PubMed Health⌕ Search

Biomedical subjects

J C Seidell

Publications and source records attributed to J C Seidell.

At least 145 records · Page 8Linked to original sources
PubMed1993

Serum LP(A) levels in randomized healthy men from different European countries.

Serum lipoprotein(a) [Lp(a)], blood lipids, serum insulin and anthropometric parameters were determined in randomized samples of 38-year-old men living in six European cities: Ede (The Netherlands), Deinze (Belgium), Warsaw (Poland), Lumiar (Portugal), Verona and Naples (respectively in northern and in southern Italy). In total, 406 healthy men were studied. Serum Lp(a), blood lipids and serum insulin were measured in one laboratory. All the anthropometric and metabolic variables considered were statistically different among the participating sites, with the exception of Lp(a) serum levels. In spite of the lack of overall significant inter-center differences (Kruskal-Wallis test), the subjects from the two Italian cities had significantly lower Lp(a) serum levels than the subjects from Belgium and Portugal (Mann-Whitney U test, p < 0.01). In all cities the distribution of serum Lp(a) levels were highly skewed; the percentage of subjects with serum Lp(a) levels higher than 30 mg/dl (i.e., the commonly accepted risk level of cardiovascular disease) was 6% in both Verona and Naples (Italy), 12% in The Netherlands, 16% in Poland, 18% in Belgium and 19% in Portugal (for the last two cities, respectively, p < 0.02 and p < 0.01 vs Italian cities, chi-square test). Neither anthropometric (body mass index, waist/hip circumference ratio) nor metabolic (serum lipids and insulin) parameters showed any significant relationship with serum Lp(a) levels in any of the sites (Spearman's rank correlation). These data support the possibility of a difference in serum Lp(a) levels among different European countries.

Adult↗
PubMed1993

Abdominal diameters as indicators of visceral fat: comparison between magnetic resonance imaging and anthropometry.

The aim of the present study was to investigate the usefulness of abdominal diameters to indicate visceral fat, their relationship with serum lipids and their capability of detecting changes in visceral fat. Before and after weight loss, visceral and subcutaneous fat, and the sagittal and transverse diameters were assessed by magnetic resonance imaging (MRI) in forty-seven obese men and forty-seven premenopausal obese women with an initial body mass index of 31.0 (SD 2.4) kg/m2. In a subsample (n 21), diameters, were also measured by anthropometry in the standing and supine positions. They were strongly correlated with the diameters derived from the MRI scans. Serum levels of total and HDL-cholesterol and triacylglycerol were measured before weight loss. In women the sagittal diameter correlated less strongly with visceral fat than anthropometrically-assessed waist circumference and waist:hip ratio (WHR). In men these associations were comparable. Changes in visceral fat with weight loss were more strongly correlated with changes in the sagittal diameter and sagittal:transverse diameter ratio (STR) than with changes in waist circumference or WHR in men. In women, changes in the anthropometric variables and the separate diameters (except STR) were not associated with visceral fat loss. In men, but not in women, both the sagittal diameter and the visceral fat area were related to serum lipids. It is concluded that the sagittal diameter and STR may have advantages over waist circumference and WHR in men, particularly in assessing changes in visceral fat, but this could not be demonstrated in women. The ability to predict visceral fat from circumferences and diameters or their ratios is, however, limited in obese men and women.

Abdomen↗
PubMed1993

Waist-hip ratio is a poor predictor of changes in visceral fat.

Magnetic resonance imaging was used to study the effect of weight loss on three fat depots: the visceral and subcutaneous abdominal depots and the subcutaneous depot at trochanter level. Changes in fat depots were compared with changes in circumference measures and the waist-hip ratio (WHR) in obese men (n = 38) and women (n = 40). Mean weight loss was (mean +/- SD) 12.9 +/- 3.5 kg (P < 0.001). The proportional reduction of fat was largest in the visceral depot (men 40%, women 33%). Less fat was lost subcutaneously, especially at trochanter level (men 29%, women 26%). WHR decreased significantly in both sexes (P < 0.001). Change in WHR was not significantly related to the absolute reduction in visceral fat. Total body-fat loss showed a stronger association with subcutaneous fat loss than with visceral fat loss. The findings suggest that fat distribution may change with weight loss, particularly by the loss of visceral fat, but changes in WHR are not appropriate for evaluating changes in this fat depot.

Abdomen↗
PubMed1993

Effect of a weight cycle on visceral fat accumulation.

