Resistin: a hormone which induces insulin resistance is increased in normal pregnancy

AIMS

Resistin, a newly discovered adipokine, is thought to play a key role in the regulation of insulin resistance. The objectives of this study were to develop a nomogram of maternal plasma concentrations of resistin from 11 weeks of gestation to term and to determine whether resistin concentrations differ between normal and overweight pregnant women.

METHODS

In this cross-sectional study, plasma concentrations of resistin were determined in normal pregnant women of normal body mass index (BMI 18.5-24.9; n=261), overweight pregnant women (BMI > or =25; n=140), and non-pregnant women of normal BMI (n=40). Blood samples were collected once from each woman between the first trimester and term. Percentiles for resistin concentration were determined for five pre-specified windows of gestational age. Plasma resistin concentration was determined by immunoassay. Non-parametric statistics were used for analysis.

RESULTS

The median maternal plasma concentration of resistin between 11 to 14 weeks of gestation in women of normal weight was significantly higher than non-pregnant women; the plasma concentration of resistin increased with gestational age.

CONCLUSIONS

Normal pregnant women have a higher median plasma concentration of resistin than non-pregnant women and the concentration of this adipokine increases with advancing gestation. Alterations in the maternal plasma concentration of resistin during pregnancy could contribute to metabolic changes of pregnancy.

Adiponectin levels in obese and non-obese middle-aged African-American women

SUMMARY

CONTEXT

Adiponectin levels in African-Americans are poorly described.

OBJECTIVE

To assess predictors of serum adiponectin levels in obese and non-obese middle-aged African-American women.

METHODS

Serum adiponectin, testosterone (T), free androgen index (FAI), estradiol, dehydroepiandrosterone sulfate (DHEAS), leptin, sex hormone binding globulin (SHBG), triglycerides and C-reactive protein (CRP) were measured in 142 obese and 102 non-obese, community-dwelling, African-American women in St. Louis, Missouri. Medical history, physical activity, anthropometry, medications and body composition were assessed.

RESULTS

Adiponectin and SHBG levels were lower and leptin and CRP were higher in obese compared to non-obese women (P's < 0.01). Overall, log adiponectin was positively associated with age (R = 0.13) and log SHBG (R = 0.29), and inversely associated with anthropometric measures (R's = -0.17 to -0.36), serum androgens (R's = -0.21 to -0.23), log estradiol (R = -0.21), log leptin (R = -0.15), log triglycerides (R = -0.33) and log CRP (R = -0.29). Overall, multivariate modelling significantly predicted 32% of variation in adiponectin level; the most significant factors were WHR (β = -1.33), SHBG (β = 0.23) and triglycerides (β = -0.34). In non-obese women, the model predicted 27% of variation in adiponectin level; no individual factor was independently associated. In obese women, the model predicted 30% of variation in adiponectin level; the most significant factors were WHR (β = -1.49), triglycerides (β = -0.34) and history of stroke (β = -0.71).

CONCLUSIONS

Adiponectin level in African-American women is predicted by WHR, SHBG, and triglycerides; stroke history adds predictive value in obese women.

Engineering approaches to energy balance and obesity: opportunities for novel collaborations and research: report of a joint national science foundation and national institutes of health workshop

Energy balance disorders account for a large public health burden. The obesity epidemic in particular is one of the most rapidly evolving public health problems of our day. At present, two-thirds of American adults and one-sixth of American children and adolescents are considered either overweight or obese. Public health concern about obesity is high because of the increased risk and increased mortality of cardiovascular disease, Type 2 diabetes, many forms of cancer, gallbladder disease, and osteoarthritis. These risks increase with the severity of the obesity. Excess adipose tissue, representing fat storage, ultimately derives from an imbalance between energy intake and energy expenditure. Conversely, undesirable and inadvertent loss of body weight and muscle mass, as seen in aging and cachectic states of chronic diseases such as heart failure and cancer, have serious clinical and functional consequences without satisfactory clinical or behavioral solutions. Innovative engineering technologies could help to address unresolved problems in energy balance, intake, and expenditure. Novel sensors, devices, imaging technologies, nanotechnologies, biomaterials, technologies to detect biochemical markers of energy balance, mathematical modeling, systems biology, and other approaches could be developed, evaluated, and leveraged through multidisciplinary collaborations. Engineers, physical scientists, and mathematicians can work with scientists from other relevant disciplines who possess expertise in obesity and nutrition. Furthermore, the possibility of re-engineering the "built environment" to encourage higher levels of physical activity has been suggested as another promising and important approach to which engineers can contribute (see http://www.obesityresearch.nih.gov). Ultimately, systematic application of the "Engineering Approach" can help in developing the needed technologies and tools to facilitate research and eventually support therapeutic advances and behavioral change. This article summarizes important public health concerns related to disordered energy balance and describes research priorities identified at a recent National Science Foundation-National Institutes of Health workshop. Research funding opportunities are described as posted on the NIH Guide to Grants and Contracts (see http://www.nih.gov/grants/guide).

Macrophages block insulin action in adipocytes by altering expression of signaling and glucose transport proteins

Obesity leads to a proinflammatory state with immune responses that include infiltration of adipose tissue with macrophages. These macrophages are believed to alter insulin sensitivity in adipocytes, but the mechanisms that underlie this effect have not been characterized. We have explored the interaction between macrophages and adipocytes in the context of both indirect and direct coculture. Macrophage-secreted factors blocked insulin action in adipocytes via downregulation of GLUT4 and IRS-1, leading to a decrease in Akt phosphorylation and impaired insulin-stimulated GLUT4 translocation to the plasma membrane. GLUT1 was upregulated with a concomitant increase in basal glucose uptake. These changes recapitulate those seen in adipose tissue from insulin-resistant humans and animal models. TNF-alpha-neutralizing antibodies partially reversed the insulin resistance produced by macrophage-conditioned media. Peritoneal macrophages and macrophage-enriched stromal vascular cells from adipose tissue also attenuated responsiveness to insulin in a manner correlating with inflammatory cytokine secretion. Adipose tissue macrophages from obese mice have an F4/80(+)CD11b(+)CD68(+)CD14(-) phenotype and form long cellular extensions in culture. Peritoneal macrophages take on similar characteristics in direct coculture with adipocytes and induce proinflammatory cytokines, suggesting that macrophage activation state is influenced by contact with adipocytes. Thus both indirect/secreted and direct/cell contact-mediated factors derived from macrophages influence insulin sensitivity in adipocytes.

[Diagnosis of insulin resistance in children and adolescents]

The high prevalence of obesity in children is one of the factors contributing to an increase in the frequency of development of the metabolic syndrome and related diseases. A key role in the development of the metabolic syndrome in both children and adults is played by insulin resistance - a violation of the biological effect of insulin and the reaction of insulin-sensitive tissues to it at the pre-, post- and receptor levels.

[Autonomic homeostasis and the specific features of adaptation in children with obesity]

The autonomic nervous system and the adaptive mechanisms associated with neuroautonomic cardiac rhythm regulation were studied in obese children. The study covered 187 untreated children aged 6-16 years who had exogenous constitutional (n = 68), diencephalic (n = 20) obesity and hypothalamic puberty syndrome (n = 99). The study was conducted by computer-aided (statistic, spectral) analysis of cardiac rhythm variability. The regulatory system activity index was calculated to assess the tension of adaptive mechanisms. The results were compared with those obtained in 107 apparently healthy children matched by gender and age. The enhanced activity of subcortical nerve centers with a predominance of sympathetic effects was observed in 38.7% of children with puberty obesity. The state of adaptive processes was regarded as a pronounced functional strain, overstrain, and exhaustion of regulatory systems in 31.1% of 6-10-year-old children and 29.5% of 11-16-year-old ones with obesity.

