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PubMed2003

Predictors of 6-minute walk test results in lean, obese and morbidly obese women.

The aim of this study was first, to assess the presence of medical conditions that might interfere with walking; second, to assess the differences in walking capacity, perceived exertion and physical complaints between lean, obese and morbidly obese women; and third, to identify anthropometric, physical fitness and physical activity variables that contribute to the variability in the distance achieved during a 6-minute walk test in lean and obese women. A total of 85 overweight and obese females (18-65 years, body mass index (BMI) > or = 27.5 kg m(-2)), 133 morbidly obese females (BMI > or = 35 kg m-2) and 82 age-matched sedentary lean female volunteers (BMI < or = 26 kg m(-2)) were recruited. Patients suffering from severe musculoskeletal and cardiopulmonary disease were excluded from the study. Prior to the test, conditions that might interfere with walking and hours of TV watching were asked for. Physical activity pattern was assessed using the Baecke questionnaire. Weight, height, body composition (bioelectrical impedance method), isokinetic concentric quadriceps strength (Cybex) and peak oxygen uptake (peakVO2_bicycle ergometer) were measured. A 6-minute walk test was performed and heart rate, walking distance, Borg rating scale of perceived exertion (RPE) and physical complaints at the end of the test were recorded. In obese and particularly in morbidly obese women suffering from skin friction, urinary stress incontinence, varicose veins, foot static problems and pain, wearing insoles, suffering from knee pain, low back pain or hip arthritis were significantly more prevalent than in lean women (P < 0.05). Morbidly obese women (BMI > 35 kg m(-2)N = 133) walked significantly slower (5.4 km h(-1)) than obese (5.9 km h(-1)) and lean women (7.2 km h(-1), P < 0.05), were more exerted (RPE 13.3, 12.8 and 12.4, respectively, P < 0.05) and complained more frequently of dyspnea (9.1%, 4.7% and 0% resp., P < 0.05) and musculoskeletal pain (34.9%, 17.7% and 11.4% resp., P < 0.05) at the end of the walk. In a multiple regression analysis, 75% of the variance in walking distance could be explained by BMI, peakVO2, quadriceps muscle strength age, and hours TV watching or sports participation. These data suggest that in contrast with lean women, walking ability of obese women is hampered not only by overweight, reduced aerobic capacity and a sedentary life style, but also by perceived discomfort and pain. Advice or programs aimed at increasing walking for exercise also need to address the conditions that interfere with walking, as well as perceived symptoms and walking difficulties in order to improve participation and compliance.

Adolescent↗
PubMed2004

Pre-obese and obese agouti mice are sensitive to the anorectic effects of peptide YY(3-36) but resistant to ghrelin.

OBJECTIVE: The role of the melanocortin system in the feeding effects of peripheral peptide YY(3-36) (PYY(3-36)) and ghrelin was investigated using the agouti (A(y)/a) mouse as a model of abnormal melanocortin signalling. Furthermore, we examined whether the ectopic expression of agouti protein in A(y)/a mice results in complete MC4-R inhibition, by studying the effects of peripheral alpha-melanocyte-stimulating hormone (alpha-MSH) and leptin on food intake. DESIGN: Adult A(y)/a mice were studied in the pre-obese state (7-8 weeks) and obese state (14-15 weeks). Animals received PYY(3-36) (0.02 micromol/kg), NDP-alpha-MSH (0.2 micromol/kg), leptin (2 micromol/kg) (all 24 h fasted state) and ghrelin (0.2 micromol/kg) (fed state) by intraperitoneal (i.p.) injection. Age-matched A(y)/a controls received i.p. saline. A separate cohort of wild-type (WT), age-matched controls received the same peptide dose or saline. Food intake was measured at 1, 2, 4, 8 and 24 h post-injection and compared in all four groups. Plasma leptin-, ghrelin- and PYY-like immunoreactivity (IR) were measured using radioimmunoassay (RIA). RESULTS: At 2 h post-injection, PYY(3-36) reduced food intake in pre-obese and obese A(y)/a mice, whereas ghrelin had no effect. Plasma ghrelin levels were significantly reduced in pre-obese and obese A(y)/a mice compared to WT controls. Peripheral administration of NDP-alpha-MSH and leptin acutely suppressed feeding (0-2 h) in pre-obese and obese A(y)/a mice. CONCLUSIONS: Responsiveness of pre-obese and obese A(y)/a mice to PYY(3-36) suggests that the melanocortin system may not be essential for the anorectic effects of this peptide. Melanocortinergic antagonism by agouti protein in A(y)/a mice may be sufficient to block the effects of endogenous, but not exogenous PYY(3-36), alpha-MSH and leptin. The mechanism underlying ghrelin resistance in A(y)/a mice may result from antagonism of hypothalamic melanocortin receptors-4 by agouti protein, supporting a role for the melanocortin system in mediating ghrelin's actions.

