Weight loss maintenance in overweight subjects on ad libitum diets with high or low protein content and glycemic index: the DIOGENES trial 12-month results.

BACKGROUND: A high dietary protein (P) content and low glycemic index (LGI) have been suggested to be beneficial for weight management, but long-term studies are scarce. OBJECTIVE: The DIOGENES randomized clinical trial investigated the effect of P and GI on weight loss maintenance in overweight or obese adults in eight centers across Europe. This study reports the 1-year results in two of the centers that extended the intervention to 1 year. METHOD: After an 8-week low-calorie diet (LCD), 256 adults (body mass index >27 kg m(-)(2)) were randomized to five ad libitum diets for 12 months: high P/LGI (HP/LGI), HP/high GI (HP/HGI), low P/LGI (LP/LGI), LP/HGI and a control diet. During the first 6 months, foods were provided for free through a shop system and during the whole 12-month period, subjects received guidance by a dietician. Primary outcome variable was the change in body weight over the 12-month intervention period. RESULTS: During the LCD period, subjects lost 11.2 (10.8, 12.0) kg (mean (95% confidence interval (CI))). Average weight regain over the 12-month intervention period was 3.9 (95% CI 3.0-4.8) kg. Subjects on the HP diets regained less weight than subjects on the LP diets. The difference in weight regain after 1 year was 2.0 (0.4, 3.6) kg (P=0.017) (completers analysis, N=139) or 2.8 (1.4, 4.1) kg (P<0.001) (intention-to-treat analysis, N=256). No consistent effect of GI on weight regain was found. There were no clinically relevant differences in changes in cardiometabolic risk factors among diet groups. CONCLUSION: A higher protein content of an ad libitum diet improves weight loss maintenance in overweight and obese adults over 12 months.

Stroke volume-directed administration of hydroxyethyl starch or Ringer's acetate in sitting position during craniotomy.

BACKGROUND: To determine the volumes required for stable haemodynamics and possible effects on the coagulation, we studied stroke volume (SV)-directed administration of hydroxyethyl starch (HES 130 kDa/0.4) and Ringer's acetate (RAC) in neurosurgical patients operated on in a sitting position. METHODS: Thirty craniotomy patients were randomised to receive either HES or RAC. Before positioning, SV, measured by arterial pressure waveform analysis, was maximised by boluses of fluid until SV did not increase more than 10%. SV was maintained by repeated administration of fluid. RAC 3 ml/kg/h was infused in both groups during surgery. RESULTS: Comparable haemodynamics were achieved with the mean [standard deviation (SD)] cumulative doses of HES or RAC 271 (47) or 264 (50) ml (P = 0.699) before the sitting position. Mean (SD) doses of HES or RAC at 30 min after the positioning were 343 (94) or 450 (156) ml (P = 0.036), and at the end of surgery 464 (284) or 707 (425) ml, respectively (P = 0.087). The intraoperative fluid balance was more positive in the RAC than in the HES group [P = 0.044, 95% confidence interval (CI) -978 to -14]. Cardiac and stroke volume indexes [CI and stroke volume index (SVI)] increased in the HES group (P < 0.05) but not in the RAC group [non significant (N.S.)]. Neither coagulation profile nor blood loss differed between the groups. CONCLUSION: Fluid filling with HES boluses resulted in a positive response in CI and SVI during the sitting position. The 34% smaller volume of HES than crystalloid and less positive fluid balance in the HES group might be important in craniotomy patients with decreased brain compliance.

Effects of bariatric surgery on disability pension in Swedish obese subjects.

