F. F. Horber

Impact of hydration status on body composition as measured by dual energy X-ray absorptiometry in normal volunteers and patients on haemodialysis*

To evaluate the influence of hydration status on the estimation of body composition using dual-energy X-ray absorptiometry (DXA), six normal volunteers and seven patients on maintenance haemodialysis were investigated using two different DXA machines (Lunar DPX, Hologic QDR 1000/W). Normal volunteers were studied (Hologic QDR 1000/W) before and 1 h after ingestion of breakfast, lunch and dinner (drinking various amounts of liquids at each meal, 0.5-2.4 kg). Whereas bone mineral content and body fat mass did not change, lean body mass of the trunk increased as a consequence of the meals. Conversely in patients on haemodialysis (Lunar DPX), lean body mass decreased in all segments of the body as a consequence of removal of 0.9-4.4 kg of salt-containing fluid by haemodialysis (trunk 61%, legs 30%, arms 5.5% and rest of the body 3.5%), whereas bone mineral content and body fat mass remained unchanged. However, this finding(s) did not hold true in one particular patient with bilateral hip prostheses. Measurement of body composition in eight normal volunteers on the same day with both machines showed similar results for lean and fat mass, whereas bone mineral content was found to be 17% higher using the Lunar DPX. In summary, in centres where both machines are available, follow-up of one individual patient should always be performed using the same equipment. In addition, hydration status and food intake must be taken into account when repetitive measurements of lean body mass are performed in the same patient.

Thigh muscle mass and function in patients treated with glucocorticoids

Abstract. Treatment with glucocorticoids causes wasting of proximal skeletal muscles. There is evidence that physical training improves muscle mass and strength in glucocorticoid‐treated rats. Whether this is also true in humans is unknown. The present investigation was designed to establish in what respect moderate physical training may alter muscle mass and function as assessed quantitatively by computed tomography (CT) and with an isokinetic dynamometer (Cybex® II). Compared with matched controls, both female (n= 17) and male (n= 22) patients treated with prednisone (15±4 ± 6±6 mg die‐1) had a lower mid‐thigh muscle area of 20 and 45% and an increased mid‐thigh fat/muscle ratio of 25 and 100%, respectively. The mean peak torque and the total work output of the thigh muscle were lower by 20–30% (n= 14). Fifty days of isokinetic training in six patients increased the thigh muscle area, decreased the thigh fat area and normalized the mean peak torque and total work output. Thus, glucocorticoid‐induced muscle wasting can be reversed by increasing physical activity.

Effect of sex and age on bone mass, body composition and fuel metabolism in humans

The mechanism(s) governing the gain of upper-body fat and its relationship to the decrease in bone mass with age is still unclear. Therefore, four groups of subjects matched for weight, height, and body mass index (n = 119; 60 women, 59 men), but differing in age (above and below 50 y) and sex were investigated using dual energy x-ray absorptiometry (DXA) to assess body composition (bone, lean, and fat mass as well as its distribution) and indirect calorimetry to determine resting fuel metabolism. Fat mass of trunk and arms (P < 0.01), but not legs, increased with advancing age in males, resulting in a continuous increase in the ratio of upper- to lower-body fat (r = 0.45, P < 0.001). In contrast, total fat mass remained stable in women, irrespective of menopause, but a redistribution of fat occurred with advancing age (r = 0.43, P < 0.001), resulting in a higher upper- to lower-body fat ratio (P < 0.05) in older than in younger women. Total lean soft-tissue mass of all segments of the body was greater in men than in women irrespective of age (P < 0.001), and lower in the older groups than in the younger ones irrespective of sex. In males, but not females, lean soft-tissue mass in arms and legs decreased (r = 0.57, P < 0.001), whereas the ratio of total fat to lean soft-tissue mass increased (r = 0.53, P < 0.001) with age. Bone mineral content correlated with total body fat in both groups of women and in young males (r > 0.5, P < 0.001), but not in older males. With advancing age, the proportion of lean soft-tissue mass occupied by total skeleton declined in women (n = 59, P < 0.001), but remained stable in males. Resting energy expenditure decreased with age in both sexes. Protein and carbohydrate oxidation were similar in all four groups of subjects. Total fat oxidation and fat oxidation per kilogram of lean soft-tissue mass decreased with age (r > 0.36, P < 0.01) in males, but not in females, whereas it increased with increasing fat mass in females (r > 0.32, P < 0.03), but not in males. In contrast, fat oxidation per kilogram of fat mass decreased with fat mass in males (r = 0.61, P < 0.001), but not in females. Our results suggest that aging affects body composition and fuel metabolism differently in each gender, leading to reduced fat oxidation and accumulation of upper-body fat with loss of striated muscle in men, and to an increased ratio of upper- to lower-body fat and bone loss in women, the latter depending on fat mass.

Effect of regular physical training on age-associated alteration of body composition in men.

