Total Body Fat Content Research Articles

The effect of the length of repeated feed deprivation between single meals on compensatory growth of pikeperch Sander lucioperca

Juvenile pikeperch ( Sander lucioperca) were reared for 58 days according to one of the following feeding regimes: control (fed once every day); 1 + 1 (fed every other day); 1 + 3 (one-day feeding followed by a three-day feed deprivation); and 1 + 6 (fed once a week). Control fish had significantly higher growth rate than the 1 + 3 and 1 + 6 fish, and consequently the final weight of the controls (125.2 ± SD 30.0 g, n = 4) was higher than that of the 1 + 3 (84.0 ± 17.9 g) and 1 + 6 fish (64.7 ± 7.2 g). Fish in the treatment groups were capable to compensate for the reduced number of feedings by increasing intake relative to the controls when feed was available. This hyperphagic response induced enlargement of the stomach but no difference in feed conversion ratio between any groups. Compensatory ability improved during the course of the experiment and it was almost identical in 1 + 3 and 1 + 6 groups. However, it appeared that only at the lowest feeding frequency the compensatory response as weight gain occurred slower than compensation of feed intake. Final visceral fat (%), total body fat (%) and energy content of the 1 + 3 and 1 + 6 fish were significantly lower and water content (%) higher than in the controls and 1 + 1 fish, but protein content was unaffected by the treatments. In conclusion, this experiment indicated that feeding pikeperch every other day (1 + 1) did not significantly affect any other measured or calculated parameter than relative feed intake when compared to the controls which indicated full compensation. At lower feeding frequencies (1 + 3 and 1 + 6) pikeperch was capable to compensate only partially for the decreased number of feedings.

How the Intestinal Peptide Transporter PEPT-1 Contributes to an Obesity Phenotype in Caenorhabditits elegans

BackgroundAmino acid absorption in the form of di- and tripeptides is mediated by the intestinal proton-coupled peptide transporter PEPT-1 (formally OPT-2) in Caenorhabditits elegans. Transporter-deficient animals (pept-1(lg601)) show impaired growth, slowed postembryonal development and major changes in amino acid status.Principal FindingsHere we demonstrate that abolished intestinal peptide transport also leads to major metabolic alterations that culminate in a two fold increase in total body fat content. Feeding of C. elegans with [U-13C]-labelled E. coli revealed a decreased de novo synthesis of long-chain fatty acids in pept-1(lg601) and reduced levels of polyunsaturated fatty acids. mRNA profiling revealed increased transcript levels of enzymes/transporters needed for peroxisomal β-oxidation and decreased levels for those required for fatty acid synthesis, elongation and desaturation. As a prime and most fundamental process that may account for the increased fat content in pept-1(lg601) we identified a highly accelerated absorption of free fatty acids from the bacterial food in the intestine.ConclusionsThe influx of free fatty acids into intestinal epithelial cells is strongly dependent on alterations in intracellular pH which is regulated by the interplay of PEPT-1 and the sodium-proton exchanger NHX-2. We here provide evidence for a central mechanism by which the PEPT-1/NHX-2 system strongly influences the in vivo fat content of C. elegans. Loss of PEPT-1 decreases intestinal proton influx leading to a higher uptake of free fatty acids with fat accumulation whereas loss of NHX-2 causes intracellular acidification by the PEPT-1 mediated proton/dipeptide symport with an almost abolished uptake of fatty acids and a lean phenotype.

Postmenopausal hormone replacement therapy modifies skeletal muscle composition and function: a study with monozygotic twin pairs

