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- Larsson, Ingrid, 1963, et al.
(författare)
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Optimized predictions of absolute and relative amounts of body fat from weight, height, other anthropometric predictors, and age 1.
- 2006
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Ingår i: The American journal of clinical nutrition. - 0002-9165. ; 83:2, s. 252-9
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Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND: Body mass index (BMI) is the dominating weight-for-height index, but its validity as a body fat (BF) index has not been properly examined. OBJECTIVES: Our aims were to establish and validate optimal weight-for-height indexes for predicting absolute and relative (percentage) amounts of BF, to examine whether other commonly available anthropometric variables or age could add to the predictive power, and to explore the upper limit for percentage BF. DESIGN: One thousand one hundred twelve randomly selected subjects, and an additional 149 obese subjects, were included in the study. The subjects were randomly allocated to either a primary study group or a validation group. BF was measured with dual-energy X-ray absorptiometry. The relations between weight/heightx (W/Hx) and BF (absolute or percentage) were examined for values of the exponent x that ranged from 0.0 to 3.0. The predictive power of equations that were based on optimal weight-for-height indexes was compared with equations based on weight, height, other anthropometric variables, and age. RESULTS: Absolute BF was optimally and linearly predicted by W/H1, whereas the percentage BF was optimally and nonlinearly predicted by W/H2. The percentage BF asymptotically approached 52% in women and 56% in men. The percentage BF increased only marginally from BMI (in kg/m2) values of >35 in women and >60 in men. Predictions of absolute BF were associated with smaller errors (8.5% for men and 5.7% for women) than were predictions of percentage BF (8.7% for men and 7.9% for women). The addition of other anthropometric measurements for both men and women, and the addition of age for women only, in the regression analyses moderately reduced these errors. CONCLUSION: Our data suggest that W/H may be a more optimal weight-for-height index than is BMI, particularly at high body weights.
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| 5. |
- Rubensdotter, Lena, 1972-
(författare)
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Alpine lake sediment archives and catchment geomorphology : causal relationships and implications for paleoenvironmental reconstructions
- 2006
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Lake sediments are frequently used as archives of climate and environmental change. Minerogenic sediment variability in alpine lakes is often used to reconstruct past glacier and slope process activity. Alpine lake sediments can however have many different origins, which may induce errors in paleoenvironmental reconstructions. The aim of this project was to enhance the understanding of minerogenic lake sedimentation in alpine lakes and improve their use as environmental archives.Catchment geomorphology and Holocene sediment sequences were analysed for five alpine lakes. Several minerogenic sediment sources were detected in catchments and sediment sequences. Slope-, fluvial-, periglacial-, nival- and aeolian sediment transportation processes contribute to create complex lake sediment patterns. Large variations in sedimentation rates were discovered within and between lakes, which has implications for sampling strategies and age-model constructions. Similar fine-grained minerogenic laminations were found in four of the investigated lakes, despite large differences in setting. The demonstrated similarity between glacial and non-glacial lakes may complicate interpretations of glaciolacustrine sediment signals.The main conclusion is that lake sedimentation in alpine environments is highly dependent on several geomorphological factors. All lakes should therefore be viewed as unique and the geomorphology should be thoroughly investigated before environmental reconstructions are based on lake sediment proxies. This study has confirmed the multi-source origin of alpine lake sediment, which also opens possibilities of more multi-faceted paleoenvironmental studies. Different process-proxies could potentially be used to separate different climate signals, e.g. precipitation, temperature and wind, in lake sediments. Analysis of grain-size distribution, detailed mineralogy and magnetic mineralogy in combination with X-ray radiography are suggested methods for such reconstructions.
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- Simonyte, Kotryna, 1979-, et al.
(författare)
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Obesity is accompanied by disturbances in peripheral glucocorticoid metabolism and changes in FA recycling.
- 2009
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Ingår i: Obesity (Silver Spring, Md.). - : Wiley. - 1930-7381 .- 1930-739X. ; 17:11, s. 1982-7
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Tidskriftsartikel (refereegranskat)abstract
- The glucocorticoid activating enzyme 11beta-hydroxysteroid dehydrogenase type 1 (11betaHSD1) is of major interest in obesity-related morbidity. Alterations in tissue-specific cortisol levels may influence lipogenetic and gluco/glyceroneogenetic pathways in fat and liver. We analyzed the expression and activity of 11betaHSD1 as well as the expression of phosphoenolpyruvate carboxykinase (PEPCK), sterol regulatory element binding protein (SREBP), and fatty acid synthase (FAS) in adipose and liver and investigated putative associations between 11betaHSD1 and energy metabolism genes. A total of 33 obese women (mean BMI 44.6) undergoing gastric bypass surgery were enrolled. Subcutaneous adipose tissue (SAT), omental fat (omental adipose tissue (OmAT)), and liver biopsies were collected during the surgery. 11betaHSD1 gene expression was higher in SAT vs. OmAT (P = 0.013), whereas the activity was higher in OmAT (P = 0.009). The SAT 11betaHSD1 correlated with waist circumference (P = 0.045) and was an independent predictor for the OmAT area in a linear regression model. Energy metabolism genes had AT depot-specific expression; higher leptin and SREBP in SAT than OmAT, but higher PEPCK in OmAT than SAT. The expression of 11betaHSD1 correlated with PEPCK in both AT depots (P = 0.05 for SAT and P = 0.0001 for OmAT). Hepatic 11betaHSD1 activity correlated negatively with abdominal adipose area (P = 0.002) and expression positively with PEPCK (P = 0.003). In human obesity, glucocorticoid regeneration in the SAT is associated with central fat accumulation indicating that the importance of this specific fat depot is underestimated. Central fat accumulation is negatively associated with hepatic 11betaHSD1 activity. A disturbance in peripheral glucocorticoid metabolism is associated with changes in genes involved in fatty acid (FA) recycling in adipose tissue (AT).
