Obesity history as a predictor of walking limitation at old age

Differences in sarcopenia indices in elderly Japanese women and their relationships with obesity classified according to waist circumference, BMI, and body fat percentage

BACKGROUND

Sarcopenic obesity (SO) is defined as a decrease in lean body mass and an increase in body fat mass (BFM) due to aging. Detecting SO in elderly women is important from the perspective of extending healthy life expectancy. While various indices of SO are currently used, there is no global consensus regarding diagnostic criteria for SO. This study aimed to examine the relationship between obesity indices (waist circumference (WC), body mass index (BMI), and body fat percentage (BFP)) and sarcopenia indices (total body muscle mass (TBM), appendicular lean mass (ALM), skeletal mass index (SMI)), and physical function (gait speed (GS), handgrip strength (HGS)).

METHODS

Subjects were 170 community-dwelling healthy elderly women aged 65-79 years (mean: 72.7 ± 5.78 years) who underwent measurements for WC, BMI, and BFP. A WC of ≥ 90cm was defined as the obese group, BMI was determined as weight (kg) divided by height squared (m2) and a cutoff of ≥ 25 kg/m2 was used to define the obesity group. BFM was measured using the bioelectrical impedance analysis (BIA) method and BFP was calculated from body weight and a cutoff of ≥ 30% was used to define the obesity group. TBM and ALM (kg) were measured using the BIA method, ALM (kg) was corrected for height (m2) to obtain SMI (kg/m2). Physical function was assessed by GS and HGS, which were measured by the 5-m walk test and a digital grip strength meter, respectively.

RESULTS

When obesity was assessed using BMI, WC and BFP, obese individuals had higher TBM, ALM and SMI, and lower GS among the sarcopenia indicators. HGS did not differ significantly between the non-obese and obese groups.

CONCLUSION

Our findings suggest HGS is thought to reflect muscle strength without being affected by obesity indices, suggesting that it may be useful in detecting possible sarcopenia in obese individuals.

The Effect of Mixture of Heavy Metals on Obesity in Individuals ≥50 Years of Age

Little is known about the association between a mixture of heavy metals and obesity among individuals ≥50 years of age with comorbidities. Thus, we identified the associations of serum cadmium (Cd), lead (Pb), and mercury (Hg) with obesity using linear regression models; weighted quantile sum (WQS) regression, quantile g-computation (qgcomp), and Bayesian kernel machine regression (BKMR) were conducted as secondary analyses. Of the 6434 subjects included in the analysis, 13.8% had obesity and 44.6% had abdominal obesity. In the logistic regression model, serum Hg was associated with obesity and abdominal obesity, and significant trends were observed for these heavy metal tertiles (p < 0.001). Serum Hg levels were also associated with body mass index (BMI) and waist circumference (WC). The WQS index was significantly associated with both obesity (OR = 1.43, 95% CI: 1.40-1.46) and abdominal obesity (β = 1.51, 95% CI: 1.48-1.54). The qgcomp index also found a significant association between heavy metals and both obesity (OR = 1.35, 95% CI: 1.12-1.63) and abdominal obesity (OR = 1.34, 95% CI: 1.12-1.60). Serum Hg was the most heavily weighed heavy metal in these models. In BKMR analysis, the overall effect of the mixture was significantly associated with obesity, BMI, and WC. Serum Hg showed positive trends and was observed as the most important factor associated with obesity, BMI, and WC. Our findings were largely robust to secondary analyses that used three novel mixture modeling approaches: WQS, qpcomp, and BKMR. Given increasing exposure to heavy metals, well-characterized cohorts of individuals aged ≥50 years are required to determine the mixed effects of heavy metals on obesity and related diseases.

Obesity in early adulthood and physical functioning in mid-life: Investigating the mediating role of c-reactive protein

INTRODUCTION

Obesity in adulthood is associated with reduced physical functioning (PF) at older ages. However, mechanisms underpinning this association are not well understood. We investigated whether and the extent to which C-reactive protein (CRP) mediates the association between early-adult obesity and mid-life PF.

METHODS

We used data from 8495 participants in the 1958 British birth cohort study. Body mass index (BMI), CRP and PF were measured at 33, 45 and 50y, respectively. Poor PF was defined as the lowest (sex-specific) 10% on the Short-form 36 Physical Functioning subscale. We accounted for prospectively measured confounders in early-life (e.g., social class at birth) and in mid-adulthood (e.g., 42y comorbidities). We decomposed the total effect of early-adult obesity on mid-life PF into direct and indirect (via CRP) effects, by employing a mediation analysis based on parametric g-computation.

RESULTS

The estimated total effect of obesity at 33y on poor PF at 50y, expressed as an odds ratio (OR), was 2.41 (95% CI: 1.89, 3.08). The direct effect of obesity on poor PF (i.e., not operating via CRP), was 1.97 (95% CI: 1.51, 2.56), with an indirect effect of 1.23 (95% CI: 1.10, 1.37). As such, the proportion of the total effect which was mediated by the effect of obesity on CRP at 45y, was 23.27% (95% CI: 8.64%, 37.90%).

CONCLUSION

Obesity in early-adulthood was associated with over twice the odds of poor PF in mid-life, with approximately 23% of the obesity effect operating via a downstream effect on CRP. As current younger generations are likely to spend greater proportions of their life course in older age and with obesity, both of which are associated with poor PF, there is an urgent need to identify mechanisms, and thus potential modifiable intermediaries, linking obesity to poor PF.

Validation of Smartphone Accelerometry for the Evaluation of Sit-To-Stand Performance and Lower-Extremity Function in Older Adults

This study tested the concurrent and construct validity of smartphone accelerometry measurement of sit-to-stand (STS) performance in individuals aged 65-89 years. Normal and fast STS times were recorded by smartphone accelerometer, force plate, and video motion systems concurrently, and isokinetic knee extension power and STS whole-body power were obtained. Normal and fast speed STS times from a smartphone accelerometer agreed closely with force plate and motion system methods (mean difference = 0.04 s). Normal and fast STS times were inversely related to isokinetic knee extension power (r = -.93, p < .001 and r = -.82, p < .001, respectively) and STS whole-body power (r = -.76, p < .001 and r = -.70, p < .001, respectively). The STS time obtained from a smartphone accelerometer was equivalent to the established, precise measures of STS time and was related to lower-extremity power, making it a potentially useful metric of lower-extremity function.

Adult obesity and mid-life physical functioning in two British birth cohorts: investigating the mediating role of physical inactivity

Background

Associations between obesity and physical inactivity are bi-directional. Both are associated with physical functioning (PF, ability to perform physical tasks of daily living) but whether obesity influences PF via inactivity is unknown. We investigated whether mid-adult obesity trajectories were associated with subsequent PF and mediated by inactivity.

Methods

Body mass index (BMI; kg/m²) and inactivity were recorded at: 36, 43, 53 and 60–64 years in the 1946 Medical Research Council (MRC) National Survey of Health and Development (1946-NSHD; n = 2427), and at 33, 42 and 50 years in the 1958 National Child Development Study (1958-NCDS; n = 8674). Poor PF was defined as the lowest (gender and cohort-specific) 10% on the Short-form 36 Physical Component Summary subscale at 60–64 years (1946-NSHD) and 50 years (1958-NCDS). Estimated randomized-interventional-analogue natural direct (rNDE) and indirect (rNIE) effects of obesity trajectories on PF via inactivity are expressed as risk ratios [overall total effect (rTE) is rNDE multiplied by rNIE].

Results

In both cohorts, most individuals (∼68%) were never obese in adulthood, 16–30% became obese and ≤11% were always obese. In 1946-NSHD, rTE of incident obesity at 43 years (vs never) on poor PF was 2.32 (1.13, 3.51); at 53 years it was 1.53 (0.91, 2.15). rNIEs via inactivity were 1.02 (0.97, 1.07) and 1.02 (0.99, 1.04), respectively. Estimated rTE of persistent obesity from 36 years was 2.91 (1.14, 4.69), with rNIE of 1.03 (0.96, 1.10). In 1958-NCDS, patterns of association were similar, albeit weaker.

Conclusions

Longer duration of obesity was associated with increased risk of poor PF. Inactivity played a small mediating role. Findings reinforce the importance of preventing and delaying obesity onset to protect against poor PF.

