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)

A high plasma insulin concentration in the presence of a normal or high plasma glucose level appears to be a common feature of glucose intolerance, obesity, and hypertension. Hyperinsulinemia has been recognized as a major risk factor for the development of coronary artery disease independent of blood pressure and plasma lipid levels. All these conditions are frequently associated, particularly in aging, a state itself characterized by hyperinsulinemia. This common association has prompted the hypothesis that hyperinsulinemia may be a causative factor rather than the consequence of obesity, diabetes, hypertension, and hyperlipidemia. If that is the case, defining the nature and mechanisms of hyperinsulinemia becomes of primary interest. Insulin resistance is also a striking feature of all of the above mentioned pathologic states. In the presence of a preserved B-cell function, hyperinsulinemia can represent the mechanism designed to overcome the defect in the biological action of the hormone. For instance, there is a clear-cut age-related decline in the body's sensitivity to insulin. In order to compensate for this defect in insulin-mediated glucose metabolism, the B-cell must increase its secretion. On the other hand, a certain degree of insulin resistance can be induced both in animals and man by prolonged euglycemic hyperinsulinemia. Little is known regarding possible primary defects of the B-cell leading to uncontrolled oversecretion of insulin and subsequent insulin resistance. The primary defect, more probably, resides in an alteration of one or more of the steps whereby insulin exerts it own action. In favor of this hypothesis are the observations that insulin resistance segregates in familial clusters and that the first defect found in normoglycemic relatives of insulin-resistant diabetic patients is a reduced transformation of glucose into glycogen. Whatever is the primary defect, it is likely that a correction of insulin resistance might reduce the circulating levels of plasma insulin, possibly playing a beneficial effect on glucose tolerance, body weight, blood pressure and plasma lipid concentration.
 ...
PMID:[Hyperinsulinism. Causes and mechanisms]. 133 21

SHHF/Mcc-cp rats, as a model of obesity and diabetes, were followed through breeding and throughout development to determine timing of obesity and sexual development. The obesity or corpulency gene (cp) follows recessive transmission characteristics with no segregation between sexes. Although the frequency of litter sizes was different, the mean litter size of heterozygous mating (8.9 +/- 0.3 pups/litter) was not different from homozygous lean matings (7.9 +/- 0.3 pups/litter). Body weights of the population of female obese rats statistically deviated from lean females at day 35 and obese males deviated from lean males at day 37. Vaginal opening of obese and lean females did not differ in time of occurrence (day 34.6 +/- 0.2 for lean and 33.6 +/- 0.4 for obese). To further evaluate development and examine onset of diabetes, animals were killed at six, eight and ten weeks of age and development of reproductive organs and plasma levels of insulin, glucose, and testosterone or oestradiol determined. Testes development was slightly retarded in the obese male with smaller testes at six weeks of age, however testes size increased at eight and ten weeks of age and was not significantly less than lean males. In contrast, testes function was impaired with smaller seminal vesicles and lower testosterone levels in the obese male rats. Both ovarian and uterine weights were significantly less in obese females. However, oestradiol levels were not significantly different at any of the time points examined. Development of elevated insulin levels were first noted in the obese female at six weeks of age, however marked hyperinsulinemia developed only in the obese males at ten weeks of age.(ABSTRACT TRUNCATED AT 250 WORDS)
 ...
PMID:Onset of obesity and puberty in genetically obese SHHF/Mcc-cp rats. 133 77

The circadian rhythm of glycogen metabolism in liver and skeletal muscle was studied in lean and gold thioglucose (GTG) induced-obese mice. The active forms of glycogen synthase (GSI) and phosphorylase (GPa) and the total activity of these enzymes were measured every three hours over a 24 h period in mice fed ad libitum. Hepatic and muscle glycogen content displayed a marked diurnal rhythm that was similar in lean and obese mice. In skeletal muscle the glycogen content, GSI and GPa were not significantly different in lean and obese animals over the 24 h period. The activities of muscle GSI and GPa were constant in both groups despite the diurnal variation in the muscle glycogen content. The absence of an increase in the glycogen content of skeletal muscle despite the pronounced hyperinsulinemia and hyperglycemia in the obese mice, may indicate the degree of insulin resistance in this tissue or the maximal capacity of muscle tissue to store glycogen. In liver, glycogen concentration and total glycogen storage were higher in obese mice. Unlike muscle, both hepatic GSI and GPa underwent significant changes in activity over the 24 h period. Hepatic GSI was lower and GPa was higher in obese mice. The circadian rhythm in enzyme activities was independent of both blood glucose and insulin levels. The total glycogen storage and the activities of total phosphorylase and GPa were significantly increased in the liver from GTG obese mice over a 24 h period and could be implicated in the development of insulin resistance and glucose intolerance in this model of obesity.
 ...
PMID:Diurnal rhythms of glycogen metabolism in the liver and skeletal muscle in gold thioglucose induced-obese mice with developing insulin resistance. 133 47