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| 7. |
- Sjöström, Lars, et al.
(författare)
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Effects of bariatric surgery on cancer incidence in obese patients in Sweden (Swedish Obese Subjects Study): a prospective, controlled intervention trial.
- 2009
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Ingår i: The lancet oncology. - 1474-5488. ; 10:7, s. 653-62
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Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND: Obesity is a risk factor for cancer. Intentional weight loss in the obese might protect against malignancy, but evidence is limited. To our knowledge, the Swedish Obese Subjects (SOS) study is the first intervention trial in the obese population to provide prospective, controlled cancer-incidence data. METHODS: The SOS study started in 1987 and involved 2010 obese patients (body-mass index [BMI] >or=34 kg/m(2) in men, and >or=38 kg/m(2) in women) who underwent bariatric surgery and 2037 contemporaneously matched obese controls, who received conventional treatment. While the main endpoint of SOS was overall mortality, the main outcome of this exploratory report was cancer incidence until Dec 31, 2005. Cancer follow-up rate was 99.9% and the median follow-up time was 10.9 years (range 0-18.1 years). FINDINGS: Bariatric surgery resulted in a sustained mean weight reduction of 19.9 kg (SD 15.6 kg) over 10 years, whereas the mean weight change in controls was a gain of 1.3 kg (SD 13.7 kg). The number of first-time cancers after inclusion was lower in the surgery group (n=117) than in the control group (n=169; HR 0.67, 95% CI 0.53-0.85, p=0.0009). The sex-treatment interaction p value was 0.054. In women, the number of first-time cancers after inclusion was lower in the surgery group (n=79) than in the control group (n=130; HR 0.58, 0.44-0.77; p=0.0001), whereas there was no effect of surgery in men (38 in the surgery group vs 39 in the control group; HR 0.97, 0.62-1.52; p=0.90). Similar results were obtained after exclusion of all cancer cases during the first 3 years of the intervention. INTERPRETATION: Bariatric surgery was associated with reduced cancer incidence in obese women but not in obese men. FUNDING: Swedish Research Council, Swedish Foundation for Strategic Research, Swedish Federal Government under the LUA/ALF agreement, Hoffmann La Roche, Cederoths, AstraZeneca, Sanofi-Aventis, Ethicon Endosurgery.
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| 8. |
- Sjöström, Lars, et al.
(författare)
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Effects of bariatric surgery on mortality in Swedish obese subjects.
- 2007
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Ingår i: The New England journal of medicine. - 1533-4406. ; 357:8, s. 741-52
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Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND: Obesity is associated with increased mortality. Weight loss improves cardiovascular risk factors, but no prospective interventional studies have reported whether weight loss decreases overall mortality. In fact, many observational studies suggest that weight reduction is associated with increased mortality. METHODS: The prospective, controlled Swedish Obese Subjects study involved 4047 obese subjects. Of these subjects, 2010 underwent bariatric surgery (surgery group) and 2037 received conventional treatment (matched control group). We report on overall mortality during an average of 10.9 years of follow-up. At the time of the analysis (November 1, 2005), vital status was known for all but three subjects (follow-up rate, 99.9%). RESULTS: The average weight change in control subjects was less than +/-2% during the period of up to 15 years during which weights were recorded. Maximum weight losses in the surgical subgroups were observed after 1 to 2 years: gastric bypass, 32%; vertical-banded gastroplasty, 25%; and banding, 20%. After 10 years, the weight losses from baseline were stabilized at 25%, 16%, and 14%, respectively. There were 129 deaths in the control group and 101 deaths in the surgery group. The unadjusted overall hazard ratio was 0.76 in the surgery group (P=0.04), as compared with the control group, and the hazard ratio adjusted for sex, age, and risk factors was 0.71 (P=0.01). The most common causes of death were myocardial infarction (control group, 25 subjects; surgery group, 13 subjects) and cancer (control group, 47; surgery group, 29). CONCLUSIONS: Bariatric surgery for severe obesity is associated with long-term weight loss and decreased overall mortality.
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