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Query: UMLS:C0028754 (obesity)
 124,988 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The content and accretion of fatty acids in 30, 45 and 60-day-old Zucker lean Fa/? and obese fa/fa rats fed either reference chow or a cafeteria diet has been studied, together with their actual fatty acid intake during each period. Diet had little overall effect on the pattern of deposition of fatty acids, but quantitatively the deposition of fat was much higher in cafeteria-fed rats. The fat-rich cafeteria diet allowed the direct incorporation of most fatty acids into the rat lipids, whilst chow feeding activated lipogenesis and the deposition of a shorter chain and more saturated pattern of fatty acids. Genetic, obesity induced a significant expansion of net lipogenesis when compared with lean controls. Cafeteria-fed obese rats accrued a high proportion of fatty acids, which was close to that ingested, but nevertheless showed a net de novo synthesis of fatty acids. It is postulated that the combined effects of genetic obesity and a fat-rich diet result in high rates of fat accretion with limited net lipogenesis. Lean Zucker rats show a progressive impairment of their delta 5-desaturase system, a situation also observed in obese rats fed a reference diet. In Zucker obese rats, cafeteria feeding resulted in an alteration of the conversion of C18:2 into C20:3. The cafeteria diet fully compensated for these drawbacks by supplying very high amounts of polyunsaturated fatty acids.
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PMID:Deposition of dietary fatty acids in young Zucker rats fed a cafeteria diet. 133 Sep 57

10 examine the relationship between obesity and chronic anovulation, we compared basal serum LH, FSH, and PRL levels, determined at 20-min intervals, and basal C21 [progesterone, 17- hydroxyprogesterone , pregnenolone, 17-hydroxypregnenolone ( 17Pe ), and cortisol], C19 [testosterone (T), delta 4-androstenedione (A), and dehydroepiandrosterone] and C18 (estrone and estradiol) steroid hormone concentrations measured at 1- to 2-h intervals for a 24-h period in five normal weight cycling women (NC) and in two groups of weight-matched obese women. Five of the obese women were regularly cycling (OC), and six were amenorrheic (OA). Sex hormone-binding globulin (SHBG) and non-SHBG-bound T and estradiol concentrations were also measured in each woman. Compared to NC women, OC women had normal basal protein and steroid hormone concentrations, except for reduced 17Pe levels (P less than 0.05). Mean SHBG concentrations were reduced by approximately 30%, and non-SHBG-bound T was increased by 70%, although the differences were not significant. In addition, when six precursors of testosterone (pregnenolone, 17Pe , dehydroepiandrosterone, progesterone, 17-hydroxyprogesterone, and A) were considered together as a group and the data analyzed by the kappa 2 test, a reduction in basal levels of these precursors was found in OC women relative to those in NC women (P less than 0.005). In OA women, mean concentrations of SHBG were markedly reduced and those of total T, A, estrone, and non-SHBG-bound T were significantly increased compared to those in both NC and OC women. Mean 24-h concentrations of LH tended to be greatest and FSH lowest in this group, but were not significantly different from those in the other groups. The mean LH pulse frequency was significantly greater in OA than in OC women (P less than 0.05). Mean 24-h PRL and cortisol levels were also reduced in OA women relative to those in NC women. These data suggest the possibility of a compensatory decline in total T production in OC women in an attempt to maintain normal hormonal homeostasis; as a consequence, ovulation continues in a cyclic fashion. In OA women, such compensatory mechanisms are no longer operative. Instead, a central and/or peripheral defect, resulting in overproduction of androgen, may also exist and lead to anovulation in OA women. In conclusion, our data imply that obesity is not a primary factor causing chronic anovulation. However, obesity may aggravate an already existing subtle defect in some women and result in amenorrhea.
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PMID:Endocrine comparison of obese menstruating and amenorrheic women. 642 58

