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

This disposition of acetaminophen was examined in an overfed rat model of human obesity following iv administration of a subtoxic 303 +/- 5 mg/kg dose based upon ideal body weight. Weanling Sprague-Dawley rats were maintained on a nutritionally complete semisynthetic diet containing 60% vegetable shortening and were compared to animals given a standard laboratory diet over the same 22-week period. At the time of study obese rats outweighed controls by 42% (637 +/- 32 g vs. 450 +/- 7 g, respectively). The absolute clearance of acetaminophen from plasma increased by 27% in obese rats. Higher partial formation clearance to acetaminophen glucuronide and sulfate conjugates accounted for most of this increase. Clearance by sulfhydryl conjugation was also substantially increased (56%), indicating that metabolism via toxic oxidation also occurred at a greater rate in obese animals. Absolute renal clearance of the glucuronide and sulfate conjugates but not acetaminophen increased with obesity, whereas parent volume of distribution remained unchanged. Some rats raised on the energy-dense diet remained lean and were examined separately as a dietary control group. Acetaminophen disposition in these animals was indistinguishable from pellet-fed controls, suggesting that acetaminophen elimination changes in overweight animals resulted from obesity itself and not from the obesity inducing energy-dense diet. Although animals placed on the energy-dense diet ate fewer grams of food per day, their caloric intake was similar to that of pellet-fed animals when adjusted for differences in body weight and caloric content of the diets.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:An overfed rat model that reproduces acetaminophen disposition in obese humans. 287 25

The current studies examine acetaminophen pharmacokinetics and biotransformation in obese animals for possible shifts in metabolic conjugation reactions. Obesity was produced in Sprague-Dawley rats with an energy-dense cafeteria feeding regimen. Acetaminophen half-life remained unchanged and apparent volume of distribution increased slightly in obese versus pellet-fed control rats following an ip dose of 287 mg/kg. However, obese animals exhibited lower plasma concentrations of acetaminophen sulfate and excreted less sulfate conjugate but more glucuronide conjugate in urine. Absolute clearance of acetaminophen from plasma was similar for both groups of rats but formation clearance of acetaminophen sulfate was lower and formation clearance of acetaminophen glucuronide and was higher than control in obese rats. Renal clearance of unchanged drug and both conjugated metabolites appeared to rise with the degree of obesity. The many parallels in acetaminophen disposition shared with the obese human show the overfed rat to be a promising model for metabolic and physiologic changes associated with human obesity.
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PMID:Acetaminophen sulfation deficit in obese rats overfed an energy-dense cafeteria diet. 362 4

The influence of obesity on the distribution or clearance of lorazepam and oxazepam, two benzodiazepines biotransformed by glucuronide conjugation, was studied in a series of obese subjects (mean weight 113 kg; mean percent IBW 179%) and healthy controls of normal body habitus matched for age and sex. Overweight subjects and controls received 2 to 3 mg of lorazepam intravenously or 30 mg of oxazepam orally. Absolute Vd in obese compared to control subjects was increased for both lorazepam (131 vs. 77 L, p less than 0.001) and oxazepam (97 vs. 38 L, p less than 0.001). When normalized to body weight, Vd/kg was similar for both drugs. Total metabolic clearance was similarly increased in the obese cohort for lorazepam (102 vs. 63 ml/min, p less than 0.005) and oxazepam (157 vs. 50 ml/min, p less than 0.001). Again, when normalized to body weight, clearance per kilogram was similar for both drugs. Since both Vd and clearance increased with body weight, elimination half-life (dependent on both Vd and clearance) was not significantly different in obese subjects (lorazepam 16.5 vs. 14.9 hr; oxazepam 7.7 vs. 8.9 hr). A random subgroup of obese and control subjects received a single intravenous dose of acetaminophen, also biotransformed by conjugation. Acetaminophen clearance was significantly correlated with that of lorazepam (r = 0.59, p less than 0.01) and oxazepam (r = 0.87, p less than 0.001), and clearance of LRZ and OXZ were similarly intercorrelated (r = 0.72, p less than 0.01). Thus obesity is associated with enhanced capacity for biotransformation of drugs via glucuronide conjugation. conjugating capacity increases in proportion to TBW and is consistent among drugs biotransformed by this mechanism.
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PMID:Enhanced glucuronide conjugation of drugs in obesity: studies of lorazepam, oxazepam, and acetaminophen. 613 1

Pharmacokinetic data in obesity are only available for a limited number of drugs. The rate or extent of drug absorption is not known to be altered by obesity which is not complicated by other medical disease. In contrast, drug distribution is in some instances significantly altered in obesity. Digoxin and bromsulphalein, both hydrophilic drugs, do not distribute into excess bodyweight over ideal bodyweight. However, antipyrine, paracetamol, aminoglycoside antibiotics and theophylline, all of intermediate lipid solubility, distribute to a limited extent into excess bodyweight over ideal bodyweight, although not as extensively as into ideal bodyweight. Benzodiazepines, halothane and enflurane, highly lipophilic agents, may distribute much more extensively into excess bodyweight over ideal bodyweight than into ideal bodyweight. This suggests some relationship between drug distribution and drug lipid-solubility in obese subjects. Whether these distributional changes in obesity will hold for other drugs is not currently known. Drug protein binding has not been demonstrated to be changed in obesity, data being presently available only for the basic drugs diazepam and desmethyldiazepam. Drug biotransformation in obesity is unchanged for oxidatively metabolised drugs studied to date. Paracetamol, the only metabolised drug which is conjugated for which pharmacokinetic parameters have been accurately determined in obesity, undergoes increased clearance in obese subjects.
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PMID:Pharmacokinetics of drugs in obesity. 703 24