BACKGROUND: Prospective controlled data on the long-term effects of bariatric surgery on disability pension are not available. This study prospectively compare disability pension in surgically and conventionally treated obese men and women. METHODS: The Swedish obese subjects study started in 1987 and involved 2010 obese patients who had bariatric surgery and 2037 contemporaneously matched obese controls, who received conventional treatment. Outcomes of this report were: (i) incidence of disability pension from study inclusion to 31 December 2006 in all subjects, and, (ii) number of disability pension days over 10 years in a subgroup of individuals (N=2901) followed for at least 10 years where partial pensions were recalculated to full number of days per year. Objective information on granted disability pension was obtained from the Swedish Social Insurance Agency and disability pension follow-up rate was 99.9%. RESULTS: In men, the unadjusted incidence of disability pension did not differ between the surgery and control groups (N=156 in both groups). When adjusting for baseline confounders in men, a reduced risk of disability pension was suggested in the surgery group (hazard ratio 0.79, 95% confidence interval 0.62-1.00; P=0.05). Furthermore, the adjusted average number of disability pension days was lower in the surgery group, 609 versus 734 days (P=0.01). In women, bariatric surgery was not associated with significant effects on incidence or number of days of disability pension. CONCLUSION: Bariatric surgery may be associated with favourable effects on disability pension for up to 19 years in men whereas neither favourable nor unfavourable effects could be detected in women.

Impact of weight change, secular trends and ageing on cardiovascular risk factors: 10-year experiences from the SOS study.

OBJECTIVE: Many short-term studies indicate that 5% weight loss in the obese is enough to induce significant improvements of cardiovascular risk factors. However, it is not known what degree of weight loss is required to improve risk factors over a more extended period of time or how ageing and secular trends per se are influencing risk factors during long-term follow-up. METHODS: Patients examined after 10 years in the intervention study Swedish Obese Subjects were used for the current analysis. Surgically treated subjects (n=959) and conventionally treated obese controls (n=842) were pooled to obtain a study group with a large range of weight changes. The patients were divided in 11 groups based on the amount of weight change. Analysis of covariance was used to determine the necessary weight change over 10 years for a significant alteration of a risk factor. In a linear regression of risk factor change by weight change, the y intercept was interpreted as the effect of 10 years ageing and secular trends on a given risk factor in the absence of weight change. RESULTS: The necessary weight loss for significant improvement of risk factors ranged from 10 to 44 kg. At zero weight change, 10 years of ageing was associated with significant increases in systolic blood pressure, pulse pressure, high-density lipoprotein cholesterol and glucose, and with significant decreases in diastolic blood pressure, total cholesterol, triglycerides and insulin. CONCLUSIONS: The necessary weight loss to maintain a favourable effect on risk factors in an obese population is larger than previously indicated by short-term studies. Treatment effects are influenced by non-weight change-dependant shifts in risk factor levels.

Effects of combined balanced colloid and crystalloid on rotational thromboelastometry in vitro.

Our objective was to investigate the in vitro effects of a totally balanced fluid concept on whole blood coagulation. Venous blood from 12 healthy volunteers was diluted by 20% and 40% with a combination of an equal amount of colloid (balanced or unbalanced 6% HES 130/0.4, or 4% gelatin) and crystalloid (balanced or unbalanced Ringer's acetate). Blood samples were analyzed with rotational thromboelastometry (ROTEM®). The initiation of coagulation was delayed in all dilutions except for the 20 vol% gelatin-dilution. In the extrinsic activation test, maximum clot firmness was decreased and clot formation time prolonged after 40 vol% hemodilution with a balanced Ringer's/unbalanced HES combination, more than in the corresponding gelatin hemodilution. In the fibrin-based test, after both 20- and 40 vol% hemodilution with unbalanced Ringer's/gelatin solution, maximum clot firmness was significantly stronger than in the Ringer's/HES-combinations. The combination of balanced colloid and crystalloid has similar coagulation effects in vitro as their respective combination of unbalanced solutions.

Inequalities in education and national income are associated with poorer diet: Pooled analysis of individual participant data across 12 European countries.

