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Biomedical subjects

G Sergi

Publications and source records attributed to G Sergi.

At least 19 recordsLinked to original sources
PubMed2006

Role of visceral proteins in detecting malnutrition in the elderly.

OBJECTIVE: In the clinical practice, visceral proteins are used as indirect markers of protein energy malnutrition (PEM), but their reliability could be reduced with advancing age. The aim of this work is to investigate the reliability of albumin, prealbumin, retinol-binding protein (RBP) and transferrin in evaluating nutritional status in old patients and their relationship with fat-free mass (FFM). DESIGN: Cross-sectional study. SETTING: Padua, Italy. SUBJECTS: In 44 underweight (body mass index < 20 kg/m(2)) (66-97 years) and 69 normal weight or overweight elderly subjects (62-98 years), albumin, prealbumin, transferrin and RBP were determined in the plasma. Body composition and particularly FFM was obtained by dual X-ray absorptiometry. FFM was also expressed as FFM index (FFMI) calculated as FFM divided by height squared. Subjects affected by acute illnesses and inflammatory states were excluded. RESULTS: Albumin, prealbumin and RBP mean values were significantly lower in underweight subjects. No differences between two groups were found for transferrin. Albumin prealbumin and RBP resulted under the normal range in 55, 25 and 54% of underweight subjects, respectively. Transferrin's values were low in about 40% of underweight and normal weight subjects, respectively. In all subjects, FFMI shows a significant correlation with albumin (r: 0.52), prealbumin (r: 0.64) and RBP (r: 0.57). No correlation between FFMI and transferrin was found. CONCLUSIONS: Visceral proteins, except for transferrin, seem to be useful indexes in detecting malnutrition in the elderly; low values still in the normal range should also be carefully evaluated because they could suggest a poor nutritional status.

Absorptiometry, Photon↗
PubMed2006

Reliability of bioelectrical impedance methods in detecting body fluids in elderly patients with congestive heart failure.

OBJECTIVE: To investigate the reliability of bioelectrical impedance analysis (BIA) in estimating total body water (TBW) and extracellular water (ECW) in elderly patients suffering from congestive heart failure (CHF). MATERIAL AND METHODS: In 72 elderly subjects, 34 with CHF (aged 83.9+/-6.9 years) and 38 healthy controls (78.7+/-7.5 years), TBW and ECW values were assessed using dilution methods, and bioelectrical variables were measured using single frequency BIA (SF-BIA) at 1 and 50 kHz, and bioelectrical spectroscopy (BIS). RESULTS: In CHF patients, Ht(2)/R(1) correlated weakly with TBW (r = 0.56) and ECW (0.47). In both healthy controls and CHF patients, TBW correlated strongly with Ht(2)/R(50), Ht(2)/R(0), Ht(2)/R(8) and Ht(2)/Zc. Using multiple regression analysis and the Bland-Altmann approach, SF-BIA at 50 kHz and BIS proved similar in predicting TBW for both the explained variance (R(2)~0.89) and the limits of agreement. In all subjects, ECW was estimated best by including height, weight and Ht(2)/R(0 )(R(2) 0.75) or Ht(2)/Zc (R(2) 0.77) in multivariate models, while SF-BIA at 50 kHz did not explain more than 71 % of ECW variability. The SEE % was nonetheless about twice the SEE % for estimating TBW. CONCLUSIONS: SF-BIA at 1 kHz is unreliable in predicting body fluids in elderly people with CHF. SF-BIA at 50 kHz and BIS are useful for estimating TBW in healthy elderly people and in cases of water imbalance, but both methods are less reliable in estimating ECW, particularly in conditions of fluid overload.

Aged↗
PubMed2005

Predictors of drop-out in overweight and obese outpatients.