Birthweight, lifetime obesity and physical functioning in mid-adulthood: a nationwide birth cohort study

BACKGROUND

Evidence is scant on long-term implications of childhood obesity and body mass index (BMI) gains over the life-course for poor physical functioning (PF). The objective was to establish whether (i) birthweight and BMI across the life-course, (ii) BMI gains at specific life-stages and (iii) age of obesity onset were associated with PF at 50 y.

METHODS

In the 1958 British birth cohort (n = 8674), BMI (kg/m2) was calculated using height and weight [measured (7, 11, 16, 33 and 45 y); self-reported (23 and 50 y)]. PF was assessed at 50 y using the validated PF subscale of the Short-form 36 survey; the bottom (gender-specific) 10% was classified as poor PF. Missing data were imputed via multiple imputation. Associations were examined using logistic regression, adjusting for health and social factors.

RESULTS

Birthweight was not associated with PF. At each adult age, odds of poor PF were highest for obese (vs normal), e.g. for 23 y obesity the odds ratio (OR)adjusted for poor PF was 2.28 (1.34, 3.91) and 2.67 (1.72, 4.14) in males and females respectively. BMI gains were associated with poor PF, e.g. for females, ORadjusted per standard deviation (SD) in BMI gain 16-23 y was 1.28 (1.13, 1.46); for BMI gains 45-50 y it was 1.36 (1.11, 1.65). Longer duration of obesity was associated with poor PF, e.g. in males, ORadjusted was 2.32 (1.26, 4.29) for childhood obesity onset and 1.50 (1.16, 1.96) for mid-adulthood onset (vs never obese, P-trend < 0.001).

CONCLUSION

Obesity, BMI gains, and earlier obesity onset were associated with poor PF in mid-adulthood, reinforcing the importance of preventing and delaying obesity onset.

Projecting the prevalence of obesity in South Korea through 2040: a microsimulation modelling approach

OBJECTIVE

To project the prevalence of obesity in 2040 among individuals 19 years and older in South Korea.

DESIGN, SETTING, AND PARTICIPANTS

Using the 'Population Health Model-body mass index' (BMI) microsimulation model, the prevalence of obesity in Korean adults 19 years and older was projected until 2040. The model integrated individual survey data from the Korea Health Panel Survey of 2011 and 2012, population statistics based on resident registration, population projections and complete life tables categorised by sex and age. Birth rate, life expectancy and international migration were based on a medium growth scenario. The base population of Korean adults in 2012, devised through data aggregation, was 39 842 730. The prediction equations were formulated using BMI as the dependent variable; the individual's sex, age, smoking status, physical activity and preceding year's BMI were used as predictive factors.

OUTCOME MEASURE

BMI categorised by sex.

RESULTS

The median BMI for Korean adults in 2040 was expected to be 23.55 kg/m² (23.97 and 23.17 kg/m² for men and women, respectively). According to the Korean BMI classification, 70.05% of all adults were expected to be 'preobese' (ie, have BMIs 23-24.9 kg/m²) by 2040 (81.23% of men and 59.07% of women) and 24.88% to be 'normal'.

CONCLUSIONS

We explored the possibility of applying and expanding on the concept of microsimulation in the field of healthcare by combining data sources available in Korea and found that more than half of the adults in this study population will be preobese, and the proportions of 'obesity' and 'normal' will decrease compared with those in 2012. The results of our study will aid in devising healthy strategies and spreading public awareness for preventing this condition.

Exploring the Impact of Obesity on Skeletal Muscle Function in Older Age

Sarcopenia is of important clinical relevance for loss of independence in older adults. The prevalence of obesity in combination with sarcopenia ("sarcopenic-obesity") is increasing at a rapid rate. However, whilst the development of sarcopenia is understood to be multi-factorial and harmful to health, the role of obesity from a protective and damaging perspective on skeletal muscle in aging, is poorly understood. Specifically, the presence of obesity in older age may be accompanied by a greater volume of skeletal muscle mass in weight-bearing muscles compared with lean older individuals, despite impaired physical function and resistance to anabolic stimuli. Collectively, these findings support a potential paradox in which obesity may protect skeletal muscle mass in older age. One explanation for these paradoxical findings may be that the anabolic response to weight-bearing activity could be greater in obese vs. lean older individuals due to a larger mechanical stimulus, compensating for the heightened muscle anabolic resistance. However, it is likely that there is a complex interplay between muscle, adipose, and external influences in the aging process that are ultimately harmful to health in the long-term. This narrative briefly explores some of the potential mechanisms regulating changes in skeletal muscle mass and function in aging combined with obesity and the interplay with sarcopenia, with a particular focus on muscle morphology and the regulation of muscle proteostasis. In addition, whilst highly complex, we attempt to provide an updated summary for the role of obesity from a protective and damaging perspective on muscle mass and function in older age. We conclude with a brief discussion on treatment of sarcopenia and obesity and a summary of future directions for this research field.

The Influence of Age and Obesity-Altered Muscle Tissue Composition on Muscular Dimensional Changes: Impact on Strength and Function

The purpose of this study was to determine if muscular dimensional changes with increases in torque production are influenced by age- and obesity-related increases in intramuscular fat, and its relationship to percent body fat (%BF), echo intensity (EI), strength, and maximum walking speed. Sixty-six healthy men were categorized into 3 groups based on age and body mass index status (young normal weight [YNW], older normal weight [ONW], and older obese [OB]). Participants underwent %BF assessments, resting ultrasonography to determine muscle size (cross-sectional area [CSA]) and EI of the superficial quadriceps, and a 10-m maximum walking speed assessment. Maximal and submaximal (rest–100% MVC in 10% increments) isometric leg extension strength was assessed while changes in rectus femoris (RF) CSA, width, and depth were obtained with ultrasonography. Echo intensity and %BF were different among all groups (p ≤ .007), with the YNW and OB groups exhibiting the lowest and highest %BF and EI values, respectively. The RF increased in depth and decreased in width with increases in torque intensity for all groups. The ONW group demonstrated no change (−0.08%) in RF CSA across torque intensities, whereas the YNW group (−11.5%) showed the greatest decrease in CSA, and the OB group showed a more subtle decrease (−4.6%). Among older men, a greater change in RF CSA was related to poorer EI (r = −0.355) and higher %BF (r = −0.346), while a greater decrease in RF width was associated with faster walking speeds (r = −0.431). Examining muscular dimensional changes during contraction is a unique model to investigate the influence of muscle composition on functional performance.

Weight change and risk of the foundation of National Institute of Health Sarcopenia-defined low lean mass: Data from the National Health and Nutrition examination surveys 1999-2004

BACKGROUND

Self-reported weight change may lead to adverse outcomes. We evaluated weight change with cutpoints of low lean mass (LLM) in older adults.

METHODS

Of 4984 subjects ≥60 years from NHANES 1999-2004, we applied LLM cutoffs of appendicular lean mass (ALM):body mass index (BMI) males<0.789, females<0.512. Self-reported weight was assessed at time of survey, and questions asked participants their weight one and 10 years earlier, and at age 25. Weight changes were categorized as greater/less/none than 5%. Logistic regression assessed weight change (gain, loss, no change) on LLM, after adjustment.

RESULTS

Of 4984 participants (56.5% female), mean age and BMI were 71.1 years and 28.2 kg/m2. Mean ALM was 19.7 kg. In those with LLM, 13.5% and 16.3% gained/lost weight in the past year, while 48.9% and 19.4% gained/lost weight in the past decade. Compared to weight at age 25, 85.2 and 6.1% of LLM participants gained and lost ≥5% of their weight, respectively. Weight gain over the past year was associated with a higher risk of LLM (OR 1.35 [0.99,1.87]) compared to weight loss ≥5% over the past year (0.89 [0.70,1.12]). Weight gain (≥5%) over 10-years was associated with a higher risk of LLM (OR 2.03 [1.66, 2.49]) while weight loss (≥5%) was associated with a lower risk (OR 0.98 [0.76,1.28]). Results were robust compared to weight at 25 years (gain OR 2.37 [1.76,3.20]; loss OR 0.95 [0.65,1.39]).

CONCLUSION

Self-reported weight gain suggests an increased risk of LLM. Future studies need to verify the relationship with physical function.

