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Objectives: To assess the reliability of bioelectric impedance analysis (BIA) for predicting total body water (TBW) and extracellular water (ECW) in obese children.Design: Comparison of five prediction models based on: (i) body weight (Wt), (ii) the impedance (Z) index (ZI = height2/Z), (iii) the association of Wt and ZI, (iv) the body surface area (SA) to impedance ratio (SA:Z) and, (v) the body volume (V) to impedance ratio (V:Z).Subjects: Thirty obese and 25 control children of 11.2 +/- 1.8 y of age.Measurements: TBW and ECW were assessed by deuterium and bromide dilution; Z was measured at frequencies of 5,50 and 100 kHz.Results: In controls, Wt explained 11% more variance of TBW than ZI (r2 = 0.977, SEE = 0.9 I, CV = 3.8%) and the association of Wt and ZI improved the prediction of TBW only slightly (r2 = 0.982, SEE = 0.8 I, CV = 3.5%). The SA:Z and V:Z indexes explained 6 and 33% less variance of TBW respectively as compared to Wt alone. In obese subjects, ZI explained 4% more variance of TBW than Wt (r2 = 0.914, SEE = 1.8 I, CV = 6.4%) and the SA:Z ratio was the most accurate predictor of TBW (r2 = 0.959, SEE = 1.2 I, CV = 4.4%). However, the increase in the explained variance of TBW associated to the use of the SA:Z ratio was of only 1% as compared to the association of ZI and Wt. The V:Z ratio explained 9% less of variance of TBW as compared to ZI. In both control and obese subjects, the association of Wt and ZI offered the best prediction of ECW (r2 = 0.807, SEE = 1.564 I and r2 = 0.826, SEE = 1.035 I, respectively). However, the values of CV were much higher in controls than in obese children (17.5% vs 8.4%) owing to their lower ECW and greater variability in ECW%. ZI was the most accurate predictor of TBW on the pooled sample (n = 55; r2 = 0.910, SEE = 1.932 I; CV = 7.4%). However, it was a poor predictor of ECW on the same sample owing to its high CV (n = 55; r2 = 0.866, SEE = 1.806 I, CV = 17.0%).Conclusions: The body surface area to impedance ratio is the most accurate predictor of TBW in obese children but the association of ZI and Wt may be of more interest when BIA is used to estimate both TBW and ECW. The impedance index offers a good prediction of TBW but not of ECW in children with different levels of fatness. [ABSTRACT FROM AUTHOR]

Scientific interest in conjugated linoleic acid (CLA) started in 1987 when Michael Pariza's team of Wisconsin University observed its inhibitory effects on chemically induced skin tumors in mice. Numerous studies have since examined CLA's role in cancer, immune function, oxidative stress, atherosclerosis, lipid and fatty acids metabolism, bone formation and composition, obesity, and diabetes. Still it's not clear yet either through which mechanisms CLA produces its numerous metabolic effects. We now know that CLA contents in cow milk fat can be enriched through dry fractionation, but this knowledge doesn't allow sufficient certainty to qualify this nutrient, as a functional food, capable of increasing well being and reducing the risk of disease.

Malnutrition is a frequent condition, both widely represented in geriatric population and underestimated in diagnostic and therapeutic work-up, and is known to affect health status and life expectancy of elderly people. The unexpected weight loss is a pathological condition, recently classified in three different ways (sarcopenia, wasting and cachexia) according to criteria of nutritional intake, functional abilities and age-related body composition modifications, that is caused by social psychological and medical factors. In this review, the authors highlight the ways that, through malnutrition, could lead to an impairment of quality of life in elderly people. Notwithstanding the great impreciseness and confusion that surrounds the term 'quality of life', the authors focus their attention on the correlation existing with the recently occurring changes to patients' health status and life-style, analysing the relationship with frailty, failure to thrive and homeostatic balance failure syndrome. With the latter term, the authors introduce a pathological condition widely represented in the late stages of malnutrition that often evolves in multiple organ failure and lastly in the death.

Objective: The present study aimed at evaluating the acute effect of increasing doses of octreotide (OCT), a long-acting somatostatin analogue, on glucose tolerance and insulin secretion., Methods: A standard and two other oral glucose tolerance tests 30 min after subcutaneous administration of OCT were performed in randomized order in each subject. Obese subjects received 10, 25, or 50 microg of OCT; control subjects received only 10 and 25 microg. Fifteen obese and 10 control subjects were studied; all of them had a normal glucose tolerance. Plasma glucose and insulin levels were measured at times -30, 0, 30, 60, 90, 120, 150, and 180 min after the glucose tolerance test., Results: The results demonstrated that, following OCT administration, both control and obese subjects developed a reduced glucose tolerance, a delayed glycemic peak, and an increase of late plasma glucose values. Fasting as well as stimulated insulin secretions were higher in obese subjects as compared with controls, and insulin secretion was inhibited in a dose-dependent manner by OCT., Conclusions: These data indicate that the action of OCT might be due to at least two different cooperative mechanisms: (1) a delayed glucose absorption, as suggested by the delay of glycemic peak, and (2) a direct or vagal-mediated effect on beta-cells, as suggested by the reduction of the area under the curve values in spite of the elevated late glycemic levels. It is noteworthy that doses of OCT as low as 10 and 25 microg are sufficient to inhibit insulin secretion both in normal and obese subjects.

In the present study, the body composition was measured in 35 Ukrainian children, 14 boys and 21 girls, aged 8-12 years, by dual-energy X-ray absorptiometry (DEXA), anthropometry, and bioelectrical impedance. The results were compared with those obtained from a sample of the same number of Italian and Dutch children of the same sex and range of age. The Ukrainian children were slightly smaller, had a lower body weight, and had a lower body fat percentage, as measured by skinfolds, as compared with the Italian and Dutch children, as well as a lower calculated fat-free mass (FFM) by impedance. Comparison between FFM as determined by different methods in the Ukrainian children showed that all assessed values differed significantly. In particular, all methods overestimated the FFM as compared with DEXA, but the differences between DEXA and the other methods were not dependent on the level of FFM as determined by DEXA. Furthermore, the difference between predicted FFM and FFM values obtained by DEXA was correlated for skinfolds and body mass index (r = 0.77, p < 0.01), but not for body mass index and impedance, or skinfolds and impedance. The mean differences were 1.8 +/- 1.5 for body mass index, 1.0 +/- 1.4 for impedance, and 3.6 +/- 1.6 for skinfolds. Some differences in the body composition have also been found between boys and girls. The boys had higher values of lean tissue (23.3 +/- 3.1 vs. 20.7 +/- 3.3; p < 0.01) and FFM (24.5 +/- 3.3 vs. 21.8 +/- 3.5; p < 0.01) as compared with the girls and slightly higher values of bone mineral content. It should be noted, however, that the differences between different groups and different methods are always small, even when they are statistically significant.