Measurements of total and regional body composition in preschool children: A comparison of MRI,DXA, and anthropometric data

Objective:

There are clear sex differences in the distribution of visceral adipose tissue (VAT) and subcutaneous adipose tissue (SAT) in adults, with males having more VAT and less SAT than females. This study assessed whether these differences between the sexes were already present in preschool children. It also evaluated which measures of body composition were most appropriate for assessing abdominal obesity in this age group.

Design and Methods:

One‐hundred and five children (57 boys and 48 girls) participated in the study. Body composition was measured using dual‐energy X‐ray absorptiometry (DXA). Weight, height, and waist circumference (WC) were also recorded. Magnetic resonance imaging (MRI) of the entire abdomen using sixteen 10‐mm‐thick T₁‐weighted slices was performed in a subgroup of 48 children (30 boys and 18 girls); SAT and VAT volumes were measured using semiautomated segmentation.

Results:

Boys had significantly more VAT than girls (0.17 versus 0.10 l, P < 0.001). Results showed that VAT correlated significantly with all measurements of anthropometry (P < 0.01) after adjusting for SAT and for total fat mass measured with DXA. The mean limits of agreement between DXA and MRI regarding truncal FM were calculated to be ?11.4 (range ?17.8 to ?3.6), using a Bland–Altman plot.

Conclusion:

Sex differences in adipose tissue distribution are apparent at an early age. MRI is the best method with which to study abdominal fat distribution in young children.

     

Adipose tissue‐specific modulation of galectin expression in lean and obese mice: Evidence for regulatory function

Objective:

Galectins (Gal) exert many activities, including regulation of inflammation and adipogenesis. We evaluated modulation of Gal‐1, ‐3, ‐9 and ‐12 in visceral (VAT) and subcutaneous (SAT) adipose tissue in mice.

Design and Methods:

We used two mouse models of obesity, high‐fat diet induced obesity (DIO) and ob/ob mice. We also evaluated the response of Gal‐1 KO mice to DIO.

Results:

Both age and diet modulated expression of galectins, with DIO mice having higher serum Gal‐1 and Gal‐3 versus lean mice after 13‐17 weeks of high‐fat diet. In DIO mice there was a progressive increase in expression of Gal‐1 and Gal‐9 in SAT, whereas Gal‐3 increased in both VAT and SAT. Expression of Gal‐12 declined over time in VAT of DIO mice, similar to adiponectin. Obesity lead to increased production of Gal‐1 in adipocytes, whereas the increased Gal‐3 and Gal‐9 of obesity mostly derived from the stromovascular fraction. Expression of Gal‐12 was restricted to adipocytes. There was increased production of Gal‐3 and Gal‐9, but not Gal‐1, in CD11c^? and CD11c⁺ macrophages from VAT of DIO versus lean mice. Expression of Gal‐1, ‐3 and ‐12 in VAT and SAT of ob/ob mice followed a trend comparable to DIO mice. Rosiglitazone reduced serum Gal‐1, but not Gal‐3 and modulated expression of Gal‐3 in VAT and Gal‐9 and Gal‐12 in SAT of DIO mice. High‐fat feeding lead to increased adiposity in Gal‐1 KO versus WT mice, with loss of correlation between leptin and adiposity and no alterations in glucose and insulin levels.

Conclusions:

Obesity leads to differential modulation of Gal‐1, 3, 9 and 12 in VAT and SAT, with Gal‐1 acting as a modulator of adiposity.

     

VAT=TAAT‐SAAT: Innovative anthropometric model to predict visceral adipose tissue without resort to CT‐Scan or DXA

Objective:

To investigate whether a combination of a selected but limited number of anthropometric measurements predicts visceral adipose tissue (VAT) better than other anthropometric measurements, without resort to medical imaging.

Hypothesis:

Abdominal anthropometric measurements are total abdominal adipose tissue indicators and global measures of VAT and SAAT (subcutaneous abdominal adipose tissue). Therefore, subtracting the anthropometric measurement the more correlated possible with SAAT while being the least correlated possible with VAT, from the most correlated abdominal anthropometric measurement with VAT while being highly correlated with TAAT, may better predict VAT.