OBJECTIVE: To investigate the impact on drop-out rates of several baseline clinical characteristics of a sample of overweight and obese outpatients. DESIGN: Retrospective clinical trial. SUBJECTS: The charts of 383 patients aged 15-82 y attending an outpatient clinic for the treatment of obesity were examined from the first clinical evaluation until 1 y of diet ambulatory treatment. MEASUREMENTS: We characterised the participants at baseline on the basis of their somatic characteristics, socioeconomic status, obesity-related diseases and dietary habits. The most significant factors resulting in univariate statistical analysis (waist, body mass index (BMI), full-time job, depressive syndrome, number of obesity-related diseases, daily frequency of fruit consumption) were then examined as independent variables in direct multiple logistic regression with the dependent variable drop-out. RESULTS: The 1-y drop-out rate was 77.3%. A total of 87 patients completed the follow-up study. The noncompleter patients had slightly lower BMI and waist circumference mean values, and they were further regularly employed in full-time jobs, while the completer patients were principally pensioners and housewives. Drop-outs had a lower number of obesity-related diseases and as a result were less depressed. By the logistic regression, full-time job is the best predictor of premature withdrawal (odds ratio=2.40). Age, gender, anthropometric measurements, lifestyle and dietary habits did not result as significant predictors of drop-out. CONCLUSION: The overweight and obese outpatients at higher risk of ambulatory treatment drop-out are more likely to work full hours, have less obesity-related complications and be less depressed. In our study, the full-time job condition seems to be the strongest predictor of premature withdrawal.

Adolescent↗
PubMed2004

Physical disability and muscular strength in relation to obesity and different body composition indexes in a sample of healthy elderly women.

OBJECTIVES: The aim of the present study was to test the association between muscular strength, functional limitations, body composition measurements and indexes of sarcopenia in a sample of community-dwelling, elderly women at the high end of the functional spectrum. DESIGN: Cross-sectional. SUBJECTS: In all, 167 women aged 67-78 y were selected from the general population in central Verona. A group of 120 premenopausal healthy women aged 20-50 y represented the young reference group. MEASUREMENTS: Body weight, height, body mass index (BMI) and the presence of acute and chronic conditions were evaluated in each subject. Body composition was measured by dual-energy X-ray absorptiometry (DXA). Physical functioning was assessed using a modified version of the Activities of Daily Living Scale. Dominant leg isometric strength was measured with a Spark Handheld Dynamometer. RESULTS: Elderly women with BMI higher than 30 kg/m(2) and in the highest quintile of body fat percent showed a significantly higher prevalence of functional limitation. In our population study, about 40% of sarcopenic elderly women and 50% of elderly women with high body fat and normal muscle mass were functionally limited. The prevalence of functional limitation significantly increased in subjects with class II sarcopenia, defined according to the skeletal muscle mass index (SMI=skeletal muscle mass/body mass x 100). In logistic regression models, after adjusting for age and different chronic health conditions, subjects with BMI higher than 30 kg/m(2), in the highest quintile of body fat, or with high body fat and normal muscle mass or class II sarcopenia according to SMI, had a 3-4 times increased risk of functional limitations. Finally, isometric leg strength was significantly lower in subjects in the lowest quintile of relative muscle mass and in sarcopenic and sarcopenic obese women. CONCLUSIONS: High body fat and high BMI values were associated with a greater probability of functional limitation in a population of elderly women at the high end of the functional spectrum. Among the different indexes of sarcopenia used in this study, only SMI predicted functional impairment and disability. Isometric leg strength was significantly lower in subjects with sarcopenia and sarcopenic obesity.

Absorptiometry, Photon↗
PubMed2003

Historical perspective: visceral obesity and related comorbidity in Joannes Baptista Morgagni's 'De sedibus et causis morborum per anatomen indagata'.