Twenty-one obese (14 women; 7 men) and 21 normal (11 women; 10 men) drug-free and age-matched subjects were given single 650-mg IV doses of acetaminophen. Mean total body weights (TBW) for the groups were as follows: obese men, 134.9 kg; control men 70.6 kg; obese women, 87.9 kg; and control women, 55.0 kg; ideal body weight (IBW) was similar for all of the groups. Acetaminophen elimination half-life (t1/2 beta) did not differ among groups. Absolute volume of distribution (Vd) was greater in obese than in control men (109 and 77 l, P less than 0.05) and greater in control men than in control women (77 and 52 l, P less than 0.05), but Vd corrected for TBW was smaller in obese than in control men (0.81 and 1.09 l/kg TBW, P less than 0.05) and smaller in obese than control women (0.71 and 0.95 l/kg TBW, P less than 0.05). Absolute metabolic clearance was greater in obese than in control men (484 and 323 ml/min, P less than 0.05), in obese than in control women (312 and 227 ml/min, P less than 0.05), and in control men than women (323 and 227 ml/min, P less than 0.05). After correction for TBW, however, clearance between control and obese subjects of the same sex did not differ. Acetaminophen Vd is increased in obesity and in men relative to women, but the drug's distribution into body weight exceeding IBW is less extensive than that into IBW. For men the distribution ratio is 0.44 and for women, 0.31. Acetaminophen clearance increases with body weight and therefore is much greater in obese patients and in men.
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PMID:Obesity, sex, and acetaminophen disposition. 707 26

The effect of genetic obesity and phenobarbital treatment on hepatic conjugation pathways was evaluated in the obese Zucker rat. Acetaminophen pharmacokinetic parameters were examined in vivo after a 30-mg/kg acetaminophen intravenous bolus dose in the presence and absence of phenobarbital treatment. Glucuronidation and glutathione conjugation pathways were studied in vitro in obese and lean Zucker rats after phenobarbital treatment. Obese Zucker rats demonstrated a higher glucuronidation capacity as evidenced by a higher formation clearance of acetaminophen glucuronide and greater UDP-glucuronosyltransferase (UDPGT) activity toward acetaminophen and p-nitrophenol compared with lean controls. Sulfate and glutathione conjugation pathways were not affected by genetic obesity. Obese Zucker rats possessed a higher total hepatic glutathione content due to greater liver weight. Phenobarbital treatment enhanced glucuronidation of acetaminophen and structurally related compounds (i.e., p-nitrophenol) similarly in both phenotypes, but the treatment failed to induce morphine UDPGT in the obese Zucker rat. No effect of phenobarbital was observed on sulfate conjugation, gamma-glutamyl cysteine synthetase activity or hepatic glutathione content in obese or lean Zucker rats. Similar increases in glutathione transferase activities were observed in animals of both phenotypes after phenobarbital treatment. This study demonstrates that glucuronidation is enhanced in genetically obese rats, whereas phenobarbital causes normal induction of several enzymes of the glucuronidation and glutathione conjugation pathways in the obese Zucker rat. However, morphine UDPGT was not induced by phenobarbital, suggesting that obese Zucker rats may possess a defect in the induction of this enzyme similar to that already described for the CYP2B gene in this strain.
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PMID:Effect of genetic obesity and phenobarbital treatment on the hepatic conjugation pathways. 851 12

Osteoarthritis is a common rheumatologic disorder. It is estimated that 40 million Americans and 70 to 90 percent of persons older than 75 years are affected by osteoarthritis. Although symptoms of osteoarthritis occur earlier in women, the prevalence among men and women is equal. In addition to age, risk factors include joint injury, obesity, and mechanical stress. The diagnosis is largely clinical because radiographic findings do not always correlate with symptoms. Knowledge of the etiology and pathogenesis of the disease process aids in prevention and management. Acetaminophen and nonsteroidal anti-inflammatory medications remain first-line drugs. Agents such as cyclooxygenase-2 inhibitors and sodium hyaluronate joint injections offer new treatment alternatives. Complementary medication use has also increased. Therapeutic goals include minimizing symptoms and improving function.
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PMID:Osteoarthritis: diagnosis and therapeutic considerations. 1189 56

