Influence of the menopause and aging on spinal density in French women

Dual photon absorptiometry (DPA) was used to measure the bone mineral density (BMD) of the lumbar spine in 510 normal women from the south of France. Long-term precision was 2.2%. BMD was stable in young adults and again in women over 70 years of age. Perimenopausal women at an average age of 51 years already evidenced a slight bone diminution (5%) compared to young adults and women within 2 years of the menopause already had a 10% diminution. The average rate of apparent bone loss in this cross-sectional study was 1% per year from age 45 to 65 years, but about 75% of this decrease occurred in the first decade after the menopause. Spinal BMD in our normal French population appears to be 5–10% lower than US values.     

Nutritional status of Ribeirinhos in Brazil and the nutrition transition

Anthropometric and household data (size, composition, economic activity) were collected from a population of Ribeirinhos living in a rural setting in the eastern Amazon. Data are compared to international reference standards and to other Amazonian populations with the goals of increasing our understanding of the Amazon's largest ethnic group and identifying the relationship between changes in subsistence strategies and nutritional status. Data on height, weight, skinfolds, and circumferences were collected from 471 adults and subadults. The population showed a high degree of stunting with an average HAZ below -2.0 for all age groups over 3 years, and 60% of adult men and 70% of adult women were stunted. Wasting was rare. Average skinfold thicknesses and upper-arm muscle area were near or below average but within the normal range compared to the reference standard, indicating adequate energy and protein stores. Thirty-one percent of males and 29% of females were overweight/obese, and the highest average BMIs were found among men and women in their 40s. Adult males who participated in wage labor had higher weights, BMIs, and UMA values, and were more likely to be overweight and obese compared with those who did not work in wage-labor jobs. Children of fathers who worked in wage labor had higher BMI and UMA values, but there was no significant effect on the nutritional status of other adults in these same households. Signs of the nutrition transition were most noticeable among adult males involved in wage labor because of changes in their diet and activity patterns.     

Predictive regression modeling of body segment parameters using individual-based anthropometric measurements

Body segment parameters such as segment mass, center of mass, and radius of gyration are used as inputs in static and dynamic ergonomic and biomechanical models used to predict joint and muscle forces, and to assess risks of musculoskeletal injury. Previous work has predicted body segment parameters (BSPs) in the general population using age and obesity levels as statistical predictors (Merrill et al., 2017). Estimated errors in the prediction of BSPs can be as large as 40%, depending on age, and the prediction method employed (Durkin and Dowling, 2003). Thus, more accurate and representative segment parameter inputs are required for attempting to predict modeling outputs such as joint contact forces, muscle forces, and injury risk in individuals. This study aims to provide statistical models for predicting torso, thigh, shank, upper arm, and forearm segment parameters in working adults using whole body dual energy x-ray absorptiometry (DXA) scan data along with a set of anthropometric measurements. The statistical models were developed on a training data set, and independently validated on a separate test data set. The predicted BSPs in validation data were, on average, within 5% of the actual in vivo DXA-based BSPs, while previously developed predictions (de Leva, 1996) had average errors of up to 60%, indicating that the new models greatly increase the accuracy in predicting segment parameters. These final developed models can be used for calculating representative BSPs in individuals for use in modeling applications dependent on these parameters.     

Trends in the prevalence of abdominal obesity and overweight in English adults (1993-2008)

The rising prevalence of generalized obesity is well documented, but less is known about trends in abdominal obesity. Levels of abdominal obesity and overweight are reported for adults in the Health Survey for England (HSE) by survey year and age for 1993-2008. HSE is a nationally representative cross-sectional population survey using an interviewer-administered questionnaire and measurement of waist circumference (WC) by nurse, allowing calculation of abdominal overweight and obesity (≥94 cm and ≥102 cm in men, and ≥80 cm and ≥88 cm in women). A total of 40,001 men and 46,397 women aged 18-67 provided data on WC in this period. Between 1993 and 2008 abdominal overweight rose from 44.9% to 62.3% in men, and from 46.6% to 66.8% in women, while abdominal obesity rose from 19.2% to 35.7% in men, and from 23.8% to 43.9% women. However, the rates of increase over time in England appear to be slowing down: curves with a less than linear increase each year were a better fit to the data than a linear trend. There was some variation across the age range in the time trend in abdominal obesity and overweight, in that the absolute increases over time were slightly less for younger adults.     

Social conditioning of health behaviors among adults in Croatia: the CroHort study

The aim of this study was to examine the social conditioning of health behaviors of adults in Croatia, based on the data from Croatian Adult Health Survey 2003. This cross-sectional study on a representative random sample of 9070 Croatian adults showed that obesity was significantly and socially conditioned in women, whereas for men the indication of social conditioning has not reached a statistically significant level. Health behaviors were socially conditioned in both sexes. Men's living habits were more irregular than those of women. Compared with women, men consumed more cured meat products, consumed alcohol excessivelly and smoked cigarettes more often, whereas they ate less fruits and vegetables. Health promotion strategies based on the behavioral correlates of overweight and obesity are needed to prevent excess weight gain in the Croatian population. While for men a unique educational model is applicable, women require more specialized programs, adapted to their social background.     

Regressions for estimating muscle parameters in the thoracic and lumbar trunk for use in musculoskeletal modeling

Musculoskeletal modeling requires information on muscle parameters such as cross-sectional area (CSA) and moment arms. A variety of previous studies have reported muscle parameters in the trunk based on in vivo imaging, but there remain gaps in the available data as well as limitations in the generalizability of such data. Specifically, available trunk muscle CSA data is very limited for older adults, lacking entirely in the thoracic region. In addition, previous studies have made measurements in groups of healthy volunteers or hospital patients who may not be representative of the population in general. Finally, such studies have not reported data for the major muscles connecting the upper limb to the thoracic trunk. In this study, muscle morphology measurements were made for major muscles present in the trunk between vertebral levels T6 and L5 using quantitative computed tomography scans from a community-based sample of 100 men and women aged 36-87. We present regression equations to predict trunk muscle CSA and position relative to the vertebral body in the transverse plane from sex, age, height and weight at vertebral levels T6 to L5. Regressions were also developed for predicting anatomical CSA and muscle moment arms, which were estimated using literature data on muscle line of action. This work thus provides a resource for estimating muscle parameters in the general population for musculoskeletal modeling of the thoraco-lumbar trunk.     

Bias Due to Sample Selection in Propensity Score Matching for a Supportive Housing Program Evaluation in New York City

Objectives

Little is known about influences of sample selection on estimation in propensity score matching. The purpose of the study was to assess potential selection bias using one-to-one greedy matching versus optimal full matching as part of an evaluation of supportive housing in New York City (NYC).

Study Design and Settings

Data came from administrative data for 2 groups of applicants who were eligible for an NYC supportive housing program in 2007–09, including chronically homeless adults with a substance use disorder and young adults aging out of foster care. We evaluated the 2 matching methods in their ability to balance covariates and represent the original population, and in how those methods affected outcomes related to Medicaid expenditures.

Results

In the population with a substance use disorder, only optimal full matching performed well in balancing covariates, whereas both methods created representative populations. In the young adult population, both methods balanced covariates effectively, but only optimal full matching created representative populations. In the young adult population, the impact of the program on Medicaid expenditures was attenuated when one-to-one greedy matching was used, compared with optimal full matching.

Conclusion

Given covariate balancing with both methods, attenuated program impacts in the young adult population indicated that one-to-one greedy matching introduced selection bias.     

Varying Body Mass Index Cutoff Points to Describe Overweight Prevalence Among U. S. Adults: NHANES III (1988 to 1994)

