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

Caffeine pharmacokinetics were studied in 16 obese (mean +/- s.e. mean body weight; 110 +/- 8 kg; % ideal body weight (IBW); 186 +/- 14%) and 23 normal body weight (64 +/- 3 kg; 103 +/- 3% IBW) subjects. Eight obese and four control subjects were cigarette smokers. After abstaining from caffeine for 48 h and an overnight fast, each subject ingested 162 mg caffeine orally. Concentrations of caffeine were measured in plasma samples obtained during the 24 h following the dose and pharmacokinetic variables were determined. The apparent volume of distribution was increased markedly in obese subjects (69.9 +/- 5.9 vs 43.6 +/- 2.8 l; P less than 0.001) in the absence of any change in oral clearance (135 +/- 14-obese vs 112 +/- 12 ml/min; NS), resulting in a trend toward increased elimination half-life (7.05 +/- 1.08-obese vs 5.40 +/- 0.40 h; NS). Apparent volume of distribution correlated well with percent IBW (r = 0.65; P less than 0.001). Caffeine clearance, suggested as a measure of in vivo cytochrome P-448 activity in humans, was not altered in obesity. In contrast, the extent of caffeine distribution increased in direct relation to body weight. If caffeine is used therapeutically, the loading dose should be calculated as a function of total body weight. Since clearance of caffeine is not related to body weight, these data indicate that a chronic dosing regimen to maintain a given plasma caffeine concentration should not be altered due to obesity.
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PMID:Caffeine disposition in obesity. 402 37

A multisite double-blind study was designed to determine the effectiveness of a phenylpropanolamine-caffeine combination in achieving weight loss. Two-hundred and one obese adult patients were divided into three separate groups in which phenylpropanolamine/caffeine was compared with either placebo (6 weeks), mazindol (6 weeks), or diethylpropion (8 weeks). In these clinical trials, phenylpropanolamine/caffeine proved to be as effective as mazindol and diethylpropion and significantly more effective than placebo in achieving weight loss. Overall, phenylpropanolamine/caffeine had fewer side effects than mazindol and diethylpropion. Its use as an effective anorectic agent in the treatment of obesity is reviewed.
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PMID:Three controlled trials of weight loss with phenylpropanolamine. 676 Dec 88

Rats consuming Coca-Cola and Purina chow ad libitum increased their total energy intake by 50% without excess weight gain. Their resistance to cold was markedly improved. These phenomena were characterized by significant increases in interscapular brown adipose tissue weight (IBAT) (91%), cellularity (59%), triglyceride content (52%), protein content (94%), and cytochrome oxidase activity (167%). In contrast, Coca-Cola consumption did not significantly affect the cellularity or triglyceride content of parametrial white adipose tissue (PWAT), although it slightly augmented PWAT weight. The effects of Coca-Cola on cold resistance, IBAT cellularity, and composition were entirely reproduced by sucrose, but not caffeine, consumption. Although caffeine also increased IBAT cellularity and composition, it significantly decreased the rate of body weight gain, PWAT weight, and adipocyte size. Moreover, it markedly inhibited adipocyte proliferation in PWAT thereby mimicking the effects of exercise training and food restriction (Bukowiecki et al., Am. J. Physiol. 239 (Endocrinol. Metab. 2): E422-E429, 1980). It is concluded a) that sucrose and Coca-Cola consumption improve the resistance of rats to cold, most probably by increasing brown adipose tissue cellularity, and b) that moderate caffeine intake might be useful for inhibiting proliferative activity in white adipose tissue, thereby preventing obesity.
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PMID:Effects of sucrose, caffeine, and cola beverages on obesity, cold resistance, and adipose tissue cellularity. 683 66

1. The metabolic response of lean and obese women to caffeine was studied to see if caffeine could be used to demonstrate the subnormal thermogenesis in obesity previously shown after standard meals or intravenous infusions of noradrenaline. 2. The rise in resting metabolic rate with caffeine was similar in the lean and obese groups and beta-adrenoceptor blockade did not reduce the increment in metabolic rate in either group. These responses did not, therefore, correspond with the other subnormal thermogenic responses of the constitutionally obese. 3. In a post-obese group, i.e. previously obese women who were now of normal weight, there was a reduced response of the resting metabolic rate to caffeine. 4. Monitoring plasma substrate concentrations showed that the change in oxygen uptake corresponded to changes in plasma free fatty acids, so that in adults the metabolic effects of caffeine seem to be mediated by increases in adipocyte lipolysis. This effect seems to be mainly independent of the adrenergic system.
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PMID:Caffeine: its effect on catecholamines and metabolism in lean and obese humans. 701 2

