Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: UMLS:C0028754 (obesity)
 124,988 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Theophylline and its derivatives, such as aminophylline, have an established role as bronchodilators, although their mode of action in man is not clear. There is circumstantial evidence that therapeutic doses of theophylline may have a phosphodiesterase inhibiting effect, thus potentiating the effects of cyclic AMP. However, it remains to be established whether this is the primary mode of action of theophylline at the biochemical level. The pathways of theophylline metabolism have been clarified, although most of the enzymes involved have not been characterized. Hepatic microsomal enzyme induction by polycyclic hydrocarbons will increase the rate of theophylline elimination. There are a number of factors which influence theophylline clearance in adults, which is known to be highly variable. These factors include obesity, smoking habit, diet and the presence of such diseases as hepatic cirrhosis, acute pulmonary oedema, cor pulmonale and viral respiratory infection. There is a good correlation between plasma theophylline level and bronchodilator effect. This can be demonstrated at plasma levels as low as 5 microgram/ml, although optimal levels are usually greater than 10 microgram/ml. Unacceptable toxicity usually occurs in association with plasma levels greater than 20 microgram/ml. The maintenance of adequate plasma theophylline levels by the use of a sustained-release aminophylline tablet is discussed.
 ...
PMID:Theophylline: biochemical pharmacology and pharmacokinetics. 22 Jan 19

The role of circulatory congestion in the cardiorespiratory dysfunction of massive obesity was investigated in 18 patients. They were hypervolemic and had increased cardiac outputs proportionate to their weight. The average resting left ventricular filling pressure was within the upper limits of normal, but it increased to abnormally high levels with increased venous return of passive leg raising, and further during exercise. The elevations in pressure were associated with high resting central blood volumes which increased significantly with exertion. These findings are consistent with reduced distensibility of the central circulation in these congested patients. Weight reduction was accompanied by a decrease in central blood volumes and restoration of a normal left ventricular response in three of four patients and a return toward normal in one. The improvement in ventricular function with relief of edema and dyspnea. In 14 patients with normal or only minimal alveolar hypoventilation, there were no significant transpulmonary diastolic pressure gradients despite a marked increase in left ventricular end-diastolic pressures. One patient, after regaining weight, subsequently had an abnormal gas exchange and an increased pulmonary vascular resistance. He and two others with severe alveolar hypoventilation demonstrated cor pulmonale on a background of left ventricular dysfunction and congestion of the circulation. Two other patients, the least obese of the group, had hypoventilation and cor pulmonale with normal left ventricular pressures. Hypervolemia and a hyperdynamic state are common features of the obese patients. High cardiac output is maintained despite marked circulatory congestion which may result in generalized anasarca and increased ventricular filling pressures. This clinical syndrome may be present in obese patients without intrinsic heart disease and may be reversible with weight reduction. The central circulatory congestion may contribute to the development of the alveolar hypoventilation syndrome in certain obese patients.
 ...
PMID:Role of circulatory congestion in the cardiorespiratory failure of obesity. 102 Jul 53

Ten patients with the Pickwickian syndrome, characterized by obesity, hypoxemia, hypercapnia, polycythemia, and cor pulmonale, underwent long-term treatment as outpatients with medroxyprogesterone acetate. Although there was no significant weight change in the group, PaO2 rose 12.6 +/- 2.7 mm Hg (SEM) from 49 +/- 2.6 mm Hg to 62 +/- 2.3 mm Hg (P less than 0.001), while PaCO2 fell 13 +/- 2.6 mm Hg from 51 +/- 1.9 mm Hg to 38 +/- 1.2 mm Hg (P less than 0.001). Hematocrit fell from 56 +/- 2.5% to 50 +/- 1.2%, a mean fall of 6% (P less than 0.01), during medroxyprogesterone acetate therapy. In the 2 patients who had cardiac catheterization before and during medroxyprogesterone acetate therapy, mean pulmonary arterial pressure fell 13 and 19 mm Hg. There were no recurrences of cor pulmonale during treatment. These effects on arterial blood gas values and clinical state were sustained during therapy. On withdrawal of medroxyprogesterone acetate during 1-month period, arterial oxygen and carbon dioxide tensions deteriorated to their previous pretreatment values. Reinstitution of medroxyprogesterone acetate caused improvement in both the oxygen and carbon dioxide tensions. We conclude that sublingual medroxyprogesterone acetate therapy is useful in the management of the Pickwickian syndrome.
 ...
PMID:Progesterone for outpatient treatment of Pickwickian syndrome. 110 59