Adiposity Markers as Predictors of 11-Year Decline in Maximal Walking Speed in Late Midlife

Background: Obesity is linked to poorer physical functioning in older adults, but impact of excess adiposity on loss of functional capacity in late midlife is unclear. This study examined associations between adiposity markers and 11-year change in maximal walking speed, a sensitive indicator of physical functioning, among adults aged 55 to 69 years. Method: Maximal walking speed over 6.1 m was assessed in 2000 and 2011 among Finnish men (n = 409) and women (n = 498) from the prospective Health 2000 Survey. Body mass index (BMI) and waist circumference were assessed in 2000. Generalized estimating equation models estimated changes in maximal walking speed by BMI and waist circumference, stratified by sex. Results: BMI greater than 30 kg/m² was associated with accelerated decline in maximal walking speed particularly in women. Associations with waist circumference were nonsignificant. Conclusion: Late midlife obesity may speed up the decline in functional capacity as measured by maximal walking speed, especially in women.

Association Between Life-Course Obesity and Frailty in Older Adults: Findings in the GAZEL Cohort

OBJECTIVE

This study aimed to assess the relationship between weight history during adulthood and frailty in late life in men and women participating in the GAZEL (GAZ and ELectricité) cohort.

METHODS

This cohort study included 8,751 men and 3,033 women (aged 61 to 76 years) followed up since 1989. Modified Fried's frailty criteria (weakness, fatigue, unintentional weight loss, low physical activity, and impaired mobility) were assessed in 2015. Reported BMI was determined each year to characterize: obesity status in 2015, obesity duration over the 1990 to 2015 period, and trajectories of BMI. Associations between frailty and weight history were assessed using multinomial regression.

RESULTS

In 2015, 12% of men had obesity, 1.8% severe obesity, and 0.4% morbid obesity; for women, these percentages were 11%, 2.2%, and 0.8%, respectively. Individuals with obesity were more likely to be frail than those with normal BMI and the risk of frailty increased with each additional year of obesity (adjusted odds ratio 1.04 [1.00-1.08] for men and 1.07 [1.02-1.13] for women). Trajectories of BMI revealed that both long-term obesity and onset of obesity in late adulthood were associated with frailty.

CONCLUSIONS

Current and past obesity appear to be important determinants of frailty. Early weight management may be beneficial in old age.

Assessment of functional ability of nonambulatory patients with obesity: after and before bariatric surgery

INTRODUCTION

Functional ability is often impaired as a direct consequence of severe obesity. Bariatric surgery is the most effective treatment for severe obesity.

OBJECTIVE

To examine the effect of weight loss after bariatric surgery on patients with impaired functional ambulatory abilities due to obesity.

SETTINGS

A high-volume university-affiliated bariatric surgery center in India.

METHOD

We conducted a prospective study in a cohort of nonambulatory patients with functional disabilities (bedridden, wheelchair-bound, or walker-dependent) who underwent bariatric surgery. Data on sex, body mass index, co-morbid conditions, the severity of pain, and types of limitations in functional abilities were collected at baseline and at 1 year after bariatric surgery and analyzed.

RESULTS

Forty-five patients were enrolled in this study with 100% follow-up at 1 year. The mean age and body mass index of the patients were 54.7 ± 8.5 years and 54.2 ± 8.6 kg/m², respectively. Thirty-four (75.5%) were female, 27 (60%) were walker-dependent, 14 (31.1%) were wheelchair-bound, and 4 (8.9%) were bedridden. At baseline 88.8% and 75.5% patients had severe knee and back pain, respectively. The percentage of total weight loss was 22% and 31% at 6 and 12 months, respectively. At 1 year, 37 (82.2%) patients were ambulating independently, only 1 (2.2%) patient was still bedridden, and 7 (15.5%) patients were walker-dependent. Mild, moderate, and severe classification on all functional ability scales were significantly improved.

CONCLUSION

Weight loss after bariatric surgery results in significant amelioration of knee and/or back pain with an improvement in functional abilities and quality of life.

Predictors of Risk and Success of Obesity Surgery

BACKGROUND

Obesity surgery has proven successful for weight loss and the resolution of comorbidities. There is, however, little evidence on its success and the risk of complications when considering age of onset of obesity (AOO), years of obesity (YOO), preoperative body mass index (BMI), Edmonton obesity staging system (EOSS) score, and age as possible predictors of weight loss, the resolution of comorbidities, and the risk of complications.

METHODS

Patients who underwent Roux-en-Y gastric bypass (RYGB) and laparoscopic sleeve gastrectomy (LSG) from a prospective database were analyzed. Multiple regression analyses were used to predict comorbidities and their resolution, percentage excess weight loss (%EWL) and total weight loss (%TWL) 12 months after surgery, and the risk of complications using the predictors AOO, YOO, age, EOSS, and BMI.

RESULTS

180 patients aged 46.8 ± 11.1 years with a preoperative BMI 49.5 ± 7.5 were included. The number of preoperative comorbidities was higher with older age (β = 0.054; p = 0.023) and a greater BMI (β = 0.040; p = 0.036) but was not related to AOO and YOO. Patients with AOO as a child or adolescent were more likely to have an EOSS score of ≥2. Greater preoperative BMI was negatively associated with %EWL (β = -1.236; p < 0.001) and older age was negatively associated with %TWL (β = -0.344; p = 0.020). Postoperative complications were positively associated with EOSS score (odds ratio [OR] 1.147; p = 0.042) and BMI (OR 1.010; p = 0.020), but not with age. AOO and YOO were not related to postoperative outcome.

CONCLUSION

Greater BMI was associated with a lower %EWL and age was associated with a low %TWL. YOO and AOO did not influence outcome. Age, BMI, and EOSS score were the most important predictors for risk and success after obesity surgery. Surgery should be performed early enough for optimal outcomes.

Relative Effort while Walking Is Higher among Women Who Are Obese, and Older Women

PURPOSE

Individuals who are obese, and older individuals, exhibit gait alterations that may result, in part, from walking with greater effort relative to their maximum strength capacity. The goal of this study was to investigate obesity-related and age-related differences in relative effort during gait.

METHODS

Four groups of women completed the study, including 10 younger healthy-weight, 10 younger obese, 10 older healthy-weight, and 9 older obese women. The protocol included strength measurements at the hip, knee, and ankle in both flexion and extension, and gait trials under self-selected and constrained (1.5 m·s gait speed and 0.65-m step length) conditions. Relative effort was calculated as the ratio of joint torques during gait, and strength from a subject-specific model that predicted strength as a function of joint angle.

RESULTS

Relative effort during self-selected gait was higher among women who were obese in knee extension (P = 0.028) and ankle plantar flexion (P = 0.013). Although both joint torques and strength were higher among women who were obese, these increases in relative effort were attributed to greater obesity-related increases in joint torques than strength. Relative effort was also higher among older women in hip flexion (P < 0.001) and knee extension (P = 0.008), and attributed to age-related strength loss. Results were generally similar between self-selected and constrained gait, indicating the greater relative effort among women who were obese and older women was not attributed to differences in gait spatiotemporal characteristics.

CONCLUSIONS

Women who were obese, as well as older women, walk with greater relative effort. These results may help explain the compromised walking ability among these individuals.

Aging and Imaging Assessment of Body Composition: From Fat to Facts

The aging process is characterized by the chronic inflammatory status called "inflammaging", which shares major molecular and cellular features with the metabolism-induced inflammation called "metaflammation." Metaflammation is mainly driven by overnutrition and nutrient excess, but other contributing factors are metabolic modifications related to the specific body composition (BC) changes occurring with age. The aging process is indeed characterized by an increase in body total fat mass and a concomitant decrease in lean mass and bone density, that are independent from general and physiological fluctuations in weight and body mass index (BMI). Body adiposity is also re-distributed with age, resulting in a general increase in trunk fat (mainly abdominal fat) and a reduction in appendicular fat (mainly subcutaneous fat). Moreover, the accumulation of fat infiltration in organs such as liver and muscles also increases in elderly, while subcutaneous fat mass tends to decrease. These specific variations in BC are considered risk factors for the major age-related diseases, such as cardiovascular diseases, type 2 diabetes, sarcopenia and osteoporosis, and can predispose to disabilities. Thus, the maintenance of a balance rate of fat, muscle and bone is crucial to preserve metabolic homeostasis and a health status, positively contributing to a successful aging. For this reason, a detailed assessment of BC in elderly is critical and could be an additional preventive personalized strategy for age-related diseases. Despite BMI and other clinical measures, such as waist circumference measurement, waist-hip ratio, underwater weighing and bioelectrical impedance, are widely used as a surrogate measure for body adiposity, they barely reflect the distribution of body fat. Because of the great advantages offered by imaging tools in research and clinics, the attention of clinicians is now moving to powerful imaging techniques such as computed tomography, magnetic resonance imaging, dual-energy X-ray absorptiometry and ultrasound to obtain a more accurate estimation of BC. The aim of this review is to present the state of the art of the imaging techniques that are currently available to measure BC and that can be applied to the study of BC changes in the elderly, outlining advantages and disadvantages of each technique.

Discriminatory Ability of Lower-Extremity Peak Torque and Rate of Torque Development in the Identification of Older Women With Slow Gait Speed

The aim was to compare torque and rate of torque development of lower limb muscles between older women with functional and slow gait speeds to determine which muscle group is the best predictor of functional gait speed, and to establish strength thresholds needed for functional walking speed. Torque and rate of torque development of hip, knee, and ankle muscles were measured in older women who were divided in 2 groups according to gait speed: slow gait speed (<1.22 m·s^-1) and functional gait speed (≥1.22 m·s^-1). For each muscle group, 3 maximal isometric contractions were performed, and peak torque and rate of torque development were recorded. Older women with slow gait speed had lower peak torque than older women with functional gait speed for hip extension (28%), knee flexion (15%), knee extension (14%), and plantar flexion (16%) (all Ps < .05). Older women with slow gait speed had lower peak rate of torque development for hip flexion (29%), hip extension (37%), knee flexion (34%), knee extension (33%), and plantar flexion (19%) (all Ps < .05). Knee extension peak rate of torque development and hip extension peak torque were the better predictors of functional gait speed with thresholds of 2.96 N·m·s^-1·kg^-1 and 1.26 N·m·kg^-1, respectively.

Higher vegetable protein consumption, assessed by an isoenergetic macronutrient exchange model, is associated with a lower presence of overweight and obesity in the web-based Food4me European study

The objective was to evaluate differences in macronutrient intake and to investigate the possible association between consumption of vegetable protein and the risk of overweight/obesity, within the Food4Me randomised, online intervention. Differences in macronutrient consumption among the participating countries grouped by EU Regions (Western Europe, British Isles, Eastern Europe and Southern Europe) were assessed. Relation of protein intake, within isoenergetic exchange patterns, from vegetable or animal sources with risk of overweight/obesity was assessed through the multivariate nutrient density model and a multivariate-adjusted logistic regression. A total of 2413 subjects who completed the Food4Me screening were included, with self-reported data on age, weight, height, physical activity and dietary intake. As success rates on reducing overweight/obesity are very low, form a public health perspective, the elaboration of policies for increasing intakes of vegetable protein and reducing animal protein and sugars, may be a method of combating overweight/obesity at a population level.

Obesity History and Daily Patterns of Physical Activity at Age 60-64 Years: Findings From the MRC National Survey of Health and Development

Background

The aim of this study was to investigate associations of current body mass index (BMI) and obesity history with daily patterns of physical activity.

Methods

At age 60-64, participants from a British birth cohort study wore accelerometers for 5 days. Accelerometry counts were log-transformed and mean log-counts were used to derive a summary variable indicating total daily log-activity counts. Among those with complete data (n = 1,388) the associations of current BMI and age of first obesity were examined with: (a) total daily log-activity counts and (b) total log-activity counts in four segments of the day.

Results

Higher current BMI and younger age at obesity were strongly associated with lower levels of total daily activity at age 60-64 even after adjustment for sex, socioeconomic factors, and health status. The fully-adjusted mean difference in total daily log-activity counts was -581.7 (95% confidence interval: -757.2, -406.3) when comparing BMI ≥35 kg/m2 with <25 kg/m2, representing an 18.4% difference. Participants who had been obese since early adulthood had the lowest levels of activity (mean difference in total daily log-activity counts was -413.1 (-638.1, -188.2) when comparing those who were obese by age 26 or 36 with those who were never obese, representing a 13.1% difference).

Conclusions

Obese older adults may require targeted interventions and additional support to improve their daily activity levels. As younger generations with greater lifetime exposure to obesity reach old age the proportion of adults achieving sufficient levels of activity to realize its associated health benefits is likely to decline.

The Importance of Mid-to-Late-Life Body Mass Index Trajectories on Late-Life Gait Speed

BACKGROUND

Prior studies suggest being overweight may be protective against poor functional outcomes in older adults.

METHODS

Body mass index (BMI, kg/m2) was measured over 25 years across five visits (1987-2011) among Atherosclerosis Risk in Communities Study participants (baseline Visit 1 n = 15,720, aged 45-64 years). Gait speed was measured at Visit 5 ("late-life", aged ≥65 years, n = 6,229). BMI trajectories were examined using clinical cutpoints and continuous mixed models to estimate effects of patterns of BMI change on gait speed, adjusting for demographics and comorbidities.

RESULTS

Mid-life BMI (baseline visit; 55% women; 27% black) was associated with late-life gait speed 25 years later; gait speeds were 94.3, 89.6, and 82.1 cm/s for participants with baseline normal BMI (<25), overweight (25 ≤ BMI < 30), and obese (BMI ≥ 30) (p < .001). In longitudinal analyses, late-life gait speeds were 96.9, 88.8, and 81.3 cm/s for participants who maintained normal, overweight, and obese weight status, respectively, across 25 years (p < .01). Increasing BMI over 25 years was associated with poorer late-life gait speeds; a 1%/year BMI increase for a participant with a baseline BMI of 22.5 (final BMI 28.5) was associated with a 4.6-cm/s (95% confidence interval: -7.0, -1.8) slower late-life gait speed than a participant who maintained a baseline BMI of 22.5.

CONCLUSION

Being overweight in older age was not protective of mobility function. Maintaining a normal BMI in mid- and late-life may help preserve late-life mobility.

Relationship Between Midlife Cardiovascular Health and Late-Life Physical Performance: The ARIC Study

OBJECTIVES

To examine the association between midlife cardiovascular health and physical performance 25 years later.

DESIGN

Cohort study (Atherosclerosis Risk in Communities Study); multinomial logistic and logistic regression adjusted for demographic characteristics and clinical measures.

SETTING

Four U.S. communities: Forsyth County, North Carolina; Washington County, Maryland; Minneapolis, Minnesota; and Jackson, Mississippi.

PARTICIPANTS

Individuals aged 54.2 ± 5.8 at baseline (N = 15,744; 55% female, 27% black).

MEASUREMENTS

Cardiovascular health was measured at baseline using the American Heart Association's Life's Simple 7 (LS7) score (0-14) and LS7 component categories (poor, intermediate, ideal) for each risk factor. The Short Physical Performance Battery (SPPB) was used to quantify physical function as ordinal (0-12) and categorical (low (0-6), fair (7-9), good (10-12) outcomes.

RESULTS

Mean baseline LS7 score was 7.9 ± 2.4; 6,144 (39%) individuals returned 25 years later for the fifth ARIC examination, at which point the SPPB was administered. Of 5,916 individuals who completed the SPPB, 3,288 (50%) had good physical performance. Each 1-unit increase in LS7 score was associated with a 17% higher SPPB score (rate ratio (RR) = 1.17, 95% confidence interval (CI) = 1.15-1.19) and a 29% greater chance of having a late-life SPPB score of 10 or greater compared to SPPB score of less than 10 (RR = 1.29, 95% CI = 1.25-1.34). Ideal baseline glucose (RR = 2.53, 95% CI = 2.24-2.87), smoking (RR = 1.97, 95% CI = 1.81-2.15), blood pressure (RR = 1.70, 95% CI = 1.54-1.88), body mass index (RR = 1.51, 95% CI = 1.37-1.66), and physical activity (RR = 1.31, 95% CI = 1.20-1.43) had the strongest associations with late-life SPPB score, adjusting for other LS7 components.

CONCLUSION

Better cardiovascular health during midlife may lead better physical functioning in older age.

Factors associated with mobility of the oldest old

Abstract Introduction: Several factors can be associated to the reduction of mobility among the elderly. Early identification of these factors is crucial, since it may lead to prevention of functional dependencies. Objective: To analyze the association between mobility, sociodemographic factors and the prevalence of noncommunicable chronic diseases (NCDs) in oldest old. Methods: The sample consisted of 120 elderly persons aged (80 and 95 years), with 76 of them being women (83 ± 3 years) and 44 of them men (83 ± 3 years). Sociodemographic factors and NCDs which we studied were: age, gender, marital status, education, nutritional status, ethnicity, hypertension, diabetes and osteoarticular diseases. Mobility was analyzed using a battery of Physical Performance Tests. For statistical analysis we used the chi-square test and binary logistic regression to examine the relationship between sociodemographic factors, NCDs and mobility. SPSS (17.0) software was used for this and the significance level was set at 5%. Results: Level of education (p ≤ 0.001) and age (p = 0.034) are the two factors related to low mobility. However, the model built by multiple logistic regression analysis revealed that age is independently related to limited mobility in oldest old people (OR 3.29; 95% CI 1.09 to 9.87). Conclusion: Thus, oldest old >85 years are at a greater risk of decreased mobility independent of their education, marital and nutritional statuses and gender. We encourage further studies in this area. Studies which will not only address those facts considered in this study but that also examine family-related aspects, especially using longitudinal studies.

Body mass index as a predictor of healthy and disease-free life expectancy between ages 50 and 75: a multicohort study

BACKGROUND

While many studies have shown associations between obesity and increased risk of morbidity and mortality, little comparable information is available on how body mass index (BMI) impacts health expectancy. We examined associations of BMI with healthy and chronic disease-free life expectancy in four European cohort studies.

METHODS

Data were drawn from repeated waves of cohort studies in England, Finland, France and Sweden. BMI was categorized into four groups from normal weight (18.5-24.9 kg m^-2) to obesity class II (⩾35 kg m^-2). Health expectancy was estimated with two health indicators: sub-optimal self-rated health and having a chronic disease (cardiovascular disease, cancer, respiratory disease and diabetes). Multistate life table models were used to estimate sex-specific healthy life expectancy and chronic disease-free life expectancy from ages 50 to 75 years for each BMI category.

RESULTS

The proportion of life spent in good perceived health between ages 50 and 75 progressively decreased with increasing BMI from 81% in normal weight men and women to 53% in men and women with class II obesity which corresponds to an average 7-year difference in absolute terms. The proportion of life between ages 50 and 75 years without chronic diseases decreased from 62 and 65% in normal weight men and women and to 29 and 36% in men and women with class II obesity, respectively. This corresponds to an average 9 more years without chronic diseases in normal weight men and 7 more years in normal weight women between ages 50 and 75 years compared to class II obese men and women. No consistent differences were observed between cohorts.

CONCLUSIONS

Excess BMI is associated with substantially shorter healthy and chronic disease-free life expectancy, suggesting that tackling obesity would increase years lived in good health in populations.

The Relationship between Body Mass Index and 10-Year Trajectories of Physical Functioning in Middle-Aged and Older Russians: Prospective Results of the Russian HAPIEE Study

OBJECTIVE

To investigate the associations of overweight and obesity with longitudinal decline in physical functioning (PF) among middle-aged and older Russians.

DESIGN

Prospective cohort study.

SETTING

Four rounds of data collection in the Russian Health, Alcohol and Psychosocial factors In Eastern Europe study with up to 10 years of follow-up.

PARTICIPANTS

9,222 men and women aged 45-69 years randomly selected from the population of two districts of Novosibirsk, Russia.

MEASUREMENTS

PF score (range 0-100) was measured by the Physical Functioning Subscale (PF-10) of the 36-item Short Form Health Survey (SF-36) at baseline and three subsequent occasions. Body mass index (BMI), derived from objectively measured body height and weight at baseline, was classified into normal weight (BMI 18.5-24.9), overweight (BMI 25.0-29.9), obesity class I (BMI 30.0-34.9), and obesity class II+ (BMI≥35.0).

RESULTS

The mean annual decline in the PF score during the follow-up was -1.92 (95% confidence interval -2.17; -1.68) in men and -1.91 (-2.13; -1.68) in women. At baseline, compared with normal weight, obesity classes I and II+ (but not overweight) were associated with significantly lower PF in both sexes. In prospective analyses, the decline in PF was faster in overweight men (difference from normal weight subjects -0.38 [-0.63; -0.14]), class I obese men and women (-0.49 [-0.82; -0.17] and -0.44 [-0.73; -0.15] respectively) and class II+ obese men and women (-1.13 [-1.73; -0.53] and -0.43 [-0.77; -0.09] respectively). Adjustment for physical activity and other covariates did not materially change the results.

CONCLUSIONS

PF decreased more rapidly in obese men and women than among those with normal weight. The adverse effect of high BMI on PF trajectories appeared to be more pronounced in men than in women, making more extremely obese Russian men an important target population to prevent/slow down the process of decline in PF.

Obesity and Muscle Weakness as Risk Factors for Mobility Limitation in Community-Dwelling Older Japanese Women: A Two-Year Follow-Up Investigation

OBJECTIVES

To examine the combined association of obesity and low muscle strength with mobility limitation in older adults.

DESIGN, SETTING AND PARTICIPANTS

This two-year follow-up longitudinal study included pooled data from 283 older community-dwelling Japanese women without mobility limitations who were 65 to 87 years of age (mean age 72.2 ± 5.0 years).

MEASUREMENTS

Muscle strength was measured by hand-grip strength (HGS). The participants were categorized by HGS (high muscle strength: HGS ≥19.6 kg, low muscle strength: HGS <19.6 kg) and body mass index (BMI) (obese: BMI ≥25 kg/m2, normal weight: BMI <25 kg/m2). The main outcome was mobility limitation, assessed by a self-reported questionnaire (difficulty walking one-half mile or climbing 10 steps without resting). Multivariate logistic regression analysis was performed to determine the combined effect of HGS and BMI on mobility limitation, adjusting for age, exercise habits, medications, and knee pain.

RESULTS

During the follow-up period, 82 of 283 participants (29.0%) developed mobility limitation. The adjusted odds ratios (95% confidence interval) for the incidence of mobility limitation were 1.53 (0.86-2.73) and 2.05 (1.08-3.91) in the obese and low muscle strength groups, respectively. Obesity combined with low muscle strength exhibited a significant and strong association with mobility limitation (odds ratio: 3.88, 1.08-13.91) compared with participants with normal weight and high muscle strength.

CONCLUSION

Among community-dwelling older Japanese women, obesity alone was not associated with the incidence of mobility limitation, but when combined with low muscle weakness, the risk of developing mobility limitation was 3.9-fold greater than for the reference group.

Cumulative Weight Exposure Is Associated with Different Weight Loss Strategies and Weight Loss Success in Adults Age 50 or Above

Objectives. To evaluate if cumulative weight exposure is associated with weight loss strategy choices and weight loss success. Methods. Data from the National Health and Nutrition Examination Survey were used; a total of 4,562 people age 50 years or older who reported trying to lose weight in the last year were studied. Cumulative weight exposure (CWE) score was defined as the sum of body mass index points above 25 kg/m(2) at the age of 25, 10 years ago, 1 year ago, and now. Weight loss strategies were self-reported and weight loss success was defined as reaching a 5% weight loss in the last year. Results. Chosen strategies for weight loss vary across tertiles of CWE. Participants in the highest CWE tertile were about 4 to 20 times more likely to lose at least 5% of body weight in the past year compared to those in the lowest CWE tertile (P < 0.05).  Discussion. Strategies used to lose weight and weight loss success using different weight loss strategies vary considerably across cumulative weight exposure. Thus, cumulative weight exposure might be a variable worth considering when intervening with this population.

Weight histories and mortality among finnish adults: the role of duration and peak body mass index

BACKGROUND

Many studies use information on weight histories to examine the association between body weight and mortality. A recent paper in Epidemiology (2013;25:707-710) developed a typology of the most common weight-history specifications.

METHODS

We use data from a sample of Finnish adults to explore the associations of body weight and mortality, using existing specifications and also peak body mass index (BMI), a new specification.

RESULTS

We confirm earlier findings that longer time in a high BMI state is predictive of mortality. Peak BMI (the highest BMI attained in life or available in the data) is also positively associated with mortality.

CONCLUSIONS

The specifications of duration in a high BMI state and peak BMI are both valuable for understanding the relationship between lifetime weight dynamics and mortality. The collection of information on peak body weight may be useful when collection of more detailed weight histories is not feasible.

The role of obesity duration on the association between obesity and risk of physical disability

OBJECTIVE

To relate measured obesity duration in mid-life with subsequent incidence of physical disability over and above body mass index (BMI) attained.

METHODS

Framingham Offspring Study is a longitudinal study that began in 1971. Examination 5 (1991-1995; "baseline") and disability onset ascertained from examinations 6-8 (2008) were used. About 2,095 disability-free participants aged 45-65 years at baseline were included. Obesity (BMI ≥ 30 kg/m(2) ) duration was calculated between examination 1 and examination 5. Cox regression was used to analyze time to disability.

RESULTS

204 participants developed disability (incidence rate=7.9 per 1,000 person-years). Obesity duration ranged from 0 to 22 years (mean of 2.0 years overall, 8.3 years for those with baseline obesity). Obesity duration increased risk of new disability (hazard ratio [HR] 1.07 per year of obesity; 95% confidence interval [CI] 1.05-1.09). This association was attenuated on further adjustment for baseline BMI (HR 1.03; 95% CI 1.00-1.06).

CONCLUSIONS

Being obese for longer during mid-life increases the risk of later-life disability over and above attained BMI. These results support the need for prevention of weight gain in young adults to avoid an increasing burden of physical disability in later life.

Racial and educational disparities in mobility limitation among older women: what is the role of modifiable risk factors?

OBJECTIVES

This research explores whether modifiable risk factors (MRFs) are potential mediators and/or moderators of racial/ethnic and educational mobility limitation disparities among older women.

METHOD

Utilizing Waves 2-9 (1994-2008) of the Health and Retirement Study (HRS), discrete-time event history models with multiple competing events were estimated using multinomial logistic regression.

RESULTS

Black women were more likely to develop mobility limitation relative to White women. This disparity was partially mediated by body mass index. Educational disparities were also observed, yet MRFs did not appreciably influence this disparity. The effect of vigorous physical activity on mobility limitation onset varied by race; physical activity was not as protective for Black women compared with White women. Being overweight appeared to weaken the benefit of additional years of education.

DISCUSSION

These results reiterate the importance of health promotion via MRFs; however, they also illustrate that the effect of MRFs on mobility limitation varies by race and education among older women, which has implications for health professionals interested in functional health interventions. Future recommendations include the development of interventions and health promotion aimed at increasing participation in positive health behaviors that address salient social factors among at-risk older women.

Impact of obesity and physical activity on functional outcomes in the elderly: data from NHANES 2005-2010

OBJECTIVE

The objective of this study was to (a) to examine whether the association between obesity and physical functioning among older adults is moderated by physical activity (PA) and (b) to test whether this moderating effect varies by gender.

METHOD

Data from adults (aged >60 years) who participated in the National Health and Nutrition Examination Surveys (2005-2010) were analyzed. Using multivariate logistic regression, we estimated the prevalence ratio (PR) of functional limitations and impairment in activities of daily living and instrumental activities of daily living, by body mass index and PA, while adjusting for age, educational level, and a comorbidity index.

RESULTS

The sample included 5,304 subjects (mean age = 70.4 years), and 50.5% were female. Overweight and obesity were associated with higher levels of functional limitations when compared with normal weight individuals regardless of the PA status (PR = 1.47, 95% confidence interval [CI] [1.17, 1.85], and PR = 2.71, 95% CI [2.00, 3.67], respectively) even after adjustment for confounders.

DISCUSSION

Overweight and obesity are associated with impairment in functional outcomes irrespective of PA.

Functional impairment in obesity: a focus on knee and back pain

SUMMARY Cross-sectional and longitudinal evidence strongly indicate that obesity is related to physical impairment and joint pain, particularly in the lumbar spine, sacroiliac and knee joints. What is most disturbing is that obese children under 15 years are now reporting joint pain and cannot perform functional tasks as well as their nonobese counterparts. As the prevalence of obesity rises, so do the rates of musculoskeletal disease and physical dysfunction. Functional tasks that involve supporting or transferring body weight are typically painful and difficult to perform. Of most concern is that some of these tasks are simply impossible depending on the severity of obesity. As a consequence, the individual's quality of life suffers. A BMI of 35 kg/m(2) is emerging as the threshold at which functional impairment rates rise dramatically. To restore functional independence and optimize functional gains over the long term, a combination of treatments for the obese patient with joint pain may be effective. The initial use of physical therapy, pain medications or joint viscosupplementation, coupled with diet, exercise, or bariatric surgery are options for weight loss and reduction of pain symptoms. Irrespective of age, weight loss can reduce or eliminate joint pain. As body weight is reduced, so should the reliance on medication with a concomitant improvement in functional mobility.

Obesity persistence and duration dependence: evidence from a cohort of US adults (1985-2010)

This study investigates dynamic patterns of obesity persistence and identifies the determinants of obesity-spell exits and re-entries. We utilize longitudinal data from the NLSY79 covering the period 1985-2010. Non-parametric techniques are applied to investigate the relationship between exit from obesity and spell duration. Multivariate discrete hazard models are also estimated, taking into account duration dependence and observed and time-invariant unobserved heterogeneity. In all cases, the probability of exiting obesity is inversely related to the duration of the obesity spell. Without controlling for unobserved heterogeneity, the probability of exit after one wave in obesity is 31.5 per cent; it is reduced to 3.8 per cent after seven or more waves. When time-invariant unobserved heterogeneity is taken into account, the estimated probabilities are slightly larger and broadly similar (36.8 and 10.3, respectively), which suggests that the identified negative duration dependence is not primarily due to composition effects. The obtained results indicate that public health interventions targeting the newly obese may be particularly effective at reducing incidence of long durations of obesity.

The effect of obesity in adolescence on adult health status

OBJECTIVE

To test the hypothesis that adolescent obesity would be associated with greater risks of adverse health in severely obese adults.

METHODS

Before weight loss surgery, adult participants in the Longitudinal Assessment of Bariatric Surgery-2 underwent detailed anthropometric and comorbidity assessment. Weight status at age 18 was retrospectively determined. Participants who were ≥80% certain of recalled height and weight at age 18 (1502 of 2308) were included. Log binomial regression was used to evaluate whether weight status at age 18 was independently associated with risk of comorbid conditions at time of surgery controlling for potential confounders.

RESULTS

Median age and adult body mass index (BMI) were 47 years and 46, respectively. At age 18, 42% of subjects were healthy weight, 29% overweight, 16% class 1 obese, and 13% class ≥2 obese. Compared with healthy weight at age 18, class ≥2 obesity at age 18 independently increased the risk of lower-extremity venous edema with skin manifestations by 435% (P < .0001), severe walking limitation by 321% (P < .0001), abnormal kidney function by 302% (P < .0001), polycystic ovary syndrome by 74% (P = .03), asthma by 48% (P = .01), diabetes by 42% (P < .01), obstructive sleep apnea by 25% (P < .01), and hypertension (by varying degrees based on age and gender). Conversely, the associated risk of hyperlipidemia was reduced by 61% (P < .01).

CONCLUSIONS

Severe obesity at age 18 was independently associated with increased risk of several comorbid conditions in adults undergoing bariatric surgery.

Obesity and muscle strength as long-term determinants of all-cause mortality--a 33-year follow-up of the Mini-Finland Health Examination Survey

OBJECTIVE

To examine the independent and combined associations of obesity and muscle strength with mortality in adult men and women.

DESIGN

Follow-up study with 33 years of mortality follow-up.

SUBJECTS

A total of 3594 men and women aged 50-91 years at baseline with 3043 deaths during the follow-up.

MEASUREMENT

Body mass index (BMI) and handgrip strength were measured at baseline.

RESULTS

Based on Cox models adjusted for age, sex, education, smoking, alcohol use, physical activity and chronic conditions, baseline obesity (BMI ≥30 kg m(-2)) was associated with mortality among participants aged 50-69 years (hazard ratio (HR) 1.14, 95% confidence interval (CI), 1.01-1.28). Among participants aged 70 years and older, overweight and obesity were protective (HR 0.77, 95% CI, 0.66-0.89 and HR 0.76, 95% CI, 0.62-0.92). High handgrip strength was inversely associated with mortality among participants aged 50-69 (HR 0.89, 95% CI, 0.80-1.00) and 70 years and older (HR 0.78, 95% CI, 0.66-0.93). Compared to normal-weight participants with high handgrip strength, the highest mortality risk was observed among obese participants with low handgrip strength (HR 1.23, 95% CI, 1.04-1.46) in the 50-69 age group and among normal-weight participants with low handgrip strength (HR 1.30, 95% CI, 1.09-1.54) among participants aged 70+ years. In addition, in the old age group, overweight and obese participants with high handgrip strength had significantly lower mortality than normal-weight participants with high handgrip strength (HR 0.79, 95% CI, 0.67-0.92 and HR 0.77, 95% CI, 0.63-0.94).

CONCLUSION

Both obesity and low handgrip strength, independent of each other, predict the risk of death in adult men and women with additive pattern. The predictive value of obesity varies by age, whereas low muscle strength predicts mortality in all age groups aged>50 years and across all BMI categories. When promoting health among older adults, more attention should be paid to physical fitness in addition to body weight and adiposity.

The "obesity paradox," frailty, disability, and mortality in older men: a prospective, longitudinal cohort study

An inverse relationship between overweight and mortality (the "obesity paradox") is well documented, but there are scarce data on how body weight during the life course affects this relationship. In the Helsinki Businessmen Study, we examined the effect of weight trajectories on incident disability, frailty, and mortality by stratifying 1,114 men (mean age of 47 years in 1974) into the following 4 groups based on body mass index (weight (kg)/height (m)(2)) values measured twice, in 1974 and 2000: 1) constantly normal weight (n = 340, reference group); 2) constantly overweight (n = 495); 3) weight gain (n = 136); and 4) weight loss (n = 143). Twelve-year mortality rates (from 2000 to 2012) and frailty and mobility-related disability in late life were determined. Compared with constantly normal weight, weight loss was associated with disability (odds ratio (OR) = 2.4, 95% confidence interval (CI): 1.1, 4.9) and frailty (OR = 3.7, 95% CI: 1.3, 10.5) in late life. Constant overweight was associated with increased disability (OR = 1.9, 95% CI: 1.1, 3.2). Men with constantly normal weight had the fewest comorbidities in late life (P < 0.001). Higher 12-year mortality rates were observed both with weight loss (hazard ratio = 1.8, 95% CI: 1.3, 2.3) and with constant overweight (hazard ratio = 1.3, 95% CI: 1.03, 1.7). Those with constantly normal weight or weight gain had similar outcomes. We observed no obesity paradox in late life when earlier weight trajectories were taken into account.

Midlife obesity and risk of frailty in old age during a 22-year follow-up in men and women: the Mini-Finland Follow-up Survey

BACKGROUND

Long-term predictors of geriatric syndrome of frailty are unclear. Several obesity-related conditions are associated with frailty. This study examines the predictive role of midlife overweight and obesity on development of frailty more than 22 years of follow-up.

METHODS

Data are from 1,119 men and women aged 30 or older without frailty at baseline participating in a population-based Mini-Finland Health Examination Survey (1978-1980) with follow-up measurement in 2000-2001. At baseline (1978-1980), body weight and height were measured. At follow-up (2000-2001), the dependent variable prefrailty was defined as the presence of one or two of five frailty indicators (shrinking, weakness, exhaustion, slowness, and low physical activity) and frailty was defined as three or more indicators.

RESULTS

The mean age at the baseline was 43.6 (SD 9.7) years, and majority of the participants (95%) were 30-60 years old. Incidence of prefrailty was 5% and frailty 36%. Based on adjusted multinomial logistic regression, persons with overweight (body mass index 25-29.9kg/m(2)) and obesity (body mass index ≥ 30kg/m(2)) at baseline had increased risk of prefrailty (odds ratio 1.45, 95% CI 1.08, 1.96; odds ratio 2.36, 95% CI 1.41, 3.93) and frailty (odds ratio 2.49, 95% CI 1.22, 5.06; odds ratio 5.02, 95% CI 1.89, 13.33) at follow-up in comparison to normal-weight persons after adjusting for age, sex, lifestyle factors and chronic conditions.

CONCLUSIONS

Development of frailty may start already in midlife, and obesity is one of the underlying causes of frailty.

Obesity and weight loss in the treatment and prevention of osteoarthritis

Obesity is associated with an increasing prevalence of musculoskeletal complaints and pain. Obesity is a major risk factor for osteoarthritis (OA), and pain can manifest in load-bearing and nonload-bearing joints. The lumbar spine and the knee are 2 primary sites for pain onset in the obese patient. Irrespective of the weight loss method, reduction of body fat can lower the mechanical and inflammatory stressors that contribute to OA. Single or combined methods of weight loss including exercise, dietary modification, medications, and bariatric surgery are associated with lower joint pain and increased physical function. Methods of weight loss or maintenance in early years may reduce the life exposure of joints to the obesity induced stressors on load bearing joints.

Birth size and childhood growth as determinants of physical functioning in older age: the Helsinki Birth Cohort Study

The study reports on the associations of infant and childhood anthropometric measurements, early growth, and the combined effect of birth weight and childhood body mass index with older age physical functioning among 1,999 individuals born in 1934-1944 and belonging to the Helsinki Birth Cohort Study. Physical functioning was assessed by the Short Form 36 scale. Anthropometric data from infancy and childhood were retrieved from medical records. The risk of lower Short Form 36 physical functioning at the mean age of 61.6 years was increased for those with birth weight less than 2.5 kg compared with those weighing 3.0-3.5 kg at birth (odds ratio (OR) = 2.73, 95% confidence interval (CI): 1.57, 4.72). The gain in weight from birth to age 2 years was associated with decreased risk of lower physical functioning for a 1-standard deviation increase (OR = 0.84, 95% CI: 0.75, 0.94). The risk of lower physical functioning was highest for individuals with birth weight in the lowest third and body mass index at 11 years of age in the highest third compared with those whose birth weight was in the middle third and body mass index at age 11 years was in the highest third (OR = 3.08, 95% CI: 1.83, 5.19). The increasing prevalence of obesity at all ages and the aging of populations warrant closer investigation of the role of weight trajectories in old age functional decline.

Time trends in leisure time physical activity and physical fitness in elderly people: 20 year follow-up of the Spanish population national health survey (1987-2006)

BACKGROUND

To estimate trends in leisure time physical activity and physical fitness between 1987-2006 in older Spanish people.

METHODS

We analyzed data collected from the Spanish National Health Surveys conducted in 1987 (n = 29,647), 1993 (n = 20,707), 1995-1997 (n = 12,800), 2001 (n = 21,058), 2003 (n = 21,650), and 2006 (n = 29,478). The number of subjects aged ≥ 65 years included in the current study was 29,263 (1987: n = 4,958-16.7%; 1993: n = 3,751-17.8%; 1995-97: n = 2,229-17.4%; 2001: n = 4,356-20.7%; 2003: 6,134-28.3%; 2006: 7,835-26.5%). Main variables included leisure-time physical activity and physical fitness. We analyzed socio-demographic characteristics, self-rated health status, lifestyle habit and co-morbid conditions using multivariate logistic regression models.

RESULTS

Women exhibited lower prevalence of leisure time physical activity and physical fitness compared to men (P < 0.05). The multivariate analysis for time trends found that practising leisure time physical activity increased from 1987 to 2006 (P < 0.001). Variables associated with a lower likelihood of practicing leisure time physical activity were: age ≥ 80 years old, ≥ 2 co-morbid chronic conditions, and obesity. Variables associated with lower physical fitness included: age ≥ 80 years, worse self rated health; ≥ 2 medications (only for walking), and obesity.

CONCLUSIONS

We found an increase in leisure time physical activity in the older Spanish population. Older age, married status, co-morbid conditions, obesity, and worse self-perceived health status were associated with lower activity. Identification of these factors can help to identify individuals at risk for physical inactivity.

Body composition (sarcopenia) in obese patients: implications for care in the intensive care unit

The study of body composition is a rapidly evolving science. In today's environment, there is a great deal of interest in assessing body composition, especially in the obese subject, as a guide to clinical and nutrition interventions. There are some strikingly different compartments of body composition between the obese and the lean patient. We do have the ability to measure body composition accurately, although these techniques can be labor intensive and expensive. The recognition of patients with sarcopenic obesity has identified a potential high-risk patient population. These body composition abnormalities may have even greater importance in the intensive care patient.

Association of body mass index with self-report and performance-based measures of balance and mobility

BACKGROUND

The incidence of obesity is increasing in older adults, with associated worsening in the burden of disability. Little is known about the impact of body mass index (BMI) on self-report and performance-based balance and mobility measures in older adults.

OBJECTIVE

The purposes of this study were (1) to examine the association of BMI with measures of balance and mobility and (2) to explore potential explanatory factors.

DESIGN

This was a cross-sectional, observational study.