Design and Methods:

BMI participants' range was from 16.3 to 52.9 kg m^?2. Anthropometric and abdominal adipose tissues data by computed tomography (CT‐Scan) were available in 253 patients (18‐78 years) (CHU Nord, Marseille) and used to develop the anthropometric VAT prediction models.

Results:

Subtraction of proximal thigh circumference from waist circumference, adjusted to age and/or BMI, predicts better VAT (Women: VAT = 2.15 × Waist C ? 3.63 × Proximal Thigh C + 1.46 × Age + 6.22 × BMI ? 92.713; R² = 0.836. Men: VAT = 6 × Waist C ? 4.41 × proximal thigh C + 1.19 × Age ? 213.65; R² = 0.803) than the best single anthropometric measurement or the association of two anthropometric measurements highly correlated with VAT. Both multivariate models showed no collinearity problem. Selected models demonstrate high sensitivity (97.7% in women, 100% in men). Similar predictive abilities were observed in the validation sample (Women: R² = 76%; Men: R² = 70%). Bland and Altman method showed no systematic estimation error of VAT.

Conclusion:

Validated in a large range of age and BMI, our results suggest the usefulness of the anthropometric selected models to predict VAT in Europides (South of France).

     

Effects of increased meal frequency on fat oxidation and perceived hunger

Objective:

Consuming smaller, more frequent meals is often advocated as a means of controlling body weight, but studies demonstrating a mechanistic effect of this practice on factors associated with body weight regulation are lacking. The purpose of this study was to compare the effect of consuming three (3M) vs. six meals (6M) per day on 24‐h fat oxidation and subjective ratings of hunger.

Design and Methods:

Lean (body mass index <25 kg/m²) subjects (7M, 8F) were studied in a whole‐room calorimeter on two occasions in a randomized cross‐over design. Subjects were provided isoenergetic, energy balanced diets with a 1‐ to 2‐week washout between conditions. Hunger, fullness, and “desire to eat” ratings were assessed throughout the day using visual analog scales and quantified as area under the curve (AUC).

Results:

There were no differences (P < 0.05) in 24‐h energy expenditure (8.7 ± 0.3 vs. 8.6 ± 0.3 mj d^?1), 24‐h respiratory quotient (0.85 ± 0.01 vs. 0.85 ± 0.01), or 24‐h fat oxidation (82 ± 6 vs. 80 ± 7 g day^‐1) between 3M and 6M, respectively. There was no difference in fullness 24‐h AUC, but hunger AUC (41850 ± 2255 vs. 36612 ± 2556 mm.24 h, P = 0.03) and “desire to eat” AUC (47061 ± 1791 vs. 41170 ± 2574 mm.24 h, P = 0.03) were greater during 6M than 3M.

Conclusion:

We conclude that increasing meal frequency from three to six per day has no significant effect on 24‐h fat oxidation, but may increase hunger and the desire to eat.

     

Sympathetic support of energy expenditure and sympathetic nervous system activity after gastric bypass surgery

Objective:

This study was designed to determine how gastric bypass affects the sympathetically‐mediated component of resting energy expenditure (REE) and muscle sympathetic nerve activity (MSNA).

Design and Methods:

We measured REE before and after beta‐blockade in seventeen female subjects approximately three years post‐gastric bypass surgery and in nineteen female obese individuals for comparison. We also measured MSNA in a subset of these subjects.

Results:

The gastric bypass subjects had no change in REE after systemic beta‐blockade, reflecting a lack of sympathetic support of REE, in contrast to obese subjects where REE was reduced by beta‐blockade by approximately 5% (P < 0.05). The gastric bypass subjects, while still overweight (BMI = 29.3 vs 38.0 kg·m^?2 for obese subjects, P < 0.05), also had significantly lower MSNA compared to obese subjects (10.9 ± 2.3 vs. 21.9 ± 4.1 bursts·min^?1, P < 0.05). The reasons for low MSNA and a lack of sympathetically mediated support of REE after gastric bypass are likely multifactorial and may be related to changes in insulin sensitivity, body composition, and leptin, among other factors.

Conclusions:

These findings may have important consequences for the maintenance of weight loss after gastric bypass. Longitudinal studies are needed to further explore the changes in sympathetic support of REE and if changes in MSNA or tissue responsiveness are related to the sympathetic support of REE.