We investigated whether long-term hormone replacement therapy (HRT) is associated with mobility and lower limb muscle performance and composition in postmenopausal women. Fifteen 54- to 62-yr-old monozygotic female twin pairs discordant for HRT were recruited from the Finnish Twin Cohort. Habitual (HWS) and maximal (MWS) walking speeds over 10 m, thigh muscle composition, lower body muscle power assessed as vertical jumping height, and maximal isometric hand grip and knee extension strengths were measured. Intrapair differences (IPD%) with 95% confidence intervals (CI) were calculated. The mean duration of HRT use was 6.9 +/- 4.1 yr. MWS was on average 7% (0.9 to 13.1%, P = 0.019) and muscle power 16% (-0.8 to 32.8%, P = 0.023) greater in HRT users than in their cotwins. Thigh muscle cross-sectional area tended to be larger (IPD% = 6%, 95% CI: -0.07 to 12.1%, P = 0.065), relative muscle area greater (IPD% = 8%, CI: 0.8 to 15.0%, P = 0.047), and relative fat area smaller (IPD% = -5%, CI: -11.3 to 1.2%, P = 0.047) in HRT users than in their sisters. There were no significant differences in maximal isometric strengths or HWS between users and nonusers. Subgroup analyses revealed that estrogen-containing therapies (11 pairs) significantly decreased total body and thigh fat content, whereas tibolone (4 pairs) tended to increase muscle cross-sectional area. This study showed that long-term HRT was associated with better mobility, greater muscle power, and favorable body and muscle composition among 54- to 62-yr-old women. The results indicate that HRT is a potential agent in preventing muscle weakness and mobility limitation in older women.

Association of body composition and β-cell function in obese females with normal glucose metabolism

Objective To explore the relationship between body composition and β-cell function in obese females with normal glucose metabolism. Methods Seventy-five obese women with normal blood glucose and without family history of diabetes were investigated. They were assigned to 4 groups based on body mass index (BMI). Body fat content was measured by dual-energy X-ray absorptiometry (DEXA), and intravenous glucose tolerance test (IVGTT) was performed. The acute insulin response (AIR), the area under the curve (AUC) of insulin (AUCins) and homeostasis model assessment (HOMA) for β-cell function (HOMA2-% B) were calculated. Insulin resistance index(HOMA2-IR) and the ratio of AUCins to AUC of glucose (AUCins/AUCglu) were calculated to assess insulin resistance. Results Women with higher BMI appeared to have more total body fat content and trunk fat content. The similar distribution was also found in other parameters, including the plasma glucose levels at 0 and 10 min, AUCins, AIR, AUCins/AUCglu and the difference of insulin level between 0 and 10 min [INS (10-0)] during IVGTF. AUCins, AIR, AUCins/AUCglu and [INS (10-0)] were positively correlated with the age, BMI,total body fat content and trunk fat content. After adjustment of age, the trunk fat content was independently associated with the AIR in a good linear manner. Conclusion The obese females show change in body composition with more trunk fat content. They show significant insulin resistance with compensated elevation of insulin secretion. Body composition assessment is a valid and more accurate method than BMI and waist circumference in predicting early damaged β-cell function in obese patients. Key words: Obesity; Body fat; Islet β-cell function; Insulin resistance

IDXA, Prodigy, and DPXL Dual-Energy X-ray Absorptiometry Whole-Body Scans: A Cross-Calibration Study

Purpose Total body fat, lean, and bone mineral content (BMC) in addition to regional fat and lean mass values for arms, legs, and trunk were compared across a pencil-beam (Lunar DPXL) and 2 fan-beam (GE Lunar Prodigy and GE Lunar iDXA) dual-energy X-ray absorptiometry (DXA) systems. Methods Subjects were a multiethnic sample of 99 healthy adult males (47%) and females (mean ± SD: age, 46.3 ± 16.9 yr; weight, 73.4 ± 16.6 kg; height, 167.6 ± 9.7 cm; body mass index, 26.0 ± 5.2 kg/m 2) who had whole-body scans performed within a 3-h period on the 3 systems. Repeated measures ANOVA was used to test the null hypothesis that the mean values for the 3 systems were equal. Translation equations between the methods were derived using regression techniques. Results Bone mineral content (BMC): For both genders, total BMC by iDXA was lower ( p ≤ 0.004) than the other systems. Lean: for males, iDXA was lower ( p ≤ 0.03) than the other systems for total, trunk, and arms. For females, DPXL estimated higher ( p < 0.001) lean mass compared with the other systems for total, trunk, and arms, but iDXA estimated greater legs lean mass. For both genders, all DPXL mean values were greater than Prodigy mean values ( p < 0.001). Fat: in females, all the 3 systems were different from each other for total, trunk, and legs ( p ≤ 0.04). For arms, DPXL and iDXA were higher than Prodigy ( p < 0.0004). For males, DPXL was less ( p < 0.001) for total body, trunk, and legs compared with the other 2 systems and greater than Prodigy only for arms ( p < 0.0007). These data were used to derive translation equations between systems. For several measurements, the differences between systems were related to gender. Conclusion For estimation of BMC and body composition, there was high agreement between all DXA systems ( R 2 = 0.85–0.99). Even so, cross-calibration equations should be used to examine data across systems to avoid erroneous conclusions.

