Susan M Rubin

University of California, San Francisco, San Francisco, California, United States

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Publications (80)404.82 Total impact

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    ABSTRACT: To examine the association between multiple measures of visual impairment (VI) and incident mobility limitations in older adults. Prospective observational cohort study. Memphis, Tennