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Biomedical subjects

H Kvist

Publications and source records attributed to H Kvist.

At least 19 recordsLinked to original sources
PubMed1997

Digital mammography using storage phosphor plate technique--optimizing image processing parameters for the visibility of lesions and anatomy.

Digital mammograms from a storage phosphor plate system for general radiography were compared to conventional mammograms by means of visual grading analysis (VGA). For the digital images, image processing parameters were optimized and evaluated through observer preference analysis (OPA). The results of the VGA showed significantly better gradings for the conventional mammograms for parenchyma, linear structures, and cysts, and significantly better gradings for the digital mammograms for the skin surface. For calcifications, no significant difference was seen. For the OPA, contrast enhanced mammograms graded significantly best. Using standard image processing, the digital mammograms were considered as adequate for diagnosis in 49% of the cases, as uncertain in 20%, and as inadequate in 31%. However, the observers differed considerably in their gradings both in the VGA and in the OPA.

Calcinosis↗
PubMed1996

Body composition and tissue distributions in growth hormone deficient adults before and after growth hormone treatment.

This study examines short and long-term effects of recombinant human growth hormone (rhGH) on body composition and regional tissue distributions by using a multicompartment technique based on computed tomography. Part I includes nine subjects aged 46 +/- 9 years with adult onset GH deficiency who were examined before and in the end of 6 months treatment with rhGH (0.4 U.kg-1.week-1) in a double-blind crossover trial. Part II is an ongoing open trial including seven of the males in part I. They were treated with rhGH (0.25 U.kg-1.week-1) over an additional period of 24 months. Adipose tissue (AT) was reduced by 4.7 kg (p < 0.01) while the muscle plus skin compartment (M) and visceral organs (V) were increased by 2.4 (p < 0.05) and 0.7 kg (p < 0.01), respectively, over 6 months of treatment with a high rhGH dose. A preferential lipid mobilization occurred in the visceral and subcutaneous trunk depots resulting in a changed AT distribution. Muscles of legs and arms increased while the increase of trunk muscles did not reach significance. The body composition changes were maintained over 2 years additional treatment. The preferential loss in visceral AT was further pronounced while other changes in tissue distributions observed during the first 6 months tended to be reversed on the lower rhGH dosage. It is concluded that growth hormone has profound and discordant effects on AT, M and V and with associated changes in tissue distributions. The beneficial effects on body composition seen in short-term treatment is preserved throughout an additional 24 months period of treatment.

Adipose Tissue↗
PubMed1996

Reduction in thigh muscle cross-sectional area and strength in a 4-year follow-up in late polio.

OBJECTIVE: To study changes in cross-sectional thigh muscle area and muscle strength in late polio subjects over a 4-year period. DESIGN: Longitudinal study of a cohort of polio survivors, comparing subjects who acknowledge (unstable) with those who do not acknowledge (stable) new muscle weakness. SETTING: University hospital. SUBJECTS: Eighteen subjects (6 men, 12 women) with polio-myelitis sequelae (39 to 46 years of age) were studied on two occasions 4 years apart; the first examination was 37 to 44 years after onset of polio. Subjects were recruited through hospital registers, newspaper advertisement, and a patient organization. OUTCOME MEASUREMENTS: Thigh muscle and intermuscular and intramuscular adipose tissue (AT) cross-sectional areas were measured by computed tomography. Isometric muscle strength for knee extension and flexion was measured using a Kin-Com dynamometer. RESULTS: Cross-sectional muscle area decreased on average 1.3 +/- 3.6 cm2 (1.4%, p < .05); the intermuscular and intramuscular AT area increased 1.8 +/- 3.4 cm2 (12.1%, p < .05). When divided by legs in which subjects reported (unstable) or did not report (unstable) or did not report (stable) increased muscle weakness, unstable legs showed significant reduction (p < .05) in muscle area, whereas stable legs did not. Estimated total thigh muscle strength decreased 7.8% +/- 2.9% (p < .01), with a significant (p < .001) reduction in unstable legs (13.4% +/- 4.3%) but not in stable legs. The reduction in strength appears to be greater than the reduction in cross-sectional muscle area, but there is still a significant correlation (r = .44, p < .05). CONCLUSION: The present results demonstrate not only progress of muscle weakness, but also of muscle atrophy in postpolio subjects.