     

Effect of the mediterranean diet with and without weight loss on markers of inflammation in men with metabolic syndrome

Objective:

Intervention studies on the Mediterranean Diet (MedDiet) have often led to weight loss, which may have contributed to the purported anti‐inflammatory effects of the MedDiet. To investigate the impact of the MedDiet consumed under controlled feeding conditions before (?WL) and after weight loss (+WL) on markers of inflammation in men with metabolic syndrome (MetS).

Design and Methods:

Subjects (N = 26, male, 24–65 years) with MetS first consumed a North American control diet for 5 weeks followed by a MedDiet for 5 weeks both in isocaloric feeding conditions. After a 20‐week weight loss period in free‐living conditions (10 ± 3% reduction in body weight, P < 0.01), participants consumed the MedDiet again under isocaloric‐controlled feeding condition for 5 weeks.

Results:

MedDiet ? WL significantly reduced plasma C‐reactive protein (CRP) concentrations (?26.1%, P = 0.02) and an arbitrary inflammatory score (?9.9%, P = 0.01) that included CRP, interleukin‐6 (IL‐6), IL‐18, and tumor necrosis factor‐α (TNF‐α) compared with the control diet. The MedDiet + WL significantly reduced plasma IL‐6 (?20.7%) and IL‐18 (?15.6%, both P ≤ 0.02) concentrations compared with the control diet but had no further significant impact on plasma CRP concentration. Participants with a reduction in waist circumference ≥8.5 cm after MedDiet + WL showed significantly greater reductions in inflammation markers than those with a change in waist circumference <8.5 cm.

Conclusions:

Thus, consuming MedDiet even in the absence of weight loss significantly reduces inflammation. However, the degree of waist circumference reduction with weight loss magnifies the impact of the MedDiet on other markers of inflammation associated with MetS in men.

     

Prediction of measured weight from self‐reported weight was not improved after stratification by body mass index

Objective:

Self‐reported weight may underestimate measured weight. Researchers have tried to reduce the error using statistical models to predict weight from self‐reported weight. We investigate whether deriving equations within separate BMI categories improves the prediction of weight compared with an equation derived regardless of an individual's BMI.

Design and Methods:

The analysis included self‐reported and measured data from 20,536 individuals participating in the EPIC‐Norfolk study. In a derivation set (n = 15,381) two approaches were used to predict weight from self‐reported weight: (1) using a linear regression model with measured weight as outcome and self‐reported weight and age as predictors, and (2) using the same model fit separately within 3 strata defined by BMI (< 25, 25‐30, ≥30 kg m^?2). The performance of these approaches was assessed in a validation set (n = 5,155). Measured weight was compared to self‐reported weight and predicted weight.

Results:

Self‐reported weight underestimated measured weight (P < 0.0001): mean difference ?1.2 ± 3.1 kg (men), ?1.3 ± 2.5 kg (women). Underestimation was greater in obese participants (P < 0.0001). Predicted weight using approach 1 was not significantly different from measured weight (P < 0.05). However, in individuals with BMI < 25 kg m^?2, weight was overestimated in men (0.90 ± 3.87 kg) and women (0.57 ± 2.06 kg), but underestimated in overweight (?0.29 ± 3.58, ?0.20 ± 2.62 kg) and obese (?1.46 ± 5.05 kg, ?0.73 ± 3.54 kg) men and women.

Conclusions:

Using separate prediction equations in strata of BMI did not further improve prediction of weight. In conclusion, predicted weight was closer to measured weight compared with self‐reported weight, but using equations derived in strata of BMI did not further improve the prediction and are not recommended for prediction of weight.

     

Normal vs. high‐protein weight loss diets in men: Effects on body composition and indices of metabolic syndrome

Objective:

This study assessed the effectiveness of a prescribed weight‐loss diet with 0.8 versus 1.4 g protein·kg^?1 day^?1 on changes in weight, body composition, indices of metabolic syndrome, and resting energy expenditure (REE) in overweight and obese men.