The impact of hyperinsulinemia on the establishment of insulin resistance was investigated. This was done by treating normal rats with insulin for 3-4 days via osmotic minipumps, and by comparing them with saline-treated controls. Hyperinsulinemia produced by prior insulin treatment (i.e. prior insulinization of the normal rats) resulted in a well tolerated hypoglycemia, increased food intake and body weight gain. Euglycemic-hyperinsulinemic clamps were carried out at the end of the insulinization to assess the acute effects of insulin in control and insulinized rats. It was found that prior insulinization of normal rats resulted in increases in total insulin-stimulated glucose utilization and hepatic lipogenesis, while hepatic glucose production (HGP) was normally suppressed by the hormone. Glucose utilization index by individual tissues was then measured (labelled 2-deoxy-D-glucose method). Prior insulinization of normal rats resulted in increased insulin-stimulated glucose utilization index of white adipose tissue, accompanied by increased insulin-stimulated de novo lipogenesis and glycogen synthesis. In contrast, prior insulinization of normal rats resulted in a decreased insulin-stimulated glucose utilization index of most muscles studied. The decreased insulin-stimulated muscle glucose utilization index brought about by prior insulinization persisted in adrenomedullectomized or propranolol-treated rats, ruling out a role of catecholamines in the effects observed. It is concluded that hyperinsulinemia is a pathological driving force in producing both incipient obesity by overstimulating white adipose tissue and liver metabolic activity, and concomitantly producing incipient muscle insulin resistance.
 ...
PMID:Hyperinsulinemia and its impact on obesity and insulin resistance. 133 81

High blood pressure of unknown etiology has been related to many pathogenetic factors, mainly dietary salt intake, mental stress, alcohol consumption, sedentary living and aging. Hypertension is more common in condition such as obesity and diabetes mellitus. Sustained elevation of arterial pressure is mediated by vasoconstriction in response to catecholamine release and activation of the renin-angiotensin-aldosterone system. In obese and diabetic subjects, insulin resistance and hyperinsulinemia have been found to be related to development of hypertension. The hypertension phenotype may correspond to many different genotypes codifying various alterations of hormone and receptor function, as well as inherited diseases linked to hypertension. An outstanding epidemiologic example of how hypertension may appear in a community is found in Easter Island. Hypertension among native adults increased from 3 to 30% in a 10 year period, in relation to influx of tourism and changes in salt intake and diet.
 ...
PMID:[Etiopathogenic factors of arterial hypertension]. 134

Fenfluramine improves glucose tolerance in obese subjects independently of its anorectic effect. Increased insulin action has been reported, but such an effect may be secondary to reduced hyperglycemia following augmented insulin secretion. For this reason, we investigated whether the dextro-enantiomer of fenfluramine (dexfenfluramine, dF) has a direct effect on insulin secretion using the glucose infusion test, a technique that can also be used to indirectly evaluate insulin action. Ten lean controls (BMI 21 +/- 0.4 kg/m2), 9 non-diabetic obese subjects (BMI 32.3 +/- 1.1) and 10 obese mild non-insulin dependent diabetics (BMI 36 +/- 2.6, fasting plasma glucose (FPG) 7.9 +/- 0.9 mmol/l) were studied with a random, double blind cross-over protocol. Each subject received 15 mg dF (or placebo) twice daily for 3 days prior to glucose infusion; 30 mg dF (or placebo) were given 90 min before the test. Obese control and diabetic subjects continued treatment with either dF or placebo for one month after which they were retested. There was no significant change in weight or fasting plasma glucose or insulin in any group. Biphasic insulin secretion was demonstrated in both non-diabetic groups, whereas a complete lack of first-phase and a delayed and reduced second phase insulin response was demonstrated in the diabetic subjects. There was no acute or chronic (obese subjects) effect of dF on insulin secretion in any group. In lean control subjects, plasma glucose curves during glucose infusion were unchanged by dF, whereas in non-diabetic obese subjects the glucose slope was improved after both acute and chronic dF, implying augmented glucose disposal. In diabetic patients, no significant acute or chronic effect of dF on glucose response was registered. When all obese subjects were re-grouped according to fasting plasma insulin levels (FPI) and not glucose tolerance, those with relative fasting hyperinsulinemia (> 100 pmol/l, mean +/- SE = 144 +/- 12 pmol/l) showed significant improvement of insulin action after dF, whereas those with low FPI (< 100 pmol/l, mean +/- SE = 65 +/- 7 pmol/l) did not. These findings, together with previously published results of improved insulin action in diabetics during hyperinsulinemic clamps, suggest that dF-mediated improvement in glucose clearance may require substantial plasma insulin concentrations.(ABSTRACT TRUNCATED AT 400 WORDS)
 ...
PMID:Acute and chronic effects of dexfenfluramine on glucose and insulin response to intravenous glucose in diabetic and non-diabetic obese subjects. 134 13

