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

In postmenopausal women, partly in relation to advancing age and partly due to oestrogen deficiency, there is a frequent increase in body weight, and more specifically, in android fat distribution. In addition, loss of ovarian function is associated with the development of a more atherogenic profile with increased triglycerides, LDL-cholesterol and its smaller dense subfractions, decreased HDL- and HDL2-cholesterol and, potentially, an irregular increase in Lp(a). Not only does oestrogen therapy counteract all these changes towards a definitely less atherogenic profile but oestrogens seem also implicated in reducing LDL oxidative products, in favouring a higher ratio of prostacyclin to thromboxane and, potentially, of endothelium derived relaxing factor to endothelin, and also in acting as a calcium antagonist in the vessel wall. All of these favourable vascular effects are not solely attributable to lipid-related oestrogen effects. Excess weight and central obesity, diet changes and lack of exercise, more frequent with advancing age, all concur to alter glucose tolerance and increase insulin resistance during the postmenopause. Impaired glucose tolerance and diabetes mellitus may be found in nearly 20% of women aged 55 to 65 years. In addition, oestrogen deficiency may be further responsible for decreased pancreatic insulin secretion and alteration of its metabolic clearance rate-changes that can be reversed toward improved insulin secretion and sensitivity by oestrogen treatment in small dosages. By contrast, synthetic androgenic progestins can counteract these effects of oestrogens more than progesterone derivatives do, and they may partly help to promote insulin resistance and hyperinsulinism.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:Postmenopausal changes of lipid and glucose metabolism: a review of their main aspects. 761 65

The aim of this study was to investigate the potential interaction between the lipoprotein lipase (LPL) HindIII polymorphism and visceral adipose tissue (AT) accumulation in the modulation of triglyceride levels in visceral obesity. The LPL-HindIII genotype was determined by polymerase chain reaction in 52 min. Twenty-three subjects were heterozygous (+/-) and 28 were homozygous (+/+) for the presence of the restriction site. One subject who was homozygous for the--allele was excluded from analysis. Body mass index (BMI), fasting insulin level, and visceral AT area as measured by computed tomography were positively correlated with triglyceride levels only in subjects homozygous for the + allele. Furthermore, whereas these variables were negatively correlated with plasma HDL2 cholesterol concentrations in the +/+ group, these associations were not found in +/- heterozygotes, with the exception of BMI. To further investigate the interaction of the LPL-HindIII polymorphism with visceral obesity and hyperinsulinemia, the two genotype groups were further subdivided on the basis of BMI (low versus high), fasting insulin level (low versus high), and visceral AT area (low versus high), and their lipoprotein profiles were compared. Elevated levels of abdominal visceral AT were significantly associated with increased triglyceride concentrations in +/+ homozygous men, suggesting that visceral obesity may lead to hypertriglyceridemia in the presence of the +/+ genotype. In the +/- group, variation in the amount of visceral AT was not associated with differences in triglyceride concentration. However, hypertriglyceridemia and an increased cholesterol-to-HDL cholesterol ratio were observed in the hyperinsulinemic state irrespective of LPL-HindIII genotype status.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:The lipoprotein lipase HindIII polymorphism modulates plasma triglyceride levels in visceral obesity. 774 85

A radiochemical method for selective measurement of postheparin lipase activities was adapted to analyze lipoprotein lipase and hepatic lipase in preheparin plasma. The assay sensitivity was increased about four-fold by doubling both the volume of plasma used and the volume of lipolytic products taken for liquid scintillation counting, and was further improved by increasing the incubation period by 50% to 90 min. Rabbit antiserum to human hepatic lipase was unsuitable for the selective measurement of lipoprotein lipase because of apparent endogenous lipolytic activity. Preheparin hepatic lipase, however, was sensitive to inactivation by sodium dodecyl sulfate (SDS), the inhibition being greatest (> 90%) for plasma incubated with an equal volume of 40 mmol/L SDS. Intra- and interassay CVs for the two enzymes were 12.5-14.6% and 17.4-19.7%, respectively. In a cross-sectional study of 84 healthy subjects, pre- and postheparin hepatic lipase activities were higher in men than women, were correlated with indices of obesity, and were significantly correlated with one another, which explained the association of the former with plasma concentrations of high-density lipoprotein (HDL), HDL2, and small, dense low-density lipoproteins. There was no significant relationship between pre- and postheparin lipoprotein lipase activities, but the former were correlated with plasma concentrations of free fatty acids (FFA) and very-low-density lipoprotein. Apparently, preheparin activities of hepatic lipase, but not of lipoprotein lipase, may be a useful measure of the physiological function of "whole body" enzyme activity in cross-sectional and metabolic studies, where heparinization is not possible. Preheparin lipoprotein lipase activities, however, may reflect displacement of the enzyme by FFA and subsequent binding to remnants of triglyceride-rich lipoproteins.
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PMID:Measurement and physiological significance of lipoprotein and hepatic lipase activities in preheparin plasma. 788 16