Agouti Signaling Protein↗
PubMed1995

Different genes for obesity are associated with insulin loss of regulation of the membrane (Ca2+ + Mg2+)-ATPase in the obesity syndrome. Lessons from animal models.

Intracellular Ca2+ homeostasis is impaired in tissues from obese humans and rats and insulin loses its regulatory effect on the plasma membrane (Ca2+ + Mg2+)-ATPase in kidney basolateral membranes (BLM) from the genetically obese fa/fa rats. We have demonstrated that loss of insulin regulation of the ATPase may impair insulin biologic effects and may therefore contribute to the insulin resistance in the obese rodents. To test whether the defect is restricted to one species or to one gene of obesity, studies were extended to an additional genetically obese rodent of another species the C57BL/6J ob/ob mice. Twelve-weeks-old obese and control male mice were used and (Ca2+ + Mg2+)-ATPase activity and its regulation by insulin were evaluated in their kidney BLM. The obese mice were heavier (56.4 +/- 2.5 vs 30.5 +/- 1.2 g P < 0.05), were hyperinsulinemic (6.32 +/- 1.87 vs 0.59 +/- 0.13 ng/ml P < 0.05) and had decreased (by 80%) specific binding of insulin to their epididymal fat cells compared with their non-obese littermates controls (ob/+, +/+). Yet, non-fasting plasma glucose levels were similar in the obese and control mice (227.0 +/- 19.3 vs 226.8 +/- 13.7 mg/dl N.S.). Basal activity of the (Ca2+ + Mg2+)-ATPase was similar in membranes from the ob/ob and control mice. However, while insulin (1-40 ng/ml) stimulated the ATPase activity in BLM form controls in a dose dependent manner (15-52%), no effect of insulin on the enzyme was seen in BLM from the obese mice even in the presence of the highest (40 ng/ml) concentration of insulin.(ABSTRACT TRUNCATED AT 250 WORDS)

Adipocytes↗
PubMed1991

Obesity among Mescalero preschool children. Association with maternal obesity and birth weight.

The prevalence of obesity among native American children ranks with the highest in the United States. However, little is known about associated risk factors for obesity among these children. We conducted a medical record review of 261 preschool children enrolled in the Mescalero Apache tribe to determine the prevalence of obesity and associated risk factors. The prevalence of obesity (weight for height greater than 95th percentile) in this population was 19.5%. The prevalence of obesity (body mass index greater than 95th percentile) in their mothers was 23%. Children with obese mothers were more than twice as likely to be obese than children of nonobese mothers. Children with a high birth weight were three times as likely to be obese as children of low or normal birth weight. The high prevalence of obesity may be due to both life-style and dietary patterns on the reservation. Family-based interventions are needed to prevent obesity and its long-term consequences in this population.

Birth Weight↗
PubMed1998

Adipose tissue secretion of plasminogen activator inhibitor-1 in non-obese and obese individuals.

High plasma plasminogen activator inhibitor-1 (PAI-1) activity is a frequent finding in obesity, and both PAI-1 and obesity are risk factors for cardiovascular disease. To study the mechanisms underlying increased PAI-1 levels in obese individuals, gene expression and secretion of PAI-1 were measured in human abdominal subcutaneous adipose tissue. A total of 32 obese, otherwise healthy subjects and 10 never-obese healthy subjects with a body mass index (BMI) of 42.6 +/- 1.2 and 24.3 +/- 1.9 kg/m2 (mean +/- SEM), respectively, were investigated. Plasma PAI-1 activity, adipose tissue PAI-1 secretion and adipocyte PAI-1 mRNA levels were increased seven-fold (p < 0.0001), sixfold (p < 0.0001) and twofold (p < 0.05), respectively, in the obese group. There were clear associations between adipose tissue secretion of PAI-1 and PAI-1 mRNA levels on the one hand and fat cell volume on the other (r = 0.68, p < 0.0001 and r = 0.51, p < 0.01, respectively, in the obese group). PAI-1 mRNA levels were also related to the amount of PAI-1 secreted among obese individuals (r = 0.31, p = 0.09). It is concluded that adipose tissue secretes significant amounts of PAI-1, that PAI-1 secretion from adipose tissue is increased in obesity, and that PAI-1 secretion is related to the lipid content and cell volume of fat cells. Plasma PAI-1 activity is elevated in obesity, at least in part due to increased gene expression in adipocytes, which, in turn, enhances PAI-1 secretion from adipose tissue.