[Reasons for obesity treatment inefficiency and modes of its overcoming]

The main problem faced by doctors involved in the treatment of obesity is relapse of the disease. There are 4 main causes of relapse. The first reason is the emotional instability resulting from the use of strict diets, which is called "dietary depression." The second reason is the appearance of a "weight plateau", when the patient continues to follow the recommendations, but body weight ceases to decrease against the background of ongoing therapy. The third reason: after the course of treatment, the patient returns to his previous lifestyle and he ricochets weight gain. The fourth reason is an incorrect account of the peculiarities of eating disorders of the patient when prescribing treatment programs.

Effect of Meal Volume on Hunger and Satiety in Obese Subjects: Volume of meal and satiety

OBJECTIVE

The results of several studies showed that energy density of food affects both satiety and food intake. None of them has checked the influence of energy density variation in solid meals in obese subjects. We examined the effect of meal volume on satiety potency of food and its effect on glucose and insulin profiles in obese subjects.

DESIGN

Subjects were served a test meal (milk pudding) equal in energy content and composition (fat, protein, carbohydrate) across two volumes : 250 ml and 500 ml.

SUBJECTS

Study group: 22 obese subjects without additional diseases, BMI: 37.9 + 7.1.

MEASUREMENTS

The satiety state was assessed on VAS before and after consumption test meal during 180 minutes of observation. During the study every 30 min the blood was taken to determine glucose and insulin profiles.

RESULTS

There were no differences in taste assessment of both test foods on VAS scale. Food consumption results in significant reduction of hunger and increase of satiety feelings independently of food volume. The food volume had no important influence on satiety status of study patients during whole study. Only just after ingestion we observed the significant more satiating efficiency of bigger than smaller volume. We didn't also notice any differences in plasma glucose and insulin levels after ingestion of both food volumes.

CONCLUSION

Food volume has only limited influence on satiety state directly after meal consumption but not glucose and insulin plasma concentrations.

Smoking during pregnancy and offspring fat and lean mass in childhood

OBJECTIVE

Maternal smoking during pregnancy has been shown to be associated with obesity in the offspring, but findings have been based mainly on BMI, which is derived from height and weight. This study examined the association between maternal and partner smoking during pregnancy and offspring total fat, truncal fat, and lean mass in childhood.

RESEARCH METHODS AND PROCEDURES

Analysis was based on 5689 white singletons born in 1991-1992 and enrolled in the Avon Longitudinal Study of Parents and Children, with maternal smoking data recorded for at least one trimester in pregnancy and their own body composition assessed by DXA at mean age 9.9 years.

RESULTS

Smoking at any time during pregnancy was associated with higher offspring BMI [0.18 (95% confidence interval, 0.12 to 0.25) standard deviation units] and total fat mass [0.17 (95% confidence interval, 0.12 to 0.23) standard deviation units], after adjustment for age, sex, height, and height squared for total fat mass. These associations were not attenuated by adjustment for the confounding factors that were measured. Maternal smoking was also associated with lean mass and, to a lesser extent, truncal fat mass. Associations with partner's smoking were in the same direction but weaker than those of the mother's for all outcomes.

DISCUSSION

Maternal smoking at any time during pregnancy is associated with higher offspring total fat mass at mean age 9.9 years. However, as the associations with partner smoking were only a little weaker than those with maternal smoking, confounding by social factors rather than a direct effect of maternal smoking is a possible explanation.

Delivery of RNAi reagents in murine models of obesity and diabetes

RNA interference (RNAi) is an exciting new tool to effect acute in vivo knockdown of genes for pharmacological target validation. Testing the application of this technology to metabolic disease targets, three RNAi delivery methods were compared in two frequently utilized preclinical models of obesity and diabetes, the diet-induced obese (DIO) and B6.V-Lep<ob>/J (ob/ob) mouse. Intraperitoneal (i.p.) and high pressure hydrodynamic intravenous (i.v.) administration of naked siRNA, and low pressure i.v. administration of shRNA-expressing adenovirus were assessed for both safety and gene knockdown efficacy using constructs targeting cJun N-terminal kinase 1 (JNK1). Hydrodynamic delivery of siRNA lowered liver JNK1 protein levels 40% in DIO mice, but was accompanied by iatrogenic liver damage. The ob/ob model proved even more intolerant of this technique, with hydrodynamic delivery resulting in severe liver damage and death of most animals. While well-tolerated, i.p. injections of siRNA in DIO mice did not result in any knockdown or phenotypic changes in the mice. On the other hand, i.v. injected adenovirus expressing shRNA potently reduced expression of JNK1 in vivo by 95% without liver toxicity. In conclusion, i.p. and hydrodynamic injections of siRNA were ineffective and/or inappropriate for in vivo gene targeting in DIO and ob/ob mice, while adenovirus-mediated delivery of shRNA provided a relatively benign and effective method for exploring liver target silencing.

Secular trends in patterns of self-reported food consumption of adult Americans: NHANES 1971-1975 to NHANES 1999-2002

BACKGROUND

The contributors to trends in increasing prevalence of obesity in the US population are poorly understood.

OBJECTIVE

We examined secular trends in food consumption behaviors to understand their possible contribution to increasing energy intakes and adiposity in the American population.

DESIGN

We used dietary data from 4 consecutive National Health and Nutrition Examination Surveys (NHANES) to examine trends (1971-2002) in frequency of eating episodes, meal and snack consumption, quantity of food consumed, and the energy density of foods reported by adult Americans (n = 39 094). Logistic and linear regression methods were used to adjust for multiple covariates and survey design.

RESULTS

The reported number of all eating episodes increased slightly in women from 4.90 in 1971-1975 to 5.04 in 1999-2002 (P for trend = 0.002). The amount (in g) of foods and beverages consumed, the energy density of foods, and energy intake per eating episode increased, but the mention of breakfast declined in both sexes (P for trend < 0.0001). The observed trends in mention of a snack (in men) and percentage of energy from evening food intake (in women) were downward. The amount (in g) of foods and their energy density were independent positive correlates of obesity in combined data from all surveys (P for trend < 0.0001).

CONCLUSIONS

Our results do not support large increases in eating frequency, snacking, or evening eating by the American population from 1971 to 2002. The quantity of foods and their energy density increased beginning in NHANES III (1988-1994) with trajectories roughly parallel to the rates of prevalence of obesity in the US population. However, we urge cautious interpretation of these results because of concurrent changes in dietary methods during this period.

Fat mass gain is lower in calcium-supplemented than in unsupplemented preschool children with low dietary calcium intakes

BACKGROUND

Dietary calcium may play a role in the stimulation of lipolysis and the inhibition of lipogenesis, thereby reducing body fat.

OBJECTIVE

The aim was to determine whether an association existed between change in percentage body fat (%BF) or fat mass and calcium intake in children aged 3-5 y.

DESIGN

A secondary analysis of a 1-y randomized calcium and activity trial in 178 children was conducted. Three-day diet records and 48-h accelerometer readings were obtained at 0, 6, and 12 mo. Body composition was measured by dual-energy X-ray absorptiometry at 0 and 12 mo.