Most patients with extreme obesity do not exhibit alveolar hypoventilation, but an intriguing minority do. The mechanism(s) of this phenomenon remain unknown. A disorder in ventilatory control has been suggested as a major factor in the pathogenesis of the obesity-hypoventilation syndrome. Accordingly, hypoxic and hypercapnic ventilatory drives were measured in 10 patients with the typical symptoms of the syndrome: obesity, hypersomnolence, hypercapnia, hypoxemia, polycythemia and cor pulmonale. Hypoxic ventilatory drive, measured as the shape parameter A, averaged 21.9 +/- 5.35, approximately one-sixth that in normal controls, A = 126 +/- 8.6 (P less than 0.01). The ventilatory response to hypercapnia also was markedly reduced, the slope of the response averaging 0.51 +/- 0.005, or about one-third the normal value of 1.83 +/- 0.13 (P less than 0.01). This decreased responsiveness in hypoxic and hypercapnic ventilatory drive was consistent throughout the group. The depression in ventilatory drive found in the obesity-hypoventilation syndrome may be causally related to the alveolar hypoventilation manifested by these patients.
 ...
PMID:Decreased hypoxic ventilatory drive in the obesity-hypoventilation syndrome. 116 44

A retrospective study was conducted to determine which types of children might have polysomnographic findings that are most compatible with obstructive sleep apnea (OSA). The charts of 93 patients who were aged 18 months to 12 years were examined. All 93 patients had symptoms that were initially suggestive of OSA, and they underwent polysomnography. The types of presenting symptoms and associated illnesses were noted. Physical findings, including height, weight, and tonsil size, were examined. Of 93 patients with symptoms that were suggestive of OSA, 34 met sleep study criteria for OSA. In 44 patients, OSA was not demonstrated, and 15 patients had other results. On the basis of age, sex, and symptoms, no significant differences could be found between the group with OSA and the group with normal polysomnographic findings. Cor pulmonale, tonsil hypertrophy, and failure to thrive were associated with OSA. Surprisingly, obesity was not significantly associated with OSA.
 ...
PMID:Polysomnographic and clinical findings in children with obstructive sleep apnea. 162 96

Increased left ventricular mass has been shown to be a significant independent predictor of cardiovascular risk. The purpose of this study was to assess the separate and combined relations of obesity and hypertension with left ventricular mass and geometry. Echocardiographic findings in subjects in the Framingham Heart Study who were free of cardiopulmonary disease and were not taking cardiovascular medications were examined. M-mode studies that were adequate for estimating left ventricular mass were available in 624 men and 1,209 women. Height and weight measured at the time of echocardiography were used to calculate body mass index (in kg/m2), a measure of obesity. Casual sitting blood pressure measurements were obtained to detect rest hypertension. In subgroup analyses of lean normotensive, obese normotensive, lean hypertensive and obese hypertensive subjects, hypertension and obesity each had significant independent associations with left ventricular mass and wall thickness (all p less than 0.001 in men and women). Obesity was also associated with left ventricular internal diameter (p less than 0.001 in men and women). There were no synergistic influences of hypertension and obesity on any echocardiographic left ventricular variables. It is concluded that obesity and hypertension each have distinct associations with left ventricular mass and geometry. These strengths of association are additive but not synergistic.
 ...
PMID:Separate and joint influences of obesity and mild hypertension on left ventricular mass and geometry: the Framingham Heart Study. 172 24