Adipose Tissue↗
PubMed1982

Obesity and the regulation of phosphofructokinase in heart: an apparent insensitivity to adrenergic activation in mature-age genetically obese rats.

The activity ratio of phosphofructokinase in perfused rat heart and its activation by epinephrine was examined in non-obese, fat-fed obese, and genetically obese rats. For non-obese colony rats there was an age-dependent increase in the activity ratio of phosphofructokinase from 0.2 at 40 days to 0.4 at mature age (greater than 200 days). Epinephrine (10 microM) treatment of the heart for 5 min increased the ratio at all ages but the proportional increase diminished with age. For mature-age lean Zucker rats carrying the genetic determinant for obesity the results were similar to those obtained for comparable non-obese colony rats. For fat-fed obese rats the activity ratio of phosphofructokinase at 200 days of age was 0.2 and was increased to 0.6 by epinephrine treatment. For mature-age obese Zucker rats the activity ratio was 0.2 and no significant response to epinephrine occurred. The activity ratio of glycogen phosphorylase and its response to epinephrine (beta-adrenergic receptor mediated) in heart was unaffected by age, diet or the gene for obesity. The present findings indicate a specific defect in the adrenergic regulatory mechanism for phosphofructokinase in genetically obese rats.

Aging↗
PubMed1995

Increased obese mRNA expression in omental fat cells from massively obese humans.

Obesity presents a significant challenge to the general health of affluent nations in terms of the number of people affected, the serious associated maladies and the lack of effective treatments. While common wisdom has held that obesity results from 'gluttony and sloth', a number of studies have indicated physiological causes of underlying the pathogenesis of obesity, with the degree of adiposity having a strong genetic component. Recently, the obese gene in the ob/ob mouse was cloned, along with its human homologue. The specific production of the obese protein by adipose tissue suggested that it may function in a feedback loop from fat tissue to the hypothalamus to control energy intake and/or energy expenditure, and that it may play a role in the pathogenesis of human obesity. In this study we report that obese mRNA expression is elevated in ex vivo omental adipocytes isolated from massively obese humans in the absence of an identifiable mutation. Therefore, we speculate that this increased expression may suggest that the massively obese are insensitive to the putative regulatory function(s) of the obese gene product.

Adipose Tissue↗
PubMed2002

The road to obesity or the path to prevention: motorized transportation and obesity in China.

OBJECTIVE: Dependence on motorized forms of transportation may contribute to the worldwide obesity epidemic. Shifts in transportation patterns occurring in China provide an ideal opportunity to study the association between vehicle ownership and obesity. Our objective was to determine whether motorized forms of transportation promote obesity. RESEARCH METHODS AND PROCEDURES: A multistage random-cluster sampling process was used to select households from eight provinces in China. Data were included on household vehicle ownership and individual anthropometric and sociodemographic status. Cross-sectional data (1997) from 4741 Chinese adults aged 20 to 55 years were used to explore the association between vehicle ownership and obesity. Cohort data (1989 to 1997) from 2485 adults aged 20 to 45 years in 1989 (59% follow-up) were used to measure the impact of vehicle acquisition on the odds of becoming obese. RESULTS: Our main outcome measure was current obesity status and the odds of becoming obese over an 8-year period. In 1997, 84% of adults did not own motorized transportation. However, the odds of being obese were 80% higher (p < 0.05) for men and women in households who owned a motorized vehicle compared with those who did not own a vehicle. Fourteen percent of households acquired a motorized vehicle between 1989 and 1997. Compared with those whose vehicle ownership did not change, men who acquired a vehicle experienced a 1.8-kg greater weight gain (p < 0.05) and had 2 to 1 odds of becoming obese. DISCUSSION: Encouraging active forms of transportation may be one way to protect against obesity.