In recent years, advances in epidemiological approaches and laboratory technology, along with the availability of sophisticated imaging methods to evaluate body fat distribution, made it possible to define the close correlation between visceral fat accumulation and the occurrence of metabolic abnormalities, cardiovascular diseases and respiratory disturbances in obese patients. Some 250 y ago, JB Morgagni with the help of only a knife for anatomical dissection, an acute mind, and an observational skillfulness was able to identify the intra-abdominal and mediastinal fat accumulation in android obesity. He clearly described the association between visceral obesity, hypertension, hyperuricemia, atherosclerosis and obstructive sleep apnea syndrome, long before the modern recognition of this syndrome.

Comorbidity↗
PubMed2003

Differential clinical expression of multiple symmetric lipomatosis in men and women.

BACKGROUND: Multiple symmetric lipomatosis (MSL) is a rare disease characterised by the growth of uncapsulated masses of adipose tissue. MSL is associated with high ethanol intake and complicated by somatic and autonomic neuropathy and the infiltration of adipose tissue at the mediastinal level. To date, the disease is considered as largely more prevalent in men. OBJECTIVE: To provide a detailed description of the clinical aspects of MSL in women. PATIENTS: A total of 11 women and 58 men with MSL. MEASUREMENTS: Morphological aspect of patient, location of the lipomatous masses, alcohol intake, extension of lipomatous tissue to the mediastinum, association with somatic and autonomic neuropathy, and metabolic profile. RESULTS: All female patients had the obesity-like appearance of type II MSL and the most frequent locations of lipomatous masses in women were at the proximal arms (90.9%) and legs (54.5%). Very few female patients (27.3%) presented with the submental deposition of lipomatous tissue typical of both type I (97.3%; P<0.001) and type II (66.7%; P<0.05) male subjects. An extension of the lipomatus tissue around the upper airways, associated with compression or dislocation of deeply located mediastinal structures, was observed less frequently in women than in men. The presence of a high ethanol intake, the association with somatic and autonomic neuropathy and the occurrence of a characteristic metabolic pattern (high HDL-cholesterol, low LDL-cholesterol, high uric acid) were similar in men and in women. CONCLUSIONS: Female patients with MSL had a sex-specific morphological aspect, characterised by a low occurrence of the typical 'Madelung collar' and a usual obesity-like appearance.

Adipose Tissue↗
PubMed2003

Can obesity be a risk factor in elderly people?

Obesity is increasing in middle-aged adults and in elderly subjects (over 65 years), owing to the concurrence of different factors: inactivity, wrong nutritional habits, and basal metabolism and nutritional need reduction. This condition is becoming a serious problem because of the increasing numbers of the aged population all over the world. In the past, obesity was considered as a 'secondary' pathology of no medical importance in old age; but nowadays, obesity is increasingly being studied in Geriatrics too, because it causes disability and because of its quality-of-life impairment consequences. The Euronut-Seneca study has confirmed the presence of obesity in both men and women in Europe. The definition of obesity, the reference values of body mass index and obesity as a mortality factor in elderly persons are still under discussion. Even when overweight does not represent a serious problem in old age, obese elderly people are certainly at risk of disability, morbidity and mortality. This review focuses on the potential risks of overweight and obesity in the aged population.

Age Factors↗
PubMed2003

Chronic obstructive pulmonary disease (COPD) in elderly subjects: impact on functional status and quality of life.

Chronic obstructive pulmonary disease (COPD) is an important cause of morbidity and disability. Many studies have investigated factors influencing quality of life (QoL) in middle-aged COPD sufferers, but little attention has been given to elderly COPD. The aim of the present study was to investigate the impact of COPD on QoL and functional status in the elderly. Sixty COPD patients and 58 healthy controls over 65 years old were administered Pulmonary Function Tests, 6 min Walking Test (6MWD) for exercise tolerance, the Barthel Index and Mini Mental State Examination (MMSE) for functional status, the Geriatric Depression Scale (GDS) for mood, and the Saint George Respiratory Questionnaire (SGRQ) for QoL. FEV1 and PaO2 were reduced in COPD patients. Also the distance walked during 6MWD was significantly shorter for patients than controls (282.5 +/- 89.5 vs. 332.9 +/- 95.2 m; P < 0.01). Moreover, COPD patients had significantly worse outcomes for the Barthel Index, GDS and SGRQ. The logistic regression model demonstrated that a decrease in FEV1 is the factor most strictly related to the deterioration of QoL in COPD patients. Mood was also an independent factor influencing QoL. In conclusion, elderly COPD patients show a substantial impairment in QoL depending on the severity of airway obstruction; symptoms related to the disease may be exaggerated by mood deflection.

