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Biomedical subjects

J Raison

Publications and source records attributed to J Raison.

At least 19 recordsLinked to original sources
PubMed1998

Plasma leptin and hunger ratings in healthy humans.

Leptin, the ob gene product, is considered as a signal involved in the regulation of energy stores through centrally mediated effects on ingestive behavior and metabolism. To investigate the relationships between appetite-related sensations and circulating leptin in humans, 12 healthy male volunteers were served two test lunches (1200 kcal, 38% carbohydrate, 50% fat, 12% protein) with comparable palatability but resulting in different postprandial hunger ratings, and plasma leptin concentrations were monitored during 8 h after meal ingestion. Whereas postprandial hunger ratings (assessed by visual analog scales) and plasma insulin patterns differed significantly between meals, no significant difference in postprandial plasma leptin concentrations was observed between the two meals. A moderate but significant increase in mean plasma leptin was found over time. We conclude that postprandial plasma leptin concentrations do not significantly differ between two meals inducing different effects on hunger subjective feelings. These data are in agreement with a role for leptin in the regulation of energy balance as a long-term adiposity-related signal rather than a short-term meal-related factor.

Adult↗
PubMed1998

Increased arterial distensibility in postmenopausal hypertensive women with and without hormone replacement therapy after acute administration of the ACE inhibitor moexipril.

Menopause and essential hypertension are associated with a decreased compliance and distensibility of the arteries. ACE inhibitors have been shown to improve arterial distensibility. Hormone replacement therapy (HRT), especially estrogens, could have a positive influence through their atheroprotective, vasodilative, and blood pressure-lowering effect. The vascular interactions of HRT and ACE inhibitors, like moexipril hydrochloride, have not been investigated so far. This trial was intended to assess the effect of combined sequential HRT for 25 days on acute changes in arterial distensibility after a single oral dose of 15 mg moexipril hydrochloride in postmenopausal women with borderline to mild essential hypertension. This study had a monocentric, randomized, parallel-group design, and was open for moexipril, and double-blind, and placebo-controlled for HRT. Assessment of arterial distensibility was by automatic noninvasive measurement of the carotid-femoral pulse wave velocity (PWV). The PWV and the pulse pressure decreased significantly after a single oral dose of 15 mg moexiprill. An influence of HRT on the changes in the PWV and pulse pressure could not be seen. The plasma concentrations of renin increased and of aldosterone decreased after moexipril administration. Arterial function improves after acute administration of 15 mg moexipril in postmenopausal women with mild to moderate essential hypertension. The changes in PWV and pulse pressure are of similar magnitude in women with and without HRT.

Aldosterone↗
PubMed1998

A polymorphism in the 5' untranslated region of the human ob gene is associated with low leptin levels.

OBJECTIVE: To search the human ob gene for mutations and evaluate their role in massive obesity. DESIGN: Direct mutation screening of the gene and case-control association study. Multivariate analyses for evaluation of differences in clinical parameters. SUBJECTS: Primary mutation screening: 24 morbidly obese subjects (body mass index (BMI) > 40 kg/m2). Association study: 395 unrelated morbidly obese subjects (BMI > 40 kg/m2), 121 lean, non-diabetic control individuals, 72 women of a random sample with an average BMI 32.5 kg/m2. RESULTS: We report the finding of a DNA variant in exon 1 of the human ob gene (A --> G substitution, base + 19). This variant showed a prevalence of 62% in our study population. Association analyses under different genetic models (dominant, co-dominant, recessive) showed no significant evidence for an association of this variant with BMI. However, obese individuals homozygous for the G-allele showed significantly lower leptin concentrations compared to obese patients either heterozygous or homozygous for the A-allele after correction for BMI. CONCLUSION: Recent linkage studies have shown evidence for linkage of the hsob locus with obesity. Our study provides further evidence that a defect in the ob gene in linkage disequilibrium with the G-allele of exon 1 might be involved in obesity by affecting leptin concentrations.

Adult↗
PubMed1998

Plasma insulin and ankle on brachial systolic blood pressure ratio in overweight men with hypertension.