Obesity is associated with increased hepatic glycogen content. In vivo and in vitro data suggest that plasma free fatty acids (FFA) may cause this increase. In this study we investigated the effect of physiological plasma FFA levels on hepatic glycogen metabolism by studying intrahepatic glucose pathways in lean and obese subjects. Six lean and 6 obese males were studied twice during a 16- to 22-hour fast, once with and once without acipimox, an inhibitor of lipolysis. Intrahepatic glucose fluxes were measured by infusion of [2-(13C1)]glycerol, [1-(2H1)]galactose, and [U-(13C6)]glucose. Acetaminophen was administered as a glucuronate probe. In both lean and obese control studies, plasma FFA levels increased progressively, whereas acipimox completely suppressed plasma FFA levels for the whole study period. In lean males glycogenolysis did not change in the acipimox study, but decreased in the control study (P < .01). In lean males, neither glycogen synthesis, glycogen synthesis retained as glycogen, nor glycogen balance differed between control and acipimox studies. In obese males glycogenolysis did not change in the acipimox study, but decreased in the control study (P < .01). Glycogen synthesis did not change in either study. Glycogen synthesis retained as glycogen did not change in acipimox study, but increased in the control study (P = .03). Glycogen balance did not change in the acipimox study, but increased in the control study (P < .01). This study demonstrates that in obese males physiological levels of FFA contribute to the retention of hepatic glycogen during short-term fasting by inhibiting breakdown of glycogen and increasing glycogen synthesis retained as glycogen, whereas in lean males this effect was absent due to unaltered glycogen synthesis retained as glycogen.
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PMID:Free fatty acids increase hepatic glycogen content in obese males. 1525 82

Osteoarthritis (OA) is currently defined by the American College of Rheumatology as a "heterogeneous group of conditions that leads to joint symptoms and signs which are associated with defective integrity of articular cartilage, in addition to related changes in the underlying bone at the joint margins." Its prevalence after the age of 65 years is about 60% in men and 70% in women. The etiology of OA is multifactorial, with inflammatory, metabolic, and mechanical causes. A number of environmental risk factors, such as obesity, occupation, and trauma, may initiate various pathological pathways. OA indicates the degeneration of articular cartilage together with changes in subchondral bone and mild intraarticular inflammation. The principal treatment objectives are to control pain adequately, improve function, and reduce disability. Acetaminophen is frequently used for symptomatic OA with mild to moderate pain. Nonsteroidal antiinflammatory drugs (NSAIDs) are more effective in the case of moderate-severe pain, but they have an increased risk of serious upper gastrointestinal adverse events. The newer cyclooxygenase COX-2 specific inhibitors (Coxibs) are as efficacious as traditional NSAIDs and have a better gastrointestinal safety profile. Other compounds (eg, chondroitin sulfate, diacerein, glucosamine sulfate) have a symptomatic effect that is slower and less than that of NSAIDs. The structure-modifying effects of drugs are currently being evaluated, and both glucosamine sulfate and diacerein have been shown in some trials to have a beneficial structural effect. Nonpharmacological interventions are frequently and widely used in the management of OA patients, but there is little evidence that they are effective: the best studied and most successful nonpharmacological interventions are patient education, self-management, and exercise. There is some evidence for the pain-relieving efficacy of thermotherapy and transcutaneous electrical nerve stimulation (TENS) but not of electrotherapy, acupuncture, homeopathy, or manual therapy. The value of interventions aimed at improving function and maximizing independence (occupational therapy, walking aids, workplace adaptation) is also unclear. The disease course and patient's requirements often change over time, thus requiring a periodic review and readjustment of therapy rather than the rigid continuation of a single treatment.
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PMID:Osteoarthritis: an overview of the disease and its treatment strategies. 1608 27

Type 2 diabetes (noninsulin-dependent diabetes mellitus) develops from a pre-diabetic condition that is characterized by insulin resistance and glucose intolerance, and is exacerbated by obesity. In this study, we compared the ability of over-the-counter analgesic drugs (OTCAD) [acetaminophen (APAP); ibuprofen (IBU); naproxen (NAP); aspirin (ASA)], to protect against the development of a pre-diabetic state in mice fed a high fat diet. After 10 weeks on the high fat diet, mice had normal fasting blood glucose (FBG) levels, but exhibited impaired glucose tolerance. Treatment with 20 mg OTCADs/kg body weight improved glucose tolerance, with the order of efficacy, APAP=ASA>IBU, while NAP proved ineffective. Mice fed the high fat diet also exhibited increases in weight gain associated with an increase in body fat. OTCADs prevented in part this increase in body fat, in the order of efficacy, APAP=IBU>NAP=ASA. In isolated liver mitochondria, OTCADs inhibited succinate-dependent H2O2 production, while in white adipose tissue, APAP inhibited NADPH-oxidase mediated H2O2 production and lipid peroxidation. Thus, OTCADs diminish pro-oxidant processes that might otherwise exacerbate inflammation and a pre-diabetic state. We conclude that OTCADs, especially APAP and IBU, may be valuable tools to delay or prevent the development of type 2 diabetes from a pre-diabetic condition.
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PMID:Over-the-counter analgesics normalize blood glucose and body composition in mice fed a high fat diet. 1855 74


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