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Biomedical subjects

B L Heitmann

Publications and source records attributed to B L Heitmann.

72 records · Page 4Linked to original sources
PubMed1995

The dietary fat: carbohydrate ratio in relation to body weight.

A review of the contemporary dietary surveys indicates that the percentage of energy derived from fat is, in general, positively associated with total energy consumption and obesity. However, dietary carbohydrate tends to show the opposite trend. Epidemiological and experimental evidence suggest that the fat: carbohydrate ratio affects body weight through energy surfeits facilitated by the high energy density and palatability of fat. Biological mechanisms for an effect of this dietary ratio on the regulation of body weight have been the topic of much recent research. In this context the fat: carbohydrate ratio might be of particular importance in individuals with an inherited susceptibility to obesity.

Body Weight↗
PubMed1995

Dietary fat and obesity: evidence from epidemiology.

The epidemiological evidence that a high-fat diet promotes the development of obesity is considered suggestive but not definitive. The purpose of this paper is to provide a review of various epidemiological methods that have been used to address this issue as well as an updated summary of the existing evidence. Ecological studies describing dietary fat intake and obesity at the population level provide mixed results and are likely to be biased by both confounding and unknown data quality factors that differ systematically across the populations studied. Cross-sectional studies are generally in agreement that the concentration of fat in the diet is positively associated with relative weight. Prospective studies of diet in relation to subsequent weight change give inconsistent results. This may be due to behavioural factors such as dieting in response to weight gain; in addition, this type of study rarely takes into account the possible interaction between genetic predisposition and dietary fat in promoting weight gain. Finally, intervention studies in free-living subjects are considered, providing evidence of a consistent but short-lived period of active weight loss on low-fat diets. The experimental evidence on this relationship is more conclusive than the epidemiological evidence, although biological mechanisms remain controversial. Some areas for future epidemiological research involve: longitudinal studies of dietary fat intake as a predictor of growth in children; observational studies relating total dietary fat and specific types of fat to overall as well as regional adiposity; and randomized intervention studies of the effect of low-fat diets with particular emphasis on and familial predisposition to obesity and other possible modifying factors.

Adult↗
PubMed1994

Changes in fat free mass in overweight patients with rheumatoid arthritis on a weight reducing regimen. A comparison of eight different body composition methods.

The aim of this work was to compare and validate seven different methods for estimating changes in fat free mass, in patients suffering from rheumatoid arthritis. Measurements were made of fat and fat free mass before and after 12 weeks on an energy restricted, protein rich diet and physical training. The subjects were sixteen female and three male overweight out-patients (mean body mass index at baseline: 30 kg/m2) suffering from rheumatoid arthritis, according to the criteria of the American Rheumatism Association. Fat free mass was estimated by eight different body composition methods (a four-compartment model, total body water, total body potassium, impedance, near infrared interactance, creatinine excretion, body mass index and skinfold measurements). Mean weight loss was 2.7 kg fat and 1.7 kg fat free mass. There was no difference between measurements of mean change in fat free mass by the four-compartment model and the other methods, except for the creatinine method (P = 0.03). Compared to the four-compartment method, the total body water method gave the most accurate estimate of individual fat free mass changes (residual Mean Square: 0.4 kg), second to this method, the impedance method, seemed most valid (residual Mean Square: 0.8 kg). Accuracies of the other methods were lower (residual Mean Square between 4.2 and 8.2 kg [corrected]). Of eight methods for estimating changes in FFM, the TBW method gave the most accurate estimate of individual FFM changes, compared to a four-compartment model used as reference.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1993

Effects of age, sex, season and diet on serum ionized calcium, parathyroid hormone and vitamin D in a random population.

OBJECTIVES: To study the influence of age, sex, season and diet on calcium status in normal subjects. DESIGN: A random population study. Setting. Institutional clinic for large population studies. SUBJECTS: The subjects were drawn randomly from the Danish Civil Registration System and represented a random sample of the background population in the area. The sample comprised 127 subjects (54 men and 73 women, aged 35-65 years). MAIN OUTCOME MEASURES: The effects of age, sex, season and diet on parathyroid hormone (PTH),1,25-dihydroxyvitamin D (1,25(OH)2D) and 25-hydroxyvitamin D (25-OHD). RESULTS: There was no statistical significant difference for the serum concentrations of ionized calcium, PTH, 1,25(OH)2D and 25-OHD between the two sexes, nor any influence by age in either sex, in contrast to serum phosphate, which declined significantly in men (P < 0.05), but tended to increase in women. Serum PTH (P < 0.009) showed seasonal fluctuations, whereas serum concentrations of 1,25(OH)2D, 25-OHD, ionized calcium, phosphate and magnesium remained stable throughout the year. Dietary intake of calcium and vitamin D were not related to any serum variables. CONCLUSIONS: In healthy subjects differences between the two sexes exist regarding phosphate metabolism. Serum PTH shows seasonal fluctuations.

