Does body mass index misclassify physically active young men

Association between relative fat mass and female infertility among reproductive-aged women from NHANES 2013-2020

Female infertility is a prevalent condition closely linked with obesity. Current evaluation metrics like body mass index (BMI) and waist circumference (WC) have limitations. Relative fat mass (RFM) is a newer, more accurate obesity metric, but its relationship with infertility lacks research. Data from 3489 female participants aged 18-45 years from the NHANES 2013-2020 cycles were extracted and analyzed. Infertility was assessed based on participants' pregnancy attempts and medical consultations. The primary exposure variables were BMI, WC, and RFM. Survey-weighted logistic regression models were conducted to compare their associations with infertility, expressed as odds ratios (ORs). RFM was further categorized into quartiles for additional regression analysis. Subgroup analyses were conducted to evaluate whether the association between RFM and infertility differs across key demographic and clinical factors, including age, race, PIR, education level, BMI, smoking status, DM, hypertension, age at menarche, and history of pelvic inflammatory disease (PID). Restricted cubic splines (RCS) were employed for robustness and linearity assessments. Our results showed an infertility prevalence of 13.41%, with affected women being older and having higher BMI. The OR (1.039, 95% CI: 1.010, 1.068) for RFM in regression analysis of fully adjusted Model was higher than for BMI (1.020, 95% CI: 1.002, 1.039) and WC (1.014, 95% CI: 1.006, 1.022), indicating that each unit increase in RFM correlates with a higher risk of infertility. Similarly, quartile analysis of fully adjusted Model indicated increased infertility risk with higher RFM quartiles (Q2: OR = 1.66, 95% CI: 1.05, 2.64; Q3: OR = 1.79, 95% CI: 1.16, 2.74; Q4: OR = 2.23, 95% CI: 1.38, 3.60). Additionally, results were consistent in the supplementary subgroup analysis without interaction, and RCS confirmed a linear relationship. Our findings demonstrate a significant association between RFM and female infertility in a population-based sample, supporting the hypothesis that excess adiposity may play a role in reproductive health. Further research is needed to explore the mechanisms and broader applications of RFM in female reproductive health.

A cohort study of body mass index changes among U.S. Air Force personnel during the COVID-19 pandemic

BACKGROUND

The impact of the COVID-19 pandemic period continues to be felt, including a resulting increase in prevalence and rates of individuals with obesity within the Unites States, which had already been trending upward prior to the pandemic. This study aims to identify changes in body mass index (BMI) among the active-duty U.S. Air Force (USAF) personnel prior to and during the pandemic.

MATERIALS AND METHODS

We conducted a retrospective cohort study of USAF active-duty personnel. BMI data points were sourced from the Military Health System Data Repository and included a measure from each period: pre- (September 1, 2018 - February 28, 2020), early (March 1, 2020 - September 30, 2020), and late pandemic (October 1, 2020 - September 30, 2022). Pregnant women delivering during or one year prior to the study periods were excluded. Statistical analysis included percent change, the Stuart-Maxwell test for marginal homogeneity, and ANOVA comparing mean BMI with post-hoc mean comparisons. Additionally, the percentage change toward obese BMI was stratified by rank and occupation.

RESULTS

We identified a cohort of 111,392 active-duty USAF personnel. The overall increase in prevalence of USAF personnel with obesity over the entire study period was 44.1%. The prevalence of USAF personnel with obesity among our cohort increased by 11.6% from the pre-pandemic period to the early pandemic period (18% pre-pandemic; 20.8% early pandemic) with a 29.1% increase in prevalence from the early to late pandemic periods (20.8% early pandemic; 26.9% late pandemic). USAF aircrew members progressed to having a BMI of obese at lower rates over the same periods increasing by 7.8%, 21.3%, and 30.7%, respectively. The most prominent changes were observed among females, personnel between the ages 20 and 24, of American Indian or Alaska Native race, and in junior enlisted ranks.

CONCLUSIONS

Our analysis indicates that like the other service branches of the U.S. military, the Air Force experienced an increase in active-duty personnel with obesity during the COVID-19 pandemic period. This indicates increases in rates of service members with obesity across the U.S. armed forces, which is likely to result in decreased force readiness.

Sleep health among US Navy afloat versus ashore personnel in the Millennium Cohort Study

Despite emerging public concern regarding the sleep health of military personnel over the past two decades, there remains a dearth of research examining sleep health among naval personnel assigned to sea duty. This study examined sleep metrics (e.g. fatigue, short sleep duration) and mental (e.g. posttraumatic stress disorder, depression) and physical health (e.g. type 2 diabetes, bodily pain) outcomes among naval personnel with recent sea duty (i.e. afloat) compared with naval personnel with recent shore duty (i.e. ashore). Prevalence ratios and mean differences for all outcomes were estimated and adjusted for demographic and military variables, and subsequently stratified by obesity. Sleep metrics were similar between afloat and ashore sailors except for short sleep duration, while sailors with recent shore duty had poorer physical health compared with those with recent sea duty. Stratified analyses suggested naval personnel with obesity had a higher proportion of nearly all adverse sleep-related health outcomes than those without obesity. Among participants without obesity, afloat personnel were more likely to report very short sleep (≤ 5 hours) and fewer hours of average nightly sleep, but were less likely to report physical health outcomes compared with ashore personnel. These findings suggest potential differences in sleep metrics and sleep-related health outcomes between afloat and ashore naval personnel. Additional research examining sleep outcomes using more objective measures is required to further investigate these findings, which may inform strategies to foster consolidated sleep despite environmental and occupational challenges in order to maintain high-performing naval personnel.

Association of relative fat mass with prevalence of erectile dysfunction in US men: an analysis of NHANES 2001-2004

The high prevalence of erectile dysfunction (ED) underscores the critical importance of interventions and preventive measures targeting potential risk factors, among which obesity stands out. Relative fat mass (RFM) emerges as a superior indicator for quantifying body fat compared to traditional metrics like body mass index (BMI) or waist circumference (WC). However, research on the relationship between RFM and ED is extremely limited. A total of 3627 participants from the National Health and Nutrition Examination Survey 2001-2004 were eligible for analysis. The RFM is calculated using the following formula: RFM = 64-(20×height/WC). Weighted multivariable logistic regression models were utilized to assess the correlation between RFM and ED, supplemented by smooth curve fitting to further explore the linear association. When all potential covariates adjusted, continuous RFM demonstrated a positive association with ED prevalence (odds ratio (OR): 1.11, 95% confidence interval (CI): 1.05-1.18, P = 0.002). When RFM was categorized into tertiles (T1-T3), participants in T3 group exhibited a significantly higher likelihood of ED (OR: 2.19, 95% CI: 1.19, 4.05, P = 0.020) compared to those in T1. Subgroup analyses revealed a stronger correlation among participants aged over 60 years, obese individuals, and those with hypertension, while weaker correlations were observed among those with diabetes and cardiovascular disease (CVD). After sensitivity analysis for severe ED, the aforementioned regression analysis results remained statistically significant. The final ROC analysis demonstrated that the predictive ability of RFM was superior to that of BMI and WC, with an AUC (95% CI) of 0.639 (0.619-0.659). Elevated RFM demonstrated a linear correlation with increased incidence of ED and exhibited strong predictive capability for ED, underscoring the importance of obesity intervention for ED. Future studies with larger clinical samples are necessary to confirm our findings and expand the application value of RFM in assessing ED risk.

Long Duration Load Carriage Performance Is Associated With Army Combat Fitness Test Scores and Fat-Free Mass

ABSTRACT

Sax van der Weyden, M, Merrigan, JJ, and Martin, J. Long duration load carriage performance is associated with Army Combat Fitness Test scores and fat free mass. J Strength Cond Res 38(11): 1959-1966, 2024-A common occupational task for the military is carrying heavy loads for long periods of time. The US Army has set a time standard of 3 hours to complete a 19.31-km march with a 15.9-kg ruck sack for combat arms training and specialty schools. The purpose of this study was to identify characteristics associated with 19.31-km foot march completion rates in Reserve Officers' Training Corps (ROTC) Cadets. Demographics, anthropometrics/body composition, Army Combat Fitness Test (ACFT) scores, and vertical countermovement jump (CMJ) data were collected on 65 ROTC cadets who conducted a 19.31-km foot march. Independent t tests and Mann-Whitney U tests compared variables between those who did and did not finish the foot march in less than 3 hours. Logistic regressions were used to calculate the odds of completing the foot march using military experience, fat-free mass, ACFT, and CMJ outcomes. Cadets who met the 3 hours standard had lower body fat percent, greater fat-free mass, higher ACFT scores, and higher CMJs than those who did not. In addition, for every one point increase in ACFT score and 1-kg increase in fat-free mass, a cadet's chances of finishing the foot march increased by 6.1 and 24%, respectively. When analyzing ACFT events separately, 2-mile run was the only significant variable, and for every 1 point increase in 2-mile run score, a cadet's chances of finishing the foot march increased by 9%. Thus, aspiring and current soldiers should train to improve aerobic fitness and build muscle mass in preparation for load carriage requirements.

BMI changes among U.S. Navy and Marine Corps active-duty service members during the COVID-19 pandemic, 2019-2021

BACKGROUND

The COVID-19 pandemic disrupted the daily life and routines of Americans across the United States (U.S.), including those of our active-duty service members (ADSMs). Limited movement orders enacted during this time to promote social distancing prohibited access to fitness and dining facilities for ADSMs. This study aims to expand on previous work identifying changes in body mass index (BMI) among U.S. Army service members by identifying changes in body mass index (BMI) among active-duty service members from both the Navy and Marine Corps during the same time period.

METHODS

We conducted a retrospective cohort study of active-duty service members from the Navy and Marine Corps using data from the Military Health System Data Repository. BMI was calculated and categorized according to CDC guidelines both before (February 2019 - January 2020) and during the pandemic (September 2020 - June 2021). Women who were pregnant or delivered during and one year prior to the study periods were excluded. Statistical analyses included paired t-tests evaluating mean BMI, percent change, and the Stuart-Maxwell test for marginal homogeneity.

RESULTS

We identified 98,330 active-duty Sailors and 55,298 active-duty Marines for inclusion in this study. During the pandemic period the percentage of Sailors with Underweight decreased by 11%, Healthy weight decreased by 11.1%, Overweight increased by 2.1%, and the percentage of Sailors with Obesity increased by 16.5%. During this same time period, Marines with Underweight decreased by 1%, Healthy weight decreased by 16%, Overweight increased by 3.0%, and Marines with Obesity increased by 51%. The largest increases in service members with overweight and obesity observed among both cohorts were among female service members, service members under age 20, and service members with a Junior Enlisted rank.

CONCLUSIONS

Significant increases in obesity were observed amongst active-duty United States Navy and Marine Corps service members during DoD pandemic mitigation efforts. Increased rates of obesity likely effected fitness and force readiness. Future interventions should be targeted at younger, Junior-Enlisted Marines and Sailors to promote healthy lifestyles and provide education on nutrition, appropriate exercise, sleep hygiene, and stress management.

Relative Strength and Physical Performance in US Army Male and Female Soldiers

ABSTRACT

Grier, T, Benedict, T, Mahlmann, O, and Canham-Chervak, M. Relative Strength and Physical Performance in U.S. Army Male and Female Soldiers. J Strength Cond Res 38(8): 1479-1485, 2024-In occupations with high physical demands, strength relative to bodymass is an important measure as it signifies an individual's ability to control and move their body mass through space. The purpose of this investigation was to examine physical characteristics, training, and performance based on different magnitudes of relative strength. Subjects were 1,806 male and 319 female US Army soldiers. Sex, age, height, body mass, and physical training data were obtained by an electronic survey. Physical performance was measured by the Army Combat Fitness Test (ACFT), which includes a three-repetition maximum deadlift, standing power throw, hand release push-up, sprint-drag-carry, leg tuck, and two-mile run. The relative body mass deadlifted was calculated and categorized into 4 groups for men and 3 groups for women. An analysis of variance and post hoc least significant difference test were used to evaluate the differences in relative strength and physical performance. Overall, 33% of men deadlifted ≥1.5 times their body mass, while 30% of women deadlifted ≥1.25 times their body mass. Men and women deadlifting the highest percentage of their body mass (≥1.5 times for men and ≥1.25 times for women) outperformed those with lower relative strength within their own sex in all 6 ACFT events. In 4 of the 6 ACFT events, women who deadlifted ≥1.25 times their body mass had similar performance compared with men deadlifting 1 to 1.24 times their body mass and outperformed men deadlifting <1 times their body mass. Greater strength relative to body mass was associated with higher physical performance.

Associations between novel anthropometric indices and the prevalence of gallstones among 6,848 adults: a cross-sectional study

Background

Traditional anthropometric measures, including body mass index (BMI), are insufficient for evaluating gallstone risk. This study investigated the association between novel anthropometric indices and gallstone risk among 6,848 participants from the National Health and Nutrition Examination Survey in the United States.

Methods

Measures calculated included weight (WT), BMI, waist circumference (WC), waist-to-height ratio (WtHR), conicity index (CI), A Body Shape Index (ABSI), Body Roundness Index (BRI), Abdominal Volume Index (AVI), and Weight-adjusted Waist Index (WWI). Logistic regression and smooth curve fitting assessed the relationships between these indices and gallstones, complemented by receiver operating characteristic (ROC) curve analysis to evaluate their discriminative power.

Results

The results indicated significant differences between study groups, with a positive and independent correlation identified between gallstones and all measures except ABSI. Specifically, per 1 SD increase in WC, WT, BMI, WtHR, and AVI was associated with a 57%, 59%, 52%, 53%, and 53% increased risk of gallstones, respectively. Dose-response analysis confirmed a positive correlation between these indices and gallstone risk. ROC analysis highlighted WtHR and BRI as having superior discriminative abilities (AUC = 0.6703). Further, among participants with a BMI < 30 kg/m2, elevated levels of WT, WtHR, CI, BRI, and WWI significantly increased the risk of gallstones (P < 0.001). Likewise, elevated BMI heightened the risk at low levels of WT, WC, WtHR, BRI, AVI, and CI (P < 0.001).

Conclusion

This study supports the positive association between various anthropometric indicators and gallstones, recommending that newer anthropometric indices be considered more extensively to enhance gallstone prevention and treatment strategies.