Adult↗
PubMed1998

Swedish obese subjects (SOS): an obesity intervention study with a nutritional perspective.

OBJECTIVES: Swedish Obese Subjects (SOS) is a multidisciplinary project involving aspects of obesity ranging from description of the severely obese state to effects of surgical intervention on long-term mortality and morbidity. Dietary studies, which represent an integral part of SOS research activities, are the focus of this review. SUBJECTS AND METHODS: Due to the large number of obese subjects included in the SOS data bases ( > 5000), an early priority of the project was to develop a dietary assessment method which: (i) described usual intake patterns; (ii) could be self-administered by subjects and rapidly processed; and (iii) was equally valid in obese and non-obese individuals. RESULTS: The SOS method has met these requirements and is now being completed by all subjects at baseline and during the intervention, and by a non-obese reference population. A number of dietary features distinguishing obese subjects have emerged, including: elevated intakes of energy and energy-percent fat; low consumption of alcohol, fruits and vegetables; high dietary disinhibition; frequent consumption of light meals and snacks; and night eating. In the surgical intervention group, a relatively high consumption of sweet foods was associated with better weight loss and maintenance. CONCLUSIONS: The SOS method appears to be less susceptible to obesity-related under-reporting than traditional dietary methods, and if the distribution of foods and nutrients can be assumed to be as unbiased as the energy intakes, this method should make it possible to capture associations between diet and obesity-related diseases in the future.

Energy Intake↗
PubMed2002

Appetite sensations and eating behaviors to complete fasting in obese and non-obese individuals.

OBJECTIVE: To investigate the response of appetite sensations and eating behaviors to fasting in obese and non-obese individuals. DESIGN: Prospective study on inpatients enrolled in weight loss program including fasting at the obesity clinic, an oriental medical center in Seoul, Korea. SUBJECTS AND MEASUREMENTS: For seven obese (body mass index BMI> or =30) and 11 non-obese (BMI<30) patients, the modified visual analog scale (VAS) was administered three times per day throughout 9 days of complete fasting. Three-Factor Eating Questionnaire (TEEQ) was administered before and 18 days after the complete fasting period. RESULTS: After treatment, average weight losses were 7.4 kg (3.0 BMI) for the obese group and 6.7 kg (2.6 BMI) for the non-obese. TFEQ scales did not differ by weight status at both before and after treatments. Eighteen days after the fasting, an increase of restraint of eating was found only for the non-obese. There was a decrease of disinhibition of eating regardless of weight status. During fasting, desire to eat, hunger and prospective consumption decreased for the non-obese, while these appetite sensations tended to increase slightly for the obese. CONCLUSIONS: BMI, independent of dieting status, appeared to be related to appetite sensations except for satiety during fasting, but not before and 18 days after fasting.

Adult↗
PubMed1997

Regulation of ammonia-metabolizing enzymes expression in the liver of obese rats: differences between genetic and nutritional obesities.

OBJECTIVE: To determine the expression of carbamoylphosphate synthetase (CPS) and glutamine synthetase (GS) in two different models of obese rats: genetically obese rats and diet obese rats. SUBJECTS: Lean and genetically obese (fa/fa) Zucker rats were used. DESIGN: Lean animals (30-60 d old) were fed for 30 d with standard chow pellets or with a hypercaloric cafeteria diet. Genetically obese rats were fed with standard chow pellets. MEASUREMENTS: Enzyme activity, protein (Western blot) and mRNA (Northern blot) contents of CPS and GS were measured in liver homogenates. RESULTS: In genetically obese animals CPS mRNA content was higher, and GS mRNA content was lower than in control animals; CPS protein content did not change and CPS activity was lower than in control rats. Diet-obese rats had higher levels of CPS and GS mRNAs than control animals; GS protein content and activity was higher than in the control group and at the same time, CPS activity was very low. CONCLUSIONS: In the genetically obese animals the expression of CPS and GS is mainly regulated at the pre-translational level, whereas in the diet obese rats there is a noticeable post-translational component. A reciprocal regulation between CPS and GS can be established at pre-translational levels, whereas at post-transcriptional levels it cannot. It can be concluded that in diet-obese animals the mechanisms involved in retaining nitrogen (low CPS activity) are modulated at the post-translational level.

Ammonia↗
PubMed2001

Physical activity and determinants of physical activity in obese and non-obese children.

