Skeletal Correlates for Body Mass Estimation in Modern and Fossil Flying Birds

Scaling relationships between skeletal dimensions and body mass in extant birds are often used to estimate body mass in fossil crown-group birds, as well as in stem-group avialans. However, useful statistical measurements for constraining the precision and accuracy of fossil mass estimates are rarely provided, which prevents the quantification of robust upper and lower bound body mass estimates for fossils. Here, we generate thirteen body mass correlations and associated measures of statistical robustness using a sample of 863 extant flying birds. By providing robust body mass regressions with upper- and lower-bound prediction intervals for individual skeletal elements, we address the longstanding problem of body mass estimation for highly fragmentary fossil birds. We demonstrate that the most precise proxy for estimating body mass in the overall dataset, measured both as coefficient determination of ordinary least squares regression and percent prediction error, is the maximum diameter of the coracoid’s humeral articulation facet (the glenoid). We further demonstrate that this result is consistent among the majority of investigated avian orders (10 out of 18). As a result, we suggest that, in the majority of cases, this proxy may provide the most accurate estimates of body mass for volant fossil birds. Additionally, by presenting statistical measurements of body mass prediction error for thirteen different body mass regressions, this study provides a much-needed quantitative framework for the accurate estimation of body mass and associated ecological correlates in fossil birds. The application of these regressions will enhance the precision and robustness of many mass-based inferences in future paleornithological studies.     

体质指数与直肠癌的关系探讨

目的：探讨体质指数（bodymassindex,BMI）与我国直肠癌发病的关系,为直肠癌的预防提供参考。方法：用病例．对照研究方法分析353例首次确诊的直肠癌患者和354名健康人的BMI,比较两组人群BMI的情况。结果：首次确诊的直肠癌患者平均BMI为（24．54±4．48）kg／m^2,健康对照人群平均BMI为（23．58±3．12）kg／m^2,直肠癌患者的BMI明显高于健康对照人群,其差别具有统计学意义（P〈0．001）。根据性别的不同进行分组后,可以看出不同性别直肠癌患者的BMI均比健康对照组高。logistic回归分析,BMI的升高是直肠癌发生的危险因素,OR值为1．056（95％CI,1．027±1．089）。结论：直肠癌的发生与BMI有关。     

Relationship between Body Mass Index and the Use of Healthcare Services in Australia

Objective: To examine the relationship between body mass index (BMI) and the use of medical and preventive health services. Research Methods and Procedures: This study involved secondary analysis of weighted data from the Australian 1995 National Health Survey. The study was a population survey designed to obtain national benchmark information about a range of health‐related issues. Data were available from 17,033 men and 17,174 women, ≥20 years or age. BMI, based on self‐reported weight and height, was analyzed in relation to the use of medical services and preventive health services. Results: A positive relationship was found between BMI and medical service use, such as medication use, visits to hospital accident and emergency departments (for women only); doctor visits, visits to a hospital outpatient clinics; and visits to other health professionals (for women only). A negative relationship was found in women between BMI and preventive health services. Underweight women were found to be significantly less likely to have Papanicolaou smear tests, breast examinations, and mammograms. Discussion: This research shows that people who fall outside the healthy weight range are more likely to use a range of medical services. Given that the BMI of industrialized populations appears to be increasing, this has important ramifications for health service planning and reinforces the need for obesity prevention strategies at a population level.     

Estimation of Total Body Skeletal Muscle Mass in Chinese Adults: Prediction Model by Dual-Energy X-Ray Absorptiometry

Background

There are few reports on total body skeletal muscle mass (SM) in Chinese. The objective of this study is to establish a prediction model of SM for Chinese adults.

Methodology

Appendicular lean soft tissue (ALST) was measured by dual energy X-ray absorptiometry (DXA) and SM by magnetic resonance image (MRI) in 66 Chinese adults (52 men and 14 women). Images of MRI were segmented into compartments including intermuscular adipose tissue (IMAT) and IMAT-free SM. Regression was used to fit the prediction model . Age and gender were adjusted in the fitted model. The piece-wise linear function was performed to further explore the effect of age on SM. ‘Leave-One-Out Cross Validation’ was utilized to evaluate the prediction performance. The significance of observed differences between predicted and actual SM was tested by t test and the level of agreement was assessed by the method of Bland and Altman.