Prevalence of Pain With Movement in Active Duty US Army Soldiers

INTRODUCTION

Soldiers must be able to perform a multitude of physically demanding tasks as part of their regular duty, but their physical readiness is often degraded due to pain and musculoskeletal injury (MSKI). The presence of pain with movement has been associated with increased MSKI risk in Soldiers. Improved awareness of the prevalence of painful movements in uninjured Soldiers could help inform Army injury mitigation efforts. The purpose of this study was to identify the prevalence of pain with movement in a population of healthy active duty Soldiers.

MATERIALS AND METHODS

The Selective Functional Movement Assessment-Top Tier Movements (SFMA-TTM), active range of motion (AROM) of the hips and shoulders, and the elicitation of pain with movement were measured in 268 healthy US Army Soldiers. Descriptive statistics were generated for the number of painful movements for each measure and inferential statistics; independent t-test and one-way independent analysis of variance (ANOVA) were used for analysis of the other measures.

RESULTS

Greater than half (59%) of the participants reported pain with at least 1 movement and more than 41% reported pain with 2 or more movements. Soldiers reported a mean of 1.35 painful movements on the SFMA-TTM assessment and a mean of 1.54 painful AROM movements.

CONCLUSIONS

Pain with functional movement patterns was common across a sample of uninjured Soldiers. The presence of pain with movement warrants further evaluation as it may impact a Soldier's physical performance, risk for future injury, and overall quality of life.

Novel anthropometric measures are positively associated with erectile dysfunction: a cross-sectional study

BACKGROUND

Currently, a growing number of research studies have shown a positive association between obesity and erectile dysfunction, while traditional anthropometric measures, such as BMI, have limited ability to assess the risk of erectile dysfunction. Therefore, this study aimed to investigate the association between the new anthropometric index and erectile dysfunction.

METHODS

A study involving 3594 participants from the National Health and Nutrition Examination Survey was conducted. The study calculated various anthropometric indices such as waist circumference (WC), waist-to-height ratio (WtHR), body mass index (BMI), a body shape index (ABSI), conicity index (CI), and body roundness index (BRI). The relationship between anthropometric indices and erectile dysfunction (ED) was investigated using multivariate logistic regression and restricted cubic splines (RCS). Interaction analysis was conducted on subgroups to confirm the findings. Additionally, the efficacy of various anthropometric indicators in predicting the risk of erectile dysfunction was assessed using the receiver operating characteristic curve (ROC).

RESULTS

After adjusting for potential confounding factors, we identified a positive and independent correlation between erectile dysfunction (ED) and all other anthropometric measures except for BMI. Additionally, the risk of ED increased by 49% and 42% for each standard deviation increment in ABSI and CI, respectively. Dose-response curve analysis demonstrated that WC, BMI, WtHR, and CI displayed a non-linear correlation with the risk of ED. The subgroup analysis revealed that individuals classified as White, who had higher levels of WC, ABSI, and CI, were more susceptible to erectile dysfunction compared to people from other races. ROC analysis showed that ABSI was superior in detecting erectile dysfunction (area under the curve: 0.750; 95% CI 0.732-0.768; optimal cutoff value: 0.083) as compared to other indices. The combination of obesity defined by BMI and other anthropometric measures showed that higher ABSI and CI levels were positively associated with the prevalence of erectile dysfunction, independent of BMI (P < .001).

CONCLUSION

In this study, anthropometric indicators including ABSI, BRI, WtHR, CI, and WC were positively associated with erectile dysfunction. To improve the prevention and treatment of this condition, it is recommended that new anthropometric indicators receive greater consideration.

Optimal Cut-Off Values for Body Mass Index and Fat Mass Index Based on Age in Physically Active Males Using Receiver Operating Characteristic Curve

This study aims to redefine obesity cut-off points for body mass index (BMI) and fat mass index (FMI) according to the different age groups of physically active males. Healthy physically active volunteers (N = 1442) aged 18-57 years (y), with a mean BMI = 22.7 ± 2.8 kg/m2, and mean FMI = 4.3 ± 1.7 kg/m2 were recruited from various fitness centers. BMI was calculated and individuals were categorized according to the Asia-Pacific BMI criterion of ≤22.9 kg/m2 and the previous WHO-guided BMI criterion of ≤24.9 kg/m2. FMI was also calculated for the study participants with a cut-off of 6.6 kg/m2. Redefining of BMI and FMI cut-off values was carried out based on different age groups categorized with a difference of 10 y and 5 y using the receiver operating characteristic (ROC) curve and Youden's index. For the entire study population, BMI redefined cut-off points for overweight and obesity were 23.7 kg/m2 and 24.5 kg/m2, respectively, while FMI redefined cut-off points for overweight and obesity were 4.6 kg/m2 and 5.7 kg/m2, respectively. With 10 y of age group difference, a constant BMI and FMI values were observed, while with 5 y of age group difference, a constant increase in the BMI cut-offs was observed as the age group increased, i.e., from 23.3 kg/m2 in 20-24 y to 26.6 kg/m2 in ≥45 y and a similar trend was seen in FMI cut-offs. To conclude, our study suggests that age-dependent BMI and FMI cut-off points may provide appropriate measurements for physically active males as the age group increases.

Accuracy of body mass index compared to whole-body dual energy X-ray absorptiometry in diagnosing obesity in adults in the Eastern Province of Saudi Arabia: A cross-sectional study

BACKGROUND

Obesity is a major health concern that requires accurate diagnosis and management. Body mass index (BMI) commonly used to diagnose obesity, has limitations in accurately assessing body fat. Body fat percentage (BF%) from whole-body dual energy X-ray absorptiometry (DEXA) scans is gaining popularity as a more accurate method in diagnosing obesity.

MATERIALS AND METHODS

This cross-sectional study included 319 adult patients who underwent whole-body DEXA scans in the Eastern Province of Saudi Arabia from May 2016 to December 2021 were recruited from three medical centers, where data for whole-body DEXA were available. Body fat percent was obtained from the whole-body DEXA scan reports and were compared to BMI to evaluate prevalence of obesity. Data was extracted by reviewing patients' records using a structured data collection tool. BMI was defined using WHO criteria, and diagnostic performance was assessed by estimating specificity, sensitivity, likelihood ratios, and predictive values, and by constructing receiver operating characteristic (ROC) curves for BMI to detect obesity by age group.

RESULTS

The gender-specific BF% cutoff points revealed a higher prevalence of obesity than BMI cutoff points. BMI misclassified 40.6% of participants, and optimal cutoff points yielding highest area under the curve were 24 kg/m2 and 24.3 kg/m2 for males and females, respectively.

CONCLUSION

The study underscores the importance of using accurate and comprehensive diagnostic tools such as whole-body DEXA scans to assess obesity.

The Medical Burden of Obesity and Overweight in the US Military: Association of BMI with Clinically Diagnosed Medical Conditions in United States Military Service Members

BACKGROUND

A high BMI is associated with various medical conditions, notably type 2 diabetes, cardiovascular disease, and mental health disorders. In the US military, BMI increased linearly between 1975 and 2015.

OBJECTIVE

This cross-sectional study investigated the associations between BMI and a comprehensive range of clinically diagnosed medical conditions (CDMCs) in US military service members (SMs).

METHODS

A stratified random sample of SMs (n=26,177) completed an online questionnaire reporting their height, weight, and demographic/lifestyle characteristics. Medical conditions for 6 mo before questionnaire completion were obtained from a comprehensive military electronic medical surveillance system and grouped into 39 CDMCs covering both broad (largely systemic) and specific medical conditions. BMI was calculated as weight/height2 (kg/m2). The prevalence of CDMCs was compared among normal weight (<25.0 kg/m2), overweight (25.0-29.9 kg/m2), and obese (≥30 kg/m2) SMs.