Adipose Tissue↗
PubMed1996

Endurance training effect on individuals with postpoliomyelitis.

OBJECTIVE: To determine the effects of an endurance training program on the exercise capacity and muscle structure and function in individuals with postpolio syndrome. DESIGN: Preexercise and postexercise testing was performed with muscle strength evaluations using isokinetic testing as well as hand-held Myometer. Muscle fatigue was determined by use of isokinetic testing, and endurance was determined by exercise testing. Enzymatic evaluation was performed with muscle biopsies taken at the same site; preexercise and postexercise muscle cross-sectional area was measured by computed tomography. Disability and psychosocial evaluation was performed by a Functional Status Questionnaire. SETTING: A university. SUBJECTS: Seventeen postpolio subjects ranging in age from 39 to 49 years volunteered for a 6-month combined endurance and strength training program. They had a history of acute poliomyelitis at least 25 years earlier and were able to walk with or without aid. INTERVENTION: Twelve of the subjects (mean age 42 years) completed the program, attending an average of 29 sessions, which were offered for 60 minutes twice a week. MAIN OUTCOME MEASURES: Strength, endurance, enzymatic activity, and cross-sectional area were measured 3 months before the beginning of training, just before training, and at the completion of the exercise program. RESULTS: Knee extension was reduced to an average of 60% of control values and did not change with training. Strength measured with a hand-held Myometer increased significantly for elbow flexion, wrist extension, and hip abduction. Exercise test on a bicycle-ergometer showed significant reduction (6beats/min) in heart rate at 70W and increase (12beats/min) in maximal heart rate with training. The training program could be performed without major complications and resulted in an increase in muscle strength in some muscle groups and in work performance with respect to heart rate at submaximal work load.

Adult↗
PubMed1996

Comparison of different body composition models in acromegaly.

The aberrant body composition of 10 patients with active acromegaly was used to evaluate the validity and limitations of several models and methods to assess body composition. Body composition was determined using either a two-compartment model, dividing the body in a body fat (BF) compartment and a fat-free mass (FFM) compartment, or a four-compartment model in which the FFM compartment comprises the three following components: body cell mass, extracellular water and the fat-free extracellular solids. The measurement techniques consisted of anthropometry, bioelectrical impedance analysis (BIA)-applying various established regression equations-tritiated water dilution, whole body 40K-counting, and whole body computed tomography (CT). This latter method was used as the reference technique. Assessment of total body water using BIA - applying the RJL or Kushner equation-correlated significantly with the assessment using tritiated water dilution (P < 0.01). Body fat assessment using the two-compartment model based on either tritiated water dilution or BIA-applying the RJL or Lukaski equation-as well as body fat assessment using the four-compartment model based on tritiated water dilution and whole body 40K-counting were significantly correlated with body fat assessment using CT (P < 0.01) and resulted in good agreement with each other with respect to the absolute values of the body fat determination. BIA using other regression equations overestimated body fat by 7.2-13.7 kg. Whole body 40K-counting was significantly correlated with CT-determined muscle plus skin volume (P < 0.001). CT-calibrated anthropometric predictions significantly overestimated body fat. It is concluded that in patients with active acromegaly, the determination of body composition using either certain two-compartment models based on measurement of total body water or bioelectrical impedance, or a four-compartment model based on total body water and total body potassium measurements show good agreement with CT-determined body composition.

Acromegaly↗
PubMed1995

Effects of recombinant human growth hormone on basal metabolic rate in adults with pituitary deficiency.

The effect of recombinant human growth hormone (rhGH) on basal metabolic rate (BMR) was studied in a placebo-controlled, double-blind, crossover trial. Ten patients with a history of complete pituitary insufficiency were randomized for 26 weeks in each period. Three patients were excluded due to withdrawal, fever, and claustrophobia, respectively. All patients had received adrenal, thyroid, and gonadal substitution therapy for at least 1 year before the study. The dose of rhGH was 0.25 to 0.5 U/kg/wk, administered subcutaneously once a day in the evening. BMR was determined by indirect calorimetry in a computerized ventilated open-hood system. Body composition was examined using four different methods--computed tomography (CT), tritium dilution, 40K determinations, and total body nitrogen (TBN) measured with neutron activation. The body composition data have previously been reported. Fat-free mass (FFM) increased and body fat (BF) decreased during the first 6 weeks of rhGH treatment, but no further changes in body composition occurred between 6 and 26 weeks. Baseline BMRs in GH-deficient (GHD) patients were in the lower part of the reference range, but BMR and the ratio between BMR and FFM (BMR/FFM) were not significantly lower than in a carefully selected control group. BMR increased between 0 and 6 weeks (mean +/- SD: from 6.68 +/- 1.55 to 7.75 +/- 1.35 MJ/24 h, P < .001) and then remained unchanged between 6 and 26 weeks. The increase in BMR was closely related to the increase in FFM (r = .91, P < .01).(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1994

Changes in body composition and adipose tissue distribution after treatment of women with Cushing's syndrome.

Longitudinal studies on changes in body composition and adipose tissue (AT) distribution in response to altered cortisol exposure have not yet been undertaken. Therefore, we determined body composition in seven women aged 34 +/- 9 years (mean +/- SD) with Cushing's disease/syndrome before and 8 +/- 2 (SD) months after surgical treatment for pituitary (n = 5) or cortical adrenal (n = 2) adenomas. The treatment resulted in a reduction of plasma and urinary cortisol by 78% and 97% (P < .01), respectively, and body weight (BW) reductions of 10.2 +/- 8.1 (SD) kg. The volumes of AT, skeletal muscle plus skin, and visceral organs were determined using a multiscan computed tomography (CT) technique. Organ and tissue volumes were converted to weight by multiplying with organ densities. After treatment, AT was reduced by 8.2 +/- 6.1 kg (P = .012), skeletal muscle plus skin by 1.3 +/- 1.7 kg (NS), and visceral organs by 0.6 +/- 1.0 kg (NS). The net change of AT, skeletal muscle plus skin, and visceral organs (delta AMV) was thus -10.1 +/- 7.8 kg, which was in good agreement with the change in BW (delta BW, -10.2 +/- 8.1 kg). The standard error of a single determination calculated on the differences between delta BW and delta AMV was 2.8%. Although total skeletal muscle plus skin was not changed, muscle of arms was reduced by 0.3 +/- 0.2 L (P = .014). Except for leg AT (P = .088), the reductions of all regional AT depots (arms, head+neck, subcutaneous trunk, viscera) were significant when expressed in liters. The total AT was reduced by 23% +/- 11%.(ABSTRACT TRUNCATED AT 250 WORDS)

Adipose Tissue↗
PubMed1994

A multicompartment body composition technique based on computerized tomography.

The objective of this study was to develop a body composition method based on computerized tomography (CT) which would make it possible to divide the body into multiple compartments at the tissue and organ level. Eight healthy males (21-42 years old) with BMIs ranging from 18.6 to 25.3 kg/m2 were used for the methodological development. Areas of tissues, organs and air/gas were measured in 28 cross-sectional scans having defined and identical positions in all examined subjects. The area determinations were performed with the following attenuation intervals (given in Hounsfield units, HU): air, gas and lungs: -1001 to -191 HU; adipose tissue (AT): -190 to -30 HU; all other soft tissues and organs: -29 to +151 HU; skeleton: 152 to 2500 HU. Various tissue and organ areas in the -29 to +151 HU interval were obtained by means of cursor circumscriptions, while area determinations in other intervals were based on the number of pixels fulfilling given attenuation criteria. Volumes of tissues, organs and gas were obtained from corresponding areas and the distances between the scans. The body was divided into 12 main volumes of tissues, organs and gas that could be further subdivided by region. The main volumes observed (in litres; mean +/- s.d.) were: skeleton (subdivisible into dense skeleton, red and yellow bone marrow): 8.7 +/- 0.9; skeletal muscle: 31.9 +/- 5.1; visceral AT (subdivisible into intra- and retroperitoneal, cardiac, other thoracic AT): 3.0 +/- 1.7; intra- and retroperitoneal organs other than AT: 4.6 +/- 0.8; gastrointestinal gas: 0.25 +/- 0.09; heart: 0.61 +/- 0.12; lungs and bronchial air: 5.1 +/- 1.1; other thoracic organs: 0.32 +/- 0.08; mammary glands: 0.001 +/- 0.004; CNS (subdivisible into brain and contents of spinal channel): 1.6 +/- 0.15; air in sinuses and trachea: 0.19 +/- 0.05; subcutaneous AT: 11.6 +/- 2.8; skin: 2.4 +/- 0.39. Precision errors as determined from double analyses of different tissue volumes ranged from 0.01 to 0.3 litres. For validation purposes, CT-estimated organ weights were obtained by multiplying organ volumes by their assumed densities. The sums of all organ weights were then compared with the measured body weights. The error calculated from the individual differences between these weights was 0.6 kg (0.85%). The multicompartmentation technique described has a high validity and reproducibility and is applicable over a wide range of medical fields which require body composition measurements at the tissue and organ level.