RESULTS

The decrease in %BF was less in girls (-0.6 +/- 2.8%) than in boys (-1.5 +/- 2.6%; P = 0.03) and correlated with age (r = 0.19, P = 0.01) and maternal body mass index (r = 0.19, P = 0.02). Changes in fat mass were not significantly different by activity group or between children randomly assigned to receive calcium or placebo (0.5 +/- 0.9 and 0.6 +/- 0.8 kg, respectively; P = 0.32). Similar findings were observed for the change in %BF. No correlations between %BF and fat mass changes and dietary calcium (r = -0.01, P = 0.9 and r = -0.05, P = 0.5) or total (dietary + supplement) calcium intake (r = -0.02, P = 0.8 and r = -0.06, P = 0.4) were observed. Among children in the lowest tertile of dietary calcium (<821 mg/d), fat mass gain was lower in the calcium group (0.3 +/- 0.5 kg) than in the placebo group (0.8 +/- 1.1 kg) (P = 0.04) but was not correlated with mean total calcium intake (r = -0.20).

CONCLUSION

These findings support a weak relation between changes in fat mass gain and calcium intake in preschool children, who typically consume below recommended amounts of dietary calcium.

Improvements in systemic metabolism, anthropometrics, and left ventricular geometry 3 months after bariatric surgery

BACKGROUND

Several lines of evidence have suggested a link between obesity and heart failure, including chronic inflammation, increased sympathetic tone, and insulin resistance. The goal of this study was to evaluate the changes in systemic metabolism, anthropometrics, and left ventricular (LV) contraction, as well as geometry, in clinically severe obese women after bariatric surgery.

METHODS

Enrollment was offered consecutively to 22 women with clinically severe obesity. Participants underwent abdominal magnetic resonance imaging to quantify the visceral adipose tissue (VAT) area and tissue Doppler imaging echocardiography to measure the LV contractile function. Fasting blood chemistries were drawn to measure inflammatory markers and to calculate insulin sensitivity. All tests were performed before surgery and 3 months postoperatively.

RESULTS

Three months after surgery, a significant increase in insulin sensitivity (mean change +/- SEM 34.0 +/- 10.4, P < .0001) was present. The VAT area had significantly decreased (-66.1 +/- 17.8 cm2, P = .002) and was associated with decreases in body mass index, serum glucose concentrations, and high-sensitivity C-reactive protein levels (r = .61 and P = .005, r = .48 and P = .033, and r = .53 and P = .016, respectively). The LV mass decreased significantly (-3.8 +/- 1.7 g/m(2.7), P = .037), and this decrease was associated with a decrease in glucose concentration (r = .46, P = .041). The LV systolic and diastolic contractile function were normal at baseline, and no change occurred after surgery.

CONCLUSION

The early phase of weight loss after bariatric surgery produces favorable changes in LV geometry, and these are associated with normalization in the glucose metabolism.

Effects on weight reduction and safety of short-term phentermine administration in Korean obese people

The phentermine, an appetite suppressant, has been widely applied in Korea since 2004. However, there have been relatively few reports about the efficacy and the safety of phentermine in Korea. The aim of this study is to verify the effect of phentermine on weight reduction and the safety in Korean patients. This randomized, double-blind, placebo- controlled study had been performed between February and July, 2005, in Seoul on 68 relatively healthy obese adults whose body mass index was 25 kg/m2 or greater. They received phentermine-HCl 37.5 mg or placebo once daily with behavioral therapy for obesity. The primary endpoints were the changes of body weight and waist circumference from the baseline in the intention-to-treat population. Mean decrease of both body weight and waist circumference in phentermine-treated subjects were significantly greater than that of placebo group (weight: -6.7 +/- 2.5 kg, p < 0.001; waist circumference: -6.2 +/- 3.5 cm, p < 0.001). Significant number of subjects in phentermine group accomplished weight reduction of 5% or greater from the baseline and 10% or more (p < 0.001). There were no significant differences in systolic and diastolic blood pressure between the groups (p = 0.122 for systolic BP; p = 0.219 for diastolic BP). Dry mouth and insomnia were the only statistically significant adverse events that occurred more frequently in phentermine group. Most side effects of phentermine were mild to moderate in intensity. Short-term phentermine administration induced significant weight reduction and reduction of waist circumference without clinically problematic adverse events on relatively healthy Korean obese people.

A polymorphism in New Zealand inbred mouse strains that inactivates phosphatidylcholine transfer protein

New Zealand obese (NZO/HlLt) male mice develop polygenic diabetes and altered phosphatidylcholine metabolism. The gene encoding phosphatidylcholine transfer protein (PC-TP) is sited within the support interval for Nidd3, a recessive NZO-derived locus on Chromosome 11 identified by prior segregation analysis between NZO/HlLt and NON/Lt. Sequence analysis revealed that the NZO-derived PC-TP contained a non-synonymous point mutation that resulted in an Arg120His substitution, which was shared by the related NZB/BlNJ and NZW/LacJ mouse strains. Consistent with the structure-based predictions, functional studies demonstrated that Arg120His PC-TP was inactive, suggesting that this mutation contributes to the deficiencies in phosphatidylcholine metabolism observed in NZO mice.

Myostatin modulates adipogenesis to generate adipocytes with favorable metabolic effects

A pluripotent cell line, C3H10T1/2, is induced to undergo adipogenesis by a mixture of factors that includes a glucocorticoid such as dexamethasone. We found that expression of myostatin (MSTN), a TGF-beta family member extensively studied in muscle, was induced by dexamethasone under those differentiation conditions. Moreover, MSTN could substitute for dexamethasone in the adipogenesis mixture. However, the adipocytes induced by MSTN in both cell culture and transgenic mice were small and expressed markers characteristic of immature adipocytes. These adipocytes exhibited cell-autonomous increases in insulin sensitivity and glucose oxidation. In mice, these effects produced elevated systemic insulin sensitivity and resistance to diet-induced obesity. Modulation of the final stages of adipogenesis may provide a novel approach to understanding and treating metabolic disease.

[Impact of impaired carbohydrate metabolism on the course of coronary heart disease]

In patients with coronary heart disease (CHD) and periodically recorded impaired fasting glycemia, the Incidence of impaired glucose tolerance and type 2 diabetes mellitus was 61.6 and 17.8%, respectively. CHD patients with a history of carbohydrate metabolic disturbance were observed to have hyperinsulinemia on fasting and 2 hours after glucose load. In these patients, ambiguous changes were found in C-peptide 2 hours following glucose load. Changes were ascertained in the lipid spectrum.

Effects of binge eating on satiation, satiety, and energy intake of overweight children

BACKGROUND

Children who report episodes of binge eating gain more weight than do children not reporting binge eating. However, how binge eating affects children's food intake at meals is unknown.

OBJECTIVE

We compared the energy intake and postmeal satiety of children with and without a history of binge eating during buffet meals.

DESIGN

Sixty overweight children aged 6-12 y were categorized into those reporting past binge-eating episodes (n = 10) and those reporting no such episodes (n = 50). Children selected lunch twice from a multiple-item, 9835 kcal, buffet meal: after an overnight fast and after a standardized breakfast. Children ate ad libitum, until they reported they were full. The main outcome measures were energy intake during meals and duration of postmeal satiety, after adjustment for covariates, including age, race, sex, socioeconomic status, and body composition.

RESULTS

After the overnight fast, children in the binge-eating group consumed more energy [x (+/-SD): 1748 +/- 581 compared with 1309 +/- 595 kcal; P = 0.04] and exhibited a shorter satiety duration (194 +/- 84 compared with 262 +/- 89 min; P = 0.03) than did children in the non-binge-eating group. After the standardized breakfast, binge-eating children reported a shorter satiety duration (75 +/- 62 compared with 132 +/- 62 min; P = 0.01) and consumed more energy at the postbreakfast meal (1874 +/- 560 compared with 1275 +/- 566 kcal; P = 0.004).

CONCLUSION

The ability to consume large quantities of palatable foods, coupled with decreased subsequent satiety, may play a role in the greater weight gain found in binge-eating children.

Type 2 diabetes in children: a growing epidemic

In the pediatric population, type 2 diabetes has become a growing concern. A correlation appears to exist among type 2 diabetes in children, obesity, and a sedentary lifestyle. If obesity and diabetes are left untreated, conditions such as cardiovascular disease, nephropathy, and retinopathy may result as well. These conditions indicate the incredible strain on the health care system caused by diabetes and obesity. This strain may be eased by logical treatments such as exercise and healthy eating habits for the child and family. However, these lifestyle changes are not always effective in controlling blood sugar. When lifestyle changes do not yield positive results, the clinician must decide which (if any) pharmacological treatments are safe to use in the pediatric population. Orlistat and sibutramine have been studied in children as treatments for obesity and appear to be safe and effective for this population. Metformin and insulin are among the medications approved to treat diabetes in children and adolescents. Healthcare practitioners must play a role in educating parents and their children about the effects of obesity on the development of diseases like diabetes, as well as various therapies used to manage diabetes. In addition, healthcare practitioners can assist patients and their parents in understanding the benefits and risks of medications used in the treatment of the disease, assistance that may result in them making informed decisions regarding their overall health.

Obesity rates among rural Ontario schoolchildren

BACKGROUND

The majority of existing studies of obesity risk among Canadian children come from urban populations. The purpose of this study is to assess the prevalence of obesity in a sample of rural Ontario children.

METHODS

Measures of height and weight were obtained for 504 children attending seven public elementary schools in Grey and Bruce Counties, a predominantly rural area of Southern Ontario. Body mass index (BMI, or weight/height2) scores were calculated and compared with reference data from the Centers for Disease Control.

RESULTS

Rates of overweight and obesity were high in this sample, with 17.7% of children classified as overweight and 10.9% classified as obese. There was a significantly high prevalence of overweight for both boys (17.8%) and girls (17.5%) (Chi-square = 75.70, p < 0.001). However there was a significant gender difference in obesity prevalence: 15.0% of boys were obese, compared with 6.8% of girls (Mann-Whitney U = 29133.0, p > 0.05).

CONCLUSION

Findings indicate that among rural children--particularly boys--risk of overweight and obesity are at least as high as in their urban Canadian counterparts. There appear to be fewer girls than boys at the extreme high end of the distribution of BMI, which may indicate differences in the growth environment of rural boys and girls.

WATCH IT: a community based programme for obese children and adolescents

BACKGROUND

The WATCH IT programme was developed to address the needs of obese children from disadvantaged communities in Leeds and has been running since January 2004. Results of the pilot phase, prior to a randomised controlled trial, are presented.

METHODS

A process evaluation to assess success of implementation was conducted in December 2004. User views (parent and child) were obtained by semi-structured interviews and focus groups. Change in BMI SD score was calculated for children attending between January 2004 and November 2005.

RESULTS

A total of 94 children (49 girls, 45 boys), mean age (SD) 12.2 (2.0) years attended. They were moderately to severely obese (mean BMI SDS 3.09 (0.45), with low quality of life and self-image scores. There was a significant reduction in overweight at 6 months (DeltaBMI SD -0.07), especially for teenagers (DeltaBMI SD -0.13) and girls (DeltaBMI SD -0.07). The programme was successfully implemented. By December 2004 mean attendance was 2.1 (0.7) clinics per month, and sports sessions 3.3 (1.7) sessions per month. Fourteen children dropped out and non-attendance was low (only 7.5% sessions missed in 12 months). Qualitative research indicated significant appreciation of the service, with reported increase in self-confidence and friendships, and reduction in self-harm.

CONCLUSION

WATCH IT offers a model for a community based service for obese children. The programme suggests that effective care can be delivered by health trainers supervised by health professionals, and so potentially provides a cost effective programme within children's communities. These findings are encouraging, and need to be substantiated by extension to other locations and evaluation by randomised controlled trial.

Primary care support for tackling obesity: a qualitative study of the perceptions of obese patients

BACKGROUND

Obesity has become a major public health issue and there is concern about the response of health services to patients who are obese. The perceptions of obese patients using primary care services have not been studied in depth.

AIM

To explore obese patients' experiences and perceptions of support in primary care.

DESIGN OF STUDY

Qualitative study with semi-structured interviews conducted in participants' homes.

SETTING

Five general practices contrasting in socioeconomic populations in Sheffield.

METHOD

Purposive sampling and semi-structured interviewing of 28 patients with a diverse range of ages, backgrounds, levels of obesity and experiences of primary care services.

RESULTS

Participants typically felt reluctance when presenting with concerns about weight and ambivalence about the services received. They also perceived there to be ambivalence and a lack of resources on the part of the health services. Participants showed a strong sense of personal responsibility about their condition and stigma-related cognitions were common. These contributed to their ambivalence about using services and their sensitivity to its features. Good relationships with primary care professionals and more intensive support partly ameliorated these effects.

CONCLUSION

The challenges of improving access to and quality of primary care support in tackling obesity are made more complex by patients' ambivalence and other effects of the stigma associated with obesity.

The burden of obesity among a national probability sample of veterans

BACKGROUND

Few national data exist about the prevalence of obesity and the resulting health burden among veterans.

METHODS

We analyzed data from the 2003 Behavioral Risk Factor Surveillance System (n = 242,362) to compare rates of obesity among veterans who do and do not utilize the VA, compared with nonveterans. We used bivariate analyses to describe the association of obesity with lifestyle factors, disability, and comorbid disease, and multivariate analysis to assess the independent association of obesity with VA care.

RESULTS

Veterans who use the VA for health care have the highest rates of obesity compared with veterans who do not use the VA and nonveterans (27.7% vs 23.9% vs 22.8%, P < .001). Only 27.8% of veterans who receive health care at the VA are of normal weight (vs 42.6% of the general population, P < .001), 44.5% are overweight, 19.9% have class I obesity, 6% have class II obesity, and 1.8% are morbidly obese (an estimated 82,950 individuals). Obese veterans who utilize the VA for services have higher rates of hypertension (65.8%) and diabetes (31.3%), are less likely to follow diet and exercise guidelines, and more likely to report poor health and disability than their normal-weight counterparts.

CONCLUSIONS

Veterans who receive care at the VA have higher rates of overweight and obesity than the general population. At present, less than half of VA medical centers have weight management programs. As the largest integrated U.S. health system, the VA has a unique opportunity to respond to the epidemic of obesity.

Combating the epidemic of obesity and cardiovascular disease: perspectives from school-aged children

This study was designed to assess students' perceptions of the obstacles to positive dietary practices and increased physical activity and to solicit the students' recommendations for addressing and possibly reducing the negative practices that are associated with the rise in obesity and the development of cardiovascular diseases. Data for the study were obtained from the administration of the 2005 Project Health High School Survey (PHHSS) which measured the students' perceptions regarding obstacles to eating more nutritious, healthier foods and obstacles to participating in daily physical activity. The reasons for students' lack of interest in practicing more life-healthy behaviors are ranked and recorded. Some of the students indicated that they usually ate what they liked to eat, and the decision about what to eat was made because of the taste of the food without regard for any health consequence or negative health outcomes. Finding ways to reach these students at their young ages is the key to successfully combating the high prevalence of obesity and the development of other chronic diseases in childhood, as well as in adulthood.

Exercise restores skeletal muscle glucose delivery but not insulin-mediated glucose transport and phosphorylation in obese subjects

CONTEXT/OBJECTIVE

Insulin resistance in obese subjects results in the impaired disposal of glucose by skeletal muscle. The current study examined the effects of insulin and/or exercise on glucose transport and phosphorylation in skeletal muscle and the influence of obesity on these processes.

