Predicting muscular strength using demographics, skeletal dimensions, and body composition measures

The purpose of this study was to develop an equation to predict strength for seven common resistance training exercises using anthropometric and demographic measures. One-hundred forty-seven healthy adults (74 males, 73 females, 35 ± 12 yr, 174 ± 10 cm, 88 ± 19 kg) volunteered to participate. Body composition values (regional/total) and body dimensions were assessed using dual-energy x-ray absorptiometry (DEXA). Subjects underwent the following maximal strength assessments: Leg Press, Chest Press, Leg Curl, Lat Pulldown, Leg Extension, Triceps Pushdown, and Biceps Curl. Multiple linear regression with stepwise removal was used to determine the best model to predict maximal strength for each exercise. Independent predictor variables identified (p < 0.05) were height (cm); weight (kg); BMI; age; sex (0 = F,1 = M); regional lean masses (LM,kg); fat mass (FM,kg); fat free mass (FFM,kg); percent fat (%BF); arm, leg, and trunk lengths (AL, LL, TL; cm); and shoulder width (SW,cm). Analyses were performed with and without regional measures to accommodate scenarios where DEXA is unavailable. All models presented were significant (p < 0.05, R² = 0.68–0.83), with regional models producing the greatest accuracy. Results indicate that maximal strength for individual resistance exercises can be reasonably estimated in adults.

Shift in body fat distribution from lower body to upper body among urban Colombian women, 1988-1989 to 2007-2008

OBJECTIVE

Body fat distribution may be a stronger predictor of metabolic risk than BMI. Yet, few studies have investigated secular changes in body fat distribution in middle-income countries or how those changes vary by socioeconomic status (SES). This study evaluated changes in body fat distribution by SES in Colombia, a middle-income country where BMI is increasing rapidly.

DESIGN

We applied factor analysis to previously published data to assess secular changes in adiposity and body fat distribution in cross-sectional samples of urban Colombian women. Anthropometry was used to assess weight, height and skinfolds (biceps, triceps, subscapular, suprailiac, thigh, calf).

SETTING

Cali, Colombia.

PARTICIPANTS

Women (18-44 years) in 1988-1989 (n 1533) and 2007-2009 (n 577) from three SES groups.

RESULTS

We identified an overall adiposity factor, which increased between 1988-1989 and 2007-2008 in all SES groups, particularly in the middle SES group. We also identified arm, leg and trunk adiposity factors. In all SES groups, leg adiposity decreased, while trunk and arm adiposity increased.

CONCLUSIONS

Factor analysis highlighted three trends that were not readily visible in BMI data and variable-by-variable analysis of skinfolds: (i) overall adiposity increased between time periods in all SES groups; (ii) the adiposity increase was driven by a shift from lower body to upper body; (iii) the adiposity increase was greatest in the middle SES group. Factor analysis provided novel insights into secular changes and socioeconomic variation in body fat distribution during a period of rapid economic development in a middle-income country.

Body fat content, fat distribution and adipocytokine production and their correlation with fertility markers in young adult men and women conceived by intracytoplasmic sperm injection (ICSI)

OBJECTIVE

Differences in body fat content during childhood and adolescence have been described in offspring conceived by in vitro fertilisation (IVF) and intracytoplasmic sperm injection (ICSI). However, data on body fat and its distribution as well as on adipocytokine production in young adults conceived by ICSI are nonexistent. We investigated if young adult men and women conceived by ICSI have a normal body fat patterning and adipocytokine production.

DESIGN

Cohort study.

PATIENTS

One hundred twenty-seven young adults conceived by ICSI and 138 peers born after spontaneous conception.

MEASUREMENTS

Anthropometric parameters (skinfold thickness, hip and waist circumferences), dual X-ray absorptiometry (whole body and regional) measurements and adipocytokine levels (leptin and adiponectin) were analysed in relation to fertility markers (serum anti-Mullerian hormone (AMH) and inhibin B).

RESULTS

While at age 18 years, a normal body fat distribution and normal leptin and adiponectin production was found in both male and female ICSI offspring, young men conceived by ICSI had a higher peripheral fat deposition in comparison with spontaneously conceived peers. No correlation between AMH and inhibin B with leptin or adiponectin was observed.

CONCLUSION

While men conceived by ICSI, but not women, had a higher peripheral fat deposition, body fat distribution as well as mean levels of adipocytokines were not affected by the mode of conception.