This study determined the associations of serum insulin and estrogen with fatty acid composition, fatty acid product/substrate ratios used as indexes of desaturase enzyme function, and platelet aggregation in obese and lean women. Thirty women were classified as obese (n = 8) or lean (n = 21) based on body mass index. Obese women were characterized by higher insulin levels (p < 0.05) but fasting glucose levels did not differ (p > 0.05) from lean women. Insulin positively correlated with increased C20:4n6/C18:3n6 (index of delta 5-desaturase) (p < 0.05) and C20:4n6/C18:2n6 (index of overall n6 pathway activity) (p < 0.01) in serum, and the n5 pathway in platelets (p < 0.01), but there was no correlation for insulin with platelet C18:3n6/C18:2n6 (index of delta 6-desaturase activity). Insulin was also positively related (p < 0.01) to aggregation as measured by impedance and negatively related to lag time (p < 0.05). Platelets of obese women aggregated more (p < 0.05) compared to lean women and began aggregating faster (p < 0.05), suggesting the possibility that the obese women were at greater risk for enhanced blood clotting. Plasma estrogen was correlated with age (p < 0.05) but not for other variables studied (p > 0.05). Insulin, but not estrogen, appears to influence desaturase activity, as demonstrated by increased desaturase function associated with hyperinsulinemia in obese women.
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PMID:Insulin, but not estrogen, correlated with indexes of desaturase function in obese women. 764 75

This study describes associations between early-stage endometrial cancer and type of dietary fat consumed, based on (i) adipose tissue fatty acid content (a biomarker for dietary fat) and (ii) self-reported frequencies of selected high-fat foods. Because obesity may be associated with high dietary fat intake as well as endometrial cancer, a secondary objective is to determine whether the observed dietary associations are statistically independent of body composition, assessed as percent body fat. To achieve these aims, we examined 20 cases of endometrial cancer in remission and 20 community controls, all aged 55-64. Abdominal adipose tissue biopsies from cases contained significantly higher concentrations of saturated fatty acids of intermediate chain length (C12-C16), lower ratios of polyunsaturated to saturated fatty acids (P:S ratio), and lower concentrations of C18 polyunsaturated as well as C18 saturated fatty acids. These differences were independent of degree of adiposity measured in a whole body 40K counter and several measurements of regional fat distribution. In addition, each subject's consumption of 20 high-fat items was reported by means of a semiquantitative food frequency questionnaire. Analysis of these data indicated that cases consumed more animal-derived fats, again independent of obesity. In particular, cases used more butter in cooking, ate more bacon, and drank more whole milk. Animal-derived fat intake displayed an inverse association both with the P:S ratio and the C18 polyunsaturated fatty acid content of adipose tissue, lending internal validity to the dietary data. These findings are consistent with the hypothesis that the type of dietary fat consumed may influence the occurrence of endometrial cancer.
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PMID:Adipose tissue fatty acids and dietary fat sources in relation to endometrial cancer: a retrospective study of cases in remission, and population-based controls. 839 29

Fatty acid composition of plasma phospholipids (PL), triglycerides (TG), and sterol esters (STE) was determined by high-resolution capillary gas-liquid chromatography in 22 obese children (age: 13.7 +/- 1.4 y, body weight relative to normal weight for height: 170 +/- 24%, mean +/- SD) and compared with data obtained in 25 age-matched healthy controls. There were no differences in the levels of linoleic acid (LA, C18:2n-6) in any of the plasma fractions from obese children and the controls. Obese children exhibited significantly higher values of arachidonic acid (AA, C20:4n-6) than controls both in PL (12.6 [2.4] vs. 8.3 [1.4], % wt/wt, [median (interquartile range)], P < 0.001) and STE (7.3 [1.8] vs. 6.0 [1.1], P < 0.05). Similarly, obese children showed higher values than controls for dihomo-gamma-linoleic acid (DHGLA, C20:3n-6) in PL (4.0 [0.5] vs. 3.0 [0.6], P < 0.001), TG (0.4 [0.1] vs. 0.2 [0.1], P < 0.001), and STE (0.9 [0.1] vs. 0.7 [0.1], P < 0.01), and for gamma-linolenic acid (C18:3n-6) in STE (1.1 [0.2] vs. 0.8 [0.2], P < 0.001). The AA/LA ratios were higher in obese children than in controls in PL (0.68 [0.16] vs. 0.42 [0.09], P < 0.0005) and STE (0.16 [0.04] vs. 0.12 [0.02], P < 0.05), whereas the AA/DHGLA ratios were lower in TG of obese children than in controls (3.40 [0.64] vs. 5.10 [1.75], P < 0.005). Plasma glucose concentrations were inversely related to AA in TG (r = 0.53, P < 0.05), and plasma TG concentrations were inversely related to AA in PL and STE (r = -0.49, P < 0.05 and r = -0.48, P < 0.05) and to the AA/DHGLA ratios in PL (r = -0.57, P < 0.01), TG (r = -0.56, P < 0.01), and STE (r = -0.56, P < 0.01). We conclude that the significantly higher values of n-6 long-chain polyunsaturated fatty acids (LCP) in plasma lipids of obese children than in age-matched controls may be caused by an enhanced activity of delta 6-desaturation, and we speculate that elevated fasting immunoreactive insulin seen in obese children (19.4 +/- 8.0 microU/mL) may stimulate synthesis of n-6 LCP fatty acids.
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PMID:Long-chain polyunsaturated fatty acids in plasma lipids of obese children. 890 Apr 60