The aim of this study was to assess any association between an Xmn1 restriction site polymorphism of the apo AI gene and lipoprotein levels in obesity. A cross sectional study was made of lipid variables in relation to genetic and anthropometric factors in obese people at the Nutrition Outpatient Clinic of Bichat Hospital in Paris, France. The subjects were 97 unrelated French Caucasian subjects (65 women and 32 men) selected on the basis of 20% over-weight. The following main outcome measures were recorded: body mass index (BMI) and waist to hip ratio (WHR), cholesterol (C) and triglyceride (TG) concentrations in serum and lipoproteins (including HDL subfractions), apolipoproteins AI and B, determination of apo AI Xmn1 genotypes. Three alleles, designated X1, X2, X3, could be detected with frequencies 0.84, 0.12, and 0.04 respectively. The X2 carriers had higher concentrations of LpA-I, A-II (HDL particles containing both Apo AI and Apo AII) in the whole group: 0.90 vs 0.77 and 0.72 g/l in X1X1 and X1X3 respectively (P < 0.01). The genotype X1X2 was also associated with higher HDL-C in obese men (0.47 vs 0.36 g/l in X1X1, P < 0.05). In X1X1 women, BMI was positively correlated with serum and VLDL-TG (P < 0.05) and negatively with HDL2-C (P < 0.05), WHR being positively correlated with serum TG (P < 0.05), VLDL-TG (P < 0.01) and negatively with HDL-(P < 0.05) and HDL2-C (P < 0.01). These correlations were not found in subjects carrying the X2 allele.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:Xmn1 restriction polymorphism of apolipoprotein AI gene and lipoprotein levels in obesity. 792 Aug 70

Metabolic disturbances such as hyperinsulinaemia, dislipoproteinaemia and glucose intolerance are often associated with essential hypertension and markedly affect cardiovascular morbidity in hypertensive patients. In order to shed some light on the prognostic significance of white coat hypertension (raised clinic and normal ambulatory blood pressure), we compared the metabolic profile in a group of white coat and sustained previously untreated hypertensives. We studied 84 newly detected hypertensive patients (49 men, 35 women, 47 +/- 8 years, range 28-59 years). Subjects with obesity (BMI > 30), NIDDM and target organ damage were excluded. Ambulatory blood pressure monitoring was performed by SpaceLabs 90207-31. Total cholesterol and triglycerides, LDL-cholesterol, HDL-cholesterol (HDL-C) and subclasses HDL2 and HDL3 cholesterol as well as apolipoprotein A1 and B were measured in fasting plasma. Glucose and insulin were determined in fasting and postload (glucose 75 g plasma. Twenty patients (24%, 8 men and 12 women) were classified as white coat hypertensives. No differences in age, BMI and waist to hip ratio were observed between white coat and sustained hypertensive patients. Plasma glucose and lipoprotein levels were similar in the two groups. Fasting and postload insulin levels were significantly lower in white coat hypertensives (fasting insulin 7.1 +/- 2.9 vs. 12 +/- 8.6 microU/ml, P < 0.02; insulin 120 minutes 48 +/- 27 vs. 65 +/- 41 microU/ml, P < 0.05); glucose/insulin rate was higher in white coat than in sustained hypertensive patients (15 +/- 7 vs. 11 +/- 7, P = 0.03).(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:Metabolic risk factors in white coat hypertensives. 793 8

The authors analyzed tracking and predictiveness of serum lipid and lipoprotein measurements in Finnish children and young adults over a 12-year follow-up period. A representative sample of 3,596 healthy subjects aged 3-18 years was examined in 1980. The follow-up studies were done in 1983, 1986, 1989, and 1992. Data were available on serum lipids and lipoproteins, anthropometric measurements, dietary and smoking habits, and use of oral contraceptives. Complete data on serum lipids in 1980 and 1992 were available for 883 subjects (47% males), and they comprised the study cohort for this analysis. Significant tracking was found in each of the serum lipid variables studied. The range of 12-year correlations was 0.48-0.58, 0.53-0.58, 0.53-0.58, 0.57-0.59, and 0.33-0.37 for serum total cholesterol, low density lipoprotein (LDL) cholesterol, high density lipoprotein (HDL) cholesterol, the LDL:HDL cholesterol ratio, and triglycerides, respectively. Males showed more tracking than females; there was no clear age trend. Tracking of HDL2 cholesterol was better than that of HDL3 cholesterol (0.64 vs. 0.43, respectively; 3-year tracking). Apolipoproteins A-I and B showed similar amounts of tracking compared with HDL and LDL cholesterol, respectively. Approximately 50% of subjects who initially fell into the extreme quintiles of total cholesterol, LDL cholesterol, and HDL cholesterol were in the same quintiles after 12 years. In multiple regression analyses, childhood obesity, exercise, diet, and smoking habits did not markedly aid the prediction of adult serum lipid values. However, the use of two childhood measurements increased the amount of adult serum lipid variability explained. Although universal screening cannot be endorsed, these findings emphasize the importance of serum lipid measurements in the early detection of familial lipoprotein disorders and in the initial evaluation of coronary heart disease risk in childhood.
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PMID:Tracking and predictiveness of serum lipid and lipoprotein measurements in childhood: a 12-year follow-up. The Cardiovascular Risk in Young Finns study. 799 92

High plasma vitamin C may lower risk of cardiovascular disease as indicated by direct association with plasma high-density-lipoprotein (HDL) cholesterol and HDL2 cholesterol. Plasma lipids and vitamin C were determined in 316 women and 511 men (aged 19-95 y). After adjustment for age, sex, obesity, and smoking, plasma vitamin C was directly associated with HDL- (P = 0.01) and HDL2 cholesterol (P = 0.0002). When men and women with diseases that might affect lipids were excluded, associations between plasma vitamin C and HDL- and HDL2 cholesterol persisted, though the relationships were strongest in older men. Comparisons of diets in a subset (n = 485) who completed 7-d diet records were made. Total fat, saturated fatty acids, energy from fat, and cholesterol intakes were not associated with plasma vitamin C. Mean intakes of vitamin C were well above recommended dietary allowances. These findings suggest that high plasma concentrations of vitamin C may lower atherogenic risk.
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PMID:High plasma vitamin C associated with high plasma HDL- and HDL2 cholesterol. 801 21

It is well known that obesity is frequently associated with low levels of serum high-density lipoprotein (HDL) cholesterol. However, the mechanism for this reduction has not been fully clarified. Cholesteryl ester transfer protein (CETP) transfers cholesteryl ester from HDL to apolipoprotein B-containing lipoproteins and plays an important role in regulating the concentration and composition of HDL. To elucidate the mechanism for the reduction of serum HDL cholesterol in obesity, we analyzed serum lipoproteins, CETP, and postheparin lipoprotein lipase (LPL) and hepatic triglyceride lipase (HTGL) activities in 30 obese subjects (17 women and 13 men, age 44 +/- 14 years, mean +/- SD). We also investigated the relationship between these variables, total adiposity, and indices of body fat distribution. The average body mass index of the obese subjects was 33.1 +/- 4.8 kg/m2 (range, 26.4 to 43.8 kg/m2). The obese subjects showed significantly lower serum HDL cholesterol levels than control subjects (1.04 +/- 0.28 versus 1.50 +/- 0.34 mmol/L, P < .01). In the obese subjects, both activities and protein mass of CETP and postheparin HTGL activities were significantly increased, whereas postheparin LPL activities were significantly decreased. CETP activities, independent of postheparin HTGL and LPL activities, were correlated negatively with HDL cholesterol (r = -.39, P < .05) and the cholesteryl ester to triglyceride ratio of HDL2 and HDL3 (r = -.36, P < .05; r = -.46, P < .05, respectively).(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:Increased plasma cholesteryl ester transfer protein in obese subjects. A possible mechanism for the reduction of serum HDL cholesterol levels in obesity. 801 69

