Dual Energy X-Ray Absorptiometry Body Composition Reference Values from NHANES

In 2008 the National Center for Health Statistics released a dual energy x-ray absorptiometry (DXA) whole body dataset from the NHANES population-based sample acquired with modern fan beam scanners in 15 counties across the United States from 1999 through 2004. The NHANES dataset was partitioned by gender and ethnicity and DXA whole body measures of %fat, fat mass/height2, lean mass/height2, appendicular lean mass/height2, %fat trunk/%fat legs ratio, trunk/limb fat mass ratio of fat, bone mineral content (BMC) and bone mineral density (BMD) were analyzed to provide reference values for subjects 8 to 85 years old. DXA reference values for adults were normalized to age; reference values for children included total and sub-total whole body results and were normalized to age, height, or lean mass. We developed an obesity classification scheme by using estabbody mass index (BMI) classification thresholds and prevalences in young adults to generate matching classification thresholds for Fat Mass Index (FMI; fat mass/height2). These reference values should be helpful in the evaluation of a variety of adult and childhood abnormalities involving fat, lean, and bone, for establishing entry criteria into clinical trials, and for other medical, research, and epidemiological uses

To treat or not to treat: comparison of different criteria used to determine whether weight loss is to be recommended

Background: Excess body fat is a major risk factor for disease primarily due to its endocrine activity. In recent years several criteria have been introduced to evaluate this factor. Nevertheless, treatment need is currently assessed only on the basis of an individual's Body Mass Index (BMI), calculated as body weight (in kg) divided by height in m2. The aim of our study was to determine whether application of the BMI, compared to adiposity-based criteria, results in underestimation of the number of subjects needing lifestyle intervention. Methods: We compared treatment need based on BMI classification with four adiposity-based criteria: percentage body fat (%BF), considered both alone and in relation to metabolic syndrome risk (MS), waist circumference (WC), as an index of abdominal fat, and Body Fat Mass Index (BFMI, calculated as fat mass in kg divided by height in m2) in 63 volunteers (23 men and 40 women, aged 20 – 65 years). Results: According to the classification based on BMI, 6.3% of subjects were underweight, 52.4% were normal weight, 30.2% were overweight, and 11.1% were obese. Agreement between the BMI categories and the other classification criteria categories varied; the most notable discrepancy emerged in the underweight and overweight categories. BMI compared to almost all of the other adiposity-based criteria, identified a lower percentage of subjects for whom treatment would be recommended. In particular, the proportion of subjects for whom clinicians would strongly recommend weight loss on the basis of their BMI (11.1%) was significantly lower than those identified according to WC (25.4%, p = 0.004), %BF (28.6%, p = 0.003), and MS (33.9%, p = 0.002). Conclusion: The use of the BMI alone, as opposed to an assessment based on body composition, to identify individuals needing lifestyle intervention may lead to unfortunate misclassifications. Population-specific data on the relationships between body composition, morbidity, and mortality are needed to improve the diagnosis and treatment of at-risk individual

Association of Serum Albumin with Markers of Nutritional Status among HIV-Infected and Uninfected Rwandan Women

The objectives of this study are to address if and how albumin can be used as an indication of malnutrition in HIV infected and uninfected Africans.In 2005, 710 HIV-infected and 226 HIV-uninfected women enrolled in a cohort study. Clinical/demographic parameters, CD4 count, albumin, liver transaminases; anthropometric measurements and Bioelectrical Impedance Analysis (BIA) were performed. Malnutrition outcomes were defined as body mass index (BMI), Fat-free mass index (FFMI) and Fat mass index (FMI). Separate linear predictive models including albumin were fit to these outcomes in HIV negative and HIV positive women by CD4 strata (CD4>350,200-350 and <200 cells/µl).In unadjusted models for each outcome in HIV-negative and HIV positive women with CD4>350 cells/µl, serum albumin was not significantly associated with BMI, FFMI or FMI. Albumin was significantly associated with all three outcomes (p<0.05) in HIV+ women with CD4 200-350 cells/µl, and highly significant in HIV+ women with CD4<200 cells/µl (P<0.001). In multivariable linear regression, albumin remained associated with FFMI in women with CD4 count<200 cells/µl (p<0.01) but not in HIV+ women with CD4>200.While serum albumin is widely used to indicate nutritional status it did not consistently predict malnutrition outcomes in HIV- women or HIV+ women with higher CD4. This result suggests that albumin may measure end stage disease as well as malnutrition and should not be used as a proxy for nutritional status without further study of its association with validated measures