METHODS

Older adults (mean age=77.6 years) who participated in an ongoing observational study (N=120) were classified as normal weight (BMI=18.5-24.9 kg/m(2)), overweight (BMI=25.0-29.9 kg/m(2)), moderately obese (BMI=30.0-34.9 kg/m(2)), or severely obese (BMI ≥ 35 kg/m(2)). Body mass index data were missing for one individual; thus, data for 119 participants were included in the analysis. Mobility and balance were assessed using self-report and performance-based measures and were compared among weight groups using analysis of variance and chi-square analysis for categorical data. Multiple linear regression analysis was used to examine the association among BMI, mobility, and balance after controlling for potential confounding variables.

RESULTS

Compared with participants who were of normal weight or overweight, those with moderate or severe obesity were less likely to report their mobility as very good or excellent (52%, 55%, 39%, and 6%, respectively); however, there was no difference in self-report of balance among weight groups. Participants with severe obesity (n=17) had the lowest levels of mobility on the performance-based measures, followed by those who were moderately obese (n=31), overweight (n=42), and of normal weight (n=29). There were no differences on performance-based balance measures among weight groups. After controlling for age, sex, minority status, physical activity level, education level, and comorbid conditions, BMI still significantly contributed to mobility (β=-.02, adjusted R(2)=.41).

CONCLUSIONS

Although older adults with severe obesity were most impaired, those with less severe obesity also demonstrated significant decrements in mobility.

Walking capacity of bariatric surgery candidates

BACKGROUND

This study characterizes the walking limitations of bariatric surgery candidates by age and body mass index (BMI) and determines factors independently associated with walking capacity. The setting was multi-institutional at research university hospitals in the United States.

METHODS

Participants of the Longitudinal Assessment of Bariatric Surgery study (n=2458; age 18-78 yr, BMI 33-94 kg/m(2)) attended a preoperative research visit. Their walking capacity was measured by self-report and the 400 m Long Distance Corridor Walk (LDCW).

RESULTS

Almost two thirds (64%) of subjects reported limitations with walking several blocks, 48% had an objectively defined mobility deficit, and 16% reported at least some walking aid use. In multivariate analysis, BMI, older age, lower income, and greater bodily pain were independently associated (P < .05) with walking aid use, physical discomfort during the LDCW, an inability to complete the LDCW, and a slower time to complete the LDCW. Female gender, Hispanic ethnicity (but not race), greater heart rate at rest, a history of smoking, several co-morbidities (history of stroke, ischemic heart disease, diabetes, asthma, sleep apnea, venous edema with ulcerations), and depressive symptoms were also independently related (P < .05) to at least one measure of reduced walking capacity.

CONCLUSIONS

Walking limitations are common in bariatric surgery candidates, even among the least severely obese and youngest patients. Physical activity counseling must be tailored to individuals' abilities. Although several factors identified in the present study (eg, BMI, age, pain, co-morbidities) should be considered, directly assessing the patient's walking capacity will facilitate appropriate goal setting.

Effect of age on the association between body fat percentage and maximal walking speed

OBJECTIVE

To study the effect of age on the association between body fat percentage and maximal walking speed in older people.

DESIGN AND PARTICIPANTS

Cross-sectional analysis of data collected in the Finnish population-based Health 2000 Survey involving 916 men and 1 222 women aged 55 years and older with complete data on body composition and a walking speed test.

METHODS

Body fat percentage was assessed using bioelectrical impedance analysis and maximal walking speed based on a timed walking test over a distance of 6.1 meters. Linear regression models were used to study the effect of age on association between body fat percentage and maximal walking speed.

RESULTS

The association between body fat percentage quartiles and maximal walking speed differed significantly between persons of different ages (p for age interaction = 0.027). In the age-stratified analyses, the association between body fat percentage and maximal walking speed remained significant among 60-69-year olds and 70-79-year-olds, but disappeared among 55-59-year-olds and 80-year and older after adjustment for potential covariates. Body fat percentage explained 11% of the variation in maximal walking speed among 55-59-year-olds, 21% among 60-69-year-olds, 17% among 70-79-year-olds and 11% among 80-year and older.

CONCLUSION

Association between body fat percentage and maximal walking speed was strongest between the ages of 60 and 79 years. The results suggest that the effects of excess body fatness are especially harmful for physical functioning among adults in their sixties and seventies and they could benefit from interventions.

Low strength is related to diminished ground reaction forces and walking performance in older women

The purpose of this study was to determine how lower-limb strength in older women affected gait speed, supportive forces, spatial, and temporal aspects of walking gait. Twenty-four women between 65 and 80 yr performed maximal voluntary isometric contractions for the knee extensors (KE), knee flexors (KF), ankle plantarflexors (PF) and ankle dorsiflexors (DF) and were separated into low strength and normal strength groups using a KE torque threshold of 1.5 Nm kg(-1). They walked at both a standard speed of 0.8 m s(-1) and at a self-selected maximal speed on an instrumented treadmill that recorded vertical ground reaction forces (vGRF) and spatiotemporal gait measures. Older women with low strength had 30% lower KE maximal torque, 36% lower PF maximal torque, 34% lower KE rate of torque development (RTD) and 30% lower KF RTD. Low strength women demonstrated slower maximal walking speeds (1.26±0.20 m s(-1) vs. 1.56±0.20 m s(-1)), lower vGRF during weight acceptance (1.15±0.10 BW vs. 1.27±0.13 BW), lower weight acceptance rates (11.3±0.5 BW s(-1) vs. 17.0±5.5 BW s(-1)), slower stride rates, shorter stride lengths, and longer foot-ground and double-limb support times (all P<0.05). Maximal gait speed was strongly correlated to peak vGRF and rate (r=0.60-0.85, P<0.01) and moderately related to lower-limb strength (r=0.42-0.60, P<0.05). In older women with low strength, diminished peak vGRFs were associated with slower walking speeds putting them at risk for mobility limitation, disability, poor health, and loss of independence.

Association between obesity history and hand grip strength in older adults--exploring the roles of inflammation and insulin resistance as mediating factors

BACKGROUND

To examine the association between obesity history and hand grip strength, and whether the association is partly explained by subclinical inflammation and insulin resistance.

METHODS

Data are from 2,021 men and women aged 55 years and older participating in the representative population-based Health 2000 Survey in Finland. Body mass and body height, maximal hand grip strength, C-reactive protein, and insulin resistance based on homeostasis model assessment (HOMA-IR) were measured in a health examination. Recalled weight at 20, 30, 40, and 50 years of age were recorded to obtain a hierarchical classification of obesity history. Obesity was defined as body mass index ≥ 30 kg/m².

RESULTS

Earlier onset of obesity was associated with lower hand grip strength (p < .001) after controlling for age, sex, education, smoking, alcohol use, physical activity, several chronic diseases, and current body weight. Based on adjusted logistic regression models, the odds (95% confidence interval) for very low relative hand grip strength were 2.76 (1.78-4.28) for currently obese, 5.57 (3.02-10.28) for obese since age of 50 years, 6.53 (2.98-14.30) for obese since age of 40 years, and 10.36 (3.55-30.24) for obese since age of 30 years compared with never obese participants. The associations remained highly significant even after adjusting for current C-reactive protein and HOMA-IR, but these variables had only minor role in explaining the association between obesity history and hand grip strength.

CONCLUSIONS

Long-term exposure to obesity is associated with poor hand grip strength later in life. Maintaining healthy body weight throughout the life span may help to maintain adequate muscle strength in old age. Prospective studies with information on prior muscle strength are needed to examine in detail the causal association between obesity history and muscle strength.

Obesity, sarcopenia and their functional consequences in old age

The prevalence of obesity is high in older persons and recent trends show a rapid increase in this prevalence. Results from observational and intervention studies (i.e. weight loss studies) show the strong negative impact of obesity on functional status in old age. There are different potential pathways through which obesity may lead to functional decline in older persons. Furthermore, the presence of overweight and obesity during the life course and trends in medical care are likely to influence the impact of obesity on disability. The concepts sarcopenia (age-related loss of muscle mass) and dynapenia (age-related loss of muscle strength) receive a lot of research attention as potential determinants of functional decline in old age. There is no consensus on the definitions of these concepts. Recent studies conducted in large cohort studies of mainly community-dwelling older persons show that poor muscle strength is strongly associated with functional decline compared to low muscle mass. In several studies, no association between muscle mass and functional status was observed. Current research on the combination of obesity with poor muscle strength (dynapenic-obesity) suggests a potential additive effect of both components on poor functional status in old age which seems independent of the level of physical activity.