Body composition changes with increasing age in men, in that lean body mass decreases whereas fat mass increases. Whether this altered body composition is related to decreasing physical activity or to the known age‐associated decrease in growth hormone secretion is uncertain. To address this question, three groups of healthy men (n = 14 in each group), matched for weight, height and body mass index, were investigated using dual‐energy X‐ray absorptiometry, indirect calorimetry and estimate of daily growth hormone secretion [i.e. plasma insulin‐like growth factor I (IGF‐I) levels]. Group 1 comprised young untrained subjects aged 31.0 ± 2.1 years (mean ± SEM) taking no regular physical exercise; group 2 consisted of old untrained men aged 68.6 ± 1.2 years; and group 3 consisted of healthy old men aged 67.4 ± 1.2 years undergoing regular physical training for more than 10 years with a training distance of at least 30 km per week. Subjects in group 3 had for the past three years taken part in the ‘Grand Prix of Berne’, a 16.5‐km race run at a speed of 4.7 ± 0.6 min km−1 (most recent race). Fat mass was more than 4 kg higher in old untrained men (P < 0.01, anova) than in the other groups (young untrained men, 12.0 ± 0.9 kg; old untrained men, 16.1 ± 1.0 kg; old trained men, 11.0 ± 0.8 kg), whereas body fat distribution (i.e. the ratio of upper to lower body fat mass) was similar between the three groups. The lean mass of old untrained men was more than 3.5 kg lower (P < 0.02, anova) than in the other two groups (young untrained men, 56.4 ± 1.0 kg; old untrained men, 52.4 ± 1.0 kg; old trained men, 56.0 ± 1.0 kg), mostly because of a loss of skeletal muscle mass in the arms and legs (young untrained men, 24.0 ± 0.5 kg; old untrained men 20.8 ± 0.5 kg; old trained men, 23.6 ± 0.7 kg; P < 0.01, anova). Resting metabolic rate per kilogram lean mass decreased with increasing age independently of physical activity (r = −0.42, P < 0.005). Fuel metabolism was determined by indirect calorimetry at rest. Protein oxidation was similar in the three groups. Old untrained men had higher (P < 0.001) carbohydrate oxidation (young untrained men, 13.2 ± 1.0 kcal kg−1 lean mass; old untrained men, 15.2 ± 1.3 kcal kg−1; old trained men, 7.8 ± 0.8 kcal kg−1), but lower (P < 0.05, anova) fat oxidation (young untrained men, 10.1 ± 1.2 kcal kg−1 lean mass; old untrained men, 6.5 ± 1.0 kcal kg−1; old trained men, 13.7 ± 1.0 kcal kg−1) than the other two groups. Mean plasma IGF‐I level in old trained men was higher than in old untrained men (P < 0.05), but was still lower than that observed in young untrained men (P < 0.005) (young untrained men, 236 ± 24 ng mL−1; old untrained men, 119 ± 13 ng mL−1; old trained men, 166 ±14 ng mL−1). In summary, regular physical training in older men seems to prevent the changes in body composition and fuel metabolism normally associated with ageing. Whether regular physical training in formerly untrained old subjects would result in similar changes awaits further study.

Differential impact of conventional oral or transdermal hormone replacement therapy or tibolone on body composition in postmenopausal women

To compare the effects on body composition and body weight of tibolone vs two different sequential oral or transdermal oestrogen‐progestogen hormone replacement therapies versus no therapy.

Imipramine and diet counseling with psychological support in the treatment of obese binge eaters: a randomized, placebo-controlled double-blind study.

OBJECTIVE This study with 31 obese binge eaters (body mass index [BMI] 39.5+/-8.6 kg/m(2) [SD]) was designed to assess whether diet counseling with psychological support and imipramine or placebo has an effect on the frequency of binge eating, body weight, and depression during an 8-week treatment phase. This was followed by an open medication-free phase of 6 months of continuous diet counseling with psychological support. METHODS Randomized double-blind placebo-controlled study of 8 weeks followed by an open phase of 6 months. Patients were evaluated in medical visits by a semistructured videotaped interview, psychometric questionnaires, and hematochemical parameters. RESULTS From Week 0 to 8, a significant reduction in binge frequency occurred in both treatment conditions (7.1+/-4.1 to 2.8+/-3.0 binges per week [imipramine] vs. 7.1+/-4.1 to 5.4+/-5.1 [placebo], p<.01). Patients on imipramine lost -2.2+/-1.8 kg compared to placebo-treated subjects (+0.2+/-3.3 kg, p<.001). On follow-up, only the patients initially treated with imipramine continued to lose weight (-5.1+/-2.8 kg [imipramine] vs. 2.2+/-6.8 kg [placebo], p<.001 [differences to Week 0]). While both treatment conditions were associated with significant improvements on a raters measure of depressive symptoms (Hamilton Depression Scale) at Week 8, only the patients treated with imipramine still showed a significant improvement at Week 32. Scores on the Self Depression Rating Scale did not show a group difference but a significant reduction at Weeks 8 and 32, compared to baseline. DISCUSSION These results suggest that adding low-dose imipramine to diet counseling with psychological support helps patients losing weight even for at least 6 months off medication. The effect might include a psychological priming of weight loss during the double-blind phase that continues at least for half a year after stopping the drug.