Obesity and hypertension in an Iranian cohort study; Iranian women experience higher rates of obesity and hypertension than American women

BACKGROUND: Once considered as the main public health problem in developed countries, obesity has become a major problem throughout the world and developing countries, like Iran, are joining the global obesity pandemic. We determined the prevalence of overweight, obesity, and hypertension in a large cohort of Iranians and compared age-adjusted rates with the rates in the US. METHODS: Golestan Cohort Study is a population-based study of 8,998 men and women, aged 35-81 years, from urban and rural areas. Anthropometric parameters were measured by interviewers. Prevalence rates were directly adjusted to the 2000 United States standard population. RESULTS: The age-adjusted prevalence rates of overweight (BMI ≥ 25 kg/m2) and obesity (BMI ≥ 30 kg/m2) in this Iranian population were 62.2% and 28.0%, respectively. Both overweight and obesity were more common in women than men. Age-adjusted prevalence of overweight was significantly higher in Iranian women compared to the American women (68.6% vs. 61.6%), while the age-adjusted prevalence of obesity is closer in these two populations (34.9% vs. 33.2%). Iranian men—compared to American men—had significantly lower age-adjusted prevalence of overweight (53.7% vs. 68.8%) and obesity (16.2% vs. 27.5%). Age-adjusted prevalence of hypertension was higher in Iranian women than American women (35.7% vs. 30.5%). Diabetes mellitus was reported in 6.2% of participants. Mean waist-to-hip ratio (WHR) among women was 0.96. Smoking rates in men and women were 33.2% and 2.2%, respectively. CONCLUSION: The prevalence of obesity, overweight, and hypertension in Iran is as high as the US. However, Iranian women are more obese than American women and Iranian men are less obese than their American counterparts. This discrepancy might be due to the low rate of smoking among Iranian women. Iranian women have higher mean WHR than what WHO has defined in 19 other populations

Relationship between chronic pain and cognition in cognitively intact older persons and patients with Alzheimer's disease; the need to control for mood

Background: Brain areas that are involved in cognition and mood also play a role in pain processing. Objective: The goal of the present study was to examine the relationship between chronic pain and cognition [executive functions (EF) and memory], while controlling for mood, in cognitively intact older persons and in patients with Alzheimer's disease (AD). Methods: Two groups of subjects participated: 20 older persons without dementia and 19 patients in an early stage of probable AD who suffered from arthrosis/arthritis. Pain intensity and pain affect were assessed by the Colored Analogue Scale for Pain Intensity and for Pain Affect, the Faces Pain Scale (FPS) and the Number of Words Chosen-Affective (NWC-A). Level of depression and anxiety were evaluated by questionnaires. EF and memory were assessed by neuropsychological tests. Results: The results show that significant correlations between specific cognitive functions, pain intensity and pain affect were lacking in the cognitively intact older persons. Cognition, in particular memory, appeared to be related to depressive symptoms. In contrast, a significant positive correlation was observed between EF, pain intensity and pain affect measured by the FPS in the AD group. Conclusions: Although older persons with depression were excluded, in studies on pain and cognition one should control for the presence of depressive symptoms in older persons with and without dementia. Copyright © 2008 S. Karger AG

Ghrelin, Sleep Reduction and Evening Preference: Relationships to CLOCK 3111 T/C SNP and Weight Loss

Circadian Locomotor Output Cycles Kaput (CLOCK), an essential element of the positive regulatory arm in the human biological clock, is involved in metabolic regulation. The aim was to investigate the behavioral (sleep duration, eating patterns and chronobiological characteristics) and hormonal (plasma ghrelin and leptin concentrations) factors which could explain the previously reported association between the CLOCK 3111T/C SNP and weight loss.We recruited 1495 overweight/obese subjects (BMI: 25-40 kg/m(2)) of 20-65 y. who attended outpatient obesity clinics in Murcia, in southeastern Spain. We detected an association between the CLOCK 3111T/C SNP and weight loss, which was particularly evident after 12-14 weeks of treatment (P = 0.038). Specifically, carriers of the minor C allele were more resistant to weight loss than TT individuals (Mean±SEM) (8.71±0.59 kg vs 10.4±0.57 kg) C and TT respectively. In addition, our data show that minor C allele carriers had: 1. shorter sleep duration Mean ± SEM (7.0±0.05 vs 7.3±0.05) C and TT respectively (P = 0.039), 2. higher plasma ghrelin concentrations Mean ± SEM (pg/ml) (1108±49 vs 976±47)(P = 0.034); 3. delayed breakfast time; 4. evening preference and 5. less compliance with a Mediterranean Diet pattern, as compared with TT homozygotes.Sleep reduction, changes in ghrelin values, alterations of eating behaviors and evening preference that characterized CLOCK 3111C carriers could be affecting weight loss. Our results support the hypothesis that the influence of the CLOCK gene may extend to a broad range of variables linked with human behaviors