Activities of Daily Living↗
PubMed2002

Health status, quality of life and mortality in a randomized Italian elderly people.

The present study constitutes the Italian part of the SENECA Study: 89 elderly (39 men and 50 women), born between 1913-1918, were studied to evaluate health status, quality of life and mortality. The great part of the subjects (84.6% of men, 76% of women) was able to move outdoors and to use stairs without difficulty. 97.4% of men and 94 % of women practised physical activities (walking). 15% of men and 40% of women declared "good health"; 2% of men and 14% of women declared "poor health". The most frequent chronic disease was arthritis/arthrosis in both genders, especially in women, followed by osteoporosis in women, hypertension in men. The use of medicines was high (79.5% in men, 82% in women); instead, few subjects used vitamin/mineral supplements. The cognitive function of almost all the subjects was good. Mortality was significantly higher) in men (71%) than is women (29%)(p<0.0001). The most frequent causes of death were malignant neoplasia (47.3% in men, 40% in women) and cardiovascular disease (28.2% in men, 40% in women). In conclusion, in sample, although the opinion of our most of subjects about their health status was good, chronic diseases were common. Arthrosis was the most frequent chronic disease. Malignant neoplasia was the first cause of death in both genders.

Aged↗
PubMed2000

Bone mineral density and body composition in underweight and normal elderly subjects.

The importance of malnutrition as a risk factor in osteoporosis is emphasized by the evidence that patients with fractures of the proximal femur are often undernourished. In this study, nutritional status, bone mineral mass and its association with body composition were investigated in underweight and normal weight elderly subjects. Moreover the hypothesis that malnutrition in elderly is associated with a higher risk of osteoporosis was tested. The participants were 111 elderly subjects divided into two groups according to body mass index (BMI): 51 patients were underweight (BMI < 22 kg/m2) while in 60 subjects BMI ranged from 22 to 30 kg/m2. In all patients anthropometric parameters and blood indices of malnutrition and of bone turnover were measured. Fat-free soft mass (FFSM), fat mass (FM), bone mineral content (BMC) and bone mineral density (BMD) 'total body' and at the hip were obtained by dual-energy X-ray densitometry. Dietary intake was evaluated with the diet history method, while resting energy expenditure (REE) was measured by indirect calorimetry. Underweight subjects had other signs of malnutrition, such as low visceral proteins, sarcopenia, and an inadequate energy intake. Moreover they showed a significant reduction of BMC and BMD compared with normal subjects. In men with BMI <22 kg/m2, T-score was below -2.5 (-3 at femoral neck and -2.7 at total hip) while men in the control group had normal bone mineral parameters. T-score at different sites was lower in underweight women than in underweight men, always showing values under -3.5, with clear osteoporosis and a high fracture risk. In healthy women the T-score values indicated the presence of mild osteoporosis. In underweight subjects, low levels of albumin (< 35 g/l) were associated with higher femoral bone loss. Using a partial correlation model, BMC, adjusted for age, bone area, knee height and albumin showed a significant association with FM in women (r = 0.48; p < 0.01) and with FFSM in men (r = 0.48; p < 0.05). Albumin, when adjusted for other variables, was significantly correlated (r = 0.52; p < 0.05) with femoral neck BMC only in women. In conclusion, the underweight state in the elderly is associated with malnutrition and osteoporosis; other factors occurring in malnutrition, besides body composition changes, such as protein deficiency, could be involved in the association between underweight and osteoporosis. Moreover bone mineral status seems to be related to fat-free soft mass tissue in men while in women it is much more closely associated with total body fat.