Results

Men had greater ALST and IMAT-free SM than women. ALST was the primary predictor and highly correlated with IMAT-free SM (R² = 0.94, SEE = 1.11 kg, P<0.001). Age was an additional predictor (SM prediction model with age adjusted R ² = 0.95, SEE = 1.05 kg, P<0.001). There was a piece-wise linear relationship between age and IMAT-free SM: IMAT-free SM = 1.21×ALST−0.98, (Age <45 years) and IMAT-free SM = 1.21×ALST−0.98−0.04× (Age−45), (Age ≥45years). The prediction performance of this age-adjusted model was good due to ‘Leave-One-Out Cross Validation’. No significant difference between measured and predicted IMAT-free SM was detected.

Conclusion

Previous SM prediction model developed in multi-ethnic groups underestimated SM by 2.3% and 3.4% for Chinese men and women. A new prediction model by DXA has been established to predict SM in Chinese adults.     

Relationship between Body Mass Index and Percent Body Fat in Vietnamese: Implications for the Diagnosis of Obesity

BackgroundThe burden of obesity in Vietnam has not been well defined because there is a lack of reference data for percent body fat (PBF) in Asians. This study sought to define the relationship between PBF and body mass index (BMI) in the Vietnamese population.MethodsThe study was designed as a comparative cross-sectional investigation that involved 1217 individuals of Vietnamese background (862 women) aged 20 years and older (average age 47 yr) who were randomly selected from the general population in Ho Chi Minh City. Lean mass (LM) and fat mass (FM) were measured by DXA (Hologic QDR 4500). PBF was derived as FM over body weight.ResultsBased on BMI ≥30, the prevalence of obesity was 1.1% and 1.3% for men and women, respectively. The prevalence of overweight and obesity combined (BMI ≥25) was ~24% and ~19% in men and women, respectively. Based on the quadratic relationship between BMI and PBF, the approximate PBF corresponding to the BMI threshold of 30 (obese) was 30.5 in men and 41 in women. Using the criteria of PBF >30 in men and PBF >40 in women, approximately 15% of men and women were considered obese.ConclusionThese data suggest that body mass index underestimates the prevalence of obesity. We suggest that a PBF >30 in men or PBF >40 in women is used as criteria for the diagnosis of obesity in Vietnamese adults. Using these criteria, 15% of Vietnamese adults in Ho Chi Minh City was considered obese.     

Relationship between Waist Circumference,Body Mass Index,and Medical Care Costs

Objective: Excessive visceral adiposity as measured by anthropomorphic measures may be more closely associated with adverse health consequences than body weight or body mass index (BMI), the more commonly obtained clinical measures. Waist circumference (WC) provides information about regional adiposity and may correlate with health care costs better than body weight or BMI. Research Methods and Procedures: A total of 424 men (37%) and women (63%) were identified as they were seen in outpatient medical clinics at Denver Health, an integrated health care system serving a largely indigent population. Height, weight, and WC were measured by one examiner. Information on outpatient, laboratory, pharmacy, inpatient, and total charges attributable to each subject for the preceding year were obtained from computerized databases. Data on health care charges were divided into quartiles based on WC and BMI. Results: Total annual health care charges were significantly greater in the highest WC quartile (WC < 83.3 cm: $6062 ± $784; 83.3 to 93.5 cm: $5968 ± $812; 93.7 to 103.5 cm: $6369 ± $1015; >103.5 cm: $8699 ± $1092; p = 0.047). Those with a WC >103.5 cm generated 85% more inpatient charges than the group with a WC <83.3 cm. Although there was a positive trend, BMI was not found to significantly correlate with total health care charges in this population sample. Discussion: These results suggest that abdominal adiposity as assessed by WC is associated with increased total health care charges and may be a better predictor of health care charges than the more widely used BMI.     

Relationship between Body Mass Index and Mortality in HIV-Infected HAART Users in the Women's Interagency HIV Study

Background

Early HIV studies suggested protective associations of overweight against mortality, yet data are lacking for the era of potent highly active antiretroviral therapy (HAART). We evaluated associations of pre-HAART initiation body mass index (BMI) with mortality among HAART-using women.

Methods

Prospective study of time to death after HAART initiation among continuous HAART users in the Women’s Interagency HIV Study. Unadjusted Kaplan–Meier and adjusted proportional hazards survival models assessed time to AIDS and non-AIDS death by last measured pre-HAART BMI.