SUBJECTS/METHODS

Seven obese and 12 lean men underwent positron emission tomography with 2-deoxy-2-[(18)F]fluoro-d-glucose in resting and isometrically exercising skeletal muscle during normoglycemic hyperinsulinemia. Data were analyzed by two-tissue compartmental modeling. Perfusion and oxidative capacity were measured during insulin stimulation by [15O]H2O and [15O]O2.

RESULTS

Exercise increased glucose fractional uptake (K), inward transport rate (K(1)), and the k(3) parameter, combining transport and intracellular phosphorylation, in lean and obese subjects. In each group, there was no statistically significant difference between plasma flow and K(1). At rest, a significant defect in K(1) (P = 0.0016), k(3) (P = 0.016), and K (P = 0.022) was found in obese subjects. Exercise restored K(1), improved but did not normalize K (P = 0.03 vs. lean), and did not ameliorate the more than 60% relative impairment in k(3) in obese individuals (P = 0.002 vs. lean). The glucose oxidative potential tended to be reduced by obesity.

CONCLUSIONS/INTERPRETATION

The study indicates that exercise restores the impairment in insulin-mediated skeletal muscle perfusion and glucose delivery associated with obesity but does not normalize the defect involving the proximal steps regulating glucose disposal in obese individuals. Our data support the use of 2-deoxy-2-[18F]fluoro-d-glucose-positron emission tomography in the dissection between substrate supply and intrinsic tissue metabolism.

The metabolic syndrome - background and treatment

The metabolic syndrome (MBS) is characterised by a clustering of cardiovascular and metabolic risk factors. This syndrome is now widely recognised as a distinct pathological entity, and it is receiving a great deal of attention in the medical literature but also in the lay press. Globally speaking, persons with MBS have a clustering of the following risk factors: [List: see text] MBS is associated with important cardio/cerebrovascular and metabolic risks. Prevention and treatment are therefore of great importance. Preventive measures involving lifestyle are mandatory. In addition, MBS patients require pharmacological treatment, usually for the rest of their lives. Complex patterns of drug treatment will be required, since all the different, heterogenous pathophysiological problems will require appropriate treatment. After an introduction to MBS, this article provides an extensive and critical review of the drug treatment of this complex pathological entity.

Sex difference in body weight gain and leptin signaling in hypocretin/orexin deficient mouse models

Recent studies in human and animal models of narcolepsy have suggested that obesity in narcolepsy may be due to deficiency of hypocretin signaling, and is also under the influence of environmental factors and the genetic background. In the current study, using two hypocretin/orexin deficient narcoleptic mouse models (i.e. preproorexin knockout (KO) and orexin/ataxin-3 transgenic (TG) mice) with cross-sectional assessments, we have further analyzed factors affecting obesity. We found that both KO and TG narcoleptic mice with mixed genetic backgrounds (N4-5, 93.75-96.88% genetic composition of C57BL/6) tended to be heavier than wild type (WT) mice of 100-200 days old. The body weight of heterozygous mice was intermediate between those of KO and WT mice. Obesity was more prominent in females in both KO and TG narcoleptic mice and was associated with higher serum leptin levels, suggesting a partial leptin resistance. Obesity is less prominent in the congenic TG narcoleptic mice, but is still evident in females. Our results confirmed that hypocretin/orexin ligand deficiency is one of the critical factors for the obese tendency in narcolepsy. However, multiple factors are also likely to affect this phenotype, and a sex difference specific alteration of leptin-hypocretin signaling may be involved.

Diet variety based on macronutrient intake and its relationship with body mass index

CONTEXT

Increased dietary variety has been associated with increased body weight; however, diet variety is not measured using a standardized methodology.

OBJECTIVE

We developed a new dietary variety score (DVS) based on food macronutrient content, and determined the relationship between DVS and measures of adiposity.

DESIGN

Cross-sectional, observation study.

SETTING

University of Alabama at Birmingham (UAB), EatRight Weight Management Program.

PATIENTS

Study subjects (n = 74) were former participants of UAB's EatRight Weight Management Program who completed the program at least 1 year ago.

MAIN OUTCOME MEASURES

Unique items from 4-day food records were converted to macronutrient categories using the diabetic exchange. Foods were categorized as a source of carbohydrate if containing > or = 5 g carbohydrate and > or = 20 calories; fat if containing > or = 5 g fat; protein if containing > or = 7 g protein. Height and weight were measured; BMI (kg/m2) was calculated. Dual energy X-ray absorptiometry measured body fat. Generalized linear modeling in SAS (Ver.9) determined relationships between adiposity and DVS.

RESULTS

On average, participants weighed 92.7 -/+ 30.9 kg (BMI = 32.5 kg/m2). Men and women's body fat were 37.4 -/+ 6.4% and 47.3 -/+ 6.4%, respectively. Separate linear regression models containing terms for sex and DVS showed significant relationships between macronutrient DVS and BMI. In a multivariate model controlling for each of the macronutrient DVS, BMI was not related to fat DVS, but was found to be positively related to protein DVS (beta = 0.87, P = .04). Sex modified the relationship between carbohydrate DVS and BMI, with an inverse relationship between BMI and carbohydrate DVS among women, and a positive relationship among men. Percent body and trunk fat were not related to DVS for either gender.

CONCLUSIONS

The new DVS, based on macronutrient content of foods, had significant associations with BMI. These dietary variety scores may provide another way to evaluate the impact of consuming a variety of food types on energy intake and BMI.

Intake of sugar-sweetened beverages and weight gain: a systematic review

Consumption of sugar-sweetened beverages (SSBs), particularly carbonated soft drinks, may be a key contributor to the epidemic of overweight and obesity, by virtue of these beverages' high added sugar content, low satiety, and incomplete compensation for total energy. Whether an association exists between SSB intake and weight gain is unclear. We searched English-language MEDLINE publications from 1966 through May 2005 for cross-sectional, prospective cohort, and experimental studies of the relation between SSBs and the risk of weight gain (ie, overweight, obesity, or both). Thirty publications (15 cross-sectional, 10 prospective, and 5 experimental) were selected on the basis of relevance and quality of design and methods. Findings from large cross-sectional studies, in conjunction with those from well-powered prospective cohort studies with long periods of follow-up, show a positive association between greater intakes of SSBs and weight gain and obesity in both children and adults. Findings from short-term feeding trials in adults also support an induction of positive energy balance and weight gain by intake of sugar-sweetened sodas, but these trials are few. A school-based intervention found significantly less soft-drink consumption and prevalence of obese and overweight children in the intervention group than in control subjects after 12 mo, and a recent 25-week randomized controlled trial in adolescents found further evidence linking SSB intake to body weight. The weight of epidemiologic and experimental evidence indicates that a greater consumption of SSBs is associated with weight gain and obesity. Although more research is needed, sufficient evidence exists for public health strategies to discourage consumption of sugary drinks as part of a healthy lifestyle.