BACKGROUND: Malnutrition linked to noncommunicable diseases presents major health problems across Europe. The World Health Organisation encourages countries to conduct national dietary surveys to obtain data to inform public health policies designed to prevent noncommunicable diseases. METHODS: Data on 27334 participants aged 19-64y were harmonised and pooled across national dietary survey datasets from 12 countries across the WHO European Region. Weighted mean nutrient intakes were age-standardised using the Eurostat 2013 European Standard Population. Associations between country-level Gross Domestic Product (GDP) and key nutrients and nutrient densities were investigated using linear regression. The potential mitigating influence of participant-level educational status was explored. FINDINGS: Higher GDP was positively associated with total sugar intake (5·0% energy for each 10% increase in GDP, 95% CI 0·6, 9·3). Scandinavian countries had the highest vitamin D intakes. Participants with higher educational status had better nutritional intakes, particularly within lower GDP countries. A 10% higher GDP was associated with lower total fat intakes (-0·2% energy, 95% CI -0·3, -0·1) and higher daily total folate intakes (14µg, 95% CI 12, 16) in higher educated individuals. INTERPRETATION: Lower income countries and lower education groups had poorer diet, particularly for micronutrients. We demonstrate for the first time that higher educational status appeared to have a mitigating effect on poorer diet in lower income countries. It illustrates the feasibility and value of harmonising national dietary survey data to inform European policy regarding access to healthy diets, particularly in disadvantaged groups. It specifically highlights the need for strong policies supporting nutritional intakes, prioritising lower education groups and lower income countries.

Should snacks be recommended in obesity treatment? A 1-year randomized clinical trial.

OBJECTIVE: To study the effect to recommend no snacks vs three snacks per day on 1-year weight loss. The hypothesis was that it is easier to control energy intake and lose weight if snacks in between meals are omitted. SUBJECTS/METHOD: In total 140 patients (36 men, 104 women), aged 18-60 years and body mass index>30 kg/m(2) were randomized and 93 patients (27 men, 66 women) completed the study. A 1-year randomized intervention trial was conducted with two treatment arms with different eating frequencies; 3 meals/day (3M) or 3 meals and 3 snacks/day (3+3M). The patients received regular and individualized counseling by dieticians. Information on eating patterns, dietary intake, weight and metabolic variables was collected at baseline and after 1 year. RESULTS: Over 1 year the 3M group reported a decrease in the number of snacks whereas the 3+3M group reported an increase (-1.1 vs +0.4 snacks/day, respectively, P<0.0001). Both groups decreased energy intake and E% (energy percent) fat and increased E% protein and fiber intake but there was no differences between the groups. Both groups lost weight, but there was no significant difference in weight loss after 1 year of treatment (3M vs 3+3M=-4.1+/-6.1 vs -5.9+/-9.4 kg; P=0.31). Changes in metabolic variables did not differ between the groups, except for high-density lipoprotein that increased in the 3M group but not in 3+3M group (P<0.033 for group difference). CONCLUSION: Recommending snacks or not between meals does not influence 1-year weight loss.

Eating habits in relation to body fatness and gender in adolescents--results from the 'SWEDES' study.

OBJECTIVE: To investigate if eating habits among adolescents are related to body fatness and gender. DESIGN: Cross-sectional study. SETTING: Obesity Unit, Huddinge University Hospital, Sweden, 2001-2002. SUBJECTS: Two hundred and seventy-five girls and 199 boys, aged 16-17 years. METHOD: Questionnaires were used for dietary intake and meal frequency, BodPod for measuring body fatness (BF%). In all, 169 girls and 128 boys were classified as adequate reporters (AR) of energy intake, and were used in the dietary analyses. The whole sample was used in the meal frequency analyses. RESULTS: The correlation between reported energy intake and weight in the AR group was 0.23 (P<0.01) for girls and 0.36 for boys (P<0.001). The correlations were inverse or not significant in the whole sample. The following variables correlated significantly with a high BF% (r (s)=+/-0.2): a low intake of milk in both girls and boys, a high intake of fibre and alcohol and a low intake of sugar in girls and a low intake of breakfast cereals in boys. Those with regular breakfast habits had healthier food choices than others, but this was not related to BF%. Boys had more meals per day (4.9 vs 4.6, P=0.02), especially early in the morning and late at night, whereas girls reported a higher relative intake of light meals and fruit and a lower intake of milk than boys. CONCLUSIONS: A few associations between eating habits and body fatness were found, but without any obvious patterns. The true differences in eating habits between lean and overweight adolescents are probably very small.