2 aspects of oral contraception (OC) were considered--the risk of arteriosclerotic cardiopathy and the interaction with other drugs. Opinions still diverge on the role of contraceptives in the etiology of myocardial infarction. In contrast to the British studies, the World Health Organization's (WHO) data and US statistics on death from cardiovascular diseases fail to show higher prevalence for OC users. Most likely the data of different countries cannot be compared due to the differing incidence of other cardiovascular morbidity and mortality risk factors such as hypertension, obesity, smoking, physical activity, and genetic predisposition. A recent study examined the prevalence of myocardial infarction in relation to the use of estroprogestinic contraceptives. Rosenberg et al. found that 156 out of 121,944 women (1.2%) had been hospitalized following myocardial infarction, and 23 of them used OCs. The authors concluded that OCs increased the risk of infarction by 1.8. Shapiro et al. studied 369 patients who suffered myocardial infarction and an adequate control group. The overall relative frequency was 4 times in OC users but it was 4.5 times in smokers and 3.9 times in nonsmokers. The smokers who did not use OCs showed a relative frequency of 7.8 times. The risk of arteriosclerotic cardiopathy depends upon the dose of both the estrogenic and progestinic components. When prescribing drugs, physicians should know whether their patients use OCs, since these hormonal steroids may interfere with the expected therapeutic effect. A phenomenon of enzymatic competition may occur which slows down the elimination of the drug, thus exposing the patient to a "relative overdose" despite the assumption of therapeutic doses. It has always been reported that the simultaneous administration of triacetiloleandomycin and OCs causes jaundice. Thus far 15 cases have been reported. OCs tend to enhance the effect of corticosteroids. Vitamin K antagonists, oral anticoagulants, are less effective in OC users. A research study conducted by Patwardhan et al. showed that caffeine is eliminated more slowly in OC users because of a mechanism of enzymatic competition with contraceptive steroids at the level of the hepatic oxygenase system linked to cytochrome P-450. ready been reported that the simultaneous administration of triacetiloleandomycin and OCs causes jaundice. Thus far 15 cases have been reported. OCs tend to enhance the effect of corticosteroids. Vitamin K antagonists, oral anticoagulants, are less effective in OC users. A research study conducted by Patwardhan et al. showed that caffeine is eliminated more slowly in OC users because of a mechanism of enzymatic competition with contraceptive steroids at the level of the hepatic oxygenase system linked to cytochrome P-450.
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PMID:Two problems in oral contraception: arteriosclerotic cardiopathy and drug interactions. 716 61

Caffeine is widely consumed in beverages to obtain mild CNS stimulant effects. Long term use produces tolerance to some of the pharmacological effects. Withdrawal of caffeine, even from moderate intake levels, can produce symptoms such as headache, fatigue and anxiety. Caffeine is used therapeutically in combination with ergotamine for migraine headaches and in combination with nonsteroidal anti-inflammatory drugs in analgesic formulations. Caffeine alone is used as a somnolytic, to treat various headache conditions, respiratory depression in neonates, postprandial hypotension and obesity, and to enhance seizure duration in electroconvulsive therapy. In some headache and in pain paradigms, caffeine may produce direct adjuvant analgesic properties, while in other headache conditions (perioperative, postdural puncture) caffeine may be effective by alleviating a manifestation of caffeine withdrawal. Other uses, such as to promote wakefulness, for respiratory stimulation and seizure prolongation, rely on central stimulant properties of caffeine. Effects of caffeine on the vasculature may contribute to the relief of some headaches and in postprandial hypotension. Blockade of methylxanthine-sensitive adenosine receptors is the currently accepted mechanism of action of caffeine.
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PMID:Pharmacological rationale for the clinical use of caffeine. 770 15