Design and Methods:

Men were randomized to groups that consumed diets containing 750 kcal day^?1 less than daily energy needs for weight maintenance with either normal protein (NP, n = 21) or higher protein (HP, n = 22) content for 12 weeks. The macronutrient distributions of the NP and HP diets were 25:60:15, and 25:50:25 percent energy from fat, carbohydrate, and protein, respectively. Assessments were made pre and post intervention. The subjects were retrospectively subgrouped into overweight and obese groups.

Results and Conclusion:

Both diet groups lost comparable body weight and fat. The HP group lost less lean body mass than the NP group (?1.9 ± 0.3 vs. ?3.0 ± 0.4 kg). The effects of protein and BMI status on lean body mass loss were additive. The reductions in total cholesterol, HDL‐C, triacylglycerol, glucose, and insulin, along with LDL‐C, total cholesterol‐to‐HDL‐C ratio, and HOMA‐IR, were not statistically different between NP and HP. Likewise, macronutrient distributions of the diet did not affect the reductions in REE, and blood pressure. In conclusion, energy restriction effectively improves multiple clinical indicators of cardiovascular health and glucose control, and consumption of a higher‐protein diet and accomplishing weight loss when overweight versus obese help men preserve lean body mass over a short period of time.

     

High‐normal tsh values in obesity: Is it insulin resistance or adipose tissue's guilt?

Objective:

Clinical evidences reported subclinical alterations of thyroid function in obesity, although the relationship between thyroid status and obesity remains unclear. We cross‐sectionally investigated the influence of metabolic features on hypothalamic–pituitary–thyroid axis in obesity.

Design and Methods:

We enrolled 60 euthyroid subjects with no history of type 2 diabetes mellitus and assessed the relationship of thyroid function with insulin resistance, measured using euglycemic clamp, and abdominal fat volume, quantified by computed tomography scan (CT scan). Thyroid stimulating hormone (TSH) correlated with BMI (r = 0.46; P = 0.02), both visceral (r = 0.58; P = 0.02) and subcutaneous adipose tissue volumes (r = 0.43; P = 0.03) and insulin resistance (inverse relationship with insulin sensitivity–glucose uptake: r = ?0.40; P = 0.04).

Results:

After performing multivariate regression, visceral adipose tissue volume was found to be the most powerful predictor of TSH (β = 3.05; P = 0.01), whereas glucose uptake, high‐density lipoprotein (HDL) cholesterol, low‐density lipoprotein (LDL) cholesterol, subcutaneous adipose tissue volume, and triglycerides were not. To further confirm the hypothesis that high‐normal TSH values could be dependent on adipose tissue, and not on insulin resistance, we restricted our analyses to moderately obese subjects' BMI ranging 30‐35 kg/m². This subgroup was then divided as insulin resistant and insulin sensitive according to the glucose uptake (≤ or >5 mg·kg^?1·min^?1, respectively). We did not find any statistical difference in TSH (insulin resistant: 1.62 ± 0.65 µU/ml vs. insulin sensitive: 1.46 ± 0.48; P = not significant) and BMI (insulin resistant: 32.2 ± 1.6 kg/m² vs. insulin sensitive: 32.4 ± 1.4; P = not significant), thus confirming absence of correlation between thyroid function and insulin sensitivity per se.

Conclusion:

Our study suggests that the increase in visceral adipose tissue is the best predictor of TSH concentration in obesity, independently from the eventual concurrent presence of insulin resistance.

     

Cardiometabolic risks during anabolic hormone supplementation in older men

Objective:

To determine the cardiometabolic risks of testosterone and growth hormone (GH) replacement therapy to youthful levels during aging.

Design and Methods:

A double‐masked, partially placebo controlled study in 112 men 65‐90 years‐old was conducted. Transdermal testosterone (5 g vs. 10 g/day) using a Leydig Cell Clamp and subcutaneous recombinant GH (rhGH) (0 vs. 3 vs. 5 μg/kg/day) were administered for 16‐weeks. Measurements included testosterone and IGF‐1 levels, body composition by DEXA, and cardiometabolic risk factors (upper body fat, blood pressure, insulin sensitivity, fasting triglycerides, HDL‐cholesterol, and serum adiponectin) at baseline and after 16 weeks of treatment.