Adult↗
PubMed1993

The influence of fatness, weight change, slimming history and other lifestyle variables on diet reporting in Danish men and women aged 35-65 years.

The association between obesity and diet is somewhat conflicting. A population study was undertaken to examine factors influencing diet reporting and the possible differences in diet reporting in relation to such factors. Data on diet, fatness, fat distribution, physical activity, smoking, subjective weight problems, slimming history, social class, education and five year weight change were collected from an age and gender stratified sub-group of Danish men (n = 199) and women (n = 201). Diet reporting was estimated as the difference between protein intake calculated from the diet (dietary interview) and from the analysis of 24 h urine nitrogen excretion. Fatness was estimated from impedance measurements, and fat distribution from body circumference measurements. All other variables were assessed by questionnaire. The study showed that diet reporting was dependent on fatness but independent of gender and age. The fattest tertile under-reported their intake by between 20-25%. The dieters, those with subjective weight problems and those who had not been weight stable since the age of 25, under-reported their intake more than others, independent of age and gender. Men gaining or losing more than 3 kg in five years were furthermore found to under-report their intake independent of age, gender and obesity. No effects of smoking, fat distribution, physical activity, social class or education were found. The results of the present study may influence the interpretation of dietary data from other studies.

Adult↗
PubMed1992

The effects of gender and age on associations between blood lipid levels and obesity in Danish men and women aged 35-65 years.

The purpose of the study was to assess the influence of gender and age on the associations between different measures of obesity, and blood lipid levels. Overall obesity (body fat, body fat percentage and body mass index) or abdominal obesity (waist/hip-ratio, waist/thigh-ratio and waist-circumference) and lipid levels [high density lipoprotein (HDL), low density lipoprotein (LDL), very low density lipoprotein (VLDL), total cholesterol and triglyceride level] were measured in 1987/88 in a random Danish population sample of men and women (N = 2987), aged 35, 45, 55 and 65 yr. All lipid levels were dependent on gender and age. The associations between most measures of obesity and HDL or LDL were independent of gender and age, whereas, with a few exceptions, associations between measures of obesity and total cholesterol, VLDL or triglycerides were dependent on gender and/or age. Compared to levels of HDL, LDL and total cholesterol, abdominal obesity specifically affected levels of VLDL or triglycerides, whereas overall obesity affected HDL, LDL, VLDL, total cholesterol and triglyceride levels more evenly. When men and women were compared, associations between the measures of obesity and blood lipids were stronger in men than in women of the same age, except for the associations between measures of abdominal obesity and VLDL or triglycerides in 45-year-old women. No age trend was found for associations between the measures of obesity and VLDL or triglycerides, whereas young age-groups showed stronger associations between obesity and total cholesterol than older age-groups. Failure to consider age/gender effects induces bias and may lead to misleading conclusions regarding the bivariate association between obesity and lipids, and further may make results from population studies incomparable.

Adult↗
PubMed1992

The variation in blood lipid levels described by various measures of overall and abdominal obesity in Danish men and women aged 35-65 years.

The purpose of the study was to describe the proportion of the variation in blood lipid levels [high-density lipoprotein cholesterol (HDLC), low-density lipoprotein cholesterol (LDLC), total cholesterol, very-low-density lipoprotein cholesterol (VLDLC) and triglycerides] explained by different measures of overall obesity [body fat (kg), percentage body fat, or body mass index (kg/m2)] and abdominal obesity [waist/hip ratio, waist/thigh ratio or waist circumference (cm)]. This was done in a Danish population sample of 1523 men and 1464 women aged 35-65 years. This was done to assess, on a population level, the effects on the different lipid levels to be expected from a possible reduction in the level of obesity. The proportion of the variation in lipid levels explained by the various measures of overall obesity differed only slightly, as did the proportion of the variation in lipid levels explained by the various measures of abdominal obesity. In men more of the variation in the blood lipids could be explained by overall obesity than by abdominal obesity, whereas in women the reverse was true. More of the variation in the lipids was explained by overall obesity in men than in women, but more of the variation was explained by abdominal obesity in women than in men. In women the obesity measures predicted between 0% and 11% of the variation in lipid level, and in men the obesity measures predicted between 0% and 14% of the variation. Between 16% and 30% in women and between 5% and 21% in men of the variation in the lipid levels could be explained by obesity, age and several lifestyle variables.(ABSTRACT TRUNCATED AT 250 WORDS)

Abdomen↗
PubMed1991

Measurement of body fat in elderly subjects by dual-energy x-ray absorptiometry, bioelectrical impedance, and anthropometry.

