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BACKGROUND: Age-related decline in muscle strength is among of the most important factors in the aging process leading to disability. This study examines age-related changes in handgrip strength through a 22-year follow-up in men and women. Because handgrip strength is associated with mortality, this study also accounts for the selection effect of right censoring by comparing the estimates of handgrip strength decline based either on only the handgrip strength data or on the data of both the handgrip strength and survival times. METHODS: Data are from 1,890 men and women aged 30 years or more at baseline participating in the population-based Mini-Finland Health Examination Survey (1978-1980) with repeated handgrip strength measurement in 2000-2001. RESULTS: In men aged 31-41 years, the annual decrease in handgrip strength was approximately 3.5 Newtons (N). After that, the decrease accelerated and stabilized around the age of 75 years, being approximately 7.3 N per year. In women, respectively, prior to 45 years, the annual decrease was approximately 2 N and after age 80 years approximately 4 N per year. The estimates for the handgrip strength decline were more pronounced when the right censoring due to death was accounted for, especially for persons aged 65 years and older. CONCLUSIONS: Our work confirms that the right censoring, which depends on the outcome of interest, should be accounted for in analyses. [ABSTRACT FROM AUTHOR]

Diabetes may impact gait mechanics before onset of frank neuropathies and other associated threats to mobility. This study aims to characterize gait pattern alterations of type 2 diabetic adults without peripheral neuropathy during walking at maximum speed (fast-walking) as well as at self-selected speed (usual-walking). One-hundred and eighty-six participants aged 60-87 from the Baltimore Longitudinal Study of Aging (BLSA) able to walk unassisted and without peripheral neuropathy were classified as non-diabetic (N=160) or having type 2 diabetes (N=26). Gait parameters from the fast-walking and usual-walking tests were compared between participants with and without type 2 diabetes. Participants with diabetes had a shorter stride length for fast-walking (p=0.033) and a longer percentage of the gait cycle with the knee in 1st flexion for both fast- and usual-walking (p=0.033, and 0.040, respectively) than non-diabetic participants. Participants with diabetes exhibited a smaller hip range of motion in the sagittal plane during usual-walking compared to non-diabetics (p=0.049). During fast-walking, participants with diabetes used lower ankle generative mechanical work expenditure (MWE) and higher knee absorptive MWE compared to non-diabetic persons (p=0.021, and 0.018, respectively). These findings suggest that individuals with type 2 diabetes without overt peripheral neuropathy exhibit altered and less efficient gait patterns than non-diabetic persons. These alterations are more apparent during walking at a maximum speed indicating that maximum gait testing may be useful for identifying early threats to mobility limitations in older adults with type 2 diabetes. [ABSTRACT FROM AUTHOR]

Background: An excessive amount of adipose tissue may contribute to sarcopenia and may be one mechanism underlying accelerated loss of muscle mass and strength with aging. We therefore examined the association of baseline total body fat with changes in leg lean mass, muscle strength, and muscle quality over 7 years of follow-up and whether this link was explained by adipocytokines and insulin resistance.Methods: Data were from 2,307 men and women, aged 70-79 years, participating in the Health, Aging, and Body Composition study. Total fat mass was acquired from dual energy X-ray absorptiometry. Leg lean mass was assessed by dual energy X-ray absorptiometry in Years 1, 2, 3, 4, 5, 6, and 8. Knee extension strength was measured by isokinetic dynamometer in Years 1, 2, 4, 6, and 8. Muscle quality was calculated as muscle strength divided by leg lean mass.Results: Every SD greater fat mass was related to 1.3 kg more leg lean mass at baseline in men and 1.5 kg in women (p < .01). Greater fat mass was also associated with a greater decline in leg lean mass in both men and women (0.02 kg/year, p < .01), which was not explained by higher levels of adipocytokines and insulin resistance. Larger fat mass was related to significantly greater muscle strength but significantly lower muscle quality at baseline (p < .01). No significant differences in decline of muscle strength and quality were found.Conclusions: High fatness was associated with lower muscle quality, and it predicts accelerated loss of lean mass. Prevention of greater fatness in old age may decrease the loss of lean mass and maintain muscle quality and thereby reducing disability and mobility impairments. [ABSTRACT FROM AUTHOR]