Results:

Some cardiometabolic factors improved (total and trunk fat, triglycerides, HDL‐cholesterol) and others worsened (systolic blood pressure, insulin sensitivity index [QUICKI], adiponectin). Cardiometabolic risk composite scores (CRCSs) improved (?0.69 ± 1.55, P < 0.001). In multivariate analyses, QUICKI, triglycerides, and HDL‐cholesterol contributed 33%, 16%, and 14% of the variance in CRCS, respectively. Pathway analyses indicated that changes in fat and lean mass were related to individual cardiometabolic variables and CRCS in a complex manner. Changes in BMI, reflecting composite effects of changes in fat and lean mass, were more robustly associated with cardiometabolic risks than changes in fat mass or LBM individually.

Conclusions:

Testosterone and rhGH administration was associated with diverse changes in individual cardiometabolic risk factors, but in aggregate appeared not to worsen cardiometabolic risk in healthy older men after 4‐months. The long‐term effects of these and similar anabolic therapies on cardiovascular events should be investigated in populations with greater functional limitations along with important health disabilities including upper body obesity and other cardiometabolic risks.

     

Liver fat and SHBG affect insulin resistance in midlife women: The Study of Women's Health Across the Nation (SWAN)

Objective:

The liver is an insulin‐responsive organ that contributes significantly to both whole body insulin sensitivity and availability of sex steroids through the production of sex hormone binding globulin (SHBG). Our objective was to explore whether lower SHBG was associated with ectopic liver fat and mediated its effect on insulin resistance in The Study of Women's Health Across the Nation (SWAN).

Design and Methods:

A subset of midlife African American and Caucasian women from SWAN (n = 208; 50.9 ± 0.18 yrs; 71% Caucasian) had computed tomography scans to quantify visceral, subcutaneous and liver fat. Blood samples were collected and assayed for hormonal and metabolic markers.

Results:

The cohort, while overweight, was generally healthy, and both liver fat and SHBG were unaffected by menopausal stage or race. Both higher liver fat and lower SHBG levels were significantly associated with higher insulin concentrations after adjustment for adiposity (r = ?0.25, P < 0.001 and r = ?0.18, P = 0.01). SHBG and liver fat had additive effects on insulin concentrations such that women with the lowest SHBG and the highest fat levels had the highest values (interaction P = 0.09). The association between SHBG and insulin was more apparent among women with fattier livers. SHBG and liver fat appear to have independent effects on insulin levels as adjustment for each other did not diminish the strength of either association (P = 0.023 and 0.001 respectively).

Conclusion:

These results confirmed the strong independent associations between increased liver fat and decreased SHBG with increased metabolic risk in midlife women. Further these data underscore the need for additional research into the role of liver fat in modifying SHBG's influence on insulin levels.

     

Using facebook and text messaging to deliver a weight loss program to college students

Objective:

Between 31 and 35% of the college‐aged population is overweight or obese, yet few weight loss trials for this population have been conducted. This study examined the feasibility, acceptability, and initial efficacy of a technology‐based 8‐week weight loss intervention among college students.

Design and Methods:

Students (N = 52) were randomly assigned to one of the three arms: Facebook (n = 17); Facebook Plus text messaging and personalized feedback (n = 18); Waiting List control (n = 17), with assessments at 4 weeks and 8 weeks (post‐treatment). Participants were 20.47 ± 2.19 years old, 86.45 ± 17.11 kg, with a body mass index of 31.36 ± 5.3 kg/m². Participants were primarily female (86.5%), and the sample was racially diverse (57.7% Caucasian, 30.8% African American, 5.8% Hispanic, and 5.7% other races).

Results:

The primary outcome was weight loss after 8 weeks (post‐treatment); 96.0% of the participants completed this assessment. At 8 weeks, the Facebook Plus group had significantly greater weight loss (?2.4 ± 2.5 kg) than the Facebook (?0.63 ± 2.4 kg) and Waiting List (?0.24 ± 2.6 kg) (both Ps < 0.05). Weight change at 8 weeks was not significantly different between the Facebook and Waiting List groups.