Endothelial dysfunction in men with small LDL particles.

BACKGROUND: It is unknown whether LDL particle size is, independent of other lipids and lipoproteins, associated with endothelial dysfunction in vivo. METHODS AND RESULTS: We determined in vivo endothelial function in 34 healthy men by measuring forearm blood flow responses to intrabrachial artery infusions of acetylcholine (ACh, an endothelium-dependent vasodilator) and sodium nitroprusside (an endothelium-independent vasodilator). LDL peak particle size was measured with gradient gel electrophoresis. Men with small LDL particles (LDL diameter 25. 5 nm, n=24, blood flow 6.9+/-3.6 versus 11.4+/-5.1 mL/dL. min, P=0. 006). The groups had comparable LDL cholesterol concentrations (3. 9+/-0.6 versus 3.7+/-1.0 mmol/L, men with small versus large LDL particles), blood pressure, glucose concentrations, and body mass indexes. LDL size (r=0.45, P=0.01) but not HDL cholesterol (r=0.31, P=0.09) or triglycerides (r=-0.19, P=0.30) was significantly correlated with endothelium-dependent vasodilation. Serum triglyceride concentrations and LDL size were inversely correlated (r=-0.44, P=0.01). In multivariate regression analysis, LDL size was the only significant determinant of the ACh-induced increase in blood flow. Sodium nitroprusside-stimulated endothelium-independent vasodilation was similar in both groups. CONCLUSIONS: Small LDL particles are associated with impaired in vivo endothelial function independent of HDL and LDL cholesterol and triglyceride concentrations. LDL size may therefore mediate adverse effects of hypertriglyceridemia on vascular function.

Intramyocellular lipid is associated with resistance to in vivo insulin actions on glucose uptake, antilipolysis, and early insulin signaling pathways in human skeletal muscle.

To examine whether and how intramyocellular lipid (IMCL) content contributes to interindividual variation in insulin action, we studied 20 healthy men with no family history of type 2 diabetes. IMCL was measured as the resonance of intramyocellular CH(2) protons in lipids/resonance of CH(3) protons of total creatine (IMCL/Cr(T)), using proton magnetic resonance spectroscopy in vastus lateralis muscle. Whole-body insulin sensitivity was measured using a 120-min euglycemic-hyperinsulinemic (insulin infusion rate 40 mU/m(2). min) clamp. Muscle biopsies of the vastus lateralis muscle were taken before and 30 min after initiation of the insulin infusion to assess insulin signaling. The subjects were divided into groups with high IMCL (HiIMCL; 9.5 +/- 0.9 IMCL/Cr(T), n = 10) and low IMCL (LoIMCL; 3.0 +/- 0.5 IMCL/Cr(T), n = 10), the cut point being median IMCL (6.1 IMCL/Cr(T)). The groups were comparable with respect to age (43 +/- 3 vs. 40 +/- 3 years, NS, HiIMCL versus LoIMCL), BMI (26 +/- 1 vs. 26 +/- 1 kg/m(2), NS), and maximal oxygen consumption (33 +/- 2 vs. 36 +/- 3 ml. kg(-1). min(-1), NS). Whole-body insulin-stimulated glucose uptake was lower in the HiIMCL group (3.0 +/- 0.4 mg. kg(-1). min(-1)) than the LoIMCL group (5.1 +/- 0.5 mg. kg(-1). min(-1), P < 0.05). Serum free fatty acid concentrations were comparable basally, but during hyperinsulinemia, they were 35% higher in the HiIMCL group than the LoIMCL group (P < 0.01). Study of insulin signaling indicated that insulin-induced tyrosine phosphorylation of the insulin receptor (IR) was blunted in HiIMCL compared with LoIMCL (57 vs. 142% above basal, P < 0.05), while protein expression of the IR was unaltered. IR substrate-1-associated phosphatidylinositol (PI) 3-kinase activation by insulin was also lower in the HiIMCL group than in the LoIMCL group (49 +/- 23 vs. 84 +/- 27% above basal, P < 0.05 between HiIMCL and LoIMCL). In conclusion, IMCL accumulation is associated with whole-body insulin resistance and with defective insulin signaling in skeletal muscle independent of body weight and physical fitness.