RESULTS

After multivariable adjustment for demographic/lifestyle characteristics, higher BMI was associated with higher odds of a diagnosed medical condition in 30 of 39 CDMCs, with all 30 displaying dose-response relationships. The 5 major CDMCs with the largest odds ratios comparing obese to normal weight were endocrine/nutritional/metabolic diseases (OR=2.67, 95%CI=2.24-3.15), nervous system diseases (odds ratio [OR]=2.59, 95%CI=2.32-2.90), circulatory system diseases (OR=2.56, 95%CI=2.15-3.06), musculoskeletal system diseases (OR=1.92, 95%CI=1.76-2.09), and mental/behavioral disorders (OR=1.69, 95%CI=1.51-1.90). Compared with normal weight SMs, overweight or obese SMs had a higher number of CDMCs (1.8±1.9 vs. 2.0±2.0 and 2.5±2.3, mean ± standard deviation, respectively, P<0.01).

CONCLUSIONS

In a young, physically active population, higher BMI was associated with a host of medical conditions, even after adjustment for demographic/lifestyle characteristics. The US Department of Defense should improve nutrition education and modify other factors that contribute to overweight and obesity. This study demonstrates that the medical burden of obesity is substantial in overweight and obese SMs.

Assessment of correlation between conventional anthropometric and imaging-derived measures of body fat composition: a systematic literature review and meta-analysis of observational studies

BACKGROUND

In studies of the association of adiposity with disease risk, widely used anthropometric measures of adiposity (e.g. body-mass-index [BMI], waist circumference [WC], waist-hip ratio [WHR]) are simple and inexpensive to implement at scale. In contrast, imaging-based techniques (e.g. magnetic resonance imaging [MRI] and dual x-ray absorptiometry [DXA]) are expensive and labour intensive, but can provide more accurate quantification of body fat composition. There is, however, limited evidence about the relationship between conventional and imaging-derived measures of adiposity.

METHODS

We searched Scopus and Web of Science for published reports in English of conventional versus imaging-derived measurements of adiposity. We identified 42 articles (MRI = 22; DXA = 20) that met selection criteria, involving 42,556 (MRI = 15,130; DXA = 27,426) individuals recruited from community or hospital settings. Study-specific correlation coefficients (r) were transformed using Fisher's Z transformation, and meta-analysed to yield weighted average correlations, both overall and by ancestry, sex and age, where feasible. Publication bias was investigated using funnel plots and Egger's test.

RESULTS

Overall, 98% of participants were 18 + years old, 85% male and 95% White. BMI and WC were most strongly correlated with imaging-derived total abdominal (MRI-derived: r = 0.88-; DXA-derived: 0.50-0.86) and subcutaneous abdominal fat (MRI-derived: 0.83-0.85), but were less strongly correlated with visceral abdominal fat (MRI-derived: 0.76-0.79; DXA-derived: 0.80) and with DXA-derived %body fat (0.76). WHR was, at best, strongly correlated with imaging-derived total abdominal (MRI-derived: 0.60; DXA-derived: 0.13), and visceral abdominal fat (MRI-derived: 0.67; DXA-derived: 0.65), and moderately with subcutaneous abdominal (MRI-derived: 0.54), and with DXA-derived %body fat (0.58). All conventional adiposity measures were at best moderately correlated with hepatic fat (MRI-derived: 0.36-0.43). In general, correlations were stronger in women than in men, in Whites than in non-Whites, and in those aged 18 + years.

CONCLUSIONS

In this meta-analysis, BMI and WC, but not WHR, were very strongly correlated with imaging-derived total and subcutaneous abdominal fat. By comparison, all three measures were moderately or strongly correlated with imaging-based visceral abdominal fat, with WC showing the greatest correlation. No anthropometric measure was substantially correlated with hepatic fat. Further larger studies are needed to compare these measures within the same study population, and to assess their relevance for disease risks in diverse populations.

Different correlation of body mass index with body fatness and obesity-related biomarker according to age, sex and race-ethnicity

The relationship between body mass index (BMI) and body fatness could differ according to age, sex, and race-ethnicity. We aimed to evaluate in which contexts BMI could be a good measure for body fatness compared to dual-energy X-ray absorptiometry (DXA) derived measures. The study population included 18,061 participants (9141 men and 8920 women) aged 18 and older who tested DXA from the National Health and Nutrition Examination Survey (NHANES) database from 1999 to 2006, and 8107 men and 10,754 women with DXA data from Korea NHANES from 2008 to 2011 to represent the Asian population. We calculated Pearson correlation coefficients between BMI and DXA derived fat mass index (FMI) and percentage body fat (PBF) depending on age, sex, and race-ethnicity. The correlation between BMI, FMI and PBF and obesity-related biomarkers was also estimated among the subgroup with both DXA and information on each biomarker. BMI was strongly correlated with FMI (r = 0.944 in men and 0.976 in women), PBF (r = 0.735 in men and 0.799 in women), and truncal fat mass (r = 0.914 in men and 0.941 in women) with correlations stronger in women than in men except for with waist-height ratio (r = 0.921 in men and 0.911 in women). The correlation between BMI and DXA derived adiposity weakened with age in both sexes. BMI was less correlated with FMI (r = 0.840 in men and 0.912 in women), PBF (r = 0.645 in men and 0.681 in women), and truncal fat mass (r = 0.836 in men and 0.884 in women) in Korean compared to other race-ethnicities. Among obesity-related biomarkers, insulin was the most strongly correlated to body adiposity indices in both sexes and strength of these correlations generally decreased with age. BMI predicted obesity-related biomarkers as well as FMI and truncal fat mass and superior to PBF. BMI could be a good measure for body fatness, particularly among young age groups, women, the US population, but less so in Korean populations. The lower correlation between BMI and body fatness in older compared to younger age groups could be related to increasing PBF and decreasing lean body mass.

Validation of HF-Bioelectrical Impedance Analysis versus Body Mass Index in Classifying Overweight and Obese Pakistani Adults

Purpose

To determine the validity of hand-to-foot bioelectrical impedance analysis (HF-BIA) versus body mass index (BMI) to assess overweight and obesity status in adults against a reference method, dual-energy x-ray absorptiometry (DXA).

Patients and Methods

It is a validation study conducted on 206 Pakistani adults ≥20 years recruited through convenience sampling technique at PNS Shifa Hospital and Jinnah Post Medical Centre, Karachi, Pakistan.

Results

HF-BIA showed better sensitivity of 90.1% and 100% specificity with no false positive, but 9% false negative as compared to BMI which indicated 80.3% sensitivity and 100% specificity with a false-negative rate of 19.6%.HF-BIA also showed better sensitivity 80.9-97.1% with 100% specificity and PPV across all age groups. The correlation coefficient between BMI and DXA bf% (r=0.67) was moderate and less than the correlation coefficient between HF-BIA and DXA bf % (r=0.87). Kappa agreement showed weak to a fair agreement between BMI and DXA bf % (0.1 overall; 0.22 men; 0.14 women) compared to HF-BIA, which had a better agreement between BIA bf% and DXA bf% (0.43 overall; 0.46 men; 0.34 women). HF-BIA bf % demonstrated a better discriminatory power than BMI (AUC of ≥0.91) and was better predictor of body fat than BMI.