Reference values for body composition and associations with blood pressure in Kenyan adults aged ≥50 years old

Objectives: To develop age and sex-specific centile reference curves for fat free mass (FFM) and fat mass (FM) adjusted for height in an adult Kenyan population and to investigate the association between FM, FFM and blood pressure (BP). Methods: Measures of body composition from bioimpedance analyses and BP were collected in 1,995 participants aged ≥50y in Nakuru County, Kenya. Reference curves were produced using the LMS method. Multivariable linear regression models were used to test the cross-sectional association between body composition indexes and BP. Results: The age and sex-specific reference curves for body composition (FMI and FFMI) confirm that FFMI is lower in both men and women with increasing age. FMI declines with age in women while among men the decline starts after 70 years. FFM was higher in men (47.4 ± 7.2 kg) than in women (38.8 ± 5.5 kg), while FM was lower in men (17.3 ± 8.1 kg) than in women (24.4 ± 10.2 kg). FMI, FFMI and BMI were all positively associated with systolic and diastolic BP, and after adjusting for body weight, FFMI remained positively associated with systolic BP and the FMI remained positively associated with diastolic BP. There was no evidence to suggest that FMI and FFMI were superior to measurement of BMI alone. Conclusion: These body composition reference curves provide normative data on body composition for older adults in Kenya. Further research should consider the prospective associations with health, including frailty-related outcomes

Treatment with a corticotrophin releasing factor 2 receptor agonist modulates skeletal muscle mass and force production in aged and chronically ill animals

<p>Abstract</p> <p>Background</p> <p>Muscle weakness is associated with a variety of chronic disorders such as emphysema (EMP) and congestive heart failure (CHF) as well as aging. Therapies to treat muscle weakness associated with chronic disease or aging are lacking. Corticotrophin releasing factor 2 receptor (CRF2R) agonists have been shown to maintain skeletal muscle mass and force production in a variety of acute conditions that lead to skeletal muscle wasting.</p> <p>Hypothesis</p> <p>We hypothesize that treating animals with a CRF2R agonist will maintain skeletal muscle mass and force production in animals with chronic disease and in aged animals.</p> <p>Methods</p> <p>We utilized animal models of aging, CHF and EMP to evaluate the potential of CRF2R agonist treatment to maintain skeletal muscle mass and force production in aged animals and animals with CHF and EMP.</p> <p>Results</p> <p>In aged rats, we demonstrate that treatment with a CRF2R agonist for up to 3 months results in greater extensor digitorum longus (EDL) force production, EDL mass, soleus mass and soleus force production compared to age matched untreated animals. In the hamster EMP model, we demonstrate that treatment with a CRF2R agonist for up to 5 months results in greater EDL force production in EMP hamsters when compared to vehicle treated EMP hamsters and greater EDL mass and force in normal hamsters when compared to vehicle treated normal hamsters. In the rat CHF model, we demonstrate that treatment with a CRF2R agonist for up to 3 months results in greater EDL and soleus muscle mass and force production in CHF rats and normal rats when compared to the corresponding vehicle treated animals.</p> <p>Conclusions</p> <p>These data demonstrate that the underlying physiological conditions associated with chronic diseases such as CHF and emphysema in addition to aging do not reduce the potential of CRF2R agonists to maintain skeletal muscle mass and force production.</p

Carbohydrate and torpor duration in hibernating golden-mantled ground squirrels ( Citellus lateralis )

Plasma glucose concentrations were increased in torpid Citellus lateralis to test the hypothesis that plasma glucose depletion stimulates periodic arousals from torpor during hibernation.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/47127/1/360_2004_Article_BF00689301.pd