Elemental analyses of pine bark and wood in an environmental study.

Bark and wood samples were taken from the same individuals of Scots pine (Pinus sylvestris L.) from a polluted area close to a Cu-Ni smelter in Harjavalta and from some relatively unpolluted areas in western Finland. The samples were analysed by thick-target particle induced X-ray emission (PIXE) after preconcentration by dry ashing at 550 degrees C. The elemental contents of pine bark and wood were compared to study the impact of heavy metal pollution on pine trees. By comparison of the elemental contents in ashes of bark and wood, a normalisation was obtained. For the relatively clean areas, the ratios of the concentration in bark ash to the concentration in wood ash for different elements were close to 1. This means that the ashes of Scots Pine wood and bark have quite similar elemental composition. For the samples from the polluted area the mean concentration ratios for some heavy metals were elevated (13-28), reflecting the effect of direct atmospheric contamination. The metal contents in the ashes of pine bark and wood were also compared to recommendations for ashes to be recycled back to the forest environment. Bark from areas close to emission sources of heavy metal pollution should be considered with caution if aiming at recycling the ash. Burning of bark fuel of pine grown within 6 km of the Cu-Ni smelter is shown to generate ashes with high levels of Cu, Ni as well as Cd, As and Pb.

Relief of cardiorespiratory symptoms and increased physical activity after surgically induced weight loss: results from the Swedish Obese Subjects study.

BACKGROUND: Obese people frequently suffer from shortness of breath and chest discomfort on exertion, and they often have a sedentary lifestyle. In the present study of patients with severe obesity, we investigated the effects of surgically induced weight loss on cardiorespiratory symptoms and leisure-time physical activity. METHODS: The Swedish Obese Subjects study is an ongoing intervention trial of obesity consisting of 1 surgically treated group and 1 matched control group. Information on smoking habits, hypertension, diabetes, and sleep apnea was obtained from 1210 surgical cases and 1099 controls who were observed for 2 years. Patients were also asked about symptoms of breathlessness and chest pain and their levels of leisure-time physical activity. RESULTS: The surgically treated group displayed a mean weight loss of 28 kg (23%) compared with the control group in which the average weight remained unchanged (P<.001). The rates of hypertension, diabetes, and apneas during sleep decreased in surgical cases compared with controls (P<.001), while smoking habits remained largely the same. The surgical group also displayed highly significant improvements in dyspnea and chest pain and increases in physical activity compared with the control group (P<.001). The odds ratio for self-reported breathlessness, chest discomfort, or sedentary behavior after 2 years decreased progressively with the degree of weight loss. Furthermore, patients who recovered from apneas during sleep reduced their odds of having dyspnea and chest discomfort at follow-up, independent of changes in weight. CONCLUSIONS: Surgically induced weight loss in patients with severe obesity is associated with a marked relief in symptoms of dyspnea and chest pain and promotes increased leisure-time physical activity. Sleep-disordered breathing may be involved in the pathophysiology of breathlessness and chest discomfort in obese subjects.

In vivo endothelial dysfunction characterizes patients with impaired fasting glucose.