Elevated insulin concentrations are frequently found in both men and women with coronary heart disease (CHD), and are likely to be due to insulin resistance. Hyperinsulinaemia may increase CHD risk by directly promoting atherogenesis, and insulin propeptides may also be important in this respect. However, increased insulin concentrations may adversely affect several other CHD risk factors, and it has been postulated that insulin resistance is a pivotal metabolic disturbance in a constellation of CHD risk factors. There is an association between hyperinsulinaemia and hypertension, although it is not known if this association is direct. Increased insulin concentrations are also associated with high triglycerides, low HDL or HDL2 concentrations, and increased small dense LDL. Obesity is also associated with insulin resistance, and it is the central or android body fat distribution which correlates with these metabolic disturbances. All these associated factors constitute a distinct syndrome--the insulin resistance syndrome--which is a frequent finding in patients with CHD, including microvascular angina. It is possible that the adverse associations of insulin resistance and dyslipidaemia are mediated through increased nonesterified fatty acid flux. Increased insulin levels are also associated with increases in the anti-fibrinolytic factor, plasminogen activator inhibitor-I (PAI-I). Whilst increased insulin levels are typically associated with insulin resistance, reduced hepatic insulin uptake may also be important. We now have techniques which can quantitate insulin secretion, hepatic uptake and release, elimination, and resistance. The menopause has appreciable effect on insulin and glucose metabolism. Estrogen and progesterone augment pancreatic insulin secretion, but the former reduces insulin resistance whilst the latter increases it.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:HRT mechanisms of action: carbohydrates. 819 41

The concentration of high-density lipoprotein (HDL) cholesterol in patients with severe obesity is generally subnormal. The exact mechanism linking obesity with reduced levels of HDL cholesterol remains unclear. In this study we evaluated the postheparin plasma lipolytic enzymes lipoprotein lipoprotein lipase (LPL) and hepatic lipase (HL) in a group of 24 obese women compared with controls and analyzed the interrelationships between insulin, postheparin lipolytic enzymes and HDL subfractions. Total HDL cholesterol was significantly lower in the obese subjects than in the controls, and the difference was mainly due to HDL2 cholesterol concentrations. Mean fasting glucose, insulin and the summated means of glucose (sigma glucose) after the oral glucose tolerance test (OGTT) were not significantly different in the two groups. The summated means of insulin (sigma IRI) after the OGTT were significantly higher in the obese women than in the controls. LPL, HL and the HL-to-LPL ratio were significantly higher in the obese women than in the controls. HL and LPL correlated positively with sigma glucose, sigma IRI and body mass index (BMI) and negatively with plasma triglycerides. Partial correlation analysis demonstrated that, when exposed to similar sigma IRI values, HL and LPL were no longer correlated with sigma glucose, plasma triglycerides and BMI. HDL2 cholesterol levels were negatively correlated with HL, posthepatic plasma lipolytic activity, sigma glucose, plasma triglycerides and BMI. HDL2 cholesterol concentrations were directly correlated with LPL. Partial correlation analysis showed that when exposed to similar HL and LPL values, HDL2 cholesterol values were no longer correlated with sigma glucose, sigma IRI, plasma triglycerides and BMI. Therefore, our results demonstrate that the low HDL2 cholesterol levels found in obese women may be related to the high levels of HL and to the high HL-to-LPL ratio which in turn could be determined by the peripheral insulin resistance.
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PMID:High-density lipoprotein cholesterol concentrations and postheparin hepatic and lipoprotein lipases in obesity: relationships with plasma insulin levels. 821 34


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