Aged↗
PubMed2000

Visceral fat loss evaluated by total body magnetic resonance imaging in obese women operated with laparascopic adjustable silicone gastric banding.

OBJECTIVE: To investigate the changes of visceral fat, as compared with total and subcutaneous adipose tissue (AT) in obese patients operated with laparascopic adjustable silicone gastric banding (LAP-BAND). SUBJECTS: Six premenopausal morbid obese (body mass index range: 41.4-44.2 kg/m2) women, aged 38-42 y, operated with LAP-BAND, evaluated before, 8 weeks after, and 24 weeks after surgery. MEASUREMENTS: Fat distribution was analysed by total body multi-slices MRI. Total AT, gluteo-femoral subcutaneous AT, abdominal subcutaneous AT, and abdominal visceral AT volumes were measured. FM was calculated from MRI-determined total AT volume and AT density. RESULTS: A weight loss of 9.9+/-3.8 kg was observed in the first 8 weeks after LAP-BAND (0-8 weeks), and a further weight loss of 7.1+/-4.9 kg in the subsequent 16 weeks (8-24 weeks). Total AT showed a statistically significant reduction of 6.2+/-4.0 l in 0-8 weeks and a further significant reduction of 7.7+/-3.9 l in 8-24 weeks (P<0.01 from baseline). A similar trend was observed for both abdominal and gluteo-femoral subcutaneous AT. Visceral AT showed a statistically significant reduction of 1.0+/-0.9 l in the 0-8 weeks (P<0.05) and a further non-significant reduction of 0.6+/-0.7 l in 8-24 weeks (P<0.05 from baseline). In 0-8 weeks, the relative reduction of visceral AT was higher than the relative reduction of both total AT and gluteo-femoral subcutaneous AT. A highly significant correlation was observed between the reduction of total AT and the reduction of both abdominal and gluteo-femoral subcutaneous AT. By contrast, in 0-8 weeks, the reduction of total AT and the reduction of visceral AT were not correlated. In a subsequent analysis, both observations collected in the first 8 weeks after LAP-BAND and observations collected in the last 16 weeks are simultaneously considered, leading to a total of 12 time periods (two time periods for each individual patient). In order to identify factors associated with preferential visceral fat reduction, we calculated for each of the 12 time periods the difference between the percentage changes of visceral AT and the percentage changes of total AT. The relationship between this difference and several other variables were investigated by simple correlation analysis. The only variables found to be associated were the initial visceral AT volume, the absolute level of weight loss (kg) per week of observation, and the relative level of weight loss (%) per week of observation. CONCLUSION: In the phase of rapid weight loss following LAP-BAND, a preferential mobilization of visceral fat, as compared with total and subcutaneous AT, can occur. However, this preferential visceral fat reduction occurs only in those patients presenting higher levels of visceral fat deposition at baseline and higher levels of weight loss. International Journal of Obesity (2000)24, 60-69

Abdomen↗
PubMed2000

Dietary intake and nutritional status in Italian elderly subjects.

Dietary intake and nutritional status was assessed in a random sample of 190 Italians (70-75 years of age) participating in the Survey in Europe on Nutrition and the Elderly (EURONUT-SENECA). The daily energy intake as assessed by a Modified Dietary History, was 2208+/-562 Kcalories in men and 1742+/-527 Kcalories in women. The alcohol intake was significantly higher in men than in women (35. 9+/-32.5 g/day vs 14.7+/-15.4 g/day; p<0.0001). As for calcium, there was a high percentage of men (77%) and women (86%) with a lower intake than the recommended values. The subjects underweight (BMI<20) were only 4.1% men and 9.7% women, while the great part was normal (BMI= 20-24.9) and overweight (BMI=25-29.9). The body composition parameters showed a significant difference between two genders. Men had a Total Body Water (56.5+/-4.5% vs 51.3+/-5.4%; p<0. 001) and Fat-Free Mass (80.4+/-5.2% vs 70.9+/-6.8%; p<0.001) higher than women. Few subjects were at high risk of deficiency with regard to plasma levels of vitamins, haemoglobin and albumin. If we analyse the composition of the diet consumed, we can remark the characteristics of a typical Mediterranean diet. We conclude that the general nutritional status of our sample was fairly good.

