| 1. |
- Arner, Peter, et al.
(author)
-
Variations in the size of the major omentum are primarily determined by fat cell number
- 2013
-
In: Journal of Clinical Endocrinology and Metabolism. - : The Endocrine Society. - 0021-972X .- 1945-7197. ; 98:5, s. E897-E901
-
Journal article (peer-reviewed)abstract
- OBJECTIVE: Accumulation of visceral adipose tissue (VAT) is strongly linked to insulin resistance. Variations in the size of any adipose depot are determined by alterations in adipocyte volume and/or number. The individual contribution of each of the latter factors was determined in the major omentum, a fully resectable VAT depot.SUBJECTS: Total removal of the major omentum (omentectomy) was performed in conjunction with bariatric surgery in 55 obese patients. Tissue weight as well as mean adipocyte size and number in the omentum were determined. In subgroups, total VAT was estimated by computerized tomography (n = 17) or dual-energy x-ray absorptiometry (n = 34).RESULTS: The weight of the major omentum (on average 0.6 kg) correlated significantly with total VAT mass estimated by computerized tomography or dual-energy x-ray absorptiometry (r = 0.48-0.7; P < .01). Omental weight in relation to total body fat correlated with several features of the metabolic syndrome and inversely with serum-leptin (P < .001). Mean adipocyte size and total adipocyte number correlated strongly with omental weight (r = 0.6-0.8; P < .0001), irrespective of body mass index and total body fat mass, and accounted almost in total for interindividual variations in omental size. However, stepwise regression analysis demonstrated that adipocyte number was significantly (P < .0001) more important (62%) than adipocyte size (35%).CONCLUSION: The size of the major omentum is representative for VAT mass and correlates with a pernicious metabolic profile. Variations in omental weight are primarily determined by adipocyte number and to a lesser degree by adipocyte size, suggesting that increased VAT mass in obesity is predominantly dependent on adipocyte proliferation.
|
|
| 2. |
- Andersson, Daniel P., et al.
(author)
-
Omentectomy in addition to gastric bypass surgery and influence on insulin sensitivity : A randomized double blind controlled trial
- 2014
-
In: Clinical Nutrition. - : Elsevier BV. - 0261-5614 .- 1532-1983. ; 33:6, s. 991-996
-
Journal article (peer-reviewed)abstract
- Background & aims: Accumulation of visceral adipose tissue is associated with insulin resistance and cardio-vascular disease. The aim of this study was to elucidate whether removal of a large amount of visceral fat by omentectomy in conjunction with Roux en-Y gastric bypass operation (RYGB) results in enhanced improvement of insulin sensitivity compared to gastric bypass surgery alone. Methods: Eighty-one obese women scheduled for RYGB were included in the study. They were randomized to RYGB or RYGB in conjunction with omentectomy. Insulin sensitivity was measured by hyperinsulinemic euglycemic clamp before operation and sixty-two women were also reexamined 2 years post-operatively. The primary outcome measure was insulin sensitivity and secondary outcome measures included cardio-metabolic risk factors. Results: Two-year weight loss was profound but unaffected by omentectomy. Before intervention, there were no clinical or metabolic differences between the two groups. The difference in primary outcome measure, insulin sensitivity, was not significant between the non-omentectomy (6.7 +/- 1.6 mg/kg body weight/minute) and omentectomy groups (6.6 +/- 1.5 mg/kg body weight/minute) after 2 years. Nor did any of the cardio-metabolic risk factors that were secondary outcome measures differ significantly. Conclusion: Addition of omentectomy to gastric bypass operation does not give an incremental effect on long term insulin sensitivity or cardio-metabolic risk factors. The clinical usefulness of omentectomy in addition to gastric bypass operation is highly questionable.
|
|
| 3. |
- Rydén, Mikael, et al.
(author)
-
Lipolysis defect in people with obesity who undergo metabolic surgery
- 2022
-
In: Journal of Internal Medicine. - : Wiley-Blackwell Publishing Inc.. - 0954-6820 .- 1365-2796. ; 292:4, s. 667-678
-
Journal article (peer-reviewed)abstract
- OBJECTIVE: Cross-sectional studies demonstrate that catecholamine stimulation of fat cell lipolysis is blunted in obesity. We investigated whether this defect persists after substantial weight loss has been induced by metabolic surgery, and whether it is related to the outcome.DESIGN/METHODS: Patients with obesity not able to successfully reduce body weight by conventional means (n = 126) were investigated before and 5 years after Roux-en-Y gastric bypass surgery (RYGB). They were compared with propensity-score matched subjects selected from a control group (n = 1017), and with the entire group after adjustment for age, sex, body mass index (BMI), fat cell volume and other clinical parameters. Catecholamine-stimulated lipolysis (glycerol release) was investigated in isolated fat cells using noradrenaline (natural hormone) or isoprenaline (synthetic beta-adrenoceptor agonist).RESULTS: Following RYGB, BMI was reduced from 39.9 (37.5-43.5) (median and interquartile range) to 29.5 (26.7-31.9) kg/m2 (p < 0.0001). The post-RYGB patients had about 50% lower lipolysis rates compared with the matched and total series of controls (p < 0.0005). Nordrenaline activation of lipolysis at baseline was associated with the RYGB effect; those with high lipolysis activation (upper tertile) lost 30%-45% more in body weight, BMI or fat mass than those with low (bottom tertile) initial lipolysis activation (p < 0.0007).CONCLUSION: Patients with obesity requiring metabolic surgery have impaired ability of catecholamines to stimulate lipolysis, which remains despite long-term normalization of body weight by RYGB. Furthermore, preoperative variations in the ability of catecholamines to activate lipolysis may predict the long-term reduction in body weight and fat mass.
|
|
