Search

Objective: We aimed to examine the effect of age of obesity onset, sex, and their interaction on abdominal and femoral subcutaneous adipose tissue (SAT) morphology (degree of adipocyte hyperplasia or hypertrophy). Methods: In this cross‐sectional study, we isolated adipocytes via collagenase digestion from abdominal and femoral SAT biopsies taken from male and female adults with childhood‐onset obesity (CO; n = 8 males, n = 16 females) or adult‐onset obesity (AO; n = 8 males, n = 13 females). Regional body composition was measured with dual‐energy x‐ray absorptiometry and a single‐slice abdominal computed tomography scan. Mean adipocyte size was measured in abdominal and femoral SAT and was used to quantify morphology in android and gynoid subcutaneous fat, respectively. Results: Abdominal SAT morphology was more hyperplastic in females with CO than females with AO (p = 0.004) but did not differ between males with CO and males with AO (p = 0.996). Conversely, femoral SAT morphology was more hypertrophic in males and females with CO than those with AO. Conclusions: Age of obesity onset appears to affect SAT morphology differently in the abdominal and femoral regions of male and female adults. Our findings challenge the notion that SAT is uniformly hyperplastic in CO and hypertrophic in AO. [ABSTRACT FROM AUTHOR]

Background: To examine substrate oxidation in prepubertal and early pubertal children as a function of body weight, body composition, and sex during an exhaustive cycling test. Methods: This study included 320 children in prepubertal and early puberty (Tanner stage 1 or 2; n = 188 males) who completed a minimum of 4 stages (2–5 min/stage) of an adapted version of the McMaster exhaustive exercise protocol on an upright cycle ergometer. Substrate utilization, relative to individual VO2peak, was determined using VO2 and VCO2 data, obtained with breath-by-breath gas analysis during exercise. Results: Both peak (mg/kg lean body mass·min) and submaximal lipid oxidation (mg/kg lean body mass·min) were highest (P <.01) in children with healthy weight (HW), then overweight, and lowest in obese (OB). Both females with HW (compared with males with HW) and females with OB (compared with males with OB) had higher (P <.01) peak and submaximal lipid oxidation. In children with OB, fat-free mass correlated positively (P <.01) with submaximal lipid oxidation (r =.50). In contrast, in children with HW and overweight, fat-free mass correlated positively (P <.01) with carbohydrate oxidation (r =.52 and r =.47, respectively). Conclusion: Obesity during childhood may alter substrate oxidation during exercise. These results may have implications in the implementation of exercise programs in prepubertal or early puberty to control adiposity. [ABSTRACT FROM AUTHOR]

Body fat distribution is an important predictor of metabolic abnormalities in obese humans. Dysregulation of free fatty acid (FFA) release, especially from upper body subcutaneous adipose tissue, appears to contribute substantially to these metabolic disturbances. Why different individuals preferentially store fat in upper vs. lower body subcutaneous fat or subcutaneous vs. visceral fat is not completely understood. Current evidence suggests that defects in regional lipolysis are not the cause of net fat retention in larger fat depots. Regional variations in the storage of fatty acids, both meal derived and direct reuptake, and storage of circulating FFAs that may help to explain why some depots expand at the expense of others have been reported. We review the quantitative data on regional lipolysis, meal, and FFA storage in adults to provide an overview of fat balance differences in adults with different fat distribution patterns. adipose tissue; lipoprotein lipase; free fatty acids; dietary fat

Many studies have attempted to identify specific positive health effects of probiotics. One of the challenges in generalizing health effects of probiotics is that different strains exert disparate effects on human health. As a result, the efficacy of one strain or species cannot necessarily be inferred from another. The objective of this review is to examine the current scientific literature that could be used as the basis for potential health claims. More specifically, this paper will review existing evidence of different probiotic strains to prevent and treat diarrhea, treat irritable bowel syndrome (IBS), treat inflammatory bowel disease, and prevent colon cancer. The strongest evidence is related to the use of Lactobacillus rhamnosus GG in the prevention and treatment of rotavirus-associated diarrhea. Further examination of the literature also shows promise in the treatment of some forms of IBS with probiotics. Future studies that use consistent supplementation regimes will allow more definitive conclusions to be drawn on the effects of probiotics on IBS, inflammatory bowel disease, and colon cancer. Key words: colon cancer, diarrhea, inflammatory bowel disease, irritable bowel syndrome, probiotic bacteria

The hand-held bioelectrical impedance analysis (BIA) is the commonly used technique to determine the suitable body composition for clinical trials. The comparison between magnetic resonance imaging (MRI) and BIA to evaluate the body composition of overweight women shows that fat mass estimates of the two methods were correlated.