Tracing the response of subcutaneous fat accumulation in two generations of males

The present study included 414 adolescent boys aged 11–17 years and their fathers who volunteered as subjects. All the subjects belonged to Punjabi speaking Khatri, an endogamous urban population residing in Delhi, India. A set of five skinfold thicknesses: biceps, triceps, subscapular, suprailiac and medial calf along with body weight and stature were taken on all the subjects to report the pattern of subcutaneous fat distribution and responsiveness of different skinfold sites to fat deposition with variation in total body fat content. It has been noticed that 16- and 17-year-old sons assumed the pattern of subcutaneous fat distribution of their fathers, which was in favour of trunkal fat. Responsiveness of the five skinfold sites towards deposition of fat varied from site to site in various age groups with suprailiac skinfold sites found to be the most responsive followed by subscapular site. The sensitivity of skinfold sites to fat deposition with increase in weight was found to be greater in middle aged men (fathers) than growing boys (adolescent sons).

Enhanced Fracture Detection With IDXA; Effect On Mild Fracture Identification

Total body fat, lean, and bone mineral content (BMC) in addition to regional fat and lean mass values for arms, legs, and trunk were compared across a pencil-beam (Lunar DPXL) and 2 fan-beam (GE Lunar Prodigy and GE Lunar iDXA) dual-energy X-ray absorptiometry (DXA) systems.Subjects were a multiethnic sample of 99 healthy adult males (47%) and females (mean ± SD: age, 46.3 ± 16.9 yr; weight, 73.4 ± 16.6 kg; height, 167.6 ± 9.7 cm; body mass index, 26.0 ± 5.2 kg/m2) who had whole-body scans performed within a 3-h period on the 3 systems. Repeated measures ANOVA was used to test the null hypothesis that the mean values for the 3 systems were equal. Translation equations between the methods were derived using regression techniques.Bone mineral content (BMC): For both genders, total BMC by iDXA was lower (p ≤ 0.004) than the other systems. Lean: for males, iDXA was lower (p ≤ 0.03) than the other systems for total, trunk, and arms. For females, DPXL estimated higher (p < 0.001) lean mass compared with the other systems for total, trunk, and arms, but iDXA estimated greater legs lean mass. For both genders, all DPXL mean values were greater than Prodigy mean values (p < 0.001).Fat: in females, all the 3 systems were different from each other for total, trunk, and legs (p ≤ 0.04). For arms, DPXL and iDXA were higher than Prodigy (p < 0.0004). For males, DPXL was less (p < 0.001) for total body, trunk, and legs compared with the other 2 systems and greater than Prodigy only for arms (p < 0.0007). These data were used to derive translation equations between systems. For several measurements, the differences between systems were related to gender.For estimation of BMC and body composition, there was high agreement between all DXA systems (R2 = 0.85–0.99). Even so, cross-calibration equations should be used to examine data across systems to avoid erroneous conclusions.

Hepatic Insulin Gene Therapy Normalizes Diurnal Fluctuation of Oxidative Metabolism in Diabetic BB/Wor Rats