BACKGROUND: Hypertension is often associated with multiple metabolic abnormalities included in the insulin resistance syndrome. In hypertensive individuals, the ratio between ankle and brachial systolic blood pressure (ABI) is considered to be an independent cardiovascular risk factor. Insulin resistance has not been studied in relation to ABI ratio in men with essential hypertension and who are moderately overweight. OBJECTIVE: To identify whether a decrease in the ABI ratio is associated with the degree of abdominal obesity and, hence, with the biochemical characteristics of resistance to insulin. METHODS: In 166 overweight men with mild-to-moderate essential hypertension, insulinaemia was measured using radioimmunoassay. The ABI ratio was measured by using a pressure cuff of appropriate diameter, a standard mercury sphygmomanometer and a Doppler probe. Patients with diabetes or arteriosclerosis obliterans of the lower limbs, or both, were excluded from the study. RESULTS: The ABI ratio was significantly associated with the degree of abdominal obesity, but also with plasma triglycerides and cholesterol, low high-density lipoprotein cholesterol, plasma glucose and insulin. In a multiple regression analysis, the ABI ratio was significantly and negatively associated with only two variables: age and plasma insulin. This result was independent of age and drug treatment of hypertension. CONCLUSION: Because alterations in the ABI ratio may be considered markers of the changes in the structure and function of the arteries of lower limbs, the study provides evidence that plasma insulin, independently of atherosclerotic occlusive lesions, can significantly influence the status of conduit arteries of the lower limbs.

Adult↗
PubMed1998

[Arterial hypertension, non-drug treatment and cardiovascular risk].

Four non-drug measures have been shown to be effective on reduction of blood pressure: low-salt diet, weight loss, reduction of alcohol consumption and sports activity. Other measures, mainly dietary (increased potassium intake, DASH diet), may also be effective. The two limits to non-drug treatment of HT are the absence of demonstrated benefit in terms of cardiovascular morbidity-mortality, and the difficulty to ensure good patient compliance with this type of often constraining measure. However, these non-drug measures could probably decrease the overall level of cardiovascular risk. The main drawback, related to the required modification of the patient's lifestyle, is poor compliance with these measures. Compliance can be improved by various methods which share in common their time-consuming nature.

Alcohol Drinking↗
PubMed1997

How the degree of unsaturation of dietary fatty acids influences the glucose and insulin responses to different carbohydrates in mixed meals.

The association of fats with carbohydrates results in a lower glucose response but the influence of the nature of the dietary fatty acids has not been investigated clearly. We examined the effect of the degree of dietary fatty acid unsaturation on the postprandial glucose and insulin responses to a mixed meal. Eight young normolipidemic men consumed four different meals in random order. The meals differed in the nature of their oils and in the type of their main carbohydrates. The meals contained either a high ratio of monounsaturated to polyunsaturated n-6 fatty acids (MUFA) or a low ratio (PUFA) and either potatoes or parboiled rice. Proteins and saturated and polyunsaturated n-3 fatty acid contents were not different among meals. Blood samples were collected every 30 min for 3 h after the test meal. The glucose response was significantly lower 30 min after the parboiled rice-PUFA meal than after parboiled rice-MUFA or potato-MUFA (P < 0.05) meals. The insulin response was lower after parboiled rice-PUFA than after potato-MUFA (P < 0.05) meals. Similarly, an effect of fat appeared after 30 min. Glucose responses (F = 1.4, P < 0.01) and insulin responses (F = 5.3, P < 0.05) to both carbohydrates were significantly lower with dietary PUFA compared with dietary MUFA. In conclusion, the degree of dietary fatty acid unsaturation (18:1 compared with 18:2) may influence the glucose and insulin responses to mixed meals.

Adult↗
PubMed1997

Weight gain at the time of menopause.

The menopause is associated with changes in body composition: a decline in bone mineral content, a decrease in collagen synthesis, a loss of lean body mass and an increase in total and abdominal fat mass. Oestrogen deficiency seems to play a role in the menopause-related changes in body composition, but life styles (diet, exercise, smoking habits, alcohol consumption) are also involved. The time course of the decrease in lean mass deserves attention since it could justify specific actions, i.e. exercising or hormonal treatment, early during the perimenopausal period. A decrease in fat-free mass may be responsible for a decrease in energy expenditure favouring weight gain if the calorie intake is not reduced.

Body Constitution↗
PubMed1996

Menopause, fat and lean distribution in obese women.