Conclusion

HF-BIA is a more accurate method than BMI and may be used consistently throughout the country in primary care and research to identify the fat-based overweight and obese in the Pakistani population.

Myocarditis and pericarditis recovery following smallpox vaccine 2002-2016: A comparative observational cohort study in the military health system

OBJECTIVES

(1) Characterize the initial clinical characteristics and long-term outcomes of smallpox vaccine-associated hypersensitivity myocarditis and pericarditis (MP) in United States service members. (2) Describe the process of case identification and adjudication using the 2003 CDC nationally defined myocarditis/pericarditis epidemiologic case definitions to include consideration of case-specific diversity and evolving evidence.

BACKGROUND

Between 2002 and 2016, 2.546 million service members received a smallpox Vaccinia vaccine. Acute MP is associated with vaccinia, but the long-term outcomes have not been studied.

METHODS

Records of vaccinia-associated MP reported to the Vaccine Adverse Event Reporting System by vaccination date were adjudicated using the 2003 MP epidemiologic case definitions for inclusion in a retrospective observational cohort study. Descriptive statistics of clinical characteristics, presentation, cardiac complications, and time course of clinical and cardiac recovery were calculated with comparisons by gender, diagnosis and time to recovery.

RESULTS

Out of over 5000 adverse event reports, 348 MP cases who survived the acute illness, including 276 myocarditis (99.6% probable/confirmed) and 72 pericarditis (29.2% probable/confirmed), were adjudicated for inclusion in the long-term follow-up. Demographics included a median age of 24 years (IQR 21,30) and male predominance (96%). Compared to background military population, the myocarditis and pericarditis cohort had a higher percentage of white males by 8.2% (95% CI: 5.6, 10.0) and age <40 years by 4.2% (95% CI: 1.7,5.8). Long-term follow-up documented full recovery in 267/306 (87.3%) with 74.9% recovered in less than a year (median ~3 months). Among patients with myocarditis, the percentage who had a delayed time to recovery at time of last follow-up was 12.8% (95% CI: 2.1,24.7) higher in those with an acute left ventricular ejection fraction (EF) of ≤50% and 13.5% (95% CI: 2.4,25.7) higher in those with hypokinesis. Patient complications included 6 ventricular arrhythmias (2 received implanted defibrillators) and 14 with atrial arrhythmias (2 received radiofrequency ablation). Three of 6 patients (50%) diagnosed with cardiomyopathy had clinical recovery at their last follow-up date.

CONCLUSIONS

Hypersensitivity myocarditis/pericarditis following the smallpox vaccine is associated with full clinical and functional ventricular recovery in over 87% of cases (74.9% <1 year). A minority of MP cases experienced prolonged or incomplete recovery beyond 1 year.

Are models of plantar heel pain suitable for competitive runners? A narrative review

Background

Plantar heel pain (PHP), or plantar fasciopathy, is a common condition in active and sedentary populations, contributing to short- and long-term reductions in quality of life. The condition's aetiology and pathophysiology are the subjects of a significant body of research. However, much of this research has been conducted with sedentary participants, and comparatively little research exists in a population of highly-trained athletes focused on performance outcomes. Models for PHP and proposed mechanisms, such as high body mass index or systemic disease, are mostly absent from an athletic population. Even less is known about the origins of pain in PHP. Pain is believed to be a complex multifactorial process and may be experienced differently by sedentary and highly active populations, particularly endurance athletes. Consequently, conservative through to surgical treatment for athletes is informed by literature for a different population, potentially hindering treatment outcomes.

Aims

The aim of this review, therefore, is to summarise what is known about PHP in athletic populations and propose potential directions for future research.

Methods

Embase, PubMed, and Scopus using MeSH search terms for PHP and competitive sport and common synonyms.

Discussion

Two explanatory models for PHP were found. These primarily propose mechanical factors for PHP. It remains unclear how gait, body composition, and psychological factors may differ in an athletic population with and without PHP. Therefore, research in these three areas is needed to inform clinical and training interventions for this population.

Phenotypic differences between people varying in muscularity

BACKGROUND

Body mass is the primary metabolic compartment related to a vast number of clinical indices and predictions. The extent to which skeletal muscle (SM), a major body mass component, varies between people of the same sex, weight, height, and age is largely unknown. The current study aimed to explore the magnitude of muscularity variation present in adults and to examine if variation in muscularity associates with other body composition and metabolic measures.

METHODS

Muscularity was defined as the difference (residual) between a person's actual and model-predicted SM mass after controlling for their weight, height, and age. SM prediction models were developed using data from a convenience sample of 492 healthy non-Hispanic (NH) White adults (ages 18-80 years) who had total body SM and SM surrogate, appendicular lean soft tissue (ALST), measured with magnetic resonance imaging and dual-energy X-ray absorptiometry, respectively; residual SM (SM_R ) and ALST were expressed in kilograms and kilograms per square meter. ALST mass was also evaluated in a population sample of 8623 NH-White adults in the 1999-2006 National Health and Nutrition Examination Survey. Associations between muscularity and variation in the residual mass of other major organs and tissues and resting energy expenditure were evaluated in the convenience sample.

RESULTS

The SM, on average, constituted the largest fraction of body weight in men and women up to respective BMIs of 35 and 25 kg/m² . SM in the convenience sample varied widely with a median of 31.2 kg and an SM_R inter-quartile range/min/max of 3.35 kg/-10.1 kg/9.0 kg in men and 21.1 kg and 2.59 kg/-7.2 kg/7.5 kg in women; per cent of body weight as SM at 25th and 75th percentiles for men were 33.1% and 39.6%; corresponding values in women were 24.2% and 30.8%; results were similar for SM_R indices and for ALST measures in the convenience and population samples. Greater muscularity in the convenience sample was accompanied by a smaller waist circumference (men/women: P < 0.001/=0.085) and visceral adipose tissue (P = 0.014/0.599), larger liver (P = 0.065/<0.001), kidneys (P = 0.051/<0.009), and bone mineral (P < 0.001/<0.001), and larger magnitude resting energy expenditure (P < 0.001/<0.001) than predicted for the same sex, age, weight, and height.

CONCLUSIONS

Muscle mass is the largest body compartment in most adults without obesity and is widely variable in mass across people of similar body size and age; and high muscularity is accompanied by distinct body composition and metabolic characteristics. This previously unrecognized heterogeneity in muscularity in the general population has important clinical and research implications.

Overweight BMI (25-29) in Active Duty Military: Excess Fat or More Lean Mass? A Look at the Evidence

Many active duty service members and their health care providers feel that the current body mass index (BMI) standard for diagnosing obesity, BMI ≥30 kg/m2, may unfairly overclassify as obese those with higher muscle mass. Unfortunately, a closer look at the data available for service members repeatedly demonstrates the exact opposite: we are actually underestimating the rates of obesity in service members using current BMI cutoffs when compared with body fat mass as measured by either dual-energy X-ray absorptiometry or bioelectrical impedance analysis as the gold standard. Using a lower BMI threshold and refining positive results via history, exam, labs, and/or more specific measurements of body composition would more accurately estimate body fat percentage in active duty service members while remaining convenient and scalable. Given the current obesity epidemic in our nation, this suggests the critical need for new approaches to screening, as well as treatment, of overweight and obesity in our military to improve service readiness.