Aged↗
PubMed1995

Influence of gingival crevicular washing on the expression of polymorphonuclear leukocyte membrane receptors before and after periodontal therapy.

Extensive data demonstrate that polymorphonuclear leukocytes (PMN) are the predominant cell type involved in periodontal disease and that gingival crevicular fluid constituents are influenced by the inflamed gingiva. The aim of the present study was to evaluate the ability of gingival crevicular washing (GCW) (a dilution of gingival crevicular fluid) from periodontal sites in different clinical conditions of modulating the PMN membrane receptors involved in motility, adhesion and phagocytosis before and after periodontal treatment. 10 patients affected by adult periodontitis (AP) were selected. From each patient, 2 test sites (TS) were chosen on the basis of a probing depth > 5 mm and attachment loss, and 2 control sites (CS) with probing depth < 3 mm without. Modifications of membrane receptor density of PMN from healthy donors incubated with GCW harvested from TS and CS was evaluated using fluorescent probes and flow cytometry. Compared to CS-GCW, TS-GCW before therapy increased the expression of the beta 2 integrin CD11b and the chemotactic receptor for the oligopeptide N-formyl methionyl leucyl phenylalanine (FMLP-R) while it reduced the expression of L-selectin. GCW collected from the same TS after the successful completion of periodontal treatment did not influence PMN receptors, indicating that the clinical improvement paralleled the disappearance of the PMN modulating capability contained in TS-GCW before therapy. In conclusion, the present data illustrate the relevant modifications occurring at PMN membrane in chronic adult periodontitis exerted by GCW obtained by a simple fluid collection technique. Thus, monitoring gingival crevicular fluid PMN activating capability may help disclose the presence of chronic periodontitis and may be useful in assessing successful treatment.

Adult↗
PubMed1994

Fasting and postprandial phenylalanine and leucine kinetics in liver cirrhosis.

To investigate body protein turnover and the pathogenesis of increased concentration of plasma phenylalanine in liver cirrhosis, we have studied phenylalanine and leucine kinetics in cirrhotic (diabetic and nondiabetic) patients, and in normal subjects, both in the postabsorptive state and during a mixed meal, using combined intravenous and oral isotope infusions. Postabsorptive phenylalanine concentration and whole body rate of appearance (Ra) were approximately 40% greater (P < 0.05) in patients than in controls. Leucine concentrations were comparable, but intracellular leucine Ra was also increased (P < 0.05), suggesting increased whole body protein breakdown. Postprandial phenylalanine Ra was also greater (P < 0.05) in the patients. This difference was due to a diminished fractional splanchnic uptake of the dietary phenylalanine (approximately 40% lower in the cirrhotics vs. controls, P < or = 0.05). Postprandial leucine Ra was also increased in the patients, but splanchnic uptake of dietary leucine was normal. Thus both increased body protein breakdown and decreased splanchnic extraction of dietary phenylalanine can account for the increased phenylalanine concentrations in liver cirrhosis.

Adult↗
PubMed1994

Accuracy of bioelectrical impedance analysis in estimation of extracellular space in healthy subjects and in fluid retention states.