OBJECTIVES: Whether menopause per se influences fat distribution independently of the effect of aging remains controversial. The lack of consistency in the menopause related changes in body fat distribution may be the result of differences in the methods for measuring fat distribution or in the characteristics of the women studied. The aim of this cross sectional study in obese women was to compare total body composition and regional fat and lean distribution, in premenopausal, perimenopausal and postmenopausal women. METHODS: Body composition was assessed by dual energy X-ray absorptiometry (DEXA) in premenopausal (n = 26), perimenopausal (n = 24) and postmenopausal (n = 73) obese women with no intercurrent diseases. RESULTS: It was shown that postmenopausal obese (n = 73) women had a higher proportion of total fat mass in the trunk and a lower proportion of total fat and lean mass in the femoral and leg regions than premenopausal women after adjustment for age and total fat mass. In the same analysis, perimenopausal women had a lower proportion of total fat in the leg and femoral regions and of total lean in the femoral region than premenopausal women; they had a regional body composition similar to that of postmenopausal women. CONCLUSION: The present data indicate that in obese women, post menopause and perimenopause are associated with differences in fat and lean distribution, independently of age and total fat.

Absorptiometry, Photon↗
PubMed1994

Microalbuminuria and body fat distribution in obese subjects.

The aim of this work was to evaluate the prevalence of microalbuminuria in an obese population and to study the relation between albumin excretion rate (AER), various clinical (body mass index, adipose tissue distribution) nutritional (macronutrient intake) and metabolic parameters. A cross-sectional study was carried out, and AER was evaluated in 182 obese subjects (BMI > 27) with no medication, no intercurrent disease, no cardiac, pulmonary or endocrinological disorders (including diabetes and hypertension) and also in 31 control subjects at the outpatient clinic of the department of Nutrition, Hôtel Dieu, Paris, France. The following were measured: BMI, waist/hip ratio (WHR), urinary AER, blood glucose, insulin and C peptide levels, cholesterol (CT), triglycerides, HDL cholesterol (HDL-CT), apoprotein A1 and B. In the obese population, 18 subjects (9.9%) were found to have an increased AER: 13 subjects (7.1%) with microalbuminuria (AER between 30 to 300 mg/24 h) and five with AER over 300 mg/24 h. AER was normal in all control subjects but one, who was found to have microalbuminuria. Log AER was positively correlated to WHR (P < 0.001), blood pressure (P < 0.05), cholesterol (P < 0.05), Apo B levels (P < 0.01) and with fasting Insulin levels and protein intake (P < 0.001). Positive association between log AER and protein intake, insulin levels, Apo B and blood pressure were found independently of BMI and WHR. It is suggested that abdominal obesity may be associated with incipient nephropathy in some obese subjects without diabetes and hypertension. Microalbuminuria may be included among metabolic abnormalities connected with abdominal-type excess weight distribution.(ABSTRACT TRUNCATED AT 250 WORDS)

Adipose Tissue↗
PubMed1992

[Cardiovascular consequences of obesity associated with arterial hypertension].

Hypertensive obese subjects run an increased cardiovascular risk. Their predominantly abdominal obesity is often associated with hypertriglyceridaemia and insulin-resistant diabetes, and their cardiovascular status is characterized by cardiac hyperdynamics and hypervolaemia responsible for left ventricular hypertrophy and dilatation. Insulin resistance and subsequent hyperinsulinaemia are thought to explain the obesity-hypertension association, the cardiovascular effects observed and the metabolic and cardiovascular complications which might result from this situation. Successful control of both arterial pressure and overweight should contribute to regression of the left ventricular hypertrophy. Simultaneous treatment of abnormalities in carbohydrate and lipid metabolism is also necessary to prevent cardiovascular complications.

Cardiovascular Diseases↗
PubMed1992

Relationships between 3-y longitudinal changes in body mass index, waist-to-hip ratio, and metabolic variables in an active French female population.

Three-year longitudinal changes in body mass index (BMI), waist-to-hip ratio (WHR), and metabolic variables were examined in 209 active French women. For the entire group, a weak but significant positive association was found between change in BMI and change in WHR. However, analysis of covariance according to the degree of abdominal fat distribution showed a heterogeneity of this association that was confined to women with abdominal fat distribution. Changes in BMI were positively associated with changes in total cholesterol (P less than 0.05), triglycerides (P less than 0.10), and blood pressure (P less than 0.001), whereas changes in WHR were associated with changes in triglycerides (P less than 0.05) and diastolic blood pressure (P less than 0.10). These longitudinal results suggest that a more favorable body-fat pattern and metabolic profile might be achieved by reducing weight, or at least by preventing weight gain, particularly in women with high abdominal-fat distribution.