Clinical, immunological and virological SARS-CoV-2 phenotypes in obese and non-obese military health system beneficiaries

Background

The mechanisms underlying the association between obesity and coronavirus disease 2019 (COVID-19) severity remain unclear. After verifying that obesity was a correlate of severe COVID-19 in US Military Health System (MHS) beneficiaries, we compared immunological and virological phenotypes of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection in both obese and nonobese participants.

Methods

COVID-19–infected MHS beneficiaries were enrolled, and anthropometric, clinical, and demographic data were collected. We compared the SARS-CoV-2 peak IgG humoral response and reverse-transcription polymerase chain reaction viral load in obese and nonobese patients, stratified by hospitalization, utilizing logistic regression models.

Results

Data from 511 COVID-19 patients were analyzed, among whom 24% were obese and 14% severely obese. Obesity was independently associated with hospitalization (adjusted odds ratio [aOR], 1.91; 95% confidence interval [CI], 1.15–3.18) and need for oxygen therapy (aOR, 3.39; 95% CI, 1.61–7.11). In outpatients, severely obese had a log₁₀ (1.89) higher nucleocapsid (N1) genome equivalents (GE)/reaction and log₁₀ (2.62) higher N2 GE/reaction than nonobese (P = 0.03 and P < .001, respectively). We noted a correlation between body mass index and peak anti-spike protein IgG in inpatients and outpatients (coefficient = 5.48, P < .001).

Conclusions

Obesity is a strong correlate of COVID-19 severity in MHS beneficiaries. These findings offer new pathophysiological insights into the relationship between obesity and COVID-19 severity.

Relationship Between Body Mass Index and Diagnosis of Obesity in the Military Health System Active Duty Population

OBJECTIVE

The overall rate of obesity is rising in the USA; this is also reflected in the military population. It is important that providers appropriately diagnose obesity and discuss treatment options with their patients.The purpose of this study was to investigate diagnosis of obesity compared to documented body mass index (BMI) in the military health system.

METHODS

Institutional review board approval was obtained by the 59th Medical Wing (Lackland Air Force Base, Texas) as an exempt study. This study included active duty military service members aged 18-65 years who sought outpatient care at a military treatment facility from September 2013 to August 2018 with a weight within the range of 31.8-226.8 kg and height between 121.9 and 215.9 cm. Data were collected from the Clinical Data Repository vitals and M2 encounter data to determine the percentage of each sub-population with a diagnosis of obesity according to BMI (≥30 kg/m2) and International Classification of Diseases diagnosis codes.

RESULTS

Using BMI, 19.2% of female and 26.8% of male service members can be diagnosed with obesity; however, only 42.2% and 35.1%, respectively, with a BMI ≥30 was diagnosed as such. This discrepancy was consistent among all service branches and BMI ranges.

CONCLUSION

This study demonstrates that obesity is underdiagnosed compared to BMI. This may result in insufficient resources being provided to patients to reduce weight. Further investigation is warranted to identify causes of underdiagnosis and potential barriers to diagnosis.

Metabolic pathways in obesity-related breast cancer

This Review focuses on the mechanistic evidence for a link between obesity, dysregulated cellular metabolism and breast cancer. Strong evidence now links obesity with the development of 13 different types of cancer, including oestrogen receptor-positive breast cancer in postmenopausal women. A number of local and systemic changes are hypothesized to support this relationship, including increased circulating levels of insulin and glucose as well as adipose tissue-derived oestrogens, adipokines and inflammatory mediators. Metabolic pathways of energy production and utilization are dysregulated in tumour cells and this dysregulation is a newly accepted hallmark of cancer. Dysregulated metabolism is also hypothesized to be a feature of non-neoplastic cells in the tumour microenvironment. Obesity-associated factors regulate metabolic pathways in both breast cancer cells and cells in the breast microenvironment, which provides a molecular link between obesity and breast cancer. Consequently, interventions that target these pathways might provide a benefit in postmenopausal women and individuals with obesity, a population at high risk of breast cancer.

Circumference Method Estimates Percent Body Fat in Male US Service Members with Lower Limb Loss

BACKGROUND

The Department of Defense circumference method (CM) is used to estimate percent body fat (%BF) in evaluation of health, physical fitness, appearance, and military readiness; however, the CM has not been validated in individuals with lower limb loss.

OBJECTIVE

To evaluate the agreement between CM and dual-energy X-ray absorptiometry (DXA) for measuring %BF in individuals with lower limb loss.

DESIGN

This study is part of a larger cross-sectional comparison study, and this analysis was included as a secondary objective. Two methods of measuring %BF included CM and DXA, with DXA as the reference standard for this study.

PARTICIPANTS/SETTING

This study was conducted at Walter Reed Army Medical Center. Data were collected from summer 2010 to summer 2011. One hundred individuals, 50 with and 50 without lower limb loss, were screened for this study; three individuals with limb loss and two without limb loss had incomplete data, and one individual (female, without limb loss) lacked a comparison participant. All participants were recruited from a military medical center, and data were collected in a clinic research laboratory.

MAIN OUTCOME MEASURES

Measurements of %BF were compared between methods for each group.

STATISTICAL ANALYSES PERFORMED

Measurements of %BF were compared using paired t-tests and intraclass correlation coefficient. Agreement and bias were assessed with Bland-Altman analysis. Receiver operating characteristic analysis was used to determine the diagnostic accuracy of the CM to identify participants with %BF levels in the obese category (≥25%).

RESULTS

A statistically significant difference was found between %BF methods in the group with limb loss (1.7%; P = 0.001) and the group without limb loss (1.4%; P = 0.005), with DXA consistently higher than CM. However, the intraclass correlation coefficient estimates for the agreement between %BF by CM and DXA were 0.848 (95% confidence interval [CI]: 0.683-0.922; P < 0.001) and 0.828 (CI: 0.679-0.906; P < 0.001), for the groups with and without limb loss, respectively, suggesting that CM has good to near excellent agreement with DXA for estimating %BF in these groups. Receiver operating characteristic analysis indicated that the area under the curve supported predictive ability to detect obesity-based %BF in males with and without limb loss.

CONCLUSIONS

Although a statistically significant difference was found between methods for individuals with limb loss, there was also good agreement between the methods, suggesting that CM may be a useful tool for estimating %BF in individuals with lower limb loss. The CM may be a useful and field expedient method for assessing %BF in a clinical setting when DXA is not available.

Body fatness in sedentary and active students with different body mass index

Study aim: Numerous data have indicated that body fat stores undergo complicated regulation by genetic and environmental factors, including physical activity. However, the majority of studies did not take into account this aspect of lifestyle in proposed body fat limits. In this context it seems that a more precise and reliable classification of body fat is provided by the American Council on Exercise (ACE), which distinguishes individuals not only with respect to sex but also activity level.

Material and methods: A total of 793 students (312 sedentary and 481 active) volunteered to participate in the study. Among sedentary participants 147 were male and 165 female. Among active subjects 206 were male and 275 were female. Active subjects were engaged in different modes of physical activity according to the study program. In all participants body mass index (BMI) was calculated. In participants with BMI 18.5–24.9 and BMI ≥ 25 body fat was determined using four skinfold measurements. Thereafter participants were classified according to the percentage of body fat using ranges for males and females provided by the American Council on Exercise (ACE) (essential fat, athletes, fitness, average and obese fatness).