Previous studies of hepatic insulin gene therapy (HIGT) focused on glycemic effects of insulin produced from hepatocytes. In this study, we extend the observations of glycemic control with metabolically regulated HIGT to include systemic responses and whole-body metabolism. An insulin transgene was administered with an adenoviral vector [Ad/(GlRE)(3)BP1-2xfur] to livers of BB/Wor rats made diabetic with polyinosinic polycytidilic acid (poly-I:C) (HIGT group), and results compared with nondiabetic controls (non-DM), and diabetic rats receiving different doses of continuous-release insulin implants (DM-low BG and DM-high BG). Blood glucose and growth normalized in HIGT, with lower systemic insulin levels, elevated glucagon, and increased heat production compared with non-DM. Minimal regulation of systemic insulin levels were observed with HIGT, yet the animals maintained normal switching from carbohydrate to lipid metabolism determined by respiratory quotients (RQs), and tolerated 24-hour fasts without severe hypoglycemia. HIGT did not restore serum lipids as we observed increased triglycerides (TGs) and increased free fatty acids, but reduced weight of visceral fat pads despite normal total body fat content and retroperitoneal fat depots. HIGT favorably affects blood glucose, normalizes metabolic switching in diabetic rats, and reduces intra-abdominal fat deposition.

Retinol Binding Protein-4 Elevation Is Associated with Serum Thyroid-Stimulating Hormone Level Independently of Obesity in Elderly Subjects with Normal Glucose Tolerance

Elevated levels of retinol binding protein-4 (RBP4) are positively correlated with insulin resistance, obesity, diabetes mellitus, and cardiovascular disease (CVD). Subclinical hypothyroidism (SCH) has also been associated with CVD; however, the factors linking SCH to CVD are not clear. The objective of the study was to evaluate risk factors for CVD in elderly patients grouped according to thyroid function. 217 subjects (> or =65 yr old) were randomly selected from a population and allocated to a euthyroid group (n = 177) and an SCH group (n = 40) on the basis of plasma concentrations of TSH and free T(4). We included subjects with normal glucose tolerance by a 75-g oral glucose tolerance test and subjects with impaired fasting glucose. We measured anthropometric parameters, levels of fasting glucose and insulin, hemoglobin A(1c), adiponectin, RBP4, lipid profiles, total body fat content, and the area of sc and visceral fat. The SCH group had higher RBP4 levels than the euthyroid group, irrespective of body mass index and fat content. Subcutaneous and visceral fat areas and total body fat percentage did not differ between groups and were not correlated with RBP4 level. Other CVD risk factors did not differ between groups. RBP4 level was positively correlated with TSH level (r = 0.241, P = 0.001) after adjustment for age, sex, and body mass index. Plasma RBP4 levels were associated with SCH independent of obesity in elderly subjects with normal glucose tolerance, indicating that RBP4 level could be used as an index of CVD risk in SCH.

Effect of energy restriction in interaction with genotype on the performance of growing rabbits I: Productive traits

The aim of this experiment was to study the effect of genotypes (rabbits selected for high or low body fat content) and level of DE intake (high, medium or low) at constant CP, CF, and EE intake on the performance of growing rabbits, separately and their interactions. Pannon White rabbits selected for high (HFAT) or low (LFAT) total body fat content were weaned at 4 weeks of age and fed one of three isocaloric diets (11.72, 11.60 and 11.66 MJ DE/kg diet, respectively). Diet one was fed ad libitum (treatment H), while diets 2 (treatment M) and 3 (treatment L) were fed at 90% and 80%, respectively of the ad libitum intake. Proportional to the reduction of feed intake the nutrient density of diets was increased (e.g. crude protein: 17.5, 19.8 and 21.9%; crude fibre: 12.9, 13.4 and 14.7%, respectively for the 3 diets). Genotype had a significant effect on feed conversion (3.26 and 3.02 g/g; P < 0.001; in groups HFAT and LFAT, respectively). With the reduction of the DE intake the daily weight gain and the body weight at 12 weeks of age decreased significantly (40.7, 38.5 and 33.7g/day, P < 0.001 and 2917, 2799 and 2527 g, P < 0.001; in groups H, M and L, respectively). On the contrary, the energy reduction had a positive effect on the feed conversion and on the mortality rate (3.29, 3.17 and 3.11 g/g, P < 0.05, and 29.5, 28.1 and 4.8%, P < 0.05; respectively). It is concluded that the genotype influenced mainly the feed conversion with higher nutrient demand for building fat than for muscle. The performance (weight gain, body weight and feed conversion) was determined by the digestible energy intake, independently of nutrient intake. The effect of reductions of DE intake was independent of the genotype (rabbits with higher or lower body fat content).

Genetics of obesity in humans: current issues.