Magnetic resonance imaging was used to study the effect of a single weight cycle on three fat depots: the visceral and subcutaneous abdominal depots and the subcutaneous depot at the trochanter level. Obese subjects (17 men, 15 women) were examined before and after weight-loss intervention and 67 wk after intervention. They lost 12.9 +/- 3.3 (mean +/- SD) kg body wt during intervention and regained 11.9 +/- 5.1 kg during follow-up. Weight regain did not result in greater body fatness than before weight loss (initial fat mass: 34.3 +/- 6.1 kg, final fat mass: 32.8 +/- 7.7 kg; P = 0.047). There was no indication of a preferential deposition of visceral fat after weight regain (initial visceral fat area: 120 +/- 41 cm2, final visceral fat area: 110 +/- 48 cm2; P = 0.087). On the contrary, there was a slight tendency to accumulate subcutaneous fat at the expense of visceral fat. It is concluded that weight loss followed by weight regain neither leads to a greater body fatness nor to a larger amount of visceral fat compared with before weight loss.

Abdomen↗
PubMed1993

Visceral fat loss measured by magnetic resonance imaging in relation to changes in serum lipid levels of obese men and women.

The effect of weight reduction on serum lipids in relation to visceral fat accumulation was studied in 78 healthy obese subjects (40 premenopausal women and 38 men) aged 27-51 years and with an initial body mass index of 30.7 +/- 2.2 kg/m2 (mean +/- SD). The subjects received a 4.2 MJ/day energy-deficit diet for 13 weeks. Magnetic resonance imaging was used to assess abdominal fat areas before and after weight loss. Weight reductions of 12.6 +/- 3.2 kg in men and 11.7 +/- 3.8 kg in women resulted in larger reductions in the fasting serum levels of total cholesterol (p < 0.05), low density lipoprotein cholesterol (p = 0.06), and triglycerides (p < 0.01) and a larger increase in the high density lipoprotein cholesterol/low density lipoprotein cholesterol ratio (p = 0.05) in men compared with women. Men also lost more visceral fat (p < 0.0001), whereas the reductions in the total and subcutaneous abdominal fat depots were similar. In women, visceral fat loss was significantly related with an increase of the high density lipoprotein cholesterol level, independent of the degree of total fat loss. In men, however, no significant correlations were observed between changes in visceral fat and any of the serum lipids. Comparisons of average changes in obese men and women suggest that visceral fat loss is associated with an improvement of the serum lipid profile. However, correlation analysis does not support a critical role of visceral fat in determining serum lipid concentrations on an individual level, except for an improvement of the high density lipoprotein cholesterol level with visceral fat loss in obese women.

Adipose Tissue↗
PubMed1993

Relative effects of weight loss and dietary fat modification on serum lipid levels in the dietary treatment of obesity.

The independent effects of weight loss and dietary fat modification on serum lipids were investigated in two groups of healthy moderately obese men and women. In one group (sequential group, n = 19), a weight-stable low-fat, low-saturated-fat diet (Low-Sat) was given for 7 weeks (= dietary modification), followed by a 4.2 MJ/day deficit Low-Sat diet for 13 weeks (i.e., weight loss alone). Another group (simultaneous group, n = 22) received a 4.2 MJ/day deficit Low-Sat diet for 13 weeks (i.e., weight loss+dietary fat modification). Each group was subject to an initial weight-stable high-fat, high-saturated fat diet for 3 weeks and a final weight stable Low-Sat diet for 3 weeks. Both groups lost similar amounts of body weight, about 13 kg, and had similar overall changes in total cholesterol, low density lipoprotein (LDL), cholesterol, high density lipoprotein (HDL) cholesterol, the HDL/LDL ratio, and triglycerides. Analysis of the separate effects of the Low-Sat diet without energy restriction and of weight loss in the sequential group showed that weight loss per se was responsible for about 50% of the total reduction in total cholesterol, and for about 60% and 70% of the fall in LDL cholesterol and triglycerides, respectively. Fat modification without weight loss reduced HDL cholesterol by 11.1% and the HDL/LDL ratio by 7.7%, while weight loss per se led to increases in HDL cholesterol of 12.5% and in the HDL/LDL ratio of 24.0%. We conclude that the effects of reduction in fat and saturated fat intake and weight loss are additive.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1993

A new index of abdominal adiposity as an indicator of risk for cardiovascular disease. A cross-population study.