OBJECTIVE: The American Diabetes Association has recently defined a new category of abnormal glucose homeostasis called "impaired fasting glucose" (IFG), where glucose levels do not meet the criteria of diabetes but are too high to be considered normal. We determined whether endothelial dysfunction is a characteristic of subjects with IFG. RESEARCH DESIGN AND METHODS: In vivo vasodilatory responses to intra-arterial infusions of endothelium-dependent (acetylcholine [ACh]) and -independent (sodium nitroprusside [SNP]) vasoactive agents were determined in 17 IFG subjects (age 63 +/- 1 years, BMI 26.5 +/- 0.8 kg/m2, serum LDL cholesterol 3.5 +/- 0.2 mmol/l) with fasting plasma glucose levels of 117 +/- 1 mg/dl and in 12 subjects with normal fasting plasma glucose concentrations. RESULTS: The blood-flow response to the low dose of ACh was 46% (5.9 +/- 0.7 vs. 10.9 +/- 1.3 ml.dl-1.min-1, IFG vs. normal, P < 0.01) and to the high dose was 31% (9.1 +/- 1.2 vs. 13.2 +/- 1.5 ml.dl-1.min-1, P < 0.05, respectively) lower in the IFG than in the normal subjects. In contrast, blood-flow responses to both low (7.8 +/- 0.5 vs. 9.0 +/- 0.9 ml.dl-1.min-1, IFG vs. normal, NS) and high (11.6 +/- 1.2 vs. 12.3 +/- 1.3 ml.dl-1.min-1, NS, respectively) doses of SNP were comparable. The ratio of endothelium-dependent to -independent blood flow was 40% lower in the IFG (0.75 +/- 0.1) than in the normal (1.24 +/- 0.1, P < 0.001) subjects. Both fasting plasma glucose (r = -0.48, P < 0.01) and glycosylated hemoglobin (r = -0.42, P < 0.05) were inversely correlated with endothelium-dependent vasodilation but not with other parameters, such as weight, blood pressure, or lipids. CONCLUSIONS: We conclude that vascular dysfunction is associated with abnormal, although nondiabetic, glucose homeostasis.

Body weight and body composition changes after treatment of hyperthyroidism.

Body composition changes in nine adults with hyperthyroidism were determined with dual energy x-ray absorptiometry and computed tomography at diagnosis and after 3 and 12 months of euthyroidism achieved by surgery, antithyroid drugs, or treatment with radioiodine. Mean body weight was 67.6 kg at diagnosis and increased 2.7 kg (P=0.06) and 8.7 kg (P < 0.001) after 3 and 12 months of euthyroidism, respectively. Basal metabolic rate decreased from 2087 Cal/24 h at diagnosis to 1601 Cal/24 h at 12 months (P=0.001), whereas reported energy intake dropped from 3244 to 2436 Cal/24 h (P=0.01). According to dual energy x-ray absorptiometry, body fat was unchanged at 3 months, but increased by 5.3 kg (P < 0.0001) at 12 months. Fat-free mass increased 2.7 kg (P=0.003) at 3 months and 3.5 kg (P < 0.0001) at 12 months. Changes in bone mineral content and density did not reach significance. According to computed tomography, skeletal muscle plus skin areas increased by 11% (trunk) and 18% (thigh) at 3 months and by 17% (trunk) and 25% (thigh) at 12 months. There was no increase in sc adipose tissue (AT) at 3 months, but at 12 months this AT depot increased by 15% (thigh) and 33% (trunk). Intraperitoneal AT showed a borderline significant increase by 28% (P=0.08) at 3 months and by 40% (P=0.015) at 12 months. Areas of visceral organs and bone tissue of femur did not change significantly during the study. It is concluded that during early recovery from hyperthyroidism, priority is given to the replenishment of skeletal muscles and ip AT, whereas sc AT is increased at a later stage.

Resistance to acute insulin induced decreases in large artery stiffness accompanies the insulin resistance syndrome.

