann angle (p=0.017) and loss of reduction in varus (p=0.059) postoperatively. The risk for pin-related complications was significantly higher in overweight and obese children (p=0.013).

CONCLUSIONS

Obesity was associated with more postoperative varus deformation and pin-related complications after surgical fixation for type III supracondylar fracture. These findings underline the importance of stable fixation and close post-operative monitoring in obese children.

Changing trends in the management of children's fractures

The management of children's fractures has evolved as a result of better health education, changes in lifestyle, improved implant technology and the changing expectations of society. This review focuses on the changes seen in paediatric fractures, including epidemiology, the increasing problems of obesity, the mechanisms of injury, non-accidental injuries and litigation. We also examine the changes in the management of fractures at three specific sites: the supracondylar humerus, femoral shaft and forearm. There has been an increasing trend towards surgical stabilisation of these fractures. The reasons for this are multifactorial, including societal expectations of a perfect result and reduced hospital stay. Reduced hospital stay is beneficial to the social, educational and psychological needs of the child and beneficial to society as a whole, due to reduced costs.

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.

Peptides from adipose tissue in monitoring energy balance in infants

BACKGROUND/AIM

Overnutrition as well as undernutrition is a serious problem in hospitalized patients, especially in infants. Routine laboratory tests detecting disturbances in energy balance are not specific or accurate. The aim of this study was to evaluate adiponectin and leptin as markers of short-time energy malnutrition.

METHODS

Forty-five infants fed orally and parenterally were included in the study. Plasma glucose, leptin and adiponectin were measured in a fasting state and postprandially (1 h after the meal), after a minimum of 24 h of total parenteral nutrition (TPN) and after a minimum of 8 h of intravenous infusion of glucose and crystalloids.

RESULTS

Postprandial glucose levels in children fed orally was similar to that observed in children who received intravenous infusion of glucose. The TPN children had slightly higher glucose concentration in contrast to leptin levels which were significantly lower in this group (1.08 mg/mL +/- 0.43) as compared to the others (p < 0.05 in both cases). The mean postprandial levels of the adiponectin in orally fed children were significantly higher (10.7 microg/mL +/- 2.4) than in children with TPN (5.8 microg/mL +/- 2.4; p < 0.001) and in children hydrated intravenously (3.3 microg/mL +/- 2.3; p < 0.001). The concentration of adiponectin correlated significantly with calorie intake.

CONCLUSIONS

Oral meal does not affect the plasma concentrations of leptin and adiponectin in infants. Adiponectin is a good short-time marker of energy malnutrition in infants.