During the last decade, we have begun to understand some of the reasons why people become obese as assessed by excess body mass for height or excess total body fat content. Obesity frequently aggregates in families. However, this familial resemblance is caused not only by genetic effects but also by lifestyle, and environmental and cultural factors. Thus the genetic heritability of the obesity phenotypes accounts for up to 50% of the age- and gender-adjusted phenotypic variances. These results have been confirmed by overfeeding and negative energy balance studies. The effects of single segregating genes can be detected only under the correct experimental conditions. Most scientists in the area believe that these genes can be identified and that the DNA mutations associated with human obesities will be uncovered. Indeed, association and linkage studies, quantitative trait loci and positional cloning research strategies, and transgenic mouse models are sufficiently promising to suggest that these aims can be achieved. A review of the evidence reported thus far reveals that there are already four loci with strong evidence of linkage with obesity phenotypes in humans.

Chronic Ethanol and Triglyceride Turnover in White Adipose Tissue in Rats: INHIBITION OF THE ANTI-LIPOLYTIC ACTION OF INSULIN AFTER CHRONIC ETHANOL CONTRIBUTES TO INCREASED TRIGLYCERIDE DEGRADATION

Chronic ethanol consumption disrupts whole-body lipid metabolism. Here we tested the hypothesis that regulation of triglyceride homeostasis in adipose tissue is vulnerable to long-term ethanol exposure. After chronic ethanol feeding, total body fat content as well as the quantity of epididymal adipose tissue of male Wistar rats was decreased compared with pair-fed controls. Integrated rates of in vivo triglyceride turnover in epididymal adipose tissue were measured using (2)H(2)O as a tracer. Triglyceride turnover in adipose tissue was increased due to a 2.3-fold increase in triglyceride degradation in ethanol-fed rats compared with pair-fed controls with no effect of ethanol on triglyceride synthesis. Because increased lipolysis accompanied by the release of free fatty acids into the circulation is associated with insulin resistance and liver injury, we focused on determining the mechanisms for increased lipolysis in adipose tissue after chronic ethanol feeding. Chronic ethanol feeding suppressed beta-adrenergic receptor-stimulated lipolysis in both in vivo and ex vivo assays; thus, enhanced triglyceride degradation during ethanol feeding was not due to increased beta-adrenergic-mediated lipolysis. Instead, chronic ethanol feeding markedly impaired insulin-mediated suppression of lipolysis in conscious rats during a hyperinsulinemic-euglycemic clamp as well as in adipocytes isolated from epididymal and subcutaneous adipose tissue. These data demonstrate for the first time that chronic ethanol feeding increased the rate of triglyceride degradation in adipose tissue. Furthermore, this enhanced rate of lipolysis was due to a suppression of the anti-lipolytic effects of insulin in adipocytes after chronic ethanol feeding.

Oscillations in total body fat content through life: an evolutionary perspective

Adipose tissue is considered an efficient system in which to store energy. Throughout life, the total amount of body fat exhibits some oscillations. Typically, there are three specific periods in which there are notable increases in fat mass, specifically early in life, during pregnancy and lactation, and with ageing. The existence of the first two peaks in fat mass has been interpreted, from an evolutionary point of view, as a beneficial manoeuvre to protect against the scarcity of energy to the offspring of the species. Nevertheless, the role of increasing body fat with ageing is more dubious. However, recent evidence suggests that the gain in adiposity in senescence may also be interpreted in the same evolutionary context. The aim of this review is to focus on the age-related changes in fat depots. In addition, an evolutionary explanation to the observed changes has been emphasized.