A new index of abdominal adiposity, the conicity index, and the waist-to-hip ratio (WHR) were compared as health indicators in seven European populations and two USA populations. The total sample included 1280 men and 960 women. Abdominal adiposity as detected by these indices is significantly associated with more cardiovascular risk indicators among women than it is among men. Both indices are equivalent as health indicators. However, the conicity index has several advantages over the WHR: (i) it has a theoretical (expected) range; (ii) it includes a built-in adjustment of waist circumference for height and weight, allowing direct comparisons of abdominal adiposity between individuals or even between populations; and (iii) it does not require the hip circumference to assess fat distribution.

Abdomen↗
PubMed1993

Techniques for the measurement of visceral fat: a practical guide.

The measurement of fat distribution has become an important issue in obesity research. Numerous techniques have been developed to assess visceral fat because this fat seems to be most strongly associated with metabolic disorders. This review focuses on methods for the direct and indirect assessment of visceral fat ranging from multiple-scan computerized tomography to anthropometric measurements. The principles of techniques, their accuracy and reproducibility as well as aspects of costs and safety are discussed. Comparison of the different methods shows that imaging techniques, such as computerized tomography and magnetic resonance imaging, are the optimal techniques available for accurate assessment of visceral fat. Methods other than imaging techniques have limited potential in the measurement of changes in visceral fat deposition. Anthropometric measurements can be useful to classify subjects into different types of fat distribution for diagnosis of abdominal obesity, and for general application in epidemiological studies. The choice of a particular technique should be based on a balance of practical and financial considerations and the aim of the study. Involvement of ionizing radiation exposure may be an important element in the decision-making process.

Adipose Tissue↗
PubMed1993

The effect of fluoxetine on body weight, body composition and visceral fat accumulation.

In this study the effect of fluoxetine versus placebo treatment on body weight, body composition and abdominal fat areas, assessed from three magnetic resonance imaging scans at umbilicus level, was investigated. Thirty-eight abdominal overweight men aged 41 +/- 7 years (mean +/- s.d.), BMI 27.9 +/- 1.2 kg/m2 and WHR 0.97 +/- 0.03 were given dietary advice and a placebo (n = 20) or fluoxetine treatment (n = 18, 60 mg/day) for 12 weeks after a placebo run-in of two weeks. Measurements were carried out during run-in and at week 12 of treatment. The treatment groups did not differ at the start of the study. After treatment, weight loss (on average) was observed in both groups: -2.4 +/- 0.6 kg and -5.9 +/- 0.7 kg for the placebo and fluoxetine groups, respectively. Weight loss was significantly larger in the fluoxetine group (P = 0.0004). The reduction of fat mass tended to be larger (P = 0.08), and the reduction of fat-free mass was considerably larger in the fluoxetine group (P = 0.0005). Absolute (and proportional) changes in visceral and subcutaneous fat areas (cm2) were +2 +/- 26 (+1%) and -9 +/- 26 (-4%) in the placebo group, and -9 +/- 30 (-3%) and -30 +/- 27 (-13%) in the fluoxetine group. In both groups the proportional change in subcutaneous fat area was larger than the change in visceral fat (P < 0.02). Only in the fluoxetine group was the decrease in subcutaneous fat area significant, and larger compared to the placebo group (P = 0.02).(ABSTRACT TRUNCATED AT 250 WORDS)

Abdomen↗
PubMed1992

Obesity and subcutaneous fat patterning in relation to breast cancer in postmenopausal women participating in the Diagnostic Investigation of Mammary Cancer Project.

Associations of body fat and body fat distribution with breast cancer were studied in 16,355 postmenopausal women with a natural menopause, aged 49 to 68 years, participating in a breast cancer screening project (the Diagnostic Investigation of Mammary Cancer [DOM] project in Utrecht, The Netherlands). One hundred nineteen women had breast cancer detected at first screening. Fat distribution was assessed by contrasting groups of subscapular and triceps skinfold thickness. No relationship between fat distribution and breast cancer was found. After adjustment for age, women in the highest quartile of Quetelet's index (QI) (weight/height2) had an odds ratio of 1.65 (95% confidence interval [CI], 0.97 to 2.81) compared with women in the the lowest quartile (test for trend, P less than 0.05). For subscapular skinfold and triceps skinfold, the odds ratios were 2.23 (95% CI, 1.28 to 3.91) and 2.01 (95% CI, 1.21 to 3.32), respectively, comparing the highest with the lowest quartile. The authors conclude that in postmenopausal women, overall obesity is associated with increased risk of breast cancer, whereas fat distribution, as measured by contrasting groups of subscapular and triceps skinfold thicknesses, is not related to breast cancer.