Chronic 5-HT6 receptor modulation by E-6837 induces hypophagia and sustained weight loss in diet-induced obese rats

E-6837 is a novel, selective and high-affinity 5-HT(6) receptor ligand (pK(i): 9.13) which in vitro demonstrates partial agonism at a presumably silent rat 5-HT(6) receptor and full agonism at a constitutively active human 5-HT(6) receptor by monitoring the cAMP signaling pathway.The effects of chronic treatment with E-6837 were determined in diet-induced obese (DIO)-rats on changes in body weight, food and water intake, plasma indices of comorbid risk factors, and weight regain on compound withdrawal. The centrally acting antiobesity drug, sibutramine, was used as the reference comparator. Sustained body weight loss and decreased cumulative food intake of DIO-rats was observed with E-6837 (30 mg kg(-1), p.o., twice a day) during the 4-week treatment period. The onset of the E-6837 effect on body weight was slower than that of sibutramine (5 mg kg(-1), p.o.), while its maximal effect was greater, that is -15.7 versus -11.0%.E-6837-induced weight loss was exclusively mediated by a decrease (31.7%) in fat mass, with a concomitant reduction (49.6%) in plasma leptin. Reduced obesity was also reflected in improved glycemic control. Although weight regain occurred after withdrawal from either compound, the body weights after E-6837 (-6.6%) remained lower than after sibutramine (-3.8%) indicating that the greater efficacy of the former did not result in profound rebound hyperphagia/weight gain. These results show that the 5-HT(6) receptor partial agonist, E-6837, is a promising new approach to the management of obesity with the potential to produce greater sustained weight loss than sibutramine.

Metabolic imprinting: critical impact of the perinatal environment on the regulation of energy homeostasis

Epidemiological studies in humans suggest that maternal undernutrition, obesity and diabetes during gestation and lactation can all produce obesity in offspring. Animal models have allowed us to investigate the independent consequences of altering the pre- versus post-natal environments on a variety of metabolic, physiological and neuroendocrine functions as they effect the development in the offspring of obesity, diabetes, hypertension and hyperlipidemia (the 'metabolic syndrome'). During gestation, maternal malnutrition, obesity, type 1 and type 2 diabetes and psychological, immunological and pharmacological stressors can all promote offspring obesity. Normal post-natal nutrition can reduce the adverse impact of some of these pre-natal factors but maternal high-fat diets, diabetes and increased neonatal access to food all enhance the development of obesity and the metabolic syndrome in offspring. The outcome of these perturbations of the perinatal environmental is also highly dependent upon the genetic background of the individual. Those with an obesity-prone genotype are more likely to be affected by factors such as maternal obesity and high-fat diets than are obesity-resistant individuals. Many perinatal manipulations appear to promote offspring obesity by permanently altering the development of central neural pathways, which regulate food intake, energy expenditure and storage. Given their strong neurotrophic properties, either excess or an absence of insulin and leptin during the perinatal period are likely to be effectors of these developmental changes. Because obesity is associated with an increased morbidity and mortality and because of its resistance to treatment, prevention is likely to be the best strategy for stemming the tide of the obesity epidemic. Such prevention should begin in the perinatal period with the identification and avoidance of factors which produce permanent, adverse alterations in neural pathways which control energy homeostasis.

Psychophysics of sweet and fat perception in obesity: problems, solutions and new perspectives

Psychophysical comparisons seem to show that obese individuals experience normal sweet and fat sensations, they like sweetness the same or less, but like fat more than the non-obese do. These psychophysical comparisons have been made using scales (visual analogue or category) that assume intensity labels (e.g. extremely) which denote the same absolute perceived intensity to all. In reality, the perceived intensities denoted by labels vary because they depend on experiences with the substances to be judged. This variation makes comparisons invalid. Valid comparisons can be made by asking the subjects to rate their sensory/hedonic experiences in contexts that are not related to the specific experiences of interest. Using this methodology, we present the evidence that the sensory and hedonic properties of sweet and fat vary with body mass index. The obese live in different orosensory and orohedonic worlds than do the non-obese; the obese experience reduced sweetness, which probably intensifies fat sensations, and the obese like both sweet and fat more than the non-obese do. Genetic variation as well as taste pathology contribute to these results. These psychophysical advances will impact experimental as well as clinical studies of obesity and other eating disorders.

The art and complexity of primary care clinicians' preventive counseling decisions: obesity as a case study

PURPOSE

Studies have often shown low rates of preventive counseling in primary care, and interventions aimed at improving counseling rates have had disappointing results. Using obesity as a case study, we looked for factors that influence clinicians' decisions to include preventive counseling in the brief primary care encounter.

METHODS

A sequential, mixed methods study was conducted among clinicians in RIOS (Research Involving Outpatient Settings) Net, a Southwestern US practice-based research network. Thirty primary care clinicians participated in in-depth interviews or analytic focus groups, and 75% of 195 network members responded to a survey used to estimate the frequency of factors influencing decisions to undertake preventive counseling.

RESULTS

Clinicians described a complex set of factors that influence decisions to provide preventive counseling for obesity. These can be grouped into 2 sets of factors: (1) relatively stable factors that "set the stage" for the encounter, such as the clinician's life values, definitions of success, and the availability of community resources; and (2) factors that are more dynamic, exerting their influence "as the door opens" into the examination room. These factors include the patient's agenda and receptivity to the proposed counseling, as well as the presence of teachable moments. Clinician, patient, and external factors are found in both groups.

CONCLUSIONS

Clinician decisions to include obesity and other types of preventive counseling in the brief encounter reflect the art and complexity of management of the encounter. Future efforts to enhance the delivery of preventive counseling will need to move beyond linear models of behavior change to recognize this complex environment.

Physical Activity, Overweight, and Perceptions of Neighborhood Environments Among Portuguese Girls

BACKGROUND

The purpose of this study was 1) to compare physical activity levels according to body-mass index; 2) to determine which, if any, neighborhood perceived attributes were related to overweight.

METHODS

The sample comprised 610 girls age 14.7 ± 1.6 y. Girls were grouped into normal weight and overweight. Environmental variables and physical activity were assessed by questionnaire.

RESULTS

No significant differences were found in physical activity levels between normal weight and overweight girls. Logistic regression analysis revealed that girls who agreed that "there is so much traffic on the streets that it makes it unpleasant to walk in the neighborhood" were more likely to be overweight (OR = 1.78; 95% CI 1.10 to 2.89).

CONCLUSION

The study found no relationship between perceptions of the environment and overweight among Portuguese girls, except for perceptions of security for walking in the neighborhood.

Dietary factors related to higher plasma fibrinogen levels of Japanese-americans in hawaii compared with Japanese in Japan

OBJECTIVE

We investigated whether dietary factors explain higher plasma fibrinogen levels in Japanese emigrants living a Western lifestyle in Hawaii compared with Japanese in Japan.

METHODS AND RESULTS

Plasma fibrinogen and nutrient intakes were examined by standardized methods in men and women 40 to 59 years of age from a Japanese-American sample in Hawaii (100 men and 106 women) and 4 population samples in Japan (569 men and 567 women). Multiple linear regression models were used to examine the relationship between dietary factors and the plasma fibrinogen difference between Hawaii and Japan. Average plasma fibrinogen was significantly higher in Hawaii compared with Japan (P<0.001 in both genders). In multiple linear regression analyses with each dietary variable considered separately, body mass index reduced the plasma fibrinogen difference between Hawaii and Japan by 20.4%; iron intake (mg/1000 kcal) and estimated total sugar intake (%kcal) reduced this difference by 30.0% and 14.4%, respectively. In a model that included body mass index, iron, estimated total sugars, and caffeine (also age and gender), this difference was reduced by 61.3% (from 42.2 to 16.3 mg/dL).

CONCLUSIONS

Higher intake of iron, sugar, and caffeine, in addition to obesity, account largely for higher fibrinogen levels with Westernized lifestyle.

Obesity in childhood and adolescence: evidence based clinical and public health perspectives

A global epidemic of paediatric obesity occurred in recent years, and prevalence of obesity is continuing to rise. In the developed world obesity is now the most common disease of childhood and adolescence. Paediatric obesity is not a cosmetic issue, being associated with a significant burden of ill health both for obese children and for adults who were obese as children. Health professionals tend to underestimate the impact of paediatric obesity, and lack the skills, knowledge, and time to treat it effectively. This short review aims to summarise recent systematic reviews on the origins, consequences, prevention, and treatment of paediatric obesity.