Results

Of 1428 continuous HAART users 39 (2.7%) were underweight, 521 (36.5%) normal weight, 441 (30.9%) overweight, and 427 (29.9%) obese at time of HAART initiation. A total of 322 deaths occurred during median follow-up of 10.4 years (IQR 5.9–14.6). Censoring at non-AIDS death, the highest rate of AIDS death was observed among underweight women (p = 0.0003 for all 4 categories). In multivariate models, women underweight prior to HAART died from AIDS more than twice as rapidly vs. normal weight women (aHR 2.04, 95% CI 1.03, 4.04); but being overweight or obese (vs. normal weight) was not independently associated with AIDS death. Cumulative incidence of non-AIDS death was similar across all pre-HAART BMI categories.

Conclusions

Among continuous HAART-using women, being overweight prior to initiation was not associated with lower risk of AIDS or non-AIDS death. Being underweight prior to HAART was associated with over double the rate of AIDS death in adjusted analyses. Although overweight and obesity may be associated with many adverse health conditions, neither was predictive of mortality among the HAART-using women.     

Exploring the Relationship between Semantics and Space

The asymmetric distribution of human spatial attention has been repeatedly documented in both patients and healthy controls. Biases in the distribution of attention and/or in the mental representation of space may also affect some aspects of language processing. We investigated whether biases in attention and/or mental representation of space affect semantic representations. In particular, we investigated whether semantic judgments could be modulated by the location in space where the semantic information was presented and the role of the left and right parietal cortices in this task. Healthy subjects were presented with three pictures arranged horizontally (one middle and two outer pictures) of items belonging to the same semantic category. Subjects were asked to indicate the spatial position in which the semantic distance between the outer and middle pictures was smaller. Subjects systematically overestimated the semantic distance of items presented in the right side of space. We explored the neural correlates underpinning this bias using rTMS over the left and right parietal cortex. rTMS of the left parietal cortex selectively reduced this rightward bias. Our findings suggest the existence of an attentional and/or mental representational bias in semantic judgments, similar to that observed for the processing of space and numbers. Spatial manipulation of semantic material results in the activation of specialised attentional resources located in the left hemisphere.     

The Relationship between Native American Ancestry,Body Mass Index and Diabetes Risk among Mexican-Americans

Higher body mass index (BMI) is a well-established risk factor for type 2 diabetes, and rates of obesity and type 2 diabetes are substantially higher among Mexican-Americans relative to non-Hispanic European Americans. Mexican-Americans are genetically diverse, with a highly variable distribution of Native American, European, and African ancestries. Here, we evaluate the role of Native American ancestry on BMI and diabetes risk in a well-defined Mexican-American population. Participants were randomly selected among individuals residing in the Houston area who are enrolled in the Mexican-American Cohort study. Using a custom Illumina GoldenGate Panel, we genotyped DNA from 4,662 cohort participants for 87 Ancestry-Informative Markers. On average, the participants were of 50.2% Native American ancestry, 42.7% European ancestry and 7.1% African ancestry. Using multivariate linear regression, we found BMI and Native American ancestry were inversely correlated; individuals with <20% Native American ancestry were 2.5 times more likely to be severely obese compared to those with >80% Native American ancestry. Furthermore, we demonstrated an interaction between BMI and Native American ancestry in diabetes risk among women; Native American ancestry was a strong risk factor for diabetes only among overweight and obese women (OR = 1.190 for each 10% increase in Native American ancestry). This study offers new insight into the complex relationship between obesity, genetic ancestry, and their respective effects on diabetes risk. Findings from this study may improve the diabetes risk prediction among Mexican-American individuals thereby facilitating targeted prevention strategies.     

The Relationship Between Body Image Discrepancy and Body Mass Index Across Ethnic Groups

Objective: This study sought to examine at what body mass index (BMI) body image discrepancy (BD) was reported in a community sample of 389 white, Hispanic, and black women. In addition, we assessed the trajectory of the BMI–BD relationship as BMI increases by ethnic group. Research Methods and Procedures: All participants were assessed on height and weight and completed the Figure Rating Scale. Results: We found no difference in the proportion of women in each ethnic group reporting BD. However, white women experienced BD at a lower BMI level (BMI = 24.6), and below the criterion for overweight (BMI = 25). In contrast, black and Hispanic women did not report BD until they were overweight (BMIs of 29.2 and 28.5, respectively). Compared with black and white women, Hispanic women registered increases in BD at smaller increases in BMI. Discussion: These findings could have unhealthful implications for weight control behavior. The results encourage a closer look at ethnicity and BD, and their relationship to obesity and weight control.     

The Body Mass Index-Mortality Relationship in White and African American Women

Objective : To examine the association of body mass index to all-cause and cardiovascular disease (CVD) mortality in white and African American women. Research methods and procedures : Women who were members of the American Cancer Society Prevention Study I were examined in 1959 to 1960 and then followed 12 years for vital status. Data for this analysis were from 8,142 black and 100,000 white women. Body mass index (BMI) was calculated from reported height and weight. Associations were examined using Cox proportional hazards modeling with some analyses stratified by smoking (current or never) and educational status (less than complete high school or high school graduate). Results : There was a significant interaction between ethnicity and BMI for both all-cause (p<0.05) and CVD mortality (p<<0.001). BMI (as a continuous variable) was associated with all-dause mortality in white women in all four groups defined by smoking and education. In black women with less than a high school education, there were no significant associations between BMI mortality. For high school-educated black women, there was a significant association between BMI and all-cause mortality. Among never smoking women with at least a high school education, models using the lowest BMI as the reference indicated a 40% higher risk of all-cause mortality at a BMI of 35.9 in black women vs. 27.3 in white women. Discussion : The impact of BMI on mortality was modified by educational level in black women; however, BMI was a less potent risk factor in black women than in white women in the same category of educational status.     

Meta-Analysis of the Effect of Excluding Early Deaths on the Estimated Relationship between Body Mass Index and Mortality

ALLISON, DAVID B., MYLES S. FAITH, MOONSEONG HEO, DIANA TOWNSEND-BUTTERWORTH, AND DAVID F. WILLIAMSON. Meta-analysis of the effect of excluding early deaths on the estimated relationship between body mass index and mortality. Obes Res. Objectives: Prospective cohort studies typically observe U-or J-shaped relationships between body mass index (BMI) (kg/m²) and mortality. However, some studies suggest that the elevated mortality at lower BMIs is due to confounding by pre-existing occult disease and recommend eliminating subjects who die during the first several (k) years of follow-up. This meta-analysis tests the effects of such early death exclusion on the BMI-mortality association. Research Methods and Procedures: Studies identified from MEDLINE, review articles, ancestry analyses, and the “invisible college.” Included studies: 1) measured relative body weight at baseline; 2) inchded at least 1000 subjects; 3) reported results with and without early-death exclusion, or relevant data; and 4) did not study exclusively diseased populations. Blank tables were mailed to 131 investigators covering 59 databases. Completed tables (n = 16 databases), electronic raw data (n = 7 databases), and original articles (n = 6 databases) provided final data. Meta-analytic regressions compared the BMI-mortality association with and without early death exclusion. The sample included 29 studies and 1,954,345 subjects. Results: The effect of eliminating early deaths was statistically significant but minuscule in magnitude. Implementation of early death exclusion was estimated to shift the BMI associated with minimum mortality only 0. 4 units for men and 0. 6 units for women at age 50. Even at a BMI 16, the estimated relative risk (compared to BMI 25) decreased only 0. 008 units for men and 0. 076 units for women at age 50. Discussion: Results indicate that either pre-existing disease does not confound the BMI—mortality association or eliminating early deaths is inefficient for reducing that confounding.     

驻某地武警机关干部体质指数与代谢性疾病的关系

目的:探讨健康体检的驻某地武警机关干部体质指数(BMI)与代谢性疾病的关系。方法:采用横断面调查方法对健康体检的1920名驻某地武警机关干部和270名地方机关干部的体质指数情况进行比较分析,探讨超重肥胖与代谢性疾病的关系。结果:1.军人组超重率及肥胖率均低于地方组(P<0.01)。2.<50岁人群组随年龄增加,超重及肥胖检出率有增高趋势(P<0.01),40~49岁人群超重率和肥胖率最高;50~65岁人群超重与肥胖率最低。3.两组机关干部随BMI升高,高总胆固醇、高甘油三酯、高尿酸血症、脂肪肝检出率增高(P<0.01);军人组高尿酸血症发病率明显高于地方组(P<0.05);高血压、高血脂发病率明显降低(P<0.05);与地方超重组比较,军人超重组脂肪肝发病率明显升高(P<0.05)。4.在30~50岁的军人中,随着年龄升高,高血压、高血糖、高血脂、高尿酸,脂肪肝发病率明显升高(P<0.01)。结论:健康体检人群超重、肥胖率较高,控制体重对高血压、高血糖、高血脂及脂肪肝等慢性病的防治具有重要意义。军人组超重与肥胖率均低于地方,但高尿酸血症和高脂肪肝发病率升高,故建议有代谢性疾病的军人限制饮酒可能会受益。     