Body fat was measured in 46 elderly subjects by dual-energy x-ray absorptiometry [BF(DEXA)], bioelectrical impedance analysis (BIA), and anthropometry. Equations for prediction of the body fat (by DEXA) of elderly people by BIA and/or anthropometry were developed. The prediction of body fat (by DEXA) by anthropometric variables alone gave an r2 of 0.94 and the corresponding SEEs were 1.61 kg for men and 2.43 kg for women. When BIA variables were added as predictors, r2 increased by 2-5% (P less than 0.05) and the corresponding SEE decreased by 25% (P less than 0.05). The prediction of body fat (by DEXA) in elderly subjects and by BIA or anthropometry with equations developed in populations of young healthy adults (adapted from the literature) was generally not good although the correlation coefficients were high (r greater than 0.9, P less than 0.001), which suggests that our equations may improve prediction of body fat in elderly subjects.

Absorptiometry, Photon↗
PubMed1991

Body fat in the adult Danish population aged 35-65 years: an epidemiological study.

The purpose of the study was: (1) to estimate body fat and body fat distribution in the general population of Danes aged 35-65 years and thus provide tables of normal values for adult Danes in these age groups; and (2) to assess the effects of age and gender on relations between measures of obesity and of fat distribution. Hitherto, the only available results from the Danish population have been on BMI. Of the 3608 invited subjects 2987 (83 per cent) attended the examination. Body fat and fat distribution were estimated from measurements of electrical impedance and from circumference measurements. The study showed large differences in body fat and fat distribution between men and women. There was a difference in total body fat of 4.5 and 6.9 kg in men and women respectively between the groups aged 35 and 65 years. Fat percentage increased 36 per cent in women and 30 per cent in men between the groups aged 35 and 65 years. There was a difference in waist/hip ratio (WH ratio) between men and women at all age groups. Of the women 46 per cent had WH ratios above 0.8 and 14 per cent of the men had WH ratios above 1.0, suggesting that cut-off points for WH ratio as an indicator of cardiovascular risk are population specific. This may be caused by a different distribution of other cardiovascular risk factors in the Danish population than in other populations. Men had larger WH ratios per body fat mass with age, whereas in women there was no effect of age on this relation. Furthermore the WH ratio increments in this population took place before the age of 55 years in men, but after 55 years in women. The results may contribute to explain gender differences in morbidity and mortality with increasing age.

Adipose Tissue↗
PubMed1990

Evaluation of body fat estimated from body mass index, skinfolds and impedance. A comparative study.

The purpose of the study was to cross-validate three different methods used in field studies for estimating body fat in a group of Danes (n = 139) aged 35-65 years with a wide range in body fat. On the first two-thirds of the participants (n = 93) multiple regressions equations were developed for body fat by means of height, weight, sex and age and either BMI, or by sum of four skinfolds or electrical impedance. A four-compartment-model based on measurements of both total body water (TBW) and potassium (TBK) was used as reference. On the remaining one-third of the subjects (n = 46) cross-validation of the developed equations was carried out. The multiple regression equation for impedance had higher R-square (R2 = 0.89) and lower residual error (SEE = 3.32 kg) than the multiple regression equations for skinfolds (R2 = 0.81, SEE = 3.91 kg) or body mass index (R2 = 0.85, SEE = 3.94 kg). The cross-validation study showed that all three simple methods give reliable average body fat estimates. The difference in estimates of body fat between the reference method and impedance, BMI and skinfolds was 0.76 kg, -0.64 kg and -0.21 kg respectively, none of these differences being different from zero. However, the variance of body fat estimated from BMI (4.84 kg) was higher than body fat estimated from impedance (4.36 kg) (P = 0.013). The multiple regression analysis further showed that measurements of skinfold do not seem to add significantly to the prediction of body fat if height and weight are included.(ABSTRACT TRUNCATED AT 250 WORDS)

Adipose Tissue↗
PubMed1990

Prediction of body water and fat in adult Danes from measurement of electrical impedance. A validation study.

The purpose of the present study was to test the validity of the electrical impedance method for estimation of total body water and lean body mass in adult Danes with large differences of obesity and fat distribution, and to develop algorithms for estimation of body water, lean body mass and fat from measurement of impedance. The results of the electrical impedance method were compared in 139 Danes aged 35-65 years, to those of a four-compartment-model based on measurements of both total body potassium (whole body counting) and total body water (dilutometry). The comparison confirmed the validity of the impedance method. Equations for predicting body water and lean body mass in Danes are given. A significant difference was found between two instruments of the same model. In spite of the fact that the test resistance supplied by the manufacturer gave identical measurements, measurements on humans diverged on average by 31 ohm. A cross-validation study showed that most of the algorithms found in the literature for predicting lean body mass from impedance yield reliable results.