Abdomen↗
PubMed1991

Skinfold and body circumferences as measures of body fat patterning in a French female active population: relationships with the metabolic risk profile.

Body mass index (BMI), various anthropometric indices of abdominal fat distribution and some metabolic variables (blood lipids, fasting glucose, blood pressure) were measured in 408 French-born women from an occupational population who volunteered for the study. The aim of the study was to determine the best index for describing the relationships between the body fat pattern and the metabolic risk profile. The four age-adjusted circumference ratios (waist/hip, waist/thigh, xiphoid/hip, xiphoid/thigh) showed similar associations with the metabolic variables whereas the three age-adjusted skinfold ratios (epigastric/thigh, mesogastric/thigh, hypogastric/thigh) tended to be more weakly associated with the metabolic variables, particularly with apolipoprotein (Apo) B and fasting glucose. Multiple regression analyses showed that age-adjusted BMI was significantly related to high density lipoprotein (HDL) cholesterol, low density lipoprotein (LDL) cholesterol, Apo A and Apo B, and blood pressure, independently of abdominal fat distribution. After controlling for the effects of BMI, the waist/thigh ratio remained significantly associated to triglyceride, Apo B, fasting glucose, and systolic blood pressure, whereas the waist/hip ratio and the mesogastric/thigh skinfold ratio were significantly related only to triglyceride and systolic blood pressure independently of BMI. With the exception of triglyceride and fasting glucose, the degree of association between the metabolic variables and the abdominal fat distribution tended to be weaker than that observed with the BMI. These results emphasize the importance of the global corpulence in the levels of metabolic variables. However, all indices of abdominal fat distribution were, to varying degrees, independently associated with an unfavorable metabolic profile. Among them, the waist/thigh circumference ratio seems to be a useful indicator of the body fat pattern in women.

Adipose Tissue↗
PubMed1990

Hormonal influences on the relationships between body fatness, body fat distribution, lipids, lipoproteins, glucose and blood pressure in French working women.

The independent associations between overall obesity, body fat distribution, lipids, lipoproteins, glucose, blood pressure and some hormonal factors (sex hormone-binding globulin (SHBG), corticosteroid binding globulin (CBG) and fasting insulin) were cross-sectionally examined in 205 French working women. After adjustment for age, overall adiposity assessed by body mass index (BMI) was significantly associated with most metabolic parameters, whereas regional adiposity assessed by the waist-hip ratio (WHR) was significantly associated only with triglyceride, systolic and diastolic blood pressure. Blood pressure, glucose but not triglyceride, were also negatively and significantly correlated with SHBG and positively with fasting insulin. Negative independent associations were found between SHBG and both BMI and WHR, whereas CBG was positively associated only with WHR. Fasting insulin was no longer related to WHR after adjustment for BMI. After controlling for the effect of SHBG or insulin, the associations between triglyceride, blood pressure and both BMI and WHR were not substantially modified. After adjustment for BMI and WHR, fasting insulin was independently associated with both HDL cholesterol and diastolic blood pressure. In conclusion, in these French women, hormonal factors under study appeared to have little influence on the relationships between body fatness, body fat distribution, metabolic variables and blood pressure.

Adipose Tissue↗
PubMed1988

[Regional hemodynamics of the forearm. Comparison between obese and non-obese hypertensive patients].

Forearm hemodynamics using pulsed Doppler flowmetry were studied in 83 men: 15 non-obese and 8 obese normotensive subjects; and 30 non-obese and 30 obese hypertensive patients. Mean ages were similar in the four subgroups. The blood pressure of normotensives and hypertensives was identical in obese and non-obese subjects. Blood flow expressed in ml/mn was significantly higher in obese subjects whether normotensive or hypertensive. However, when blood flow was expressed per unit liter of forearm volume, it was similar in the four subgroups. Forearm vascular resistance, whether expressed as absolute of normalized values, was significantly higher (p less than 0.001) in non-obese hypertensives. When obese and non-obese hypertensives were compared, the former were characterized by higher values of blood velocity and blood flow, and lower values of vascular resistance, whether absolute or normalized values were used. The present study shows that: (i) forearm vascular resistance in hypertensives is increased exclusively in non-obese subjects, and (ii) obese hypertensives, when compared with non-obese hypertensives, are characterized by a hyperkinetic forearm circulation.

Adult↗