Adipose Tissue↗
PubMed1992

Visceral fat accumulation measured by magnetic resonance imaging in relation to serum lipids in obese men and women.

In 91 apparently healthy obese subjects (45 premenopausal women and 46 men) the associations between specific fat depots and serum lipids were studied. Magnetic resonance imaging was used to quantify fat depots at abdominal and hip level. In women, an accumulation of visceral fat was associated with a less favourable lipid profile, even after adjustment for age and body fat percentage: higher triglycerides levels (P less than 0.001), lower levels of HDL-cholesterol (P less than 0.01) and a diminished HDL-cholesterol/LDL-cholesterol ratio (P less than 0.01). In men, however, the significant inverse relationship between an abundance of visceral fat and the HDL-cholesterol/LDL-cholesterol ratio and the significant positive correlations with total-, LDL-cholesterol and triglycerides disappeared after adjustment for age and fat percentage. Within each sex, subcutaneous fat neither at abdominal level nor at hip level was significantly related to serum lipids. It is concluded that there are gender differences in the associations between visceral fat accumulation and serum lipids.

Abdomen↗
PubMed1992

Components of adult height and height loss. Secular trend and effects of aging in women in the DOM project.

Between 1984 and 1987, adult height, sitting height, arm span, and iliac crest height were measured in 13,386 women of the DOM project. Combined effects of secular trends between cohorts born in 1911 to 1945 and aging between ages 40 to 74 years showed a decrease in stature of 4.9 +/- 0.3 cm (mean +/- standard error of mean) and in sitting height of 3.9 +/- 0.2 cm. Height and sitting height diminished but no effect of aging on arm span was found in 380 women measured again after 5 years. When arm span and iliac crest height did not change with age, they reflected a secular trend (1.6 +/- 0.3 cm and 0.5 +/- 0.3 cm). This implies an age-related decline in stature of -3 cm in 35 years.

Adult↗
PubMed1992

Visceral fat accumulation in obese subjects: relation to energy expenditure and response to weight loss.

Seventy-eight healthy obese subjects, 40 premenopausal women and 38 men aged 27-51 yr received a 4.2 MJ/day energy-deficit diet for 13 wk. Resting metabolic rate (RMR) and diet-induced thermogenesis (DIT) were measured by indirect calorimetry. Abdominal subcutaneous and visceral fat areas were calculated from magnetic resonance imaging scans before and after weight loss. Before weight loss, visceral fat accumulation was positively correlated with higher levels of RMR (P < 0.05) and DIT (P < 0.01) in women but not in men. The mean weight reduction was 12.2 +/- 3.5 (SD) kg. In men but not in women, an initially large visceral fat depot was associated with a reduced loss of weight and total fat mass (P < 0.05). Within each sex, an initial abundance of visceral fat was significantly related to a larger loss of visceral fat (P < 0.001) and in men to a smaller loss of subcutaneous fat (P < 0.05). These results suggest that there may be gender differences in the associations between visceral fat accumulation and components of energy expenditure (RMR and DIT) in obese subjects. Obese subjects with an initial abundance of visceral fat do not lose more body weight but more visceral fat than subjects with less visceral fat.

Adipose Tissue↗
PubMed1992

Fat distribution in European men: a comparison of anthropometric measurements in relation to cardiovascular risk factors.

It has been proposed that subcutaneous fat patterning assessed by skinfolds is measuring different aspects of fat distribution compared to circumferences and circumference ratios. In this study in 510 men born in 1950 selected from six European towns we compared the associations between five skinfolds, eight circumferences and several skinfold and circumference ratios and metabolic risk factors after adjustment for body mass index (BMI). All skinfolds were independently of BMI positively related to diastolic blood pressure. Waist circumferences at most levels were independently of BMI positively related to blood pressure and triglycerides and negatively to HDL-cholesterol. Circumferences at the levels of chest, hips, thigh and arm were not related to any of the risk factors studied. Waist/thigh ratios were generally more strongly and more consistently related to risk factors than waist/hip ratios. The partial correlations of anthropometric variables with risk factors were relatively weak and never exceeded r = 0.20. The results give an indication, however, that subcutaneous fat patterning is related to different risk factors compared to waist/hip ratios. Moreover, waist/thigh and waist circumference alone (measured either as the minimal circumference or midway between the lower rib margin and the iliac crest) were stronger correlates of cardiovascular risk factors compared to waist/hip ratio.