冠心病患者血清CRP的变化及其临床意义

目的:探讨冠心病(CAD)患者血清C-反应蛋白(CRP)的变化及其临床意义.方法:运用全自动生化分析仪检测97例CAD患者和28例对照组人群的血清CRP,将CAD患者进一步分为稳定性心绞痛组(SAP)、不稳定心绞痛(UAP)、心肌梗死组(AMI)三组.另外,将97例CAD惠者分为1支病变组、2支病变组和3支病变组.所有研究对象均行选择性冠状动脉造影检查.结果:(1)与对照组比较,CAD患者血清CRP显著升高(P<0.05);(2)与对照组比较,SAP组、UAP组和AMI组患者血清CRP均显著升高(P<0.05);与SAP组比较,UAP组和AMI组患者血清CRP亦显著升高(P<0.05);(3)与对照组比较,1支病变组、2支病变组和3支病变组患者血清CRP均显著升高(P<0.05);与1支病变组比较,2支病变组和3支病变组患者血清CRP亦显著升高(P<0.05);与2支病变组比较,3支病变组患者血清CRP亦显著升高(P<0.05).结论:(1)CRP可能与CAD有关;(2)CRP异常升高可能反映冠状动脉斑块的不稳定和CAD的严重程度.     

Relationship between Chronic Short Sleep Duration and Childhood Body Mass Index: A School-Based Cross-Sectional Study

Objective

To assess relationship between obesity and chronic shorter sleep duration in children and to determine if lack of sleep represents an independent determinant of childhood Body Mass Index.

Methods

This cross-sectional study was conducted in all children enrolled in the fifth class (approximately 10 years of age) of all public primary schools in Catanzaro (Southern Italy). The overall response rate was 62% resulting in 542 participating children. Parents completed a questionnaire with information on their demographics and socio-economic characteristics, their health status, characteristics of their child birth and health status. The sleeping habits were investigated in the 3 months preceding the consultation and parents were asked to indicate hours of bedtime and wake-up of their children. Multivariate linear regression analysis was performed to examine the association between child BMI and chronic lack of sleep.

Results

36.7% of the children surveyed were overweight or obese. A quarter of children did not routinely play sports and many of them spent more than an hour a day watching TV (60.7%) and using videogames or computer (51.1%). Widespread dietary habits were inadequate, especially concerning vegetables and fruit intake with more than 95% of children who consumed insufficient amounts. The average duration of sleep was equal to 9.4 (SD = ±0.6) hours, and the short-sleepers accounted for 38.9% of the total sample. The results of multivariate analysis showed a significant 0.77 Kg/m² increase of BMI for children classified as short compared to normal sleepers (95%CI = 0.16–1.38, p = 0.01).

Conclusions

Chronic lack of sleep appears to be associated to higher BMI even in middle childhood and strongly suggests that public health strategies, focused on promoting healthy lifestyles should include an innovative approach to ensure an adequate duration of sleep at night especially in children, alongside more traditional approaches.     

Relationship between Body Mass Index,C-Peptide,and Delta-5-Desaturase Enzyme Activity Estimates in Adult Males