Results: None of the sedentary and active males with BMI 18.5–24.9 had high (obese) fat. In contrast, in sedentary males with BMI ≥ 25 16.4% were obese vs. 1.8% of obese active ones. In sedentary females BMI from 18.5 to 24.9 did not exclude obesity, which was found in 16.9% of participants. In sedentary females with BMI ≥ 25 most of the subjects (97.1%) were obese. In contrast, in active females with BMI ≥ 25 a similar percentage of participants had average and obese fat (53.3% and 46.7, respectively).

Discussion: Our study clearly demonstrated that BMI as a simple measure of body composition provides false information concerning true adiposity in physically active male and female students. A similar BMI did not exclude marked differences in the percentage of body fat in sedentary and active students.

Five-Year Change in Body Mass Index Predicts Conversion to Mild Cognitive Impairment or Dementia Only in APOE ɛ4 Allele Carriers

BACKGROUND

Body mass index (BMI) has been identified as an important modifiable lifestyle risk factor for dementia, but less is known about how BMI might interact with Apolipoprotein E ɛ4 (APOE ɛ4) carrier status to predict conversion to mild cognitive impairment (MCI) and dementia.

OBJECTIVE

The aim of this study was to investigate the interaction between APOE ɛ4 status and baseline (bBMI) and five-year BMI change (ΔBMI) on conversion to MCI or dementia in initially cognitively healthy older adults.

METHODS

The associations between bBMI, ΔBMI, APOE ɛ4 status, and conversion to MCI or dementia were investigated among 1,289 cognitively healthy elders from the National Alzheimer's Coordinating Center (NACC) database.

RESULTS

After five years, significantly more carriers (30.6%) converted to MCI or dementia than noncarriers (17.6%), p < 0.001, OR = 2.06. Neither bBMI (OR = 0.99, 95%CI = 0.96-1.02) nor the bBMI by APOE interaction (OR = 1.02, 95%CI = 0.96-1.08) predicted conversion. Although ΔBMI also did not significantly predict conversion (OR = 0.90, 95%CI = 0.78-1.04), the interaction between ΔBMI and carrier status was significant (OR = 0.72, 95%CI = 0.53-0.98). For carriers only, each one-unit decline in BMI over five years was associated with a 27%increase in the odds of conversion (OR = 0.73, 95%CI = 0.57-0.94).

CONCLUSION

A decline in BMI over five years, but not bBMI, was strongly associated with conversion to MCI or dementia only for APOE ɛ4 carriers. Interventions and behaviors aimed at maintaining body mass may be important for long term cognitive health in older adults at genetic risk for AD.

Sample Preparation Methods for Lipidomics Approaches Used in Studies of Obesity

Obesity is associated with alterations in the composition and amounts of lipids. Lipids have over 1.7 million representatives. Most lipid groups differ in composition, properties and chemical structure. These small molecules control various metabolic pathways, determine the metabolism of other compounds and are substrates for the syntheses of different derivatives. Recently, lipidomics has become an important branch of medical/clinical sciences similar to proteomics and genomics. Due to the much higher lipid accumulation in obese patients and many alterations in the compositions of various groups of lipids, the methods used for sample preparations for lipidomic studies of samples from obese subjects sometimes have to be modified. Appropriate sample preparation methods allow for the identification of a wide range of analytes by advanced analytical methods, including mass spectrometry. This is especially the case in studies with obese subjects, as the amounts of some lipids are much higher, others are present in trace amounts, and obese subjects have some specific alterations of the lipid profile. As a result, it is best to use a method previously tested on samples from obese subjects. However, most of these methods can be also used in healthy, nonobese subjects or patients with other dyslipidemias. This review is an overview of sample preparation methods for analysis as one of the major critical steps in the overall analytical procedure.

The performance of anthropometric tools to determine obesity: a systematic review and meta-analysis

The aim of this systematic review was to assess the performance of anthropometric tools to determine obesity in the general population (CRD42018086888). Our review included 32 studies. To detect obesity with body mass index (BMI), the meta-analyses rendered a sensitivity of 51.4% (95% CI 38.5-64.2%) and a specificity of 95.4% (95% CI 90.7-97.8%) in women, and 49.6% (95% CI 34.8-64.5%) and 97.3% (95% CI 92.1-99.1%), respectively, in men. For waist circumference (WC), the summary estimates for the sensitivity were 62.4% (95% CI 49.2-73.9%) and 88.1% for the specificity (95% CI 77.0-94.2%) in men, and 57.0% (95% CI 32.2-79.0%) and 94.8% (95% CI 85.8-98.2%), respectively, in women. The data were insufficient to pool the results for waist-to-hip ratio (WHR) and waist-to-height ratio (WHtR) but were similar to BMI and WC. In conclusion, BMI and WC have serious limitations for use as obesity screening tools in clinical practice despite their widespread use. No evidence supports that WHR and WHtR are more suitable than BMI or WC to assess body fat. However, due to the lack of more accurate and feasible alternatives, BMI and WC might still have a role as initial tools for assessing individuals for excess adiposity until new evidence emerges.

Effects of Daily Probiotics Supplementation on Anxiety Induced Physiological Parameters among Competitive Football Players

Competitive football players who undergo strenuous training and frequent competitions are more vulnerable to psychological disorders. Probiotics are capable of reducing these psychological disorders. The present study aimed to determine the effect of daily probiotics supplementation on anxiety induced physiological parameters among competitive football players. The randomized, double-blinded, placebo-controlled trial was conducted on 20 male footballers who received either probiotics (Lactobacillus Casei Shirota strain 3 × 1010 colony forming units (CFU) or a placebo drink over eight weeks. Portable biofeedback devices were used to measure the electroencephalography, heart rate, and electrodermal responses along with cognitive tests at the baseline, week 4, and week 8. Data were statistically analyzed using mixed factorial ANOVA and results revealed that there is no significant difference between the probiotic and placebo groups for heart rate (61.90 bpm ± 5.84 vs. 67.67 bpm ± 8.42, p = 0.09) and electrodermal responses (0.27 µS ± 0.19 vs. 0.41 µS ± 0.12, p = 0.07) after eight weeks. Similarly, brain waves showed no significant changes during the study period except for the theta wave and delta wave at week 4 (p < 0.05). The cognitive test reaction time (digit vigilance test) showed significant improvement in the probiotic group compared to the placebo (p < 0.05). In conclusion, these findings suggest that daily probiotics supplementation may have the potential to modulate the brain waves namely, theta (relaxation) and delta (attention) for better training, brain function, and psychological improvement to exercise. Further research is needed to elucidate the mechanism of current findings.