Body composition and fuel metabolism after kidney grafting

Abstract. Kidney transplant patients display decreased muscle mass and increased fat mass. Whether this altered body composition is due to glucocorticoid induced altered fuel metabolism is unclear. To answer this question, 16 kidney transplant patients were examined immediately after kidney transplantation (12±4 days, mean ±SEM) and then during months 2, 5, 11 and 16, respectively, by whole body dual energy X‐ray absorptiometry (Hologic QDR 1000W) and indirect calorimetry. Results were compared with those of 16 age, sex and body mass index matched healthy volunteers examined only once. All patients received dietary counselling with a step 1 diet of the American Heart Association and were advised to restrict their caloric intake to the resting energy expenditure plus 30%. Immediately after transplantation, lean mass of the trunk was higher by 7±1% (P<0.05) and that of the limbs was lower by more than 10% (P<0.01) in patients than in controls. In contrast, no difference in fat mass and resting energy expenditure could be detected between patients and controls. During the 16 months of observation, total fat mass increased in male (+4.9± 1.5 kg), but not in female patients (0.1 ±0.8 kg). The change in fat mass observed in men was due to an increase in all subregions of the body analysed (trunk, arms + legs as well as head + neck), whereas in women only an increase in head + neck by 9 ±2% (P= 0.05) was detected. Body fat distribution remained unchanged in both sexes over the 16 months of observation. Lean mass of the trunk mainly decreased between days 11 and 42 (P<0.01) and remained stable thereafter. After day 42, lean mass of arms and legs (mostly striated muscle) and head + neck progressively increased over the 14 months of observation by 1.6±0.6 kg (P < 0.05) and 0.4±0.l kg (P < 0.01). respectively. Resting energy expenditure was similar in controls and patients at 42 days (30.0 ±0.7 vs. 31.0±0.9 kcal kg‐1 lean mass) and did not change during the following 15 months of observation. However, composition of fuel used to sustain resting energy expenditure in the fasting state was altered in patients when compared with normal subjects, i.e. glucose oxidation was higher by more than 45% in patients (P<0.01) during the second month after grafting, but gradually declined (P<0.01) over the following 15 months to values similar to those observed in controls. Protein oxidation was elevated in renal transplant patients on prednisone at first measurement, a difference which tended to decline over the study period. In contrast to glucose and protein oxidation, fat oxidation was lower in patients 42 days after grafting (P<0.01), but increased by more than 100% reaching values similar to those observed in controls after 16 months of study. Mean daily dose of prednisone per kg body weight correlated with the three components of fuel oxidation (r>0.93, P<0.01), i.e. protein, glucose and fat oxidation. These results indicate that in prednisone treated renal transplant patients fuel metabolism is regulated in a dose‐dependent manner. Moreover, dietary measures, such as caloric and fat intake restriction as well as increase of protein intake, can prevent muscle wasting as well as part of the usually observed fat accumulation. Furthermore, the concept of preferential upper body fat accumulation as consequence of prednisone therapy in renal transplant patients has to be revised.

Altered body composition and fuel metabolism in stable kidney transplant patients on immuno‐suppressive monotherapy with cyclosporine A

Abstract. Glucocorticoid associated altered body fat distribution and muscle wasting are well known following kidney grafting. Whether an immunosuppressive regimen after glucocorticoid withdrawal (i.e. monotherapy with cyclosporine A (CsA)) is associated with normalization of altered body fat distribution and muscle mass remains to be determined. Therefore 18 renal transplant patients (nine males and nine females, 64 ± 5 (mean ± SEM) months since transplantation; CsA‐monotherapy: 38 ± 7 months) and 18 age, sex and body mass index matched healthy volunteers were investigated using indirect calorimetry and dual energy X‐ray absorptiometry. Lean body mass (LBM) was decreased in patients mostly due to loss of striated muscle in the legs (P<0·01), Compared to healthy controls, fat mass was increased in head and trunk (P<0·01) and similar in extremities. Resting energy expenditure expressed per kg LBM was increased by more than 10% (P<0·05) in patients vs. controls. Plasma insulin and glucose concentrations, total serum cholesterol (C), triglyceride levels and the ratio of LDL‐C to HDL‐C were all elevated (P<0·01) in patients as compared with controls. In summary, renal transplant patients on immunosuppressive mono therapy with CsA demonstrate decreased muscle mass despite discontinuation of prednisone therapy. The increased upper body fat might account, at least in part, for peripheral hyperinsulinaemia and dyslipidaemia observed in kidney transplant patients even years after successful transplantation.