OBJECTIVE: To compare the physical activity (PA) patterns and the hypothesized psychosocial and environmental determinants of PA in an ethnically diverse sample of obese and non-obese middle school children. DESIGN: Cross-sectional study. SUBJECTS: One-hundred and thirty-three non-obese and 54 obese sixth grade children (mean age of 11.4+/-0.6). Obesity status determined using the age-, race- and gender-specific 95th percentile for BMI from NHANES-1. MEASUREMENTS: Objective measurements were collected of PA over a 7-day period using the CSA 7164 accelerometer: total daily counts; daily moderate (3-5.9 METs) physical activity (MPA); daily vigorous physical activity (> or =6 METs; VPA); and weekly number of 5, 10 and 20 min bouts of moderate-to-vigorous physical activity (> or =3 METs, MVPA). Self-report measures were collected of PA self-efficacy; social influences regarding PA, beliefs about PA outcomes; perceived PA levels of parents and peers, access to sporting and/or fitness equipment at home, involvement in community-based PA organizations; participation in community sports teams; and hours spent watching television or playing video games. RESULTS: Compared to their non-obese counterparts, obese children exhibited significantly lower daily accumulations of total counts, MPA and VPA as well as significantly fewer 5, 10 and 20 min bouts of MVPA. Obese children reported significantly lower levels of PA self-efficacy, were involved in significantly fewer community organizations promoting PA and were significantly less likely to report their father or male guardian as physically active. CONCLUSIONS: The results are consistent with the hypothesis that physical inactivity is an important contributing factor in the maintenance of childhood obesity. Interventions to promote PA in obese children should endeavor to boost self-efficacy perceptions regarding exercise, increase awareness of, and access to, community PA outlets, and increase parental modeling of PA.

Australia↗
PubMed2006

Circulating adiponectin levels, body composition and obesity-related variables in Prader-Willi syndrome: comparison with obese subjects.

BACKGROUND: People with obesity and/or the metabolic syndrome have an increased risk for developing diabetes and cardiovascular disease and may have low adiponectin levels. The obesity associated with Prader-Willi syndrome (PWS) would be expected to have similar complications. However, it was recently reported that, despite their adiposity, people with PWS have reduced visceral fat and are less likely to develop diabetes mellitus or the metabolic syndrome compared with people with simple obesity. OBJECTIVE: To determine if plasma adiponectin levels and other variables relevant to diabetes and cardiovascular risk are different in a cohort of PWS subjects with known genetic subtypes compared with age-, sex- and weight-matched control subjects. RESULTS: Fasting plasma glucose, C-peptide, triglycerides, leptin and cholesterol levels were similar in PWS and obese subjects. Our 20 PWS subjects (mean age = 27.7 years) had higher percent body fat (54.1 vs 48.5%) determined by DEXA measurements and lower percent lean mass (45.9 vs 51.5%) compared with 14 obese controls (mean age = 26.9 year). Plasma adiponectin levels were significantly higher in PWS (15.5 +/- 8.2 microg/ml) than in obese controls (7.5 +/- 2.7 microg/ml). A significant positive correlation was found with insulin sensitivity in PWS subjects (r = 0.75, P = 0.0003) but not in obese controls (r = 0.36, P = 0.20). DISCUSSION: Our study confirmed an earlier observation of higher adiponectin levels in PWS subjects and less insulin resistance proportionate to their obesity status than found in subjects with simple obesity. Furthermore, no differences were seen in PWS subjects with the chromosome 15 deletion or maternal disomy 15. The reported excessive visceral adiposity in subjects with simple obesity compared with PWS may be associated with decreased production and lower circulating levels of adiponectin.

Adiponectin↗
PubMed2006

Circulating levels of MCP-1 and IL-8 are elevated in human obese subjects and associated with obesity-related parameters.

BACKGROUND: Chemotactic cytokines, referred to as chemokines, play an important role in leukocyte trafficking. The circulating levels of chemokines have been shown to increase in inflammatory processes including obesity-related pathologies (e.g. atherosclerosis and diabetes). However, little is currently known about the relationship between chemokines and human obesity. In the present study, we investigated the circulating levels of selected chemokines (monocyte chemoattractant protein-1 (MCP-1), macrophage inflammatory protein-1alpha (MIP-1alpha), leukotactin-1, interleukin-8 (IL-8)) and the association between the chemokine levels and obesity-related parameters: body mass index (BMI), waist circumference, fasting glucose and insulin levels, lipids profile, and the level of C-reactive protein (CRP). METHODS: A total of 100 subjects, 50 obese (BMI>or=25 kg/m2) and 50 who were not obese (BMI<25 kg/m2) participated in the present study. The levels of chemokines and CRP were measured in a fasting state serum by sandwich enzyme-linked immunosorbent assay. Total cholesterol, high-density lipoprotein (HDL)-cholesterol, triglyceride, glucose, and insulin levels were measured by enzymatic analysis and immunoassay. RESULTS: The circulating levels of MCP-1 and IL-8 in the serum were significantly (P<0.05) higher in obese subjects (BMI>30 kg/m2) compared with those of nonobese controls (BMI<25 kg/m2). The levels of CRP were positively correlated with BMI (P<0.001) or waist circumference (P<0.0001). The levels of MCP-1 and IL-8 were positively related to BMI (MCP-1, P<0.02; IL-8, P<0.01) and/or waist circumference (MCP-1, P<0.009; IL-8, P<0.03). The levels of MCP-1 were positively related to the levels of CRP (P<0.007) or interleukin-6 (IL-6) (P<0.0001), and negatively related to the levels of HDL-cholesterol (P<0.01). Homeostasis model assessment (HOMA) score was positively related to the levels of MCP-1 (P<0.02) or IL-8 (P<0.03) in obese subject. DISCUSSION: Our data demonstrated that the circulating levels of MCP-1 and IL-8 are related to obesity-related parameters such as BMI, waist circumference, CRP, IL-6, HOMA and HDL-cholesterol. These findings suggest that the circulating MCP-1 and/or IL-8 may be a potential candidate linking obesity with obesity-related metabolic complications such as atherosclerosis and diabetes.

Adult↗
PubMed1998

Serum concentrations of insulin, insulin-like growth factor(IGF)-I, IGF binding protein (IGFBP)-1 and -3 and growth hormone binding protein in obese children: fasting IGFBP-1 is suppressed in normoinsulinaemic obese children.

OBJECTIVE: Simple obesity is characterized by normal or accelerated growth in the presence of reduced serum levels of GH, whereas its detailed mechanism remains unknown. We, therefore, evaluated interrelationships among serum levels of insulin, IFG-I, IGF binding protein (IGFBP)-1 and -3 and growth hormone binding protein (GHBP) in prepubertal obese children. SUBJECTS: Prepubertal 20 obese children and 20 age-matched control children were included in the study. RESULTS: Serum levels of insulin, IGF-I and IGFBP-3 in obese children did not differ from those in controls. The serum level of IGFBP-1 was significantly lower in obese children (22.1 +/- 18.4 micrograms/l, P < 0.001) than in control children (76.0 +/- 62.9 micrograms/l). No relationship was found between the serum levels of insulin and IGF-I, IGFBP-1, or IGFBP-3 in obese subjects. The serum level of GHBP in obese children was significantly elevated as compared with that in controls and was positively correlated with body mass index (BMI). No relationship was found between the serum levels of GHBP and IGF-I in obese subjects. CONCLUSIONS: The present study showed for the first time that the fasting IGFBP-1 level was suppressed in prepubertal obese children with fasting normoinsulinaemia. We speculate that the hyperinsulinaemia which cannot be detected in the fasting state may have suppressed hepatic production of IGFBP-1. Alternatively, the reduced IGFBP-1 is likely to be a compensatory response to impaired insulin sensitivity. Thus, the IGFBP-1 level may be a useful predictor for the early identification in the development of insulin resistance in prepubertal obese children.

Adolescent↗
PubMed1999

The impact of gender, puberty and body mass on reference values for urinary growth hormone (GH) excretion in normally growing non-obese and obese children.