A male fat distribution pattern with abdominal obesity increases the risk for hypertension and cardiovascular disease, and is closely linked to a number of metabolic aberrations including insulin resistance. Recent observations suggest that changes in the peripheral vasculature may be of pathophysiological importance for the development of hypertension and its associated metabolic disturbances. We therefore investigated the hemodynamic correlates of abdominal obesity. A central fat distribution was found to be associated with a specific hemodynamic profile, characterized by elevated total peripheral resistance and lower cardiac output. In response to sympathoadrenal activation during mental stress, the normal cardiac output-dependent pressor response was reversed into a systemic vasoconstrictor response. There was a direct relationship between degree of abdominal obesity (expressed as waist-hip ratio) and fasting serum insulin. Furthermore, the stress-induced increase in total peripheral resistance correlated positively with fasting serum insulin concentration, whereas there was an inverse relation between serum insulin and cardiac output and heart rate. In a second study, the circulatory responses to stress during physiological hyperinsulinemia were investigated. During hyperglycemic hyperinsulinemia the central hemodynamic response to stress was changed into a systemic vasoconstrictor response. In the forearm the physiological vasodilation during stress was markedly attenuated, suggesting that insulin may have peripheral vascular effects. In conclusion, central obesity is associated with a specific hemodynamic pattern characterized by higher total peripheral resistance and lower cardiac output, and a vasoconstrictor response to psychosocial stress. This hemodynamic response pattern may be related to insulin metabolism.
 ...
PMID:Hemodynamics of the male fat distribution pattern. 134 31

Trace metals are known to have important effects on the activity of metalloenzymes and insulin secretion and to be involved in the etiology of various diseases. This study was designed to investigate the distribution and concentration of selected trace metals in the tissues of genetically obese mice, which were known to have hyperinsulinemia. Different phenotypes (ob/ob; +/?) and sexes of 4, 8, 12 week-old mice were killed by decapitation. Metal levels (Zn, Cu, Cd, Cr) in the brain, liver, serum, hair and carcass were determined by an atomic absorption spectrometer. The results showed that obese mice had lower concentrations of zinc in the serum, hair, liver and carcass than lean controls (p less than 0.05), but there was no difference in the brain. Obese mice also had a low carcass cadmium concentration (p less than 0.01), which depended on the sex-age interaction. When expressed in terms of total content, obese mice had higher total liver zinc and carcass chromium contents (p less than 0.05). Obese mice had a higher total carcass copper content at 8 weeks of age. Serum and carcass zinc were showed to be inversely related to body fat in obese mice. The results indicate that zinc may play a special role in thermoregulation and fat metabolism in the liver of obese mice. The tissue distribution and absorption of zinc may have an important correlation in the development of obesity. The roles of copper, cadmium and chromium are still obscure, the related regulations are still open for further questions.(ABSTRACT TRUNCATED AT 250 WORDS)
 ...
PMID:[Investigation of the profile of selected trace metals in genetically obese (ob/ob) and lean (+/?) mice]. 135 9

The Obese Zucker rat is a model of genetic obesity characterized by hyperphagia, hyperinsulinemia and other endocrine abnormalities. In order to elucidate pathogenetic mechanisms contributing to disturbed feeding behavior in these animals, the effect of food restriction on three hypothalamic neuropeptides involved in the control of food intake was studied. Eighteen male obese and 18 lean Zucker rats were randomly divided into two groups: half of the animals were food-restricted for 2 weeks, while the other half served as controls and were fed ad libitum. The levels of preproneuropeptide Y (preproNPY), preprocorticotropin releasing factor (preproCRF) and preprosomatostatin (preproSOM) mRNAs were determined using in situ hybridization technique. In addition, plasma insulin and corticosterone concentrations were analyzed. Food restriction significantly increased the expression of preproNPY mRNA in the arcuate nucleus in both Zucker phenotypes, while the expressions of preproCRF mRNA in the paraventricular nucleus (PVN) and preproSOM mRNA in the periventricular nucleus (PeV) were not altered. The expression of preproNPY mRNA was significantly greater in control obese animals compared to control lean animals. Food restriction lowered plasma insulin levels, but did not change plasma corticosterone levels. It is concluded that food restriction specifically activates NPY gene transcription in the arcuate nucleus the response being similar in both Zucker phenotypes. The results suggest that orexigenic NPY plays a role in the adaptation to altered feeding status.
 ...
PMID:Hypothalamic neuropeptide expression after food restriction in Zucker rats: evidence of persistent neuropeptide Y gene activation. 136 27

The study reviews current knowledge about metabolic X syndrome characterized by android obesity, arterial hypertension, insulin resistance with hyperinsulinemia and disturbed carbohydrate tolerance, a decrease of HDL cholesterol and an increase of the triglyceride rich VLDL particle level. The study describes 4 female patients having been diagnosed for this syndrome. Only an ontime and vigorous reduction of overweight, along with intensified physical activity can prevent later development of serious complications, first of all, in cardiovascular system.
 ...
PMID:[The metabolic X syndrome--4 case reports]. 136 60


<< Previous 1 2 3 4 5 6 7 8 9 10 Next >>