Abdomen↗
PubMed1993

Distribution of adipose tissue and muscle mass in alcoholic men.

An elevated waist to hip ratio (WHR) has been found to be a predictor for several prevalent diseases. To examine the potential role of alcohol in the elevation of WHR, established alcoholic men without severe liver damage who were in adequate nutritional condition were compared with organized teetotalers matched for age, height, and body weight; the groups had similar total body fat content and lean body mass. Computed tomographic (CT) measurements at thigh and trunk levels showed a significant increase in the visceral adipose tissue (AT) areas and a slight decrease of muscle areas in the gluteal and femoral regions of the alcoholics. The alcoholic men had 48% of their AT areas of trunk scans localized retroperitoneally and intraperitoneally compared with 38% for the teetotalers (P < .01). The difference seemed to be more marked for retroperitoneal than for intraperitoneal AT (97 v 60 cm2, P < .01). The elevated visceral AT areas seemed to be independent of smoking. It was concluded that the increased WHR of alcoholics may include not only changes in AT, but also in muscle tissue distribution.

Abdomen↗
PubMed1993

Adipose tissue and muscle volume determination by computed tomography in acromegaly, before and 1 year after adenomectomy.

The adipose tissue volume, skeletal muscle and skin volume and visceral organ volume were determined using the multiscan CT (computed tomography) technique in 15 patients with acromegaly. The examinations were performed before treatment and 1 year after transsphenoidal adenectomy. The mean body weight did not change significantly after treatment; 91.3 kg and 92.3 kg pre and postoperatively in men and 66.7 kg and 65.9 kg in women respectively. The total adipose tissue volume increased by 7.11 (59.2%, P < 0.01) in the male group and 3.9 1 (20.3%, P < 0.05) in the female group. Muscle and skin mass and visceral organ mass decreased significantly after treatment. The muscle and skin mass decreased by 3.6 1 (-7.4%, P < 0.01) in males and by 3.2 1 in females (-11.5%, P < 0.02). The corresponding decrease in visceral organ mass was 1.5 1 (-17.0%, P < 0.01) in males and 1.0 1 (15.4%, P < 0.05) in females respectively. On average, the fractions of adipose tissue in the subcutaneous trunk and the intra-abdominal depots increased after treatment, while the fractions of adipose tissue in the limbs and the head and neck region decreased. The change in adipose tissue distribution pattern reached significance (P < 0.005) in men only.

Acromegaly↗
PubMed1993

Treatment of adults with growth hormone (GH) deficiency with recombinant human GH.