Upper and lower limbs composition: a comparison between anthropometry and dual-energy X-ray absorptiometry in healthy people

The detection of changes in lean mass (LM) distribution can help to prevent disability. This study assessed the degree of association between anthropometric measurements and dual-energy X-ray absorptiometry (DXA) body composition (BC) parameters of the upper and lower limbs in a healthy general population and collected DXA age- and sex-specific values of BC that can be useful to build a reference standard.

PURPOSE

The primary aim of this study was to investigate the reliability of some widely available anthropometric measurements in the assessment of body composition (BC) at the limbs, especially in terms of muscle mass, in a large sample of healthy subjects of different age bands and sex, using fat mass (FM) and lean mass (LM) parameters derived by dual-energy X-ray absorptiometry (DXA) as the gold standard. The secondary aim was to collect DXA age- and sex-specific values of BC of left and right limbs (upper and lower) in a healthy Italian population to be used as reference standards.

METHODS

Two hundred fifty healthy volunteers were enrolled. Arm circumference (AC) and thigh circumference (ThC) were measured, and total and regional BC parameters were obtained by a whole-body DXA scan (Lunar iDXA, Madison, WI, USA; enCORE™ 2011 software version 13.6).

RESULTS

FM/LM showed only fair correlation with AC and ThC in females (r = 0.649 and 0.532, respectively); in males and in the total population, the correlation was low (r = 0.360 or lower, and p non-statistically significant). AC and ThC were not well representative of arms LM in both genders (females r = 0.452, males r = 0.530) independently of age. In general, men of all age groups showed higher values of LM and lean mass index (LMI) in both total and segmental upper and lower limbs. In males, the maximum LM and LMI were achieved in the fifth decade in both upper and lower limbs and then started to decrease with aging. In females, no significant modification with aging was identified in LM and LMI.

CONCLUSION

According to our results, anthropometry is not well representative of LM of arms in both genders, independently of age; therefore, a densitometric examination should be considered for a correct assessment of BC at limbs.

Prediction of Android and Gynoid Body Adiposity via a Three-dimensional Stereovision Body Imaging System and Dual-Energy X-ray Absorptiometry

OBJECTIVE

Current methods for measuring regional body fat are expensive and inconvenient compared to the relative cost-effectiveness and ease of use of a stereovision body imaging (SBI) system. The primary goal of this research is to develop prediction models for android and gynoid fat by body measurements assessed via SBI and dual-energy x-ray absorptiometry (DXA). Subsequently, mathematical equations for prediction of total and regional (trunk, leg) body adiposity were established via parameters measured by SBI and DXA.

METHODS

A total of 121 participants were randomly assigned into primary and cross-validation groups. Body measurements were obtained via traditional anthropometrics, SBI, and DXA. Multiple regression analysis was conducted to develop mathematical equations by demographics and SBI assessed body measurements as independent variables and body adiposity (fat mass and percentage fat) as dependent variables. The validity of the prediction models was evaluated by a split sample method and Bland-Altman analysis.

RESULTS

The R(2) of the prediction equations for fat mass and percentage body fat were 93.2% and 76.4% for android and 91.4% and 66.5% for gynoid, respectively. The limits of agreement for the fat mass and percentage fat were -0.06 ± 0.87 kg and -0.11% ± 1.97% for android and -0.04 ± 1.58 kg and -0.19% ± 4.27% for gynoid. Prediction values for fat mass and percentage fat were 94.6% and 88.9% for total body, 93.9% and 71.0% for trunk, and 92.4% and 64.1% for leg, respectively.

CONCLUSIONS

The three-dimensional (3D) SBI produces reliable parameters that can predict android and gynoid as well as total and regional (trunk, leg) fat mass.

Use of anthropometry for the prediction of regional body tissue distribution in adults: benefits and limitations in clinical practice

Regional body composition changes with aging. Some of the changes in composition are considered major risk factors for developing obesity related chronic diseases which in turn may lead to increased mortality in adults. The role of anthropometry is well recognized in the screening, diagnosis and follow-up of adults for risk classification, regardless of age. Regional body composition is influenced by a number of intrinsic and extrinsic factors. Therapeutic measures recommended to lower cardiovascular disease risk include lifestyle changes. The aim of this review is to systematically summarize studies that assessed the relationships between anthropometry and regional body composition. The potential benefits and limitations of anthropometry for use in clinical practice are presented and suggestions for future research given.