Arterial stiffness has recently been recognized as an important cardiovascular risk marker. Physiological concentrations of insulin diminish wave reflection in the aorta in vivo. This decreases central blood pressure augmentation and augmentation divided by pulse pressure [the augmentation index (AgI)], a measure of arterial stiffness. In the present study, we examined whether a defect in this action of insulin is a feature of insulin resistance and how it relates to other acute actions of insulin, including stimulation of glucose uptake, peripheral blood flow, and autonomic control of heart rate variation. These actions of insulin were quantitated in 50 healthy men (age, 34 +/- 2 yr; body mass index, 27 +/- 1 kg/m2) during 2 sequential insulin infusions, each lasting 120 min (1 and 2 mU/kg x min). Insulin decreased AgI significantly within 30 min, whereas significant increases in peripheral blood flow and normalized low frequency power of heart rate variation, a measure of sympathetic control of heart rate variation, were observed at 150 and 210 min. A blunted decrease in the AgI was significantly associated with a low rate of insulin-stimulated glucose uptake, but not with the other actions of insulin. Insulin action of the AgI was correlated with body mass index and the waist to hip ratio independently of basal AgI, age, and low density lipoprotein cholesterol. We conclude that physiological concentrations of insulin diminish large artery stiffness within 30 min in nondiabetic men. This action precedes insulin action on peripheral vasodilation, heart rate, and autonomic control of heart rate variation. It is correlated with insulin stimulation of glucose uptake and is blunted by known causes of insulin resistance, including overall and abdominal obesity. Resistance of large arteries to insulin-induced decrease in their stiffness is therefore another facet of insulin resistance that could contribute to the association between insulin resistance and cardiovascular disease.

Insulin sensitivity regulates autonomic control of heart rate variation independent of body weight in normal subjects.

It is unclear whether insulin sensitivity independent of body weight regulates control of heart rate variation (HRV) by the autonomic nervous system. Insulin action on whole-body glucose uptake (M-value) and heart rate variability were measured in 21 normal men. The subjects were divided into 2 groups [normally insulin sensitive (IS, 8.0 +/- 0.4 mg/kg.min) and less insulin sensitive (IR, 5.1 +/- 0.3 mg/kg.min)] based on their median M-value (6.2 mg/kg x min). Spectral power analysis of heart rate variability was performed in the basal state and every 30 min during the insulin infusion. The IS and IR groups were comparable, with respect to age (27 +/- 2 vs. 26 +/- 2 yr), body mass index (22 +/- 1 vs. 23 +/- 1 kg/m(2)), body fat (13 +/- 1 vs. 13 +/- 1%), systolic (121 +/- 16 vs. 117 +/- 14 mm Hg) and diastolic (74 +/- 11 vs. 73 +/- 11 mm Hg) blood pressures, and fasting plasma glucose (5.4 +/- 0.1 vs. 5.5 +/- 0.1 mmol/L) concentrations. Fasting plasma insulin was significantly higher in the IR (30 +/- 4 pmol/L) than in the IS (17 +/- 3 pmol/L, P < 0.05) group. In the IS group, insulin significantly increased the normalized low-frequency (LFn) component, a measure of predominantly sympathetic nervous system activity, from 36 +/- 5 to 48 +/- 4 normalized units (nu; 0 vs. 30-120 min, P < 0.001); whereas the normalized high-frequency (HFn) component, a measure of vagal control of HRV, decreased from 66 +/- 9 to 48 +/- 5 nu (P < 0.001). No changes were observed in either the normalized LF component [35 +/- 5 vs. 36 +/- 2 nu, not significant (NS)] or the normalized HF component (52 +/- 6 vs. 51 +/- 4 nu, NS) in the IR group. The ratio LF/HF, a measure of sympathovagal balance, increased significantly in the IS group (0.92 +/- 0.04 vs. 1.01 +/- 0.04, P < 0.01) but remained unchanged in the IR group (0.91 +/- 0.04 vs. 0.92 +/- 0.03, NS). Heart rate and systolic and diastolic blood pressures remained unchanged during the insulin infusion in both groups. We conclude that insulin acutely shifts sympathovagal control of HRV toward sympathetic dominance in insulin-sensitive, but not in resistant, subjects. These data suggest that sympathetic overactivity is not a consequence of hyperinsulinemia.