Following an overnight fast and 2 days of abstention from caffeine, a single 1.0-g oral dose of antipyrine was administered to 20 obese but otherwise healthy subjects (group A) and 11 healthy volunteers (group B). Weight, Body Mass Index (BMI) and % of Ideal Body Weight (IBW) were significantly greater in the obese than in the lean group. (Mean 110.4 vs 62.7 kg; 38.5 vs 22.3 kg.m-2 and 181 vs 106% respectively). In a subgroup of 6 obese subjects (group C) antipyrine was given again 11.3 months later after a 29.8 kg mean weight loss. Antipyrine apparent volume of distribution (V) and elimination half-life (t1/2) were significantly greater in the obese than in the lean group (V 49.9 vs 34.3 l respectively; t1/2 15.5 vs 12.0 h respectively), but its clearance rate (CL0) values were similar. V corrected for total body weight was significantly reduced in group A than in group B (0.45 vs 0.55 l.kg-1 respectively). Stratified comparison of antipyrine pharmacokinetics between obese and lean subjects according to age, gender and smoking habits did not alter the overall results. In group C, weight reduction was associated with a significant decrease in antipyrine V (from 51.8 to 47.5 l) and t1/2 (from 15.1 to 12.7 h), and a non-significant increase in antipyrine CL0. We conclude that in severely obese subjects, antipyrine total V is mildly increased but V corrected for total body weight is significantly decreased. In addition, obesity is associated with a slight prolongation of antipyrine t1/2 whereas its CL0 is unaltered. These findings may indicate that obesity, even in its extreme form, has a negligible effect on the oxidative metabolic capacity of the liver.
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PMID:Antipyrine disposition in obesity: evidence for negligible effect of obesity on hepatic oxidative metabolism. 776 56

A preliminary case-control study was conducted on Saudi women to detect possible risk factors for spontaneous abortion (SA). Two hundred and twenty six consecutive women hospitalised for SA and 226 women admitted for normal delivery and used as controls, were studied. Women with SA were significantly older at menarche (Relative Risk (RR) = 3.2), more frequently married to blood-related husbands (RR = 2.1) and husbands older than 50 years (RR = 2.4). Number of previous abortions related linearly to the risk of aborting spontaneously in the next pregnancy. Compared to primigravidas, the RR was 3.2 if the outcome of the most recent pregnancy was SA, and 0.8 if it was a livebirth. A family history of SA was more common among cases (RR = 4.6). Spontaneous abortion was also associated with daily consumption of more than 150 mg of caffeine, abdominal trauma, infection and fever during pregnancy. No significant association, however, emerged with maternal age, social class, education, exposure to video display terminals, parity, use of contraception, diabetes or obesity. The application of these data in clinical practice and future research needs are discussed.
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PMID:Risk factors for spontaneous abortion: a preliminary study on Saudi women. 793 96

The purpose of this study was to investigate the relationship between the changes in mean skin temperature and the energy expenditure induced by drinking coffee containing 4 mg of caffeine/kg body weight. Twelve healthy, weight-stable subjects were studied (five males, seven females; mean age +/- s.d., 25.3 +/- 3.3 years; BMI 22.5 +/- 3.1). Energy expenditure (EE) was measured by open-circuit indirect calorimetry, and skin temperature was determined with thermometric probes applied to the four body regions indicated by Ramanathan (chest, arm, thigh, calf). The calorimetric and thermometric measurements were carried out for 120 min with the participants lying down quietly. A significant correlation was found between the total thermogenic responses (net responses) and the temperature changes between 90 and 120 min from the coffee intake. Multiple regression analysis using mean EE after coffee intake as the dependent variable, and mean skin temperature and body weight as the independent variables yields the following equation: EE (kcal/min/m2) = -1.44 + 0.052 (mean skin temperature) + 0.004 (body weight). (r = 0.71 and P = 0.01) Our results indicate that small interindividual differences in mean skin temperature could explain energy expenditure differences in subjects with the same body weight, body composition and physical activity. This, in turn, could help explain variations in proneness to obesity.
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PMID:Coffee induced thermogenesis and skin temperature. 795 73

Fenfluramine (Fen), an amphetamine-derivative widely used in the treatment of obesity, has been evaluated in vivo in the bone marrow cells of Swiss albino mice for assessing its clastogenic potentials. Concentrations of 0.75, 1.50 and 5.0 mg Fen/kg body weight (b.w.) were administered orally for the study. Long-term treatment for 21 days showed dose-dependent significant increase in chromosomal aberrations on the 8th day. A significant decrease in aberration levels was seen in the late treatment period. Caffeine alone produced dose- and duration-dependent clastogenicity at doses of 2.0, 4.0 and 6.0 mg/kg b.w. when given by gavage. Using caffeine post-treatment (4.0 and 6.0 mg/kg b.w.) 2 h after Fen application, a strong synergism could be seen in the late treatment period as shown by the dose-response curves and by statistical analysis using the principle of least squares. The results support the hypothesis that prolonged Fen application induces dose-dependent increase in post-replication repair and caffeine enhanced toxicity by inhibiting repair process(es). The study suggests that Fen is a clastogen and since caffeine may have a synergistic effect, it should be avoided during treatment.
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PMID:Potentiation by caffeine of the frequencies of chromosomal aberrations induced by chronic exposure to fenfluramine in mice. 806 39


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