Conclusions:

Results show preliminary efficacy and acceptability of the two active intervention arms (97.0% found the program helpful, 81.3% found the videos/handouts helpful, and 100% would recommend the program to others). Results indicate the potential for an innovative weight loss intervention that uses technology platforms (Facebook and text messaging) that are frequently used and already integrated into the cultural life of college students.

     

Utility‐based quality of life associated with overweight and obesity: The australian diabetes,obesity, and lifestyle study

Objective:

This study aimed to estimate utility‐based quality of life (UQoL) differences between healthy body weight and excess body weight categories.

Design and Methods:

Cross‐sectional analysis of 10,959 adults, participating in baseline data collection of the nationally representative Australian Diabetes, Obesity, and Lifestyle (AusDiab) Study was undertaken. Height and weight were measured by trained personnel. Body weight categories were assigned as healthy weight, overweight, and obesity subclasses I, II and III. UQoL was assessed using the SF‐6D, which captures physical functioning, role limitation, social functioning, pain, mental health, and vitality on a score of 0.00–1.00 (worst‐best). The relationship between body weight categories and UQoL was assessed using linear regression, adjusting for age, sex, education, and smoking.

Results:

Relative to the healthy weight group (mean UQoL score 0.77), mean adjusted UQoL differences (95% confidence intervals) were 0.001 (?0.008, 0.010) for overweight, ?0.012 (?0.022, ?0.001) for class‐I obese, ?0.020 (?0.041, 0.001) for class‐II obese, and ?0.069 (?0.099, ?0.039) for class‐III obese groups. Adding metabolic syndrome markers to the covariates had little impact on these differences.

Conclusion:

Results confirmed an inverse dose–response relationship between body weight and UQoL in this study of Australian adults. This highlights the need to incorporate UQoL measures which are sensitive to the subclasses of obesity when evaluating obesity interventions.

     

The species–area relationship does not have an asymptote!

Aim

To attack a widespread myth.

Location

World‐wide.

Methods

Simple mathematical logical and empirical examples.

Results

As both species and area are finite and non‐negative, the species–area relationship is limited at both ends. The log species–log area relationship is normally effectively linear on scales from about 1 ha to 10⁷ km². There are no asymptotes. At the intercontinental scale it may get steeper; at small scales it may in different cases get steeper or shallower or maintain its slope.

Main conclusion

The species–area relationship does not have an asymptote.

     

Body adiposity index assess body fat with high accuracy in nondialyzed chronic kidney disease patients

Objective:

High body fat (BF) is an alarming condition that also affects nondialyzed chronic kidney disease (CKD) patients. Distinct methods are used to evaluate BF; however, in CKD population it remains unclear which one is more reliable showing high accuracy. Dual‐energy X‐ray absorptiometry (DXA), used as reference method to estimate adiposity, is expensive and time consuming to be applied in clinical settings. Recently, a new body adiposity index (BAI), that estimates BF from easily accessible measures, was validated in the general population. The aim of this study was to evaluate which simple and practical method, routinely used to estimate BF, shows the highest accuracy compared with DXA, in nondialyzed CKD patients.

Design and Methods:

In this cross‐sectional study BF was estimated by DXA, bioelectrical impedance analysis (BIA), anthropometry (ANTHRO), and BAI. Serum leptin levels were determined.

Results:

Studied patients (n = 134) were 55% males, 54% overweight/obese, and 64.9 ± 12.5 years old, with estimated glomerular filtration rate (eGFR) = 29.0 ± 12.7 ml/min. The correlation coefficient was higher between DXA vs. ANTHRO (r = 0.76) and BAI (r = 0.61) than with BIA (r = 0.57), after adjusting for gender, age, and eGFR (P < 0.0001). Therefore, the Lin's concordance correlation coefficient and Bland–Altman plots were performed to measure the accuracy (C_b) between DXA with both ANTHRO and BAI. A higher accuracy (C_b = 0.82) and lower mean difference (?3.4%) was observed for BAI than for ANTHRO (C_b = 0.61; ?8.4%). Leptin levels correlated (P < 0.0001) with DXA (r = 0.56) and BAI (r = 0.59).

Conclusions:

These findings suggest that BAI estimates BF with high accuracy in nondialyzed CKD patients and may be helpful in the treatment of this population with increased BF.