Background: Although both obesity and the metabolic syndrome (MetS) are known risk factors for decline in physical function, the joint association of obesity and metabolic alterations with risk of incident mobility limitation is unknown.Methods: Data are from 2,984 women and men aged 70-79 years participating in the Health, Aging, and Body Composition Study without mobility limitation at baseline. Obesity was defined as body mass index greater than or equal to 30 kg/m(2) and the MetS as meeting greater than or equal to 3 of the ATP III criteria. Mobility limitation was defined as any difficulty walking one-quarter mile or climbing 10 steps during two consecutive semiannual assessments for more than 6.5 years.Results: Incidence of mobility limitation was 55% in women and 44% in men. In women, adjusted risk of developing mobility limitation was progressively greater in nonobese participants with the MetS (hazard ratio [HR] = 1.49, 95% confidence interval [CI] = 1.24-1.80), obese participants without the MetS (HR = 1.95, 95% CI = 1.51-2.53), and obese participants with the MetS (HR = 2.16, 95% CI = 1.78-2.63) relative to the nonobese without the MetS. In men, the corresponding adjusted HRs (95% CI) were 1.07 (0.87-1.32), 1.64 (1.19-2.25), and 1.41 (1.12-1.78). Elevated inflammatory markers partly explained the association between obesity, the MetS, and mobility limitation, particularly in nonobese and obese participants with the MetS.Conclusions: Obesity itself, independent of its metabolic consequences, is a risk factor for mobility limitation among obese older adults. In addition, having the MetS increases the risk of functional decline in older nonobese women but not in men. [ABSTRACT FROM AUTHOR]

BACKGROUND AND AIMS: Obesity among older persons is rapidly increasing, thus affecting their mobility negatively. The aim of this study was to examine the association of high body mass index (BMI) with walking limitation, and the effect of obesity-related diseases on this association. METHODS: In a representative sample of the Finnish population of 55 years and older (2055 women and 1337 men), maximal walking speed, chronic diseases, and BMI were ascertained in a health examination. Walking limitation was defined as maximal walking speed of less than 1.2 m/s or difficulty in walking 500 meters. To analyze the effects of chronic conditions, smoking, marital status, and education on BMI class differences in walking limitation, covariates were sequentially adjusted in logistic regression analyses. RESULTS: In women, an increasing gradient in the age-adjusted risk of walking limitation was observed with higher BMI: overweight (OR 1.47, 95% CI 1.10-1.96), obese (OR 2.77, 95% CI 2.01-3.82), and severely obese (OR 5.80, 95% CI 3.52-9.54). In men, the risk was significantly increased among the obese (OR 1.63, 95% CI 1.04-2.55) and severely obese (OR 4.33, 95% CI 2.20- 8.53). After adjustment of multiple covariates, the association remained significant among the obese (OR 1.99, 95% CI 1.38-2.86) and severely obese women (OR 3.64, 95% CI 2.12-6.26), as well as severely obese men (OR 2.78, 95% CI 1.30-5.95). Knee osteoarthritis in women and diabetes in men contributed most to the excess risk of walking limitation among obese persons, 18 and 32% respectively. CONCLUSIONS: Obesity increases the risk of walking limitation, independent of obesity-related diseases, smoking, marital status, and education, especially in older women. The results of this study emphasize the importance of maintaining normal body weight, in order to prevent obesity-related health risks and loss of functioning in older age. [ABSTRACT FROM AUTHOR]