This report describes an unusual case of severe obstructive sleep apnea and alveolar hypoventilation leading to hypersomnolence and cor pulmonale, which were corrected by tracheostomy. Four years later, after a 22.5-kg weight gain, nocturnal apneas of similar frequency, duration, and depth of desaturation reappeared but were totally central in origin. The central apneas were eliminated with home nocturnal positive-pressure ventilation via cuffed tracheostomy tube. Each time the patient's apneas were corrected (obstructive: tracheostomy; central: mechanical ventilation), daytime alveolar hypoventilation disappeared rapidly. Yearly right heart catheterizations and radionuclide ejection fractions documented pulmonary hypertension and right heart failure, with resolution following tracheostomy and recurrence after appearance of central apneas. The changes in hemodynamic status corresponded to the patient's weight, presence of apnea, daytime alveolar hypoventilation, and treatment of nocturnal oxyhemoglobin desaturation. This case illustrates the theory of a common etiology of both central and obstructive apnea through abnormal respiratory controller gain and points to several roles obesity may play in apnea.
 ...
PMID:Recurrence of sleep apnea syndrome following tracheostomy. A shift from obstructive to central apnea. 273 81

Echocardiography and cardiac catheterization were performed in 30 patients of chronic pulmonary disease and cor pulmonale. We studied the relation of echo-cardiographic data and pulmonary hemodynamics to prognosis in these patients. In the nonsurvival group (12 patients) the extent of dyspnea was worse significantly (p less than 0.05), PaO2 was decreased significantly (p less than 0.05, 7 +/- 8.2 Torr), right ventricular preejection period (RPEP)/right ventricular ejection time (RVET) ratio increased significantly (p less than 0.05, 0.51 +/- 0.07), left ventricular diastolic diameter index (LVDdI) was shortened significantly (p less than 0.05, 23.5 +/- 3.1 mm/m2), and pulmonary capillary wedge mean pressure (PCWm) rose significantly (p less than 0.05, 11.9 +/- 6.9 mmHg) in comparison with the survival group (12 patients). In the survival group PaO2, RPEP/RVET ratio, LVDdI and PCWm averaged 60.9 +/- 12.8 Torr, 0.41 +/- 0.09, 27.5 +/- 5.1 mm/m2, 6.2 +/- 3.3 mmHg, respectively. The rate of survival was decreased significantly (p less than 0.05) in pulmonary vascular resistance (PVR) of greater than 400 dyne.sec.cm-1 or stroke volume index (SVI) of less than 35 ml/m2. These factors and 3 factors of obesity, %VC and pulmonary artery mean pressure (PAPm) differentiated nonsurvivors from survivors with linear discriminant function.
 ...
PMID:[Prognosis in chronic pulmonary disease and cor pulmonale]. 281 Sep 66

Factors related to risk of perioperative pulmonary complications include site of incision, obstructive lung disease, prolonged anesthesia time, smoking history with productive cough, and obesity. Hypercapnia is a consistent indicator of high risk. There is no difference between spinal and general anesthesia with regard to risk of pulmonary complications. In patients being evaluated for lung resection, high-risk indicators include predicted postoperative forced expiratory volume in one second of less than 1000 mL, hypercapnia, severe dyspnea on exertion, or advanced age when it is associated with advanced cardiopulmonary disease. Newer methods of assessing cardiopulmonary reserve may prove useful in identifying which patients with one or more of these risk factors are suitable operative candidates. Prevention of postoperative complications in chronic obstructive pulmonary disease patients should begin in the preoperative period with discontinuation of smoking at least eight weeks before surgery and vigorous pulmonary toilet in the 48 to 72 hours before surgery. Prophylactic lung expansion maneuvers can be effective in decreasing the incidence of postoperative atelectasis in high-risk patients undergoing high-risk operations.
 ...
PMID:Preoperative pulmonary evaluation. 233 Nov 91

Theophylline plasma levels and FEV1 were measured in patients affected by chronic obstructive pulmonary disease and a concomitant disease state (congestive heart failure, chronic cor pulmonale, obesity, peptic disease, hepatic cirrhosis, chronic renal failure) and treated with a sustained release theophylline preparation. Our results indicate that, only in patients affected by congestive heart failure and chronic cor pulmonale, is there a decreased plasma clearance of the drug. Low levels of plasma theophylline were measured in obese patients probably because they received an inadequate posology.
 ...
PMID:Effect of various disease states on theophylline plasma levels and on pulmonary function in patients with chronic airway obstruction treated with a sustained release theophylline preparation. 330 82


1 2 3 4 5 Next >>