Relation of Body Mass Index to Outcome in Patients With Known or Suspected Coronary Artery Disease

Increased body mass index (BMI), a parameter of total body fat content, is associated with an increased mortality in the general population. However, recent studies have shown a paradoxic relation between BMI and mortality in specific patient populations. This study investigated the association of BMI with long-term mortality in patients with known or suspected coronary artery disease. In a retrospective cohort study of 5,950 patients (mean age 61 +/- 13 years; 67% men), BMI, cardiovascular risk markers (age, gender, hypertension, diabetes, current smoking, angina pectoris, old myocardial infarction, heart failure, hypercholesterolemia, and previous coronary revascularization), and outcome were noted. The patient population was categorized as underweight, normal, overweight, and obese based on BMI according to the World Health Organization classification. Mean follow-up time was 6 +/- 2.6 years. Incidences of long-term mortality in underweight, normal, overweight, and obese were 39%, 35%, 24%, and 20%, respectively. In a multivariate analysis model, the hazard ratio (HR) for mortality in underweight patients was 2.4 (95% confidence interval [CI] 1.7 to 3.7). Overweight and obese patients had a significantly lower mortality than patients with a normal BMI (HR 0.65, 95% CI 0.6 to 0.7, for overweight; HR 0.61, 95% CI 0.5 to 0.7, for obese patients). In conclusion, BMI is inversely related to long-term mortality in patients with known or suspected coronary artery disease. A lower BMI was an independent predictor of long-term mortality, whereas an improved outcome was observed in overweight and obese patients.

Upregulation of liver VLDL receptor and FAT/CD36 expression in LDLR−/− apoB100/100 mice fed trans-10,cis-12 conjugated linoleic acid

This study explores the mechanisms responsible for the fatty liver setup in mice fed trans-10,cis-12 conjugated linoleic acid (t10c12 CLA), hypothesizing that an induction of low density lipoprotein receptor (LDLR) expression is associated with lipid accumulation. To this end, the effects of t10c12 CLA treatment on lipid parameters, serum lipoproteins, and expression of liver lipid receptors were measured in LDLR(-/-) apoB(100/100) mice as a model of human familial hypercholesterolemia itself depleted of LDLR. Mice were fed t10c12 CLA over 2 or 4 weeks. We first observed that the treatment induced liver steatosis, even in the absence of LDLR. Mice treated for 2 weeks exhibited hypertriglyceridemia with high levels of VLDL and HDL, whereas a 4 week treatment inversely induced a reduction of serum triglycerides (TGs), essentially through a decrease in VLDL levels. In the absence of LDLR, the mRNA levels of other proteins, such as VLDL receptor, lipoprotein lipase, and fatty acid translocase, usually not expressed in the liver, were upregulated, suggesting their involvement in the steatosis setup and lipoprotein clearance. The data also suggest that the TG-lowering effect induced by t10c12 CLA treatment was attributable to both the reduction of circulating free fatty acids in response to the severe lipoatrophy and the high capacity of liver to clear off plasma lipids.

Abstracts for Poster Presentation

Abstracts for Poster Presentation

Influence of Body Fat Content and Distribution on Variation in Metabolic Risk

Several reports indicate that the body fat compartments, especially ip fat, predict metabolic risk better than total body fat. The objective of the study was to determine whether this can be confirmed and generalized throughout the population. A representative sample of 1934 Black and White women and men of the Dallas Heart Study participated in the study. We measured the fat in total body, trunk, and lower body with dual-energy x-ray absorptiometry and in abdominal compartments (sc, ip, and retroperitoneal) with magnetic resonance imaging. Other measurements included body mass index (BMI), waist circumference, blood pressure, plasma lipids, glucose, insulin (including homeostasis model), and C-reactive protein. In all groups, total body fat correlated positively with key metabolic risk factors, i.e. homeostasis model, triglyceride/high-density lipoprotein-cholesterol ratios, C-reactive protein, and blood pressure; however, it explained less than one third of the variability of all the risk factors. After adjustment for total body fat, truncal fat conferred additional positive correlation with risk factors. Furthermore, with multivariable regression analysis, ip fat conferred independent correlation with plasma lipids beyond a combination of other compartments including truncal fat. Still, except for insulin levels, all combinations including ip fat still explained less than one third of the variability in risk-factor levels. Conversely, lower body fat correlated negatively with risk factors; i.e. lower body fat appeared to offer some protection against risk factors. Body fat distribution has some influence on risk factors beyond total body fat content. Both waist circumference and BMI significantly predicted risk factors after adjustment for total body fat, and for clinical purposes, most of the predictive power for men was contained in waist circumference, whereas for women, BMI and waist circumference were similarly predictive. Finally, even though the correlations between combined body fat parameters and risk factors explained only a portion of the variation in the latter, the average number of categorical metabolic risk factors increased progressively with increasing obesity. Hence, obesity seemingly has more clinical impact than revealed in these correlative studies.

