| 1. |
- Karimi, Mahssa, et al.
(författare)
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Increased neck soft tissue mass and worsening of obstructive sleep apnoea after growth hormone treatment in men with abdominal obesity : Growth hormone and obstructive sleep apnoea in abdominally obese men
- 2010
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Ingår i: Journal of Clinical Sleep Medicine. - 1550-9389. ; 6:3, s. 256-263
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Tidskriftsartikel (refereegranskat)abstract
- Background Risk factors for obstructive sleep apnea (OSA) are male gender, obesity and abnormalities in neck soft tissue mass. OSA is associated with both growth hormone (GH) excess and severe GH deficiency in adults. Adults with abdominal obesity have markedly suppressed GH secretion. Aim To study the effect of GH treatment on OSA in abdominally obese men with impaired glucose tolerance. Patients and Methods Forty men with abdominal obesity and glucose intolerance were randomized in a prospective, 12-month, double-blind trial to receive either GH or placebo. The treatment groups had similar BMI and waist circumference. Overnight polysomnography and computed tomography to assess muscle and fat distribution in the neck and abdomen were performed at baseline and after 12 months. Results GH treatment increased insulin-like growth-factor-1 from (mean (SD)) 168(17) to 292(28) μg/L, the apnea-hypopnea index from (n/h) 31(20) to 43(25) and oxygen-desaturation index from (n/h) 18(14) to 29(21) (p=0.0001, 0.001, 0.002). Neck transverse diameter, circumference and total cross-sectional area (p=0.007, 0.01, 0.02) increased while abdominal visceral adipose tissue (p=0.007) was reduced. No between-group differences in total sleep time, REM sleep, non-REM sleep and time spent in supine position were found. The Epworth sleepiness scale score was unchanged. Conclusions GH treatment increased the severity of OSA in abdominally obese men. The possible mechanism appears to be reflected by the GH-induced increase of measures of neck volume. The present results, to some extent, argue against that low GH/IGF-I activity is a primary cause of OSA in abdominally obese men.
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| 2. |
- Kellis, Dimitrios, 1982, et al.
(författare)
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Associations between obstructive sleep apnea and CT-determined abdominal and liver fat content in severe obese subjects
- 2010
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Ingår i: Obesity Reviews (Poster presentations). - 1467-7881. ; 11:Supplement s1
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Konferensbidrag (refereegranskat)abstract
- Introduction: Obstructive Sleep Apnea (OSA) is a common co-morbidity in obese patients. OSA is also frequently associated with various metabolic complications. In this study, we have evaluated the associations between measures of OSA and abdominal and liver fat subjects with untreated OSA. Methods: A total of 470 subjects (73% females) were examined during a screening process at the Obesity unit at the Sahlgrenska University Hospital. OSA was determined by the ApneaLink system and visceral and liver fat content were determined by CT using a two slice technique at the liver and L4-5 level. The included subjects had a mean age of 42.4 years (SD: 13.5 years), mean weight of 116.6 kg (SD: 20.3 kg), and a mean BMI of 40.8 kg/m2 (SD: 5.7 kg/m2). From the ApneaLink examinations the Apnea - Hypopnea Index (AHI), Respiratory Distress Index (RDI), Oxygen Desaturation Index (ODI) and mean oxygen saturation (SO2) was determined. From the CT examinations visceral adipose tissue mass (VAT) and hepatic fat content (HFC) was determined. Results: VAT was strongly correlated to AHI, RDI, ODI, and SO2 (r = 0.397, 0.388, 0.449, and )0.424 respectively, P < 0.001). There was also a correlation between HFC and AHI, RDI, ODI, and SO2 (r = 0.193, 0.198, 0.214, and 0.173 respectively, P < 0.001). Conclusion: The present study demonstrates that untreated OSA in severe obesity is associated to both measures of visceral fat and hepatic fat content. Evaluations of abdominal fat content should be considered in obese subjects with OSA.
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| 3. |
- Angelhed, Jan-Erik, 1948, et al.
(författare)
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Measurement of Lower-Leg Volume Change by Quantitative Computed Tomography
- 2008
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Ingår i: Acta Radiologica. - : SAGE Publications. - 0284-1851 .- 1600-0455. ; 49:9, s. 1024-1030
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Tidskriftsartikel (refereegranskat)abstract
- Background: Lower-leg edema is a common symptom in many diseases. A precise method with low variability for measurement of edema is warranted in order to obtain optimal conditions for investigation of treatment effects. Purpose: To evaluate computed tomography for precise measurement of lower-leg muscle and adipose tissue volumes using a very low level of effective radiation dose. Material and Methods: Eleven volunteers were examined three times during 1 day, either as two consecutive examinations in the morning and one single examination in the afternoon, or as one examination in the morning and two in the afternoon. Eleven scans with computed tomography were made at each examination, and lower-leg volumes were calculated from automatically measured scan areas and interscan distances. Volumes for muscle, adipose tissue, and bone were calculated separately. Minimal radiation dose was used. Results: Mean difference between the repeated examinations was −0.1 ml for total volume, −1.4 ml for muscle, and 1.6 ml for adipose tissue volume. The corresponding 95% confidence intervals were −6.5 to 6.0 ml, −3.5 to 6.5 ml, and −7.0 to 4.0 ml, respectively. The resulting effective dose was 0.5 µSv to one leg. Conclusion: Computed tomography can be used as a precise quantitative method to measure small volume changes of the lower leg as a whole, and separately for muscle and adipose tissue. The results were obtained with a negligible effective dose, lower than that delivered by modern fan-beam dual-energy X-ray absorptiometry whole-body examinations and equal to a few hours of background radiation.
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| 4. |
- Kindblom, Jenny, 1971, et al.