Introduction: Hip fracture often leads to decline in mobility and increased need for assistance in activities of daily living (ADL). The purpose of our study was to elucidate post-fracture functional outcome and physical performance according to hip fracture type. Methods: The study material comprised all 2052 consecutive patients aged 65 and over who sustained their first hip fracture between September 2007 and February 2018 in the Hospital District of Southern Ostrobothnia, Finland. Fractures of the upper femur were categorized as neck of femur, intertrochanteric and subtrochanteric fracture. Data were collected on admission and with telephone interview by a geriatric nurse 4 months postoperatively. Follow-up visit at the geriatric outpatient clinic with comprehensive geriatric assessment (CGA) including ADL assessments was carried out 4 to 6 months post-fracture. The CGA was preceded by a physiotherapist's examination including physical performance tests such as the Timed Up and Go (TUG), Elderly Mobility Scale (EMS) and measurement for grip strength. Logistic regression analyses were used. Results: Of the 2052 patients 62% had a neck of femur, 32% an intertrochanteric and 6% a subtrochanteric fracture. Of patient's characteristics age, living arrangements, American Society of Anesthesiologists (ASA) grade, diagnosis of cognitive disorder and need of mobility aid were significantly associated with other hip fracture type than the femoral neck fracture. During the follow-up, mobility level had deteriorated in 39% of the femoral neck, 52% of the intertrochateric and 51% of the subtrochanteric fracture patients. Change in mobility was most significant in patients moving independently before the fracture. Advanced age and abnormal/low results in physical performance tests and low ADL performance were more common in patients with other hip fracture type than the femoral neck fracture. In the multivariable analyses adjusted for age, gender and mobility level at baseline, poor results in each of the physical performance tests and ADLs were significantly associated with intertrochanteric vs femoral neck fractures. Conclusion: Femoral neck fracture patients are more likely to regain their pre-fracture mobility level after hip fracture compared to inter- and subtrochanteric fractures but mobility decline is common in all hip fracture types. In order to regain pre-fracture mobility, all hip fracture patients need intensive rehabilitation. [ABSTRACT FROM AUTHOR]

In this paper we consider the laser cooling of a trapped particle when the discrete nature of the quantum levels must be taken into account. We particularize the equations to the Lamb-Dicke limit when the oscillational, amplitude is much less than the optical wavelength. Then the quantum levels are coupled only to the neighbouring ones, and we can also find a small parameter to use for adiabatic elimination of rapidly varying terms. There emerges one rate equation for the probability distribution over the quantum states. The ultimate distribution is found to be of the Planckian type independently of the initial one. We solve the equation, generally and obtain the time evolution for an arbitrary initial distribution. In particular we look at an initially thermal, Poisson, or pure state distribution. For the thermal one we find that its shape is preserved during the cooling. The results are discussed. [ABSTRACT FROM AUTHOR]

We solve the previously derived Fokker-Planck equations of laser cooling for several cases: no diffusion processes included, the final stage when the distribution is narrow, and for an ansatz of Gaussian shape at all times. The results are particularized to a transition (j=0)→(j=1) and the numerical values for Mg atoms are used. The results are compared with earlier work on laser cooling and discussed. [ABSTRACT FROM AUTHOR]

We discuss laser cooling of a trapped ion. The problem is formulated for a harmonic trapping well and one-dimensional cooling. We carry out an adiabatic elimination and a Fokker-Planck expansion in the limit of a slowly oscillating particle. The ensuing Fokker-Planck equation is discussed and solved in certain limits. Especially the final cooling stages and ultimate width are of interest. The approach is related to earlier work and its validity is discussed. [ABSTRACT FROM AUTHOR]

The question of choosing optimum laser intensities, detunings and relaxation rates in two-photon excitation is considered. It is shown that under steady state conditions the best excitation efficiency is achieved when rather modest laser powers are used and the atoms excited are not extracted too rapidly. The latter conclusion relates to coherence effects playing a non-negligible role in the excitation, which fact can be exploited to enhance the yield. [ABSTRACT FROM AUTHOR]

Data on how body mass index (BMI), waist circumference (WC) and waist-to-hip ratio (WHR) are associated with body fat in the oldest-old people are scarce. The purpose of this study was to examine if BMI, WC or WHR are associated with leptin, a biological surrogate measure of body fat in 90-year-old people. The data comes from the Vitality 90+ Study, a prospective population-based study of people living in Tampere, Finland. BMI, WC, WHR and plasma concentration of leptin were available for 160 women and 54 men aged 90 years. BMI and WC had a strong significant positive association with leptin both in women and in men, but WHR was associated with leptin only in men. In conclusion, based on the circulating level of leptin, BMI and WC, and WHR in men, reflect body fat in 90-year-old people, but WHR seems to be a poor indicator of body fat in 90-year-old women. [ABSTRACT FROM AUTHOR]