A cardiologist's guide to waist management

Clinical management of obesity remains a challenge.

[Prevalence of obesity in the Republic of Daghestan]

Monitoring of body mass in the dwellers of this or that region is of indisputable value for practical public health. The sample size (n = 1,500) required to study of the prevalence of obesity among the population was calculated in terms of the size of the population of the Republic of Daghestan, by using the well-known formula. The median of age was 27 years, from 14 to 79 years, its mean was 34 years; the standard deviation was 17.4. The distribution of the obtained values of the body mass index did not correspond to the normal values. The median of body mass indices was 23.9 from 13.95 to 50.15 respectively; quartiles (25%:75%) were 21.45:27.56; percentiles (5%:95%) were (18.59 33.98); the mean was 24.87; the standard deviation was 4.83%. Out of the 1,500 examinees, 65 (4.3%) persons had a low body mass; 801 (53.4%) had a normal body mass; and 416 (27.7%) had an excessive one. Obesity was observed in 218 (14.5%) examinees, including first-, second-, and third-degree obesity in 164 (10.9%), 43 (2.9%), and 11 (0.7%) examinees, respectively. There were some differences (statistically insignificant in some cases) in body mass and obesity in relation to the place of residence (a climatic and geographical zone, town-village), gender, and ethnicity.

Orthopedic complications of overweight in children and adolescents

OBJECTIVE

Few studies have quantified the prevalence of weight-related orthopedic conditions in otherwise healthy overweight children. The goal of the present investigation was to describe the musculoskeletal consequences of pediatric overweight in a large pediatric cohort of children that included severely overweight children.

METHODS

Medical charts from 227 overweight and 128 nonoverweight children and adolescents who were enrolled in pediatric clinical studies at the National Institutes of Health from 1996 to 2004 were reviewed to record pertinent orthopedic medical history and musculoskeletal complaints. Questionnaire data from 183 enrollees (146 overweight) documented difficulties with mobility. In 250, lower extremity alignment was determined by bilateral metaphyseal-diaphyseal and anatomic tibiofemoral angle measurements made from whole-body dual-energy x-ray absorptiometry scans.

RESULTS

Compared with nonoverweight children, overweight children reported a greater prevalence of fractures and musculoskeletal discomfort. The most common self-reported joint complaint among those who were questioned directly was knee pain (21.4% overweight vs 16.7% nonoverweight). Overweight children reported greater impairment in mobility than did nonoverweight children (mobility score: 17.0 +/- 6.8 vs 11.6 +/- 2.8). Both metaphyseal-diaphyseal and anatomic tibiofemoral angle measurements showed greater malalignment in overweight compared with nonoverweight children.

CONCLUSIONS

Reported fractures, musculoskeletal discomfort, impaired mobility, and lower extremity malalignment are more prevalent in overweight than nonoverweight children and adolescents. Because they affect the likelihood that children will engage in physical activity, orthopedic difficulties may be part of the cycle that perpetuates the accumulation of excess weight in children.

Anti-ghrelin Spiegelmer NOX-B11 inhibits neurostimulatory and orexigenic effects of peripheral ghrelin in rats

BACKGROUND AND AIMS

Ghrelin, the natural ligand of the growth hormone secretagogue receptor 1a, is the most powerful peripherally active orexigenic agent known. In rodents, ghrelin administration stimulates growth hormone release, food intake, and adiposity. Because of these effects, blocking of ghrelin has been widely discussed as a potential treatment for obesity. Spiegelmer NOX-B11 is a synthetic l-oligonucleotide, which was previously shown to bind ghrelin. We examined the effects of NOX-B11 on ghrelin induced neuronal activation and food intake in non-fasted rats.

METHODS

Animals received various doses of NOX-B11, inactive control Spiegelmer, or vehicle intravenously. Ghrelin or vehicle was administered intraperitoneally 12 hours later and food intake was measured over four hours. Neuronal activation was assessed as c-Fos-like immunoreactivity in the arcuate nucleus.

RESULTS

Treatment with NOX-B11 30 nmol suppressed ghrelin induced c-Fos-like immunoreactivity in the arcuate nucleus and blocked the ghrelin induced increase in food intake within the first half hour after ghrelin injection (mean 1.13 (SEM 0.59) g/kg body weight; 4.94 (0.63) g/kg body weight versus 0.58 (0.58) g/kg body weight; p<0.0001). Treatment with NOX-B11 1 nmol or control Spiegelmer had no effect whereas treatment with NOX-B11 10 nmol showed an intermediate effect on ghrelin induced food intake.

CONCLUSIONS

Spiegelmer NOX-B11 suppresses ghrelin induced food intake and c-Fos induction in the arcuate nucleus in rats. The use of an anti-ghrelin Spiegelmer could be an innovative new approach to inhibit the biological action of circulating ghrelin. This may be of particular relevance to conditions associated with elevated plasma ghrelin, such as the Prader-Willi syndrome.

Designing Spiegelmers to antagonise ghrelin

Use of an anti‐ghrelin Spiegelmer could be an innovative new approach to inhibit the biological actions of circulating ghrelin

Nonalcoholic Steatohepatitis: Clinical Presentation, Diagnosis, and Treatment

Nonalcoholic fatty liver disease (NAFLD) is reaching epidemic proportions in our society and is the most common etiology for patients presenting with elevated liver enzymes. Given the significant numbers of patients presenting with NAFLD, it is important to distinguish between simple fatty liver and nonalcoholic steatohepatitis (NASH). Whereas simple fatty liver is thought to have a benign prognosis generally, NASH may progress to cirrhosis in a subset of patients. Performance of liver biopsies in all NAFLD patients is not feasible but recent studies have identified several clinical factors that may predict the patients at greatest risk for NASH and advanced fibrosis, and thus biopsy procedures may be confined to the patients meeting these criteria. Treatment remains focused on improving the underlying insulin resistance that is invariably present in the majority of patients. Diet and exercise remain the cornerstone of therapy, but insulin-sensitizing medication and other agents aimed at reducing oxidative stress or fibrosis may be considered as further studies demonstrating efficacy become available.

Childhood asthma and extreme values of body mass index: the Harlem Children's Zone Asthma Initiative

To examine the association between body mass index (BMI) percentile and asthma in children 2-11 years of age, we performed a cross-sectional analysis of 853 Black and Hispanic children from a community-based sample of 2- to 11-year olds with measured heights and weights screened for asthma by the Harlem Children's Zone Asthma Initiative. Current asthma was defined as parent/guardian-reported diagnosis of asthma and asthma-related symptoms or emergency care in the previous 12 months. Among girls, asthma prevalence increased approximately linearly with increasing body mass index (BMI) percentile, from a low of 12.0% among underweight girls (BMI </=5th percentile) to a high of 33.3% among girls at risk for overweight (BMI 85th-94th percentile). Among boys, asthma prevalence was associated in a U-shaped curve with the extremes of BMI percentile, that is, 36.4% among underweight boys, 19.1% among normal weight boys (BMI 6th-84th percentile), and 34.8% among overweight boys (>95th percentile). After adjusting for age, race/ethnicity, and household smoking, among girls, having asthma was associated with being at risk for overweight (odds ratio [OR], 2.6; 95% confidence interval [CI], 1.4-5.0) and being overweight (OR, 2.1; 95% CI, 1.2-3.8) compared to normal weight; among boys, having asthma was associated both with overweight (OR, 2.4; 95% CI, 1.4-4.3) and with underweight (OR, 2.9; 95% CI, 1.1-7.7). Large, prospective studies that include very young children are needed to further explore the observed association between underweight and asthma among boys. Early interventions that concomitantly address asthma and weight gain are needed among pre-school and school-aged children.