(författare)
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Pubertal timing is an independent predictor of central adiposity in young adult males: the Gothenburg osteoporosis and obesity determinants study
- 2006
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Ingår i: Diabetes. - : American Diabetes Association. - 0012-1797 .- 0012-1797 .- 1939-327X. ; 55:11, s. 3047-52
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Tidskriftsartikel (refereegranskat)abstract
- The role of puberty and normal variations in pubertal timing for the development of obesity in men is unclear. The aim of the current study was to investigate the impact of pubertal timing and prepubertal BMI (kg/m(2)) for young adult BMI and fat mass distribution. Detailed growth charts from birth to age 18-20 years were retrieved for the men participating in the population-based Gothenburg Osteoporosis and Obesity Determinants study. Age at peak height velocity (PHV) and BMI at age 10 years were estimated for 579 subjects, and PHV was used as an assessment of pubertal timing. The fat mass characterization and distribution were analyzed using dual X-ray absorptiometry and peripheral as well as abdominal computed tomography at age 18.9 +/- 0.5 years. We demonstrate that age at PHV is an independent negative predictor of young adult BMI and whole-body fat mass. Interestingly, age at PHV is an independent negative predictor of central, but not peripheral, fat mass. In contrast, BMI at 10 years of age predicts both central and peripheral subcutaneous fat mass. In conclusion, we demonstrate that early pubertal onset specifically predicts a central fat mass distribution, while a predominantly subcutaneous obese phenotype is strongly predicted by a high prepubertal BMI.
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| 5. |
- Kullberg, Joel, et al.
(författare)
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Whole-body adipose tissue analysis: comparison of MRI, CT and dual energy X-ray absorptiometry.
- 2009
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Ingår i: The British journal of radiology. - : British Institute of Radiology. - 1748-880X .- 0007-1285. ; 82:974, s. 123-30
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Tidskriftsartikel (refereegranskat)abstract
- The aim of this study was to validate a recently proposed MRI-based T(1)-mapping method for analysis of whole-body adipose tissue (AT) using an established CT protocol as reference and to include results from dual energy X-ray absorptiometry (DEXA). 10 subjects, drawn from the Swedish Obese Subjects Sibling-pairs study, were examined using CT, MRI and DEXA. The CT analysis was based on 28 imaged slices. T(1) maps were calculated using contiguous MRI data from two different gradient echo sequences acquired using different flip angles. CT and MRI comparison was performed slice-wise and for the whole-body region. Fat weights were compared between all three modalities. Strong correlations (r > or = 0.977, p<0.0001) were found between MRI and CT whole-body and AT volumes. MRI visceral AT volume was underestimated by 0.79 +/- 0.75 l (p = 0.005), but total AT was not significantly different from that estimated by CT (MRI - CT = -0.61+/-1.17 l; p = 0.114). DEXA underestimated fat weights by 5.23 +/- 1.71 kg (p = 0.005) compared with CT. MRI underestimated whole-body volume by 2.03 +/- 1.61 l (p = 0.005) compared with CT. Weights estimated either by CT or by DEXA were not significantly different from weights measured using scales. In conclusion, strong correlations were found between whole-body AT results from CT, MRI-based T(1) mapping and DEXA. If the differences between the results from T(1)-mapping and CT-based analysis are accepted, the T(1)-mapping method allows fully automated post-processing of whole-body MRI data, allowing longitudinal whole-body studies that are also applicable for children and adolescents.
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| 6. |
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| 7. |
- 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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| 8. |
- Simonyte, Kotryna, 1979-, et al.
(författare)
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Weight Loss after Gastric Bypass Surgery in Women Is Followed by a Metabolically Favorable Decrease in 11 beta-Hydroxysteroid Dehydrogenase 1 Expression in Subcutaneous Adipose Tissue
- 2010
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Ingår i: JOURNAL OF CLINICAL ENDOCRINOLOGY & METABOLISM. - : Williams & Wilkins Co.. - 0021-972X .- 1945-7197. ; 95:7, s. 3527-3531
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Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND AND AIMS: The role of 11beta-hydroxysteroid dehydrogenase 1 (11beta-HSD1) in the pathogenesis of obesity has been elucidated in humans and in various rodent models. Obesity is accompanied by disturbances in glucocorticoid metabolism, circulating adipokine levels, and fatty acid (FA) reesterification. This study was undertaken to evaluate glucocorticoid metabolism in sc fat before and after weight loss and to explore putative associations between 11beta-HSD1 and leptin, adiponectin, and FA recycling. SUBJECTS AND METHODS: Twenty-seven obese (mean body mass index 44.4 + or - 4.4 kg/m(2)) women underwent gastric bypass surgery. Subcutaneous fat biopsies were collected before and 2 yr after surgery. The expression of 11beta-HSD1, leptin, adiponectin, and phosphoenolpyruvate carboxykinase (PEPCK) mRNA was evaluated with real-time PCR. Serum leptin and adiponectin protein levels were estimated by ELISA. RESULTS: Two years after gastric bypass surgery, significant reductions were observed in the mean body mass index (from 44.4 to 30.8 kg/m(2)) and mean waist circumference (from 121.9 to 90.6 cm). After weight loss, 11beta-HSD1 mRNA expression decreased 4-fold (P < 0.001). Both leptin and adiponectin mRNA expression decreased, with concomitantly decreased circulating leptin and increased circulating adiponectin levels. PEPCK mRNA expression did not change. CONCLUSION: Weight loss after gastric bypass surgery was followed by metabolically favorable changes in insulin sensitivity, circulating leptin and adiponectin, and peripheral glucocorticoid metabolism. A significant reduction in 11beta-HSD1 expression was observed in sc adipose tissue after weight loss. This suggests that up-regulation of 11beta-HSD1 is a consequence, rather than a cause, of obesity.
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