We investigated the effect of long-term administration of highly purified eicosapentaenoic acid ethyl ester (EPA-E), an n-3 polyunsaturated fatty acid derived from fish oil, in comparison to the effects of lard, olive oil, safflower oil, or distilled water as the control on the development of insulin resistance in Otsuka Long-Evans Tokushima Fatty (OLETF) rats, a model of spontaneous non-insulin-dependent diabetes mellitus (NIDDM) with obesity. After 17 or 18 weeks of treatment, the glucose infusion rate (GIR) in the euglycemic insulin-glucose clamp test only showed a significant increase in EPA-E-treated rats compared with control rats given distilled water alone as the vehicle. The GIR in EPA-E-treated animals was approximately three times greater than in the controls. This is the first report to display the influence of various fatty acids on the development of insulin resistance in OLETF rats. We demonstrated that EPA-E prevents the onset of insulin resistance, whereas olive oil and safflower oil have no effect and lard exacerbates insulin resistance. Fatty acid analysis of phospholipids in skeletal muscle showed a significant increase of the C18:2, C20:5, and C22:5 components in EPA-E-treated rats and, conversely, a significant decrease in C20:4. In addition, EPA-E-treated rats showed a significant increase in GLUT4 mRNA in skeletal muscle when compared with control rats. Our results indicate that the beneficial effect of EPA-E on insulin resistance in OLETF rats is likely to be dependent on modification of the phospholipid components of the skeletal muscle membrane. These findings suggest that dietary fatty acids may play a key role in the development of insulin resistance in patients with NIDDM.
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PMID:Influence of highly purified eicosapentaenoic acid ethyl ester on insulin resistance in the Otsuka Long-Evans Tokushima Fatty rat, a model of spontaneous non-insulin-dependent diabetes mellitus. 943 43

In the present case-control study several dietary and nutritional factors were investigated to determine if a relationship exists between diet and development of mammary tumors in female dogs. Control female dogs (n = 86) were compared with a case group of dogs (n = 102) with dysplasias or tumors of the mammary gland. A questionnaire providing information on the dog's body conformation and dietary and reproductive histories was answered by the owners. Serum selenium and retinol concentrations and the fatty acid profile in subcutaneous adipose tissue were analyzed as indicators of nutritional status. Obesity at 1 year of age and 1 year before the diagnosis of mammary nodules was found to be significantly related to a higher prevalence of mammary tumors and dysplasias. The intake of homemade meals (compared to that of commercial foods) was also significantly related to a higher incidence of tumors and dysplasias. Other significant risk factors were a high intake of red meat, especially beef and pork, and a low intake of chicken. The subcutaneous fatty acid profile and the serum selenium concentration were not significantly different in the cases and the controls, with the exception of C18:1 fatty acid (oleic acid) content, which was significantly higher in the cases than in healthy controls. Serum retinol concentration was significantly lower in the cases than in the controls. In the multivariate analysis, older age, obesity at 1 year of age, and a high red meat intake were independently and significantly associated with the risk of developing mammary tumor and dysplasias.
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PMID:Relation between habitual diet and canine mammary tumors in a case-control study. 959 73