Adipose Tissue↗
PubMed1992

History of body weight and physical activity of elderly women differing in current physical activity.

Development of overweight and physical activity during life was studied retrospectively in a group of physically active and a group of sedentary elderly women. The two groups of elderly women were selected based on a validated physical activity questionnaire. A previous study on their current dietary intake and nutritional status showed a 12 kg higher body weight in the sedentary group compared to the physically active group, whereas body height did not differ. In order to study the relationship between development of overweight and physical activity in these elderly women, a retrospective study was carried out in 45 subjects. Information about former physical activity was collected by means of a detailed structured interview. Information about body shape and fatness, expressed as 'weight index', was obtained using silhouettes and subjective rating of obesity of subjects compared with peers. Classification of obesity was checked by old photographs rated by interviewers, sizes of clothing and recalled body weight and height. Information was collected about the situation at age 12, 25, 40 and 55 years whereas the mean current age is 71. Weight index was statistically significantly different between the active and sedentary group from age 25 onwards (P less than 0.05). Photographs proved to be useful for a valid and objective categorization. No differences were found in physical activity scores between the groups at age 12, 25, 40 and 55 years. It is concluded that the current difference in body shape and fatness between physically active and inactive elderly women was already present at age 25 and persisted throughout their adult life.(ABSTRACT TRUNCATED AT 250 WORDS)

Aged↗
PubMed1992

Body fat distribution in pubertal girls quantified by magnetic resonance imaging.

We examined body fat distribution in relation to anthropometrically derived variables in 24 girls in early and late stages of puberty. The amounts of subcutaneous and intra-abdominal body fat were derived from transverse slices at the levels of the waist, hip and trochanter using magnetic resonance imaging (MRI), and were compared to the related circumferences, the circumference ratios and the trunk-to-extremity skinfold ratios. Waist, hip and trochanter circumferences were highly correlated to the respective related MRI total fat surface area both in early and late pubertal girls (r = 0.79-0.97), while waist circumference, and waist-hip, waist-thigh or skinfold ratios were not significantly correlated to intra-abdominal fat areas. Late pubertal girls (n = 11) were significantly taller, heavier and fatter compared to early pubertal girls (n = 13), yet their anthropometric waist-to-hip or waist-to-trochanter circumference ratios were significantly lower. The intra-abdominal fat area measured in a transverse MRI section at the level of the waist was 24.1 +/- 4.1 cm2 in early pubertal girls and 25.7 +/- 4.1 cm2 in late pubertal girls (mean +/- s.e.m.). As compared to early pubertal girls, the MRI derived amount of subcutaneous fat in late pubertal girls was significantly higher at the trochanter level (142.1 +/- 12.7 vs. 201.3 +/- 26.3 cm2; P less than 0.05). We conclude that circumferences at the trunk are good measures for the related amounts of fat in pubertal girls. In contrast conventional anthropometric measurements, such as trunk-to-extremity skinfold ratio or waist-to-hip circumference ratio, cannot be used to predict the amount of intra-abdominal fat in pubertal girls.(ABSTRACT TRUNCATED AT 250 WORDS)

Abdomen↗
PubMed1992

Fasting respiratory exchange ratio and resting metabolic rate as predictors of weight gain: the Baltimore Longitudinal Study on Aging.

The authors followed 775 men (aged 18-98 years) participating in the Baltimore Longitudinal Study in Aging for an average of ten years. Resting metabolic rate and fasting respiratory exchange ratio (RER) were measured by indirect calorimetry on their first visit and related to subsequent weight change. Deviations from the predicted value of resting metabolic rates (predicted from their estimated fat-free mass) were calculated. Average weight change was 0.07 kg (s.d. 6.4 kg); 122 men (15.3%) gained more than 5 kg and 40 (5.2%) more than 10 kg during the follow-up. After adjustment for initial age, body mass index, fat-free mass, and duration of follow-up, RER, but not RMR or deviations from predicted RMR, was positively related to weight change (P less than 0.001). Major weight gain (from at least 5 kg to at least 15 kg) was related to initial RER in non-obese men only (initial body mass index less than 25 kg/m2). From Cox proportional hazard regression analyses the adjusted relative risk of gaining 5 kg or more in initially non-obese men with a fasting RER of 0.85 or more was calculated to be 2.42 (95% confidence interval: 1.10-5.32) compared to men with a fasting RER less than 0.76. It was concluded that a relatively high fasting RER is a weak but significant predictor of substantial weight gain in non-obese white men.

Adolescent↗