KUCZMARSKI, ROBERT J, MARGARET D CARROLL, KATHERINE M FLEGAL, RICHARD P TROIANO. Varying body mass index cutoff points to determine overweight prevalence among U. S. adults: NHANES III (1988 to 1994). Body mass index (BMI; kg/m²) distributions are commonly reported in the scientific literature to describe weight for stature. These data are collected for various groups of subjects in local health and body composition studies, and comparisons with national distributions are often desirable. Tabular data for population prevalence estimates from thethird National Health and Nutrition Examination Survey (NHANES III, 1988 to 1994) at selected gender- and age-specific BMI levels ranging from <18. 0 to >45. 0 are presented and compared with various examples of BMI criteria reported in the scientific literature. NHANE HI was a statistically representative national probability sample of the civilian, noninstitutionalized population of the United States in which height and weight were measured as part of a more comprehensive health examination. The implications of varying population prevalence estimates based on varying BMI cutoff points are briefly discussed for selected examples including World Health Organization overweight/obesity criteria and the U. S. Dietary Guidelines for Americans. The median BMI for U. S. adults aged 20 years and older is 25. 5 kg/m². Median stature and weight for men are 175. 5 cm and 80. 0 kg and for women are 161. 6 cm and 65. 6 kg, respectively. The percentage of the population with BMI <19. 0 is 1. 6% for men, 5. 7% for women; BMI 19. 0 to <25. 0 is 39. 0% for men, 43. 6% for women; BMI 25. 0 is 59. 4% for men, 50. 7% for women. An estimated 97. 1 million adults have a BMI 25. 0. Additional prevalence estimates based on other BMI cutoff points and ages are presented.     

Gender Difference in Relationship between Health-Related Quality of Life and Work Status

This study investigated the association of employment status with health-related quality of life in adult Koreans, as well as the gender difference in the relationship, using a large, nationally representative sample. Using data from the Korea Health Panel survey, we examined the relationship between quality of life measured by EQ-5D and work status among Korean adults. We also tested whether and how the relationship between quality of life and work status differed by gender. Quality of life among working adults was better than among non-working adults. The gap between the two groups was larger among male than female participants. Further, the gender differential effect was larger in the 41–60-year-old age group than in the 18–40-year-old and 61-or-older groups. Being employed has a positive relation to quality of life among adults. Work status plays a more important role in quality of life for men than for women, especially for the working elderly men than working elderly women.     

Disentangling basal and accumulated body mass for cross‐population comparisons

Measures of human body mass confound 1) well‐established population differences in body form and 2) exposure to obesogenic environments, posing challenges for using body mass index (BMI) in cross‐population studies of body form, energy reserves, and obesity‐linked disease risk. We propose a method for decomposing population BMI by estimating basal BMI (bBMI) among young adults living in extremely poor, rural households where excess body mass accumulation is uncommon. We test this method with nationally representative, cross‐sectional Demographic and Health Surveys (DHS) collected from 69,916 rural women (20–24 years) in 47 low‐income countries. Predicting BMI by household wealth, we estimate country‐level bBMI as the average BMI of young women (20–24 years) living in rural households with total assets <400 USD per capita. Above 400 USD per capita, BMI increases with both wealth and age. Below this point, BMI hits a baseline floor showing little effect of either age or wealth. Between‐country variation in bBMI (range of 4.3 kg m^?2) is reliable across decades and age groups (R² = 0.83–0.88). Country‐level estimates of bBMI show no relation to diabetes prevalence or country‐level GDP (R² < 0.05), supporting its independence from excess body mass. Residual BMI (average BMI minus bBMI) shows better fit with both country‐level GDP (R² = 0.55 vs. 0.40) and diabetes prevalence (R² = 0.23 vs. 0.17) than does conventional BMI. This method produces reliable estimates of bBMI across a wide range of nationally representative samples, providing a new approach to investigating population variation in body mass. Am J Phys Anthropol 153:542–550, 2014. © 2013 Wiley Periodicals, Inc.     

Individual limb work does not explain the greater metabolic cost of walking in elderly adults.

Elderly adults consume more metabolic energy during walking than young adults. Our study tested the hypothesis that elderly adults consume more metabolic energy during walking than young adults because they perform more individual limb work on the center of mass. Thus we compared how much individual limb work young and elderly adults performed on the center of mass during walking. We measured metabolic rate and ground reaction force while 10 elderly and 10 young subjects walked at 5 speeds between 0.7 and 1.8 m/s. Compared with young subjects, elderly subjects consumed an average of 20% more metabolic energy (P=0.010), whereas they performed an average of 10% less individual limb work during walking over the range of speeds (P=0.028). During the single-support phase, elderly and young subjects both conserved approximately 80% of the center of mass mechanical energy by inverted pendulum energy exchange and performed a similar amount of individual limb work (P=0.473). However, during double support, elderly subjects performed an average of 17% less individual limb work than young subjects (P=0.007) because their forward speed fluctuated less (P=0.006). We conclude that the greater metabolic cost of walking in elderly adults cannot be explained by a difference in individual limb work. Future studies should examine whether a greater metabolic cost of stabilization, reduced muscle efficiency, greater antagonist cocontraction, and/or a greater cost of generating muscle force cause the elevated metabolic cost of walking in elderly adults.     

Dietary Behaviour and Socioeconomic Position: The Role of Physical Activity Patterns

Background

The positive association between education level and health outcomes can be partly explained by dietary behaviour. We investigated the associations between education and several indices of food intake and potential influencing factors, placing special emphasis on physical-activity patterns, using a representative sample of the German adult population.

Methods

The German National Health Interview and Examination Survey 1998 (GNHIES98) involved 7,124 participants aged between 18 and 79. Complete information on the exposure (education) and outcome (nutrition) variables was available for 6,767 persons. The associations between ‘education’ and indices of ‘sugar-rich food’, ‘fat-rich food’, ‘fruit-and-vegetable’ and ‘alcohol’ intake were analysed separately for men and women using multivariate logistic regression analysis. Odds ratios (OR) of education level on nutrition outcomes were calculated and adjusted for age, region (former East/West Germany), occupation, income and other influencing factors such as physical activity indicators.

Results

Men and women with only a primary education had a more frequent intake of sugar-rich and fat-rich foods and a less frequent intake of fruit and vegetables and alcohol than people with a tertiary education. ‘Physical work activity’ partly explained the associations between education and sugar-rich food intake. The interference with physical work activity was stronger among men than women. No significant associations between education and energy-dense food intake were observed in the retirement-age group of persons aged 65+ and among persons with low energy expenditure.

Conclusions

In Germany, adults with a low level of education report that they consume energy-dense foods more frequently – and fruit and vegetables and alcohol less frequently – than adults with a high education level. High levels of physical work activity among adults with a low education level may partly explain why they consume more energy-dense foods.     

Effect of rotator cuff exercise on humeral rotation torque in healthy individuals

Conservative management of rotator cuff pathology often involves certain therapeutic exercises. Although a major goal of these exercises is to increase strength of the rotator cuff, little empirical evidence supports this assertion. In this study, 34 nonpathologic young adults were pretested using a LIDO Multijoint II isokinetic device for average and peak torque generated during internal and external rotation. Subjects were arbitrarily assigned to a right-arm- or left-arm-trained group, exercised for 4 weeks, and then posttested for changes in humeral rotation torque. Moderate but significant increases in torque (8-10%) as well as in total work done were observed in both groups, only in the trained arm. Subjects who trained the nondominant (left) arm experienced gains similar to those who trained the right arm. Gains were significant in the case of both internal and external rotation (also average as well as peak torque), with men and women experiencing the same relative increases. These data, in addition to supporting the use of selected exercises to increase humeral rotation torque in a healthy population, offer a potential model for the rehabilitation of patients with rotator cuff injury.     

Measuring weight outcomes for obesity intervention strategies: The case of a sugar-sweetened beverage tax

Taxing unhealthy foods has been proposed as a means to improve diet and health by reducing calorie intake and raising funds to combat obesity, particularly sugar-sweetened beverages (SSBs). A growing number of studies have examined the effects of such food taxes, but few have estimated the weight-loss effects. Typically, a static model of 3500 calories for one pound of body weight is used, and the main objective of the study is to demonstrate its bias. To accomplish the objective, we estimate income-segmented beverage demand systems to examine the potential effects of a SSB tax. Elasticity estimates and a hypothetical 20 percent effective tax rate (or about 0.5 cent per ounce) are applied to beverage intake data from a nationally representative survey, and we find an average daily reduction of 34–47 calories among adults and 40–51 calories among children. The tax-induced energy reductions are translated into weight loss using both static and dynamic calorie-to-weight models. Results demonstrate that the static model significantly overestimates the weight loss from reduced energy intake by 63 percent in year one, 346 percent in year five, and 764 percent in year 10, which leads to unrealistic expectations for obesity intervention strategies. The tax is estimated to generate $5.8 billion a year in revenue and is found to be regressive, although it represents about 1 percent of household food and beverage spending.     

Over, under, or about right: misperceptions of body weight among food stamp participants

The purpose of this research was to investigate the associations between misperception of body weight and sociodemographic factors such as food stamp participation status, income, education, and race/ethnicity. National Health and Nutrition Examination Survey (NHANES) data from 1999-2004 and multivariate logistic regression are used to estimate how sociodemographic factors are associated with (i) the probability that overweight adults misperceive themselves as healthy weight; (ii) the probability that healthy-weight adults misperceive themselves as underweight; and (iii) the probability that healthy-weight adults misperceive themselves as overweight. NHANES data are representative of the US civilian noninstitutionalized population. The analysis included 4,362 men and 4,057 women. BMI derived from measured weight and height was used to classify individuals as healthy weight or overweight. These classifications were compared with self-reported categorical weight status. We find that differences across sociodemographic characteristics in the propensity to underestimate or overestimate weight status were more pronounced for women than for men. Overweight female food stamp participants were more likely to underestimate weight status than income-eligible nonparticipants. Among healthy-weight and overweight women, non-Hispanic black and Mexican-American women, and women with less education were more likely to underestimate actual weight status. We found few differences across sociodemographic characteristics for men. Misperceptions of weight are common among both overweight and healthy-weight individuals and vary across socioeconomic and demographic groups. The nutrition education component of the Food Stamp Program could increase awareness of healthy body weight among participants.     

The Effect of Productive Activities on Depressive Symptoms Among Older Adults With Dual Sensory Loss

The purpose of this study was to evaluate the ability of three productive activities (paid employment, volunteer work, and informal helping) to mitigate the negative effects of dual sensory loss (DSL) on depressive symptoms among older adults. Multilevel modeling was used to analyze longitudinal data from the nationally representative Health and Retirement Study. The sample consisted of 2,688 persons: 1,380 who developed DSL during the study and 1,308 who did not. Although participation in each of the productive activities was associated with fewer depressive symptoms for older adults with DSL, volunteering was also the only variable that moderated the relationship between DSL and depressive symptoms. Persons with a DSL who volunteered exhibited a larger decrease in depressive symptoms compared to persons without sensory loss who volunteered. A volunteer intervention for older adults with DSL may be a viable option to help reduce depression in this population.     

Mortality associated with HIV-1 infection over five years in a rural Ugandan population: cohort study.

OBJECTIVE: To assess the impact of HIV-1 infection on mortality over five years in a rural Ugandan population. DESIGN: Longitudinal cohort study followed up annually by a house to house census and medical survey. SETTING: Rural population in south west Uganda. SUBJECTS: About 10,000 people from 15 villages who were enrolled in 1989-90 or later. MAIN OUTCOME MEASURES: Number of deaths from all causes, death rates, mortality fraction attributable to HIV-1 infection. RESULTS: Of 9777 people resident in the study area in 1989-90, 8833 (90%) had an unambiguous result on testing for HIV-1 antibody; throughout the period of follow up adult seroprevalence was about 8%. During 35,083 person years of follow up, 459 deaths occurred, 273 in seronegative subjects and 186 in seropositive subjects, corresponding to standardised death rates of 8.1 and 129.3 per 1000 person years. Standardised death rates for adults were 10.4 (95% confidence interval 9.0 to 11.8) and 114.0 (93.2 to 134.8) per 1000 person years respectively. The mortality fraction attributable to HIV-1 infection was 41% for adults and was in excess of 70% for men aged 25-44 and women aged 20-44 years. Median survival from time of enrollment was less than three years in subjects aged 55 years or more who were infected with HIV-1. Life expectancy from birth in the total population resident at any time was estimated to be 42.5 years (41.4 years in men; 43.5 years in women), which compares with 58.3 years (56.5 years in men; 60.5 years in women) in people known to be seronegative. CONCLUSIONS: These data confirm that in a rural African population HIV-1 infection is associated with high death rates and a substantial reduction in life expectancy.