Twenty-nine obese female Zucker rats (fa/fa) were fed with a laboratory chow supplemented or not with a selenium-rich yeast (Selenion), or Selenion + vitamin E, or vitamin E alone. Twelve lean female Zucker rats (Fa/Fa) of the same littermates fed with the same diet were used as control. After 32 wk of diet, obesity induced a large increase in plasma insulin and lipid levels. A significant decrease in the plasma vitamin E/triglycerides ratio (p<0.005) and an increase in plasma thiobarbituric reactive substances (TBARS) (p<0.005) were also observed. Plasma selenium and vitamin E increased in all supplemented rats. The plasma insulin level was decreased by selenion supplementation and the vitamin E/triglycerides ratio was completely corrected by double supplementation with Selenion + vitamin E. TBARS were also efficiently decreased in two obese groups receiving vitamin E. In plasma, adipose tissue and aorta, obesity induced an increase in palmitic acid (C16:0), a very large increase in monounsaturated fatty acids (palmitoleic acid C16:1, stearic acid C18:1) associated with a decrease in polyunsaturated n-6 fatty acids (linoleic acid C18:2 n-6, arachidonic C20:4 n-6). These alterations in fatty acid distribution were only partly modulated by Se and vitamin E supplements. However, in the aorta, antioxidant treatment in obese rats significantly reduced the increase in C16:0 and C16:1 (p<0.05 and p<0.01, respectively) and the decrease in arachidonic acid (p<0.05). These changes could be beneficial in the reduction of insulin resistance and help to protect the vascular endothelium.
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PMID:Effect of selenium and vitamin E supplementation on lipid abnormalities in plasma, aorta, and adipose tissue of Zucker rats. 989 95

We previously demonstrated that taste receptor cells (TRCs) respond to cis-polyunsaturated fatty acids (PUFAs) through an inhibition of delayed rectifying K channels (KDR), which may represent the transduction mechanism for dietary fat. To determine if there is a link between the sensitivity of fungiform TRCs to PUFAs and dietary fat preferences, we compared the PUFA-sensitivity of TRCs using patch clamp techniques from Osborne-Mendel (O-M) and S5B/Pl rats, which display dietary preferences for fat over carbohydrate and carbohydrate over fat, respectively. In isolated TRCs, the PUFAs, linoleic (C18:2), linolenic (C18:3) and arachidonic acid (C20:4) inhibit KDR in a concentration-dependent manner in both strains, while the unsaturated lauric acid (C12:0) was ineffective. KDR from TRCs of S5B/Pl rats were significantly more sensitive to inhibition by all three PUFAs (10 microM) than were TRCs from O-M rats. We are currently investigating whether this differential responsiveness is due to (i) the relative affinity of the interaction between cis-PUFAs and the delayed rectifying K channels or (ii) the relative density of delayed rectifying K channels in the two rat strains. Whatever the mechanism, these data suggest an inverse correlation between peripheral gustatory sensitivity to PUFAs and the dietary preference for fat. This finding may provide insight into the mechanism for sensing dietary fat that allows the S5B rats to reduce fat intake on a high-fat diet and avoid the obesity which results when O-M rats eat a high-fat diet.
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PMID:Dietary fat preferences are inversely correlated with peripheral gustatory fatty acid sensitivity. 992 99

We investigated the effect of long-term administration of highly purified eicosapentaenoic acid ethyl ester (EPA-E), an n-3 polyunsaturated fatty acid derived from fish oil, in comparison to lard on the development of hypertension and insulin resistance in Dahl salt-sensitive (Dahl-S) rats fed a high-sucrose diet (HSD), a model of salt-sensitive hypertension. After 16 weeks of treatment, the glucose infusion rate (GIR) during the euglycemic insulin-glucose clamp test significantly increased in the HSD-EPA-E group compared with the HSD-water or -lard control group. The GIR was approximately three times higher in the HSD-EPA-E group versus the HSD-water or -lard control group, and it was about 70% of the rate in the calorically deprived control group fed a low-fat-high-fiber diet (LF-HFD). In addition, EPA-E significantly suppressed the elevation of plasma glucose and insulin levels after oral glucose loading. These results indicate that EPA-E prevents the development of insulin resistance in Dahl-S rats fed a HSD. Fatty acid analysis of phospholipids in skeletal muscle showed a significant increase in C18:2, C20:5, and C22:5 components in the HSD-EPA-E group and, conversely, a significant decrease in C16:0, C20:4, and C22:6. The present results indicate that the beneficial effect of EPA-E on insulin resistance in Dahl-S rats fed a HSD is likely dependent on the modification of phospholipid components in the skeletal muscle membrane. These findings suggest that EPA-E might prevent the development of insulin resistance in dietary obesity. In addition, the HSD-EPA-E group showed a significant increase in the level of uncoupling protein (UCP) in brown adipose tissue as compared with the HSD-water or -lard control group. However, EPA-E had no effect on the development of hypertension and obesity in Dahl-S rats fed the HSD.
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PMID:Effect of highly purified eicosapentaenoic acid ethyl ester on insulin resistance and hypertension in Dahl salt-sensitive rats. 1048 46


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