Obesity, in particular abdominal obesity, alters the composition of plasma and tissue fatty acids (FAs), which contributes to inflammation and insulin resistance. FA metabolism is modulated by desaturases and may affect adipokine and insulin secretion. Therefore, we examined relationships between adipokines, a marker of insulin production, and plasma FA desaturase enzyme activity estimates (EAEs) in obesity. Plasma phospholipid (PPL) FAs were isolated from 126 males (ages 48 to 65 years), derivatized, and analyzed using gas chromatography. Delta-6 desaturase (D6D) and delta-5 desaturase (D5D) EAEs were calculated as the ratio of PPL 20:3/18:2 and 20:4/20:3, respectively. In body mass index (BMI) and waist circumference (WC) adjusted polytomous logistic regression analyses, PPL FAs and FA desaturase EAEs were associated with C-peptide and adiponectin. Individuals with elevated D6D EAEs were less likely (OR 0.33) to have serum adiponectin concentrations > 5.37 μg/mL, compared with adiponectin concentrations ≤ 3.62 μg/mL. Individuals with increased D5D EAEs were less likely (OR 0.8) to have C-peptide concentrations ≥ 3.32 ng/mL, and > 1.80 and ≤ 3.29 ng/mL, compared with those with C-peptide ≤ 1.76 ng/mL. The proinflammatory cytokine tumor necrosis factor-α (TNF- α) was positively associated with C-peptide, but TNF- α was not associated with the D5D EAE. C-peptide and adiponectin concentrations are associated with specific PPL FAs and FA desaturase EAEs. The relationship between C-peptide concentrations and D5D EAEs remained significant after adjusting for BMI, WC, and TNF-α. Thus, future research should investigate whether D5D inhibition may occur through a C-peptide mediated pathway.     

The Relationship between Body Mass Index and Post-Cessation Weight Gain in the Year after Quitting Smoking: A Cross-Sectional Study

Introduction

There is wide variability in the amount of weight gained when quitting smoking, but little is known about key predictors of weight gain. We examined the impact of body mass index (BMI) category and sociodemographic variables on post-cessation weight gain.

Materials and Methods

We utilized National Health and Nutrition Examination Survey data from five consecutive cycles of data collection from 2003–2004 to 2011–2012 to estimate post-cessation weight gain by BMI category among recent quitters (n = 654). We analyzed data on their “current weight” and their “past year weight”. We also compared the recent quitters with current smokers, in order to estimate the amount of weight that could be attributed to quitting smoking.

Results

Recent quitters gained 1.4 kg (95% CI: 0.8 to 2.0), while current smokers had a non-significant weight change (-0.01 kg (95% CI: -0.3 to 0.2). Weight gain was significant for those in the normal weight (3.1 kg, 95% CI: 2.3 to 3.9) and overweight BMI categories (2.2 kg, 95% CI: 1.1 to 3.2).

Conclusions

BMI category is a key factor in the extent of post-cessation weight gain, with normal and overweight recent quitters gaining significant amounts of weight.     

Scaling Relationships between Leaf Mass and Total Plant Mass across Chinese Forests

Biomass partitioning is important for illustrating terrestrial ecosystem carbon flux. West, Brown and Enquist (WBE) model predicts that an optimal 3/4 allometric scaling of leaf mass and total biomass of individual plants will be applied in diverse communities. However, amount of scientific evidence suggests an involvement of some biological and environmental factors in interpreting the variation of scaling exponent observed in empirical studies. In this paper, biomass information of 1175 forested communities in China was collected and categorized into groups in terms of leaf form and function, as well as their locations to test whether the allocation pattern was conserved or variable with internal and/or environmental variations. Model Type II regression protocol was adopted to perform all the regressions. The results empirically showed that the slopes varied significantly across diverse forested biomes, between conifer and broadleaved forests, and between evergreen and deciduous forests. Based on the results, leaf form and function and their relations to environments play a significant role in the modification of the WBE model to explore more accurate laws in nature.     

Defining the Relationship between Obesity and Total Joint Arthroplasty

Objective: The purpose of this study was to examine the relationship between obesity and patient‐administered outcome measures after total joint arthroplasty. Research Methods and Procedures: A voluntary questionnaire‐based registry contained 592 primary total hip arthroplasty patients and 1011 primary total knee arthroplasty patients with preoperative and 1‐year data. Using logistic regression, the relationships between body mass index and the several outcome measures, including Short Form‐36 and Western Ontario and McMaster Universities Osteoarthritis Index, were examined. Results: There was no difference between obese and non‐obese patients regarding satisfaction, decision to repeat surgery, and Δphysical component summary, Δmental component summary, and ΔWestern Ontario and McMaster Universities Osteoarthritis Index scores (p > 0.05 for all). Body mass index was associated with an increased risk of having difficulty descending or ascending stairs at 1 year (odds ratio, 1.2 to 1.3). Discussion: Obese patients enjoy as much improvement and satisfaction as other patients from total joint arthroplasty.