Recent studies suggest that the obese population may have been growing healthier since the 1960s, as indicated by a decrease in mortality and cardiovascular risk factors. However, whether these improvements have conferred decreased risk for disability is unknown. The obese population may be living longer with better-controlled risk factors but paradoxically experiencing more disability.To determine whether the association between obesity and disability has changed over time.Adults aged 60 years and older (N = 9928) with measured body mass index from 2 waves of the nationally representative National Health and Nutrition Examination Surveys (NHANES III [1988-1994] and NHANES 1999-2004).Reports of much difficulty or inability to perform tasks in 2 disability domains: functional limitations (walking one-fourth mile, walking up 10 steps, stooping, lifting 10 lb, walking between rooms, and standing from an armless chair) and activities of daily living (ADL) limitations (transferring, eating, and dressing).Among obese individuals, the prevalence of functional impairment increased 5.4% (from 36.8%-42.2%; P = .03) between the 2 surveys, and ADL impairment did not change. At time 1 (1988-1994), the odds of functional impairment for obese individuals were 1.78 times greater than for normal-weight individuals (95% confidence interval [CI], 1.47-2.16). At time 2 (1999-2004), this odds ratio increased to 2.75 (95% CI, 2.39-3.17), because the odds of functional impairment increased by 43% (OR 1.43; 95% CI, 1.18-1.75) among obese individuals during this period, but did not change among nonobese individuals. With respect to ADL impairment, odds for obese individuals were not significantly greater than for individuals with normal weight (OR, 1.31; 95% CI, 0.92-1.88) at time 1, but increased to 2.05 (95% CI, 1.45-2.88) at time 2. This was because the odds of ADL impairment did not change for obese individuals but decreased by 34% among nonobese individuals (OR, 0.66; 95% CI, 0.50-0.88).Recent cardiovascular improvements have not been accompanied by reduced disability within the obese older population. Rather, obese participants surveyed during 1999-2004 were more likely to report functional impairments than obese participants surveyed during 1988-1994, and reductions in ADL impairment observed for nonobese older individuals did not occur in those who were obese. Over time, declines in obesity-related mortality, along with a younger age at onset of obesity, could lead to an increased burden of disability within the obese older population.
Background. Inflammatory proteins including interleukin-6 (IL-6) and C-reactive protein (CRP) have been associated with incident cognitive impairment, but little research has addressed their effects on the rate of cognitive change, and findings are mixed. The purpose of this study was to examine the relationship between serum levels of IL-6 and CRP and the rate of cognitive change across a range of cognitive domains in a sample of healthy older persons.
There is an analogy between single-chip color cameras and the human visual system in that these two systems acquire only one limited wavelength sensitivity band per spatial location. We have exploited this analogy, defining a model that characterizes a one-color per spatial position image as a coding into luminance and chrominance of the corresponding three colors per spatial position image. Luminance is defined with full spatial resolution while chrominance contains subsampled opponent colors. Moreover, luminance and chrominance follow a particular arrangement in the Fourier domain, allowing for demosaicing by spatial frequency filtering. This model shows that visual artifacts after demosaicing are due to aliasing between luminance and chrominance and could be solved using a preprocessing filter. This approach also gives new insights for the representation of single-color per spatial location images and enables formal and controllable procedures to design demosaicing algorithms that perform well compared to concurrent approaches, as demonstrated by experiments.
Objectives To compare the relative predictive power of handgrip and leg extension strength in predicting slow walking. Design Report of correlative analysis from two epidemiological cohort studies. Setting Foundation of the National Institutes of Health Sarcopenia Project. Participants Men and women aged 67 to 93 (N = 6,766). Measurements Leg strength, handgrip strength, and gait speed were measured. Strength cutpoints associated with slow gait speed were developed using classification and regression tree analyses and compared using ordinary least squares regression models. Results The cutpoints of lower extremity strength associated with slow gait speed were 154.6 N‐m in men and 89.9 N‐m in women for isometric leg extension strength and 94.5 N‐m in men and 62.3 N‐m in women for isokinetic leg extension strength. Weakness defined according to handgrip strength (odds ratios ( OR ) = 1.99 to 4.33, c‐statistics = 0.53 to 0.67) or leg strength ( OR s = 2.52 to 5.77; c‐statistics = 0.61 to 0.66) was strongly related to odds of slow gait speed. Lower extremity strength contributed 1% to 16% of the variance and handgrip strength contributed 3% to 17% of the variance in the prediction of gait speed depending on sex and mode of strength assessment. Conclusion Muscle weakness of the leg extensors and forearm flexors is related to slow gait speed. Leg extension strength is only a slightly better predictor of slow gait speed. Thus, handgrip and leg extension strength appear to be suitable for screening for muscle weakness in older adults.
OBJECTIVES: To estimate meaningful improvements in gait speed observed during recovery from hip fracture and to evaluate the sensitivity and specificity of gait speed changes in detecting change in self‐reported mobility. DESIGN: Secondary longitudinal data analysis from two randomized controlled trials SETTING: Twelve hospitals in the Baltimore, Maryland, area. PARTICIPANTS: Two hundred seventeen women admitted with hip fracture. MEASUREMENTS: Usual gait speed and self‐reported mobility (ability to walk 1 block and climb 1 flight of stairs) measured 2 and 12 months after fracture. RESULTS: Effect size–based estimates of meaningful differences were 0.03 for small differences and 0.09 for substantial differences. Depending on the anchor (stairs vs walking) and method (mean difference vs regression), anchor‐based estimates ranged from 0.10 to 0.17 m/s for small meaningful improvements and 0.17 to 0.26 m/s for substantial meaningful improvement. Optimal gait speed cutpoints yielded low sensitivity (0.39–0.62) and specificity (0.57–0.76) for improvements in self‐reported mobility. CONCLUSION: Results from this sample of women recovering from hip fracture provide only limited support for the 0.10‐m/s cut point for substantial meaningful change previously identified in community‐dwelling older adults experiencing declines in walking abilities. Anchor‐based estimates and cut points derived from receiver operating characteristic curve analysis suggest that greater improvements in gait speed may be required for substantial perceived mobility improvement in female hip fracture patients. Furthermore, gait speed change performed poorly in discriminating change in self‐reported mobility. Estimates of meaningful change in gait speed may differ based on the direction of change (improvement vs decline) or between patient populations.