In a double blind, cross-over placebo-controlled trial, we studied the effects of 26 weeks of replacement therapy with recombinant human GH on body composition, metabolic parameters, and well-being in 10 patients with adult-onset GH deficiency (GHD). All patients received appropriate thyroid, adrenal, and gonadal replacement therapy. The dose of recombinant human GH was 0.25-0.5 U/kg.week (0.013-0.026 mg/kg.day) and was administered sc daily at bedtime. One patient was withdrawn from the study because of edema and atrial fibrillation. Body composition was estimated with three independent methods: computed tomography, bioelectric impedance, and total body potassium combined with total body water assessments. The Comprehensive Psychological Rating Scale and the Symptom Check List-90 were used to assess any change in psychopathology. After 26 weeks of treatment, adipose tissue (AT) mass decreased 4.7 kg (P < 0.001). Subcutaneous AT decreased by an average of 13%, whereas visceral AT was reduced by 30%. Muscle volume increased by 2.5 kg (5%; P < 0.05). According to the four-compartment model derived from assessments of total body potassium and total body water, body cell mass and extracellular fluid volume increased significantly by 1.6 and 3.0 kg, whereas body fat decreased by 6.1 kg. Results obtained by the bioelectric impedance technique were similar. The mean (+/- SD) concentrations of insulin-like growth factor-I increased from 0.26 (0.06) at baseline to 2.56 (1.55) and 2.09 (1.03) kU/L after 6 and 26 weeks of treatment. Calcium and serum phosphate, osteocalcin, and procollagen-III concentrations were significantly higher, and intact PTH concentrations were reduced after 6 and 26 weeks of treatment, respectively. Total and free T3 concentrations were significantly increased after 6 and 26 weeks of treatment, whereas free T4 concentrations were reduced at 6 weeks, but after 26 weeks, free T4 concentrations had returned to pretreatment values. Finally, after 26 weeks of treatment, there was a decrease in the Comprehensive Psychological Rating Scale score (P < 0.05). The results show that GH replacement in GHD adults results in marked alterations in body composition, fat distribution, and bone and mineral metabolism and reduces psychiatric symptoms. Finally, we conclude that the observed beneficial effects of replacement therapy with GH are of sufficient magnitude to consider treatment of GHD adults.

Adipose Tissue↗
PubMed1993

CT-determined changes in adipose tissue distribution during a small weight reduction in obese males.

Nine obese males of Scandinavian origin were examined with a multiscan (n = 22) computerized tomography (CT) technique before and after a small weight reduction (4.4 kg). The total adipose tissue (AT) volume was reduced by 2.6 litres. Expressed as a percentage of initial depot volume, there were significant reductions (P < 0.02) in the AT depots of viscera (9.6%), upper limbs (7.0%), subcutaneous trunk (6.0%) and lower limbs (4.9%), while the AT of head and neck (1.9%) did not decrease significantly (P = 0.08). These results indicated a changed fat patterning and evidence for this was obtained by expressing the AT volume of each depot as a percentage of the total AT volume both before and after the weight reduction. Visceral AT constituted 21.7% of the total AT before and 20.9% after weight reduction. Thus, the fraction of AT in viscera was changed by -0.8 +/- 0.9% units which was significantly different from the change in leg AT (+0.5 +/- 1.1% units) (P < 0.02) and tended to be different from the change of subcutaneous AT (+0.2 +/- 1.0% units) (P < 0.07). Thus, the AT distribution was changed in a favourable direction by weight reduction. Changes in visceral/total AT area ratios of different trunk scans were not consistent and, in a stricter sense, fat patterning cannot be studied with area determinations since AT areas cannot be expressed as fractions of the total AT volume.

Adipose Tissue↗
PubMed1993

Low concentrations of insulin-like growth factor-I in abdominal obesity.

Growth hormone secretion is blunted in obesity. Recent studies have shown that the sub-group of obesity with preponderance of accumulation of fat in visceral depots is associated with endocrine abnormalities. We therefore measured IGF-I concentrations in serum in 27 men who also underwent computerized tomography measurements of regional and total body fat mass. Furthermore, euglycemic-hyperinsulinemic glucose clamps were used to determine insulin resistance, and established 'risk factors' for cardiovascular disease and non-insulin dependent diabetes mellitus were measured, i.e. blood pressure, plasma lipids, and blood glucose, as well as sex steroid hormones. Visceral fat mass systolic blood pressure and triglycerides were higher (P < 0.05) in the group with low (87 +/- 4 micrograms/l) IGF-I values, compared to those with high (126 +/- 6 micrograms/l) IGF-I values, divided after the median value. IGF-I was negatively correlated with visceral fat mass (r = 0.40), independently of subcutaneous and total fat mass. As described before visceral fat mass was directly associated to a majority of the measured 'risk factors', as well as indirectly to testosterone and sex hormone binding globulin (SHBG) concentrations. The latter were also strongly related statistically to the 'risk factors'. IGF-I concentrations showed, however, weaker correlations with the metabolic factors, blood pressure or sex steroid hormones. Multivariate analyses revealed that the correlations of visceral fat with the risk factors were not influenced by IGF-I, while testosterone or SHBG totally abolished these associations. The results indicate that low serum IGF-I concentrations, suggesting deficient growth hormone secretion, are associated with visceral but not with subcutaneous or total fat masses.(ABSTRACT TRUNCATED AT 250 WORDS)

Abdomen↗
PubMed1992

The morphology and metabolism of intraabdominal adipose tissue in men.