Familial predisposition for obesity may modify the predictive value of serum leptin concentrations for long-term weight change in obese women.

Leptin is believed to play a role in regulating food intake and body weight. The aim of this study was to examine the influence of parental history of obesity on the association between baseline serum leptin concentrations and subsequent 4-y weight changes. Changes in food intake were also considered in the analysis. Middle-aged, obese women with no obese parent (n = 25) or at least one obese parent (n = 24) were included in the analysis. At baseline, women with no parental history of obesity and women with a parental history of obesity did not differ in body mass index (in kg/m2: 41.2 and 40.2, respectively) or median leptin concentrations (40.8 and 38.8 microg/L, respectively). Four-year weight changes varied widely in both groups combined (from -30 to 24 kg). Stratified regression analysis, adjusted for age, weight, and height, revealed that high leptin concentrations predicted less weight gain (or more weight loss) in women with no obese parent (beta = -21.2, P = 0.0006) but played no significant role in predicting weight gain in women with at least one obese parent (beta = -3.8, P = 0.41). Adding changes in energy and fat intakes to the model reduced the association between leptin and weight change to nonsignificance in the women with no obese parent, indicating that the effect of leptin could be explained largely by dietary changes. In conclusion, serum leptin concentrations predict long-term weight change in obese women with no history of parental obesity, an association largely mediated by changes in food intake.

Validity and reproducibility of a self-administered dietary questionnaire in obese and non-obese subjects.

The validity and reproducibility of a self-administered dietary questionnaire has been tested with specific attention to differences between obese and non-obese subjects. To test the validity, the dietary questionnaire was compared with 4-day food records, 24-h energy expenditure (24EE) and nitrogen excretion in 45 obese and 19 non-obese men and women. Energy intake was 2% higher (non-significantly) from questionnaire than from food records in the non-obese, but 35% higher (P < 0.001) in the obese. Comparing energy intake from the questionnaire with estimated 24EE, the questionnaire gave 4% higher values in both the non-obese and obese, differences which were not significant. The reproducibility in the obese sample that completed the questionnaire twice was comparable to that observed in normal populations. These data suggest that it is possible to obtain information on obese subjects' dietary intake that is at least as valid and reproducible as that from normal weight individuals.

Does degree of obesity influence the validity of reported energy and protein intake? Results from the SOS Dietary Questionnaire. Swedish Obese Subjects.

OBJECTIVE: To test the validity of a dietary questionnaire which was developed with the particular goal of measuring dietary intake in obese subjects. DESIGN: Reported energy intake was compared with 24 h energy expenditure measured in a chamber for indirect calorimetry (24 EE) and reported nitrogen intake with nitrogen in urine collected during the 24 h in the chamber. SUBJECTS: Twenty-nine overweight men and women, body mass index (BMI) ranging from 25.5 49.5 kg/m2. RESULTS: Reported energy intake correlated significantly with 24 EE (r = 0.50, P = 0.006) and reported urinary nitrogen correlated significantly with urinary nitrogen excretion (r=0.56, P=0.0015). Mean reported energy intake+/-s.d. was 10.2+/-3.6 MJ and mean 24 EEi s.d. was 10.3+/-1.9 MJ. Although this difference was small and non significant, it indicates some underreporting if one can assume that these overweight subjects are less physically active in the chamber than in free-living conditions. Reported nitrogen intake also suggested underreporting at the group level. However, when the data were analysed at the individual level it was clear that the underreporting errors did not increase with increasing degree of obesity. CONCLUSIONS: Previous studies with the SOS dietary questionnaire have demonstrated that it is possible to obtain plausible energy intakes from both obese and nonobese subjects. This present analysis further demonstrates that the questionnaire discriminates overweight subjects with high and low intakes of energy and protein, using unbiased biomarkers to judge validity. These data provide additional support for the usefulness of the SOS dietary questionnaire.

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.