     

Serum hemorphin‐7 levels are decreased in obesity

Objective:

Hemorphin peptides exhibit biological activities that interfere with the endorphin system, the inflammatory response, and blood‐pressure control. VV‐hemorphin‐7 and LVV‐hemorphin‐7 peptides exert a hypotensive effect, in particular, by inhibiting the renin–angiotensin system. Furthermore, levels of circulating hemorphin‐7 peptides have been found to be decreased in diseases such as type 1 and type 2 diabetes.

Design and Methods:

Because type 2 diabetes and obesity share common features, such as insulin resistance, microinflammation, high glomerular‐filtration rate (GFR), and cardiovascular risk, we evaluated serum VV‐hemorphin‐7 like immunoreactivity (VVH7‐i.r.) levels, using an enzyme‐linked immunosorbent assay method, on a group of 54 obese subjects without diabetes or hypertension, compared with a group of 33 healthy normal‐weight subjects.

Results:

Circulating VVH7‐i.r. levels were significantly decreased in the obese group compared with the control group (1.98 ± 0.19 vs. 4.86 ± 0.54 µmol/l, respectively, P < 0.01), and a significant negative correlation between VVH7‐i.r. and diastolic blood pressure (DBP) was found in obese patients (r = ?0.35, P = 0.011). There was no significant correlation between VVH7‐i.r. level and insulin resistance, metabolic syndrome, or GFR.

Conclusions:

The decreased serum hemorphin‐7 found in obese subjects, as in diabetes, may contribute to the development of hypertension and to the cardiovascular risk associated with these metabolic diseases.

     

Oncoretroviral gene transfer to NOD/SCID repopulating cells using three different viral envelopes

Background

The aim of this study was to investigate gene transfer to human umbilical cord blood (CB) CD34⁺/CD38^low and NOD/SCID repopulating cells using oncoretroviral vectors and to compare the transduction efficiency using three different viral envelopes.

Methods

CB cells were transduced on Retronectin using an MSCV‐based vector with the gene for GFP (MGIN), which was packaged into three different cell lines giving different envelopes: PG13‐MGIN (GALV), 293GPG‐MGIN (VSV‐G) or AM12‐MGIN (amphotropic).

Results

Sorted CD34⁺/CD38^low cells were efficiently transduced after 3 days of cytokine stimulation and the percentage of GFP‐positive cells was 61.8±6.6% (PG13‐MGIN), 26.9±3.5% (293GPG‐MGIN), and 39.3±4.8% (AM12‐MGIN). For transplantation experiments, CD34⁺ cells were pre‐stimulated for 2 days before transduction on Retronectin preloaded with vector and with the addition of 1/10th volume of viral supernatant on day 3. On day 4, the expanded equivalent of 2.5×10⁵ cells was injected into irradiated NOD/SCID mice. All three pseudotypes transduced NOD/SCID repopulating cells (SRCs) equally well in the presence of serum, but engraftment was reduced when compared with freshly thawed cells. Simultaneous transduction with all three vector pseudotypes increased the gene transfer efficiency to SRCs but engraftment was significantly impaired. There were difficulties in producing amphotropic vectors at high titers in serum‐free medium and transduction of CD34⁺ cells using VSV‐G‐pseudotyped vectors under serum‐free conditions was very inefficient. In contrast, transduction with PG13‐MGIN under serum‐free conditions resulted in the maintenance of SRCs during transduction, high levels of engraftment (29.3±6.6%), and efficient gene transfer to SRCs (46.2±4.8%).

Conclusions

The best conditions for transduction and engraftment of CB SRCs were obtained with GALV‐pseudotyped vectors using serum‐free conditions. Copyright © 2002 John Wiley & Sons, Ltd.

     

Specific inhibition of epithelial Na+ channels by antisense oligonucleotides for the treatment of Na+ hyperabsorption in cystic fibrosis

Background

Cystic fibrosis (CF) respiratory epithelia are characterized by a defect Cl^? secretion and an increased Na⁺ absorption through epithelial Na⁺ channels (ENaC). The present study aimed to find an effective inhibitor of human ENaC with respect to replacing amiloride therapy for CF patients. Therefore, we developed specific antisense oligonucleotides (AON) that efficiently suppress Na⁺ hyperabsorption by inhibiting the expression of the α‐ENaC subunit.