Mass, morphology, and metabolism of total adipose tissue and its subcutaneous, visceral, and retroperitoneal subcompartments were examined in 16 men with a wide variation of total body fat. Computerized tomography (CT) scans showed that the intraabdominal fat mass comprised approximately 20% of total fat mass. Visceral and retroperitoneal fat masses were approximately 80% and 20% of total intraabdominal fat mass, respectively. Enlargement of intraabdominal fat depots was due to a parallel adipocyte enlargement only. Direct significant correlations were found between these adipose tissue masses and blood glucose and plasma insulin levels, blood pressure, and liver function tests, while glucose disposal rate during euglycemic glucose clamp measurements at submaximal insulin concentrations (GDR), plasma testosterone, and sex hormone-binding globulin concentrations correlated negatively. The correlations for glucose, insulin, and GDR were strongest with visceral fat mass. Adipose tissue lipid uptake, measured after oral administration of labeled oleic acid in triglyceride, was approximately 50% higher in omental than in subcutaneous adipose tissues. Adipocytes from omental fat also showed a higher lipolytic sensitivity and responsiveness to catecholamines. Furthermore, these adipocytes were less sensitive to the antilipolytic effects of insulin. Both lipid uptake and lipolytic sensitivity and responsiveness showed strong correlations (r = 0.8 to 0.9) to blood glucose and plasma insulin concentrations and also to the GDR (negative), while no such correlations were found with lipid uptake in subcutaneous or retroperitoneal abdominal adipose tissues. Taken together, these results suggest a higher turnover of lipids in visceral than in the other fat depots, which is closely correlated to systemic insulin resistance and glucose metabolism in men.

Abdomen↗
PubMed1992

Training can improve muscle strength and endurance in 78- to 84-yr-old men.

Nine men, 78-84 yr of age, participated in a dynamometer training program 2-3 times/wk, totaling 25 sessions, using voluntary maximal isometric, concentric, and eccentric right knee-extension actions (30 and 180 degrees/s). Measurements of muscle strength with a Kin-Com dynamometer and simultaneous electromyograms (EMG) were performed of both sides before and after the training period. Muscle biopsies were taken from the right vastus lateralis muscle. The total quadriceps cross-sectional area was measured with computerized tomography. Training led to an increase in maximal torque for concentric (10% at 30 degrees/s) and eccentric (13-19%) actions in the trained leg. The EMG activity increased at maximal eccentric activities. The total cross-sectional quadriceps area of the trained leg increased by 3%, but no changes were recorded in muscle fiber areas in these subjects, who already had large mean fiber areas (5.15 microns 2 x 10(3)). The fatigue index measured from 50 consecutive concentric contractions at 180 degrees/s decreased and the citrate synthase activity increased in all but one subject. The results demonstrate that increased neural activation accompanies an increase in muscle strength at least during eccentric action in already rather active elderly men and that muscle endurance may also be improved with training.

Aged↗
PubMed1992

The effects of testosterone treatment on body composition and metabolism in middle-aged obese men.

Twenty-three middle-aged abdominally obese men were treated for eight months with testosterone or with placebo. Testosterone treatment was followed by a decrease of visceral fat mass, measured by computerized tomography, without a change in body mass, subcutaneous fat mass or lean body mass. Insulin resistance, measured by the euglycemic/hyperinsulinemic glucose clamp method, improved and blood glucose, diastolic blood pressure and serum cholesterol decreased with testosterone treatment. A small increase in prostate volume was noted, but serum prostate specific antigen concentrations were unchanged and no adverse functional side-effects were found. Insulin sensitivity improved more in men with relatively low testosterone values at the outset. The mechanisms involved in these changes might act either via effects on visceral fat accumulation, followed by metabolic improvements, and/or via direct effects on muscle insulin sensitivity, as suggested by results of other recent studies. It is concluded that testosterone treatment of middle-aged abdominally obese men gives beneficial effects on well-being and the cardiovascular and diabetes risk profile, results similar to those observed after hormonal replacement therapy in postmenopausal women.

Adipose Tissue↗