OBJECTIVE: There is a lack of normal reference data on urinary GH (u-GH) excretion in children. We have investigated the impact of age, gender, pubertal development and body mass on reference values for u-GH excretion in normally growing non-obese and obese children. STUDY DESIGN: u-GH levels were evaluated in 1153 healthy normal children (aged 5-14) and in 684 obese children (body mass index, BMI: > 75th). u-GH levels (ng/8 h) were determined by ELISA as the mean value of three consecutive first morning voidings. RESULTS: Reference values (5-95th centile) for u-GH excretion in obese and non-obese children of both sexes are reported. In normal prepubertal children median u-GH levels were relatively stable and superimposable in the two sexes; subsequently, u-GH levels increased, reaching a peak value at 13 years in both sexes. Significant increments (P < 0.0001) in u-GH levels were shown at B2 for females and at G3 for males. A slight decline was evident at 14 years. In obese children, median u-GH concentrations were significantly lower than those recorded in normal children of prepubertal age and at all stages of puberty (except in females at B2), in spite of their comparable normal height. u-GH levels significantly increased at puberty also in obese children, although the pubertal rise was significantly (P < 0.001) lower (1.7-fold in both sexes) than that observed in normal children (2.5-fold in boys and 2.3-fold in girls). A multiple regression analysis showed that both chronological age (beta: 0.20), BMI (beta: - 0.11), gender (beta: - 0.04) and pubertal stage (beta: 0.25) contributed significantly to the physiological variation in u-GH levels (multiple R: 0.44, P < 0.00001). CONCLUSIONS: This study provides reference values for u-GH in normally growing non-obese and obese children, analysing the impact of gender, puberty and body mass on this parameter. In agreement with previous studies, which demonstrate blunted GH-responses to provocative stimuli and reduced nocturnal GH concentration, obese children have significantly lower u-GH levels than age-matched normal weight children, both before and during puberty.

Adolescent↗
PubMed2003

Differences in plasminogen activator inhibitor 1 in subcutaneous versus omental adipose tissue in non-obese and obese subjects.

Human adipose tissue can produce plasminogen activator inhibitor-1 (PAI-1). It has been suggested that high levels of PAI-1 are of importance in enhanced cardiovascular disease observed among obese subjects, especially abdominally obese individuals. In the present study, we investigated the level of mRNA and production of PAI-1 in adipose tissue from two adipose tissue depots (omental vs. subcutaneous). Adipose tissue from both depots was obtained from obese (mean BMI, 46.9 kg/m 2) and non-obese (mean BMI, 23.9 kg/m 2) women. PAI-1 mRNA was measured both in fresh adipose tissue obtained immediately after surgery and after the adipose tissue (fragments) had been incubated for up to 72 h. In immediately frozen adipose tissue, PAI-1 mRNA expression was similar in omental and subcutaneous adipose tissue. No differences between obese and non-obese women were found. However, when adipose tissue fragments were cultured, PAI-1 mRNA and PAI-1 production were significantly higher in omental than in subcutaneous adipose tissue (p < 0.05). In the culture system, the production of PAI-1 in obese subjects was higher than in non-obese subjects in both subcutaneous (p < 0.05) and in omental adipose tissue (p = 0.19). In order to test whether these regional differences observed after incubation of the adipose tissue were due to differences in local accumulation of cytokines that may stimulate PAI-1 by a paracrine or autocrine manner, we investigated the expression of transforming growth factor beta1 (TGF-beta1) mRNA and tumor necrosis factor alpha (TNF-alpha) mRNA and protein. No differences between the two fat depots were found. In conclusion, no differences in PAI-1 expression between omental and subcutaneous adipose tissue were observed in biopsies frozen immediately after removal, but after incubation of adipose tissue (which somehow stimulates PAI-1 production), higher levels of PAI-1 were found in omental adipose tissue than in subcutaneous adipose tissue. Finally, PAI-1 production in adipose tissue from obese women was higher in non-obese women after incubation for 72 h.

Adipose Tissue↗
PubMed1994

Interpersonal dependency correlates and locus of control orientation among obese adults in outpatient treatment for obesity.

Interpersonal dependency and locus of control orientation were studied in obese and nonobese samples. The Interpersonal Dependency Inventory (Hirschfeld, Klerman, Gough, Barrett, & Korchin, 1977) and the I-E Scale (Rotter, 1966) were administered to 106 obese adults in outpatient treatment for obesity. The I-E Scale was also administered to 97 nonobese control subjects. As predicted, the obese subjects were significantly more internally oriented than has been previously identified in obese populations. These findings challenge currently held assumptions about locus of control in obese groups. Although the obese and nonobese subjects maintained similar overall dependency scores, the obese subjects were more likely to show low levels of autonomy in comparison with the nonobese subjects. Interpersonal dependency and locus of control dimensions associated with obese conditions may serve as useful predictor variables influencing obesity treatment approaches and outcome.

Adult↗