Methods

We heterologously expressed ENaC in oocytes of Xenopus laevis for mass screening of AON. Additionally, primary cultures of human nasal epithelia were transfected with AON and were used for Ussing chamber experiments, as well as biochemical and fluorescence optical analyses.

Results

Screening of several AON by co‐injection or sequential microinjection of AON and ENaC mRNA in X. laevis oocytes led to a sustained decrease in amiloride‐sensitive current and conductance. Using primary cultures of human nasal epithelia, we show that AON effectively suppress amiloride‐sensitive Na⁺ absorption mediated by ENaC in CF and non‐CF tissues. In western blot experiments, it could be shown that the amount of ENaC protein is effectively reduced after AON transfection.

Conclusions

Our data comprise an initial step towards a preclinical test with AON to reduce Na⁺ hyperabsorption in CF epithelia. Copyright © 2009 John Wiley & Sons, Ltd.

     

Lifestyle intervention and/or statins for the reduction of C‐reactive protein in type 2 diabetes: From the look AHEAD study

Objective:

Cardiovascular risk remains high despite statin use. Overweight/obese diabetic persons usually have normal/low LDL‐cholesterol but high C‐reactive protein (CRP) levels. We aimed to examine the effects of intensive lifestyle intervention for weight loss (ILI) on CRP levels in overweight/obese diabetic individuals by statin use.

Design and Methods:

Look AHEAD was a randomized trial in overweight/obese type 2 diabetic individuals testing whether ILI would reduce cardiovascular mortality, when compared to usual care. CRP changes in 1,431 participants with biomarker levels, who remained on or off statin treatment for 1 year, were evaluated.

Results:

The reduction in CRP levels with ILI at 1 year in men and women on statins was ?44.9 and ?42.3%, respectively, compared to ?13.7 and ?21.0% for those on statins and usual care (P < 0.0001). At 1 year, median CRP levels were: 1.8 mg L^?1 in participants randomized to ILI on statin therapy; 2.6 mg L^?1 for those on statins randomized to usual care and 2.9 mg L^?1 for participants not on statins but randomized to ILI. Weight loss was associated with 1‐year CRP reduction (P < 0.0001) in statin and nonstatin users.

Conclusions:

Our findings suggest that in overweight/obese diabetic persons, ILI and statin therapy may have substantial additive anti‐inflammatory benefits.

     

Associations of testosterone and sex hormone binding globulin with adipose tissue hormones in midlife women

Objective:

Regulators of adipose tissue hormones remain incompletely understood, but may include sex hormones. As adipose tissue hormones have been shown to contribute to numerous metabolic and cardiovascular disorders, understanding their regulation in midlife women is of clinical importance. Therefore, we assessed the associations between testosterone (T) and sex hormone binding globulin (SHBG) with leptin, high molecular weight (HMW) adiponectin, and the soluble form of the leptin receptor (sOB‐R) in healthy midlife women.

Design and Methods:

Cross‐sectional analyses were performed using data from 1,881 midlife women (average age 52.6 (±2.7) years) attending the sixth Annual follow‐up visit of the multiethnic Study of Women's Health Across the Nation.

Results:

T was weakly negatively associated with both HMW adiponectin and sOB‐R (r = ?0.12 and r = ?0.10, respectively; P < 0.001 for both), and positively associated with leptin (r = 0.17; P < 0.001). SHBG was more strongly and positively associated with both HMW adiponectin and sOB‐R (r = 0.29 and r = 0.24, respectively; P < 0.001 for both), and more strongly and negatively associated with leptin (r = ?0.27; P < 0.001). Adjustment for fat mass, insulin resistance, or waist circumference only partially diminished associations with HMW adiponectin and sOB‐R, but attenuated associations with leptin. In conclusion, in these midlife women, lower SHBG values, and to a lesser extent, higher T levels, were associated with lower, or less favorable, levels of adiponectin and sOB‐R, independent of fat mass.

Conclusions:

These data suggest that variation in these adipose hormones resulting from lower SHBG levels, and possibly, though less likely, greater androgenicity, may contribute to susceptibility for metabolic and cardiovascular outcomes during midlife in women.