Maternal body composition in relation to infant birth weight and subcutaneous adipose tissue

Infant birth weight has increased recently, representing an obstetric and potentially a public health problem since high birth weight involves a risk of obesity later in life. Maternal nutritional status is important for fetal growth and therefore relationships between maternal body weight and composition v. birth weight and infant subcutaneous adipose tissue were investigated in twenty-three healthy women and their newborn infants using multiple and simple linear regression analysis. Furthermore, using previously published data for nineteen infants, it was demonstrated that an anthropometric method could provide useful estimates of the amount of subcutaneous adipose tissue. Birth weight was correlated with the maternal content of total body fat (TBF) both before pregnancy and in gestational week 32 and, together with gestational age at birth, TBF (%) before pregnancy explained 45% of the variation in birth weight. This figure was not increased when gestational gains in weight or TBF were added to the model. Furthermore, in infants, birth weight correlated with the amount of their subcutaneous adipose tissue. Together maternal TBF (%) and amount of subcutaneous adipose tissue in infants explained 61-63% of the variation in birth weight while the amount of infant subcutaneous adipose tissue alone explained only 55%. The maternal TBF content is likely to be important for the recent increase in birth weight. This factor probably causes a general augmentation in fetal growth rather than a specific stimulation of adipose tissue growth.

Effect of adipocyte β3-adrenergic receptor activation on the type 2 diabetic MKR mice

The antiobesity and antidiabetic effects of the beta3-adrenergic agonists were investigated on nonobese type 2 diabetic MKR mice after injection with a beta3-adrenergic agonist, CL-316243. An intact response to acute CL-316243 treatment was observed in MKR mice. Chronic intraperitoneal CL-316243 treatment of MKR mice reduced blood glucose and serum insulin levels. Hyperinsulinemic euglycemic clamps exhibited improvement of the whole body insulin sensitivity and glucose homeostasis concurrently with enhanced insulin action in liver and adipose tissue. Treating MKR mice with CL-316243 significantly lowered serum and hepatic lipid levels, in part due to increased whole body triglyceride clearance and fatty acid oxidation in adipocytes. A significant reduction in total body fat content and epididymal fat weight was observed along with enhanced metabolic rate in both wild-type and MKR mice after treatment. These data demonstrate that beta3-adrenergic activation improves the diabetic state of nonobese diabetic MKR mice by potentiation of free fatty acid oxidation by adipose tissue, suggesting a potential therapeutic role for beta3-adrenergic agonists in nonobese diabetic subjects.

Maximum oxygen uptake corrected for skeletal muscle mass accurately predicts functional improvements following exercise training in chronic heart failure

Skeletal muscle mass and peak oxygen uptake are important predictors of functional status and outcome in patients with stable chronic heart failure. To assess changes in skeletal muscle mass and peak oxygen uptake following an exercise training program. Thirty-six patients with moderate stable chronic heart failure were randomly allocated to either a bicycle ergometer (bike) or functional electrical muscle stimulators (FES) applied to quadriceps and gastrocnemius muscles to be used daily for six weeks. Dual-energy X-ray absorptionometry (DEXA) scanning was performed before and after training along with symptom limited cardiopulmonary exercise test, quadriceps strength and fatigue resistance, and 6-min walk test. Both exercise modalities resulted in improvements in treadmill exercise time, leg strength, 6-min walk test and peak oxygen uptake per kilogram of skeletal muscle. Despite significant improvements in functional capacity, there were no significant changes in body composition for total skeletal muscle mass, leg muscle mass or total body fat content. Skeletal muscle mass was strongly predictive of maximum oxygen uptake at baseline (r=0.61, p<0.001) and after exercise training (r=0.68, p<0.001). In moderate stable chronic heart failure, exercise training using bicycle ergometer or FES results in favourable qualitative rather than quantitative changes in skeletal muscle. Correction of maximum oxygen uptake for skeletal muscle mass rather than total body mass is a more sensitive measure of changes associated with exercise training.