Adipose Tissue↗
PubMed1989

[The use of the impedance measurement technic for calculating body fat mass. A validity study].

The body composition of water and fat may be calculated on the basis of measurements of its impedance. Calculations are based on algorithms developed by all measurements of the body compositions of a reference material, by means of standard methods (eg hydrodensiometry, total body water by isotope dilutimetry). A commencial impedance analyser with built-in algorithm for calculation of total body water and body fat mass was evaluated and compared with measurements of the total body water in 42 young men and women. Very good agreement was found (mean values for total water were 34.2 and 33.5, respectively, for women and 46.8 and 47.0, respectively, for men). These calculations of total body water correlated better with the reference values than calculations from four other algorithms published in the literature. Simple anthropometric measurements (skin-fold thickness, BMI) resulted in significantly higher calculations of body fat mass than calculations based on impedance measurement. This study has shown that the technique of impedance measurement has good reliable validity for calculation of the body fat mass and that, on account of its simplicity, the method is suitable for field studies and also individual measurements.

Adipose Tissue↗
PubMed1989

[Bioimpedance analysis in determining body composition. Testing of a new simple apparatus].

In the assessment of human body composition, only expensive and time consuming methods have hitherto been available. Recently, the new bioimpedance method has been introduced. It offers an easy, quick, inexpensive and noninvasive measurement with an accuracy comparable to that of the classical methods. A new inexpensive Danish apparatus was tested against the most used and validated equipment. Fifteen normal subjects underwent measurements with both apparatuses. The two methods gave identical results with a coefficient of correlation of 0.99 and a coefficient of variation of 5.6%. The apparatus can be recommended for clinical and scientific purposes.

Adolescent↗
PubMedDate not supplied

Changes in body water distribution during treatment with inhaled steroid in pre-school children.

PRIMARY OBJECTIVE: The study aimed to examine the changes in water distribution in the soft tissue during systemic steroid activity. RESEARCH DESIGN: A three-way cross-over, randomized, placebo-controlled, double-blind trial was used, including 4 weeks of fluticasone propionate pMDI 200 microg b.i.d. delivered via Babyhaler, budesonide pressurized metered dose inhaler (pMDI) 200 microg b.i.d. delivered via Nebuchamber and placebo. Spacers were primed before use. In total, 40 children aged 1-3 years, with mild intermittent asthma were included. Twenty-five of the children completed all three treatments. At the end of each treatment period body impedance and skin ultrasonography were measured. METHODS AND PROCEDURES: We measured changes in water content of the soft tissues by two methods. Skin ultrasonography was used to detect small changes in dermal water content, and bioelectrical impedance was used to assess body water content and distribution. MAIN OUTCOMES AND RESULTS: We found an increase in skin density of the shin from fluticasone as measured by ultrasonography (p = 0.01). There was a tendency for a consistent elevation of impedance parameters from active treatments compared to placebo although overall this effect was not statistically significant (0.1 < p < 0.2). However, sub-analyses indicated a significant effect on whole-body and leg impedance from budesonide treatment (p < 0.05). CONCLUSION: Decreased growth during inhaled steroid treatment seems to partly reflect generalized changes in body water.

Administration, Inhalation↗
PubMedDate not supplied

Weight reduction in obese patients with rheumatoid arthritis, with preservation of body cell mass and improvement of physical fitness.

OBJECTIVE: To reduce body weight in obese patients with rheumatoid arthritis (RA) without loss of body cell mass (BCM) and without impairment of physical performance. METHODS: Nineteen overweight RA patients were studied before, during, and after a 12-week weight reducing regime consisting of reduced dietary energy intake, supplemented with a high-protein-low-energy powder preparation, and moderate physical training. Body composition was measured by a four compartment method, which by combining determinations of total body water and total body potassium allows a distinction between the two variable components of fat free mass (FFM): BCM and extracellular water (ECW). Physical fitness was measured by a bicycle exercise test. RESULTS: Mean weight loss during the study was 4.5 kg. The patients lost 9% of their initial fat mass, 3% of initial BCM and 5% of initial ECW. Physical fitness was slightly, but significantly, improved. CONCLUSION: The regime described was successful in achieving a significant weight loss with minimal loss of BCM and maintenance of physical fitness.

Adipose Tissue↗