Bioelectrical impedance analysis (BIA) is a noninvasive method recently introduced for body fluid evaluation in healthy subjects. The purpose of this paper is to verify the reliability of bioelectrical measurements in extracellular water (ECW) prediction in healthy subjects and in fluid retention states. We studied 40 subjects (19 males and 21 females) aged 21-81 years; 22 were healthy subjects, 12 were affected by chronic heart failure, and 6 by chronic renal failure. In all subjects resistance (R) and reactance (Xc) at 1 and 50 kHz corrected for height were compared with ECW measured by the bromide dilution method. Our results suggested a different behavior of the current in fluid-retention states with respect to healthy subjects. ECW was best predicted by resistance at 1 kHz corrected for height, group (considered as dummy variable), weight and gender (R2 = 0.89, p < 0.001, SEE = 1.7 liters). The bioelectrical impedance analysis at 50 kHz explained the 89% of ECW variability when resistance and reactance corrected for height are considered with gender group and weight (R2 = 0.89, p < 0.001, SEE = 1.7 liters). In conclusion, the bioelectrical method at 1 kHz can be considered sufficiently accurate in ECW prediction in healthy subjects and in fluid retention states. Also, the bioelectrical impedance analysis at 50 kHz is useful for predicting ECW, but his role must be further investigated.

Adult↗
PubMed1993

Leucine and phenylalanine kinetics in compensated liver cirrhosis: effects of insulin.

BACKGROUND: The pathogenesis of the altered ratio of branched-chain amino acid to aromatic amino acid concentration in liver cirrhosis is poorly known. We explored the possible link between altered amino acid concentrations and kinetics in cirrhosis. METHODS: Post-absorptive leucine and phenylalanine rates of appearance (Ra) and their response to insulin were studied in patients with compensated, nondiabetic cirrhosis and in controls. RESULTS: In the cirrhotics, concentration of postabsorptive phenylalanine was greater and that of alpha-ketoisocaproate lower than in controls, whereas concentration of leucine was comparable. Leucine Ra was lower, phenylalanine Ra was greater, and the ratio of leucine Ra to phenylalanine Ra was markedly decreased (P < 0.001) in patients vs. controls (2.40 +/- 0.23 vs. 3.67 +/- 0.19, respectively). During an euglycemic-hyperinsulinemic clamp, glucose disposal was reduced and leucine Ra was suppressed more profoundly in cirrhotics than in controls, whereas suppression of phenylalanine Ra was comparable. CONCLUSIONS: In compensated liver cirrhosis, postabsorptive phenylalanine Ra is increased with respect to leucine Ra, suggesting the existence either of altered amino acid pools and/or transport or of abnormally sequenced proteins and/or peptides. Insulin resistance is restricted to glucose, but not to amino acid metabolism.

Adult↗
PubMed1993

Body composition study in the elderly: comparison between tritium dilution method and dual photon absorptiometry.

BACKGROUND: The methods commonly employed in body composition study in elderly persons derive fat-free mass (FFM) by measures of total body water (TBW); these methods assume FFM hydration constant (TBW/FFM = 0.732). The aim of our study was to verify the accuracy of the TBW method in FFM estimation and to study the variability of fat-free mass hydration (TBW/FFM) in healthy elderly subjects. METHODS: We assessed FFM in 27 healthy old subjects (76 +/- 7 yrs) by dual photon absorptiometry (DPA) and by TBW measured by 3H2O. Furthermore, to verify the accuracy in FFM estimation by our methods, we measured resting metabolic rate (RMR) by indirect calorimetry. RESULTS: FFM hydration was 71.9 +/- 4.9 (range 63.6-80.4%), a range larger than that reported by direct chemical analysis in adults. The FFM hydration measured in our subjects was not different from the 73.2 value currently used in healthy adults. FFM values derived by TBW (assuming TBW/FFM = 0.732) were not significantly different from FFM measured by DPA. We correlated FFM with resting metabolic rate and found a similar correlation between RMR and FFM-DPA (r = .89, p < .001) and FFM-TBW (r = .85, p < .001). CONCLUSIONS: Both methods employed in our study have proved to be accurate in estimating FFM in elderly persons; particularly, the value of 0.732 assigned to FFM hydration to derive fat-free mass in adults can be employed also in body composition study of the elderly.

Absorptiometry, Photon↗