Tackling the obesity pandemic: a call for sedentary behaviour research

An emerging threat to public health is seen in the dramatic rise in obesity status of Canadians, especially among young people. In addressing the possible factors responsible for these dramatic increases, this paper outlines the importance of understanding sedentariness as an important health behaviour, distinct from physical activity, and identifying the modifiable determinants of sedentary behaviours.

Etiology of insulin resistance

Type 2 diabetes mellitus is a major cause of morbidity and mortality worldwide, and the prevalence is set to increase dramatically over the coming decades. Understanding the metabolic pathways that lead to type 2 diabetes is therefore an important healthcare objective. Novel investigational techniques based on magnetic resonance spectroscopy (MRS) have allowed real-time insight into the molecular defects in patients with type 2 diabetes, revealing that insulin resistance is a product of decreased insulin-stimulated skeletal muscle glycogen synthesis, which can mostly be attributed to decreased insulin-stimulated glucose transport (Glut 4) activity. This defect appears to be a result of intracellular lipid-induced inhibition of insulin-stimulated insulin-receptor substrate (IRS)-1 tyrosine phosphorylation resulting in reduced IRS-1-associated phosphatidyl inositol 3 kinase activity. The hypothesis that insulin resistance is a result of accumulation of intracellular lipid metabolites (e.g., fatty acyl CoAs, diacylglycerol) in skeletal muscle and hepatocytes is supported by observations in patients and mouse models of lipodystrophy. Furthermore, the increase in hepatic insulin sensitivity observed in patients with type 2 diabetes following weight loss is also accompanied by a significant reduction in intrahepatic fat without any changes in circulating adipocytokines (interleukin-6, resistin, leptin). Finally, recent MRS studies in healthy, lean, elderly subjects and lean insulin-resistant offspring of parents with type 2 diabetes have demonstrated that reduced mitochondrial activity may also lead to increased intramyocellular lipid content and insulin resistance in skeletal muscle in these individuals. In summary, in vivo MRS has proved to be an important tool for elucidating the causal chain of events that causes insulin resistance. Understanding the cellular mechanism(s) of insulin resistance in turn offers the prospect of better targeted and more effective therapeutic interventions for treatment and prevention of type 2 diabetes.

What use is the BMI?

The BMI is the best available tool for monitoring progress in the campaign against obesity

Prevalence of obesity in type 2 diabetes in secondary care: association with cardiovascular risk factors

AIMS

To determine the prevalence of overweight and obesity among patients with type 1 and type 2 diabetes mellitus attending a secondary care diabetes clinic in the United Kingdom, and to assess the impact of overweight and obesity on glycaemic control and cardiovascular risk factors in patients with type 2 diabetes.

METHODS

3637 patients with diabetes were identified from the hospital electronic diabetes register, 916 with type 1 diabetes (mean (SD) age 40.4 (15.1) years, 496 male) and 2721 with type 2 diabetes (mean (SD) age 62.5 (11.8) years, 1436 male). Data on body mass index (BMI), glycaemic control, lipid profiles, and blood pressure were extracted.

RESULTS

Of patients with type 1 diabetes, 55.3% were overweight (BMI >or=25 kg/m(2)), 16.6% were obese (BMI >or=30 kg/m(2)), and 0.4% had morbid obesity (BMI >or=40 kg/m(2)). In contrast, 86% of patients with type 2 diabetes were overweight or obese, 52% were obese, and 8.1% had morbid obesity. Obese patients with type 2 diabetes were younger, had poorer glycaemic control, higher blood pressures, worse lipid profiles, and were more likely to be receiving antihypertensive and lipid lowering drugs compared with patients with BMI <30 kg/m(2).

CONCLUSIONS

Obesity is the rule among patients attending this hospital diabetes clinic, with 86% of those with type 2 diabetes overweight or obese. Obesity is associated with significantly worse cardiovascular risk factors in this patient group, suggesting that more active interventions to control weight gain would be appropriate.

Non-response to antiviral therapy is associated with obesity and increased hepatic expression of suppressor of cytokine signalling 3 (SOCS-3) in patients with chronic hepatitis C, viral genotype 1

BACKGROUND

Interferon alpha (IFN-alpha) activated cellular signalling is negatively regulated by inhibitory factors, including the suppressor of cytokine signalling (SOCS) family. The effects of host factors such as obesity on hepatic expression of these inhibitory factors in subjects with chronic hepatitis C virus (HCV) are unknown.

OBJECTIVES

To assess the independent effects of obesity, insulin resistance, and steatosis on response to IFN-alpha therapy and to determine hepatic expression of factors inhibiting IFN-alpha signalling in obese and non-obese subjects with chronic HCV.

METHODS

A total of 145 subjects were analysed to determine host factors associated with non-response to antiviral therapy. Treatment comprised IFN-alpha or peginterferon alpha, either alone or in combination with ribavirin. In a separate cohort of 73 patients, real time-polymerase chain reaction was performed to analyse hepatic mRNA expression. Immunohistochemistry for SOCS-3 was performed on liver biopsy samples from 38 patients with viral genotype 1 who had received antiviral treatment.

RESULTS

Non-response (NR) to treatment occurred in 55% of patients with HCV genotypes 1 or 4 and 22% with genotypes 2 or 3. Factors independently associated with NR were viral genotype 1/4 (p < 0.001), cirrhosis on pretreatment biopsy (p = 0.025), and body mass index > or = 30 kg/m2 (p = 0.010). Obese subjects with viral genotype 1 had increased hepatic mRNA expression of phosphoenolpyruvate carboxy kinase (p = 0.01) and SOCS-3 (p = 0.047), in comparison with lean subjects. Following multivariate analysis, SOCS-3 mRNA expression remained independently associated with obesity (p = 0.023). SOCS-3 immunoreactivity was significantly increased in obesity (p = 0.013) and in non-responders compared with responders (p = 0.014).

CONCLUSIONS

In patients with chronic HCV viral genotype 1, increased expression of factors that inhibit interferon signalling may be one mechanism by which obesity reduces the biological response to IFN-alpha.

Adiponectin promotes endothelial cell differentiation from human peripheral CD14+ monocytes in vitro

Adiponectin was revealed to have anti-atherogenic and anti-inflammatory properties and has been recently found to stimulate angiogenesis in vivo and in vitro. However, the role of adiponectin in endothelial differentiation remains unclear. The objective of this study was to investigate whether adiponectin can promote peripheral CD14(+) monocytes differentiation into endothelial cells (ECs). Human peripheral blood CD14(+) monocytes were cultured with or without adiponectin (10 microg/ml) for 10 days. Adiponectin significantly promoted EC morphology formation from CD14(+) monocytes. By flow cytometery analysis, cells treated with adiponection substantially increased mean fluorescence intensity of vascular endothelial growth factor receptor-2 (VEGFR-2) and endothelial nitric oxide synthase (eNOS), two specific endothelial markers, by 49.2 % and 53.9 %, respectively, as compared to control cells. By real time PCR analysis, the mRNA level of eNOS in adiponectin-treated cells was also increased by 31.9 % of that of the control cells. However, the mRNA levels of calponin and SMMHC, two specific SMC markers, in adiponectin-treated cells were decreased by 81.1 % and 79.7 % of that of the control cells, respectively. These data demonstrated that adiponectin could promote endothelial differentiation from peripheral blood CD14(+) monocytes by morphology change, upregulation of EC markers and downregulation of SMC markers. Adiponectin-promoted EC differentiation may contribute to vascular healing and angiogenesis.