Association Between Diet, Physical Activity and Body Mass Index, Fat Mass Index and Bone Mineral Density of Soldiers of the Polish Air Cavalry Units

Research from recent years indicates a problem of excessive body weight among soldiers, who, due to the kind of work carried out, should possess good health and fitness levels. The aim of the study was to determine the association between diet and physical activity and the nutritional status of soldiers of the Polish Air Cavalry Units. One hundred and twenty male soldiers (aged 28 ± 5 years) completed a questionnaire (food frequency questionnaire, long-form International Physical Activity Questionnaire). Body composition was determined by bioelectrical impedance analysis, and bone calcification of the forearm was assessed by the DXA (Dual Energy X-ray Absorptiometry) densitometric method. This study confirmed the association between both the diet and physical activity and body mass index (BMI), fat mass index (FMI), and bone mineral density (BMD) expressed as T-score. Significant negative correlations were found between BMI and the frequency of consumption of cereal products, meat products and fish, and nonalcoholic beverages, between FMI and cereal products, and between BMD T-score and meat products and fish, fat, nuts, and grains, sweets and snacks, and nonalcoholic beverages. Physical activity expressed as metabolic equivalent (MET-minutes/week) negatively correlated with FMI (but not BMI) and positively correlated with the BMD T-score. This study confirmed numerous irregularities in eating behavior and in nutritional status indices; therefore, there is a need for nutritional education and further monitoring of both dietary behaviors and nutritional status of soldiers.

Musculoskeletal training injury prevention in the U.S. Army: Evolution of the science and the public health approach

Injuries cause more morbidity among soldiers in the U.S. Army than any other health condition. Over two-thirds of U.S. soldiers' injuries occur gradually from cumulative micro-traumatic damage to the musculoskeletal system as a result of physical training activities. Paradoxically, the very physical training activities required to improve soldier performance also result in injury. Determining the amounts and types of physical training that maximize performance while minimizing injuries requires scientific evidence. This evidence must be incorporated into a framework that ensures scientific gaps are addressed and prevention efforts are evaluated. The five-step public health approach has proven to be an effective construct for Army public health to organize and build an injury prevention program. Steps include: 1) surveillance to define the magnitude of the problem, 2) research and field investigations to identify causes and risk factors, 3) intervention trials and systematic reviews to determine what works to address leading risk factors, 4) program and policy implementation to execute prevention, and 5) program evaluation to assess effectiveness. Dissemination is also needed to ensure availability of scientific lessons learned. Although the steps may not be conducted in order, the capability to perform each step is necessary to sustain a successful program and make progress toward injury control and prevention. As with many U.S. public health successes (e.g., seatbelts, smoking cessation), the full process can take decades. As described in this paper, the U.S. Army uses the public health approach to assure that, as the science evolves, it is translated into effective prevention.

Associations of age, aerobic fitness, and body mass index with injury in an operational Army brigade

OBJECTIVES

To investigate the effects of age, aerobic fitness, and body mass index (BMI) on injury risk in operational Army soldiers.

DESIGN

Retrospective cohort study.

METHODS

Male soldiers from an operational Army brigade were administered electronic surveys regarding personal characteristics, physical fitness, and injuries occurring over the last 12 months. Injury risks were stratified by age, 2-mile run time, and BMI. Analyses included descriptive incidence, a Mantel-Haenszel χ² test to determine trends, a multivariable logistic regression to determine factors associated with injury, and a one-way analysis of variance (ANOVA).

RESULTS

Forty-seventy percent of 1099 respondents reported at least one injury. A linear trend showed that as age, 2-mile run time, and BMI increased, so did injury risk (p<0.01). When controlling for BMI, the most significant independent injury risk factors were older age (odd ratio (OR) 30years-35years/≤24years=1.25, 95%CI: 1.08-2.32), (OR≥36years/≤24years=2.05, 95%CI: 1.36-3.10), and slow run times (OR≥15.9min/≤13.9min=1.91, 95%CI: 1.28-2.85). An ANOVA showed that both run times and BMI increased with age.

CONCLUSIONS

The stratified analysis and the multivariable logistic regression suggested that older age and poor aerobic fitness are stronger predictors of injury than BMI.

Overfat Adults and Children in Developed Countries: The Public Health Importance of Identifying Excess Body Fat

The global overfat pandemic is a serious public health crisis that places a substantial burden on economic resources in developed countries. The term overfat refers to the presence of excess body fat that can impair health, even for normal weight non-obese individuals. Excess body fat is associated with cardiometabolic dysfunction, a clinical situation that can progressively worsen, potentially leading to various common disease risk factors, chronic diseases, increased morbidity and mortality, and reduced quality of life. The prevalence of overfat populations in 30 of the world’s most developed countries is substantially higher than recent global estimations, with the largest growth due to a relatively recent increased number of people with excess abdominal fat. Abdominal overfat is the most unhealthful form of this condition, so it is concerning that average waist circumference measures, generally indicative of abdominal overfat, have increased. Despite a leveling off appearance of being overweight and/or obese in some developed countries, the overfat pandemic continues to grow.

The Role of Gender and Physical Performance on Injuries: An Army Study

INTRODUCTION

In basic combat training, women experience twice as many injuries as men; however, evidence at the operational Army level is limited. This study aims to investigate the association between gender and injury likelihood while controlling for certain confounding factors in the operational Army.

METHODS

Data were analyzed in 2015 from a cross-sectional study utilizing data from a 2010-2011 survey of light infantry Army Soldiers. Gender, age, body fat, tobacco use, Army Physical Fitness Test (2-mile run, push-ups, and sit-ups), occupational physical demand, and injury data were obtained via paper survey. ORs and 95% CIs from a multivariable analysis were calculated.

RESULTS

Surveys were completed by 4,384 male and 363 female Soldiers. Injury incidence was 42% for men and 53% for women. After adjusting for the aforementioned variables, injury likelihood was higher in Soldiers aged ≥27 years (OR [age 27-29/22-26 years]=1.26, 95% CI=1.07, 1.48; OR [age ≥30/22-26 years]=1.28, 95% CI=1.08, 1.51), Soldiers with body fat ≥23.38% (OR [body fat ≥23.38%/≤19.28%]=1.30, 95% CI=1.08, 1.57), and Soldiers with the slowest 2-mile run times (OR [≥15.68/≤14.13 minutes]=1.53, 95% CI=1.26, 1.85). Women were no more likely than men to sustain an injury.

CONCLUSIONS

When accounting for age, body fat, physical performance, and occupational physical demand, there was no gender difference in the likelihood of injury among Soldiers. Although women, on average, have lower aerobic and muscular performance than men, results suggest men and women of similar physical performance experience similar injury likelihood.

Specific BIVA recognizes variation of body mass and body composition: Two related but different facets of nutritional status

OBJECTIVE

The aim of this study was to demonstrate the different information provided by body mass index (BMI) in combination with specific bioelectrical impedance vector analysis (specific BIVA) in the measure of relative body fat.

METHODS

Anthropometric and bioelectrical values and dual-energy x-ray absorpitometry measurements from a sample of 1590 US adults of both sexes were retrieved from the National Health and Nutrition Examination Survey 2003-2004. The sample distribution of the BMI of each sex was divided into deciles. Quartiles were calculated for percent fat mass (FM%) after stratifying by BMI deciles. Body composition and bioelectrical characteristics of groups below the first and above the third quartile were compared using analysis of variance and the Hotelling's T-square test.

RESULTS

BMI and specific BIVA showed a different accuracy in detecting body composition variations: BMI showed similar values in groups represented by different FM percentages, whereas the bioelectrical differences were statistically significant. The mean impedance vectors corresponding to cases below the first FM% quartiles were shorter and located on the left side of the ellipses (the region of higher fat-free mass), whereas those above the third FM% quartiles were on the right and toward the upper pole (the region of higher FM%).

CONCLUSIONS

Specific BIVA is a technique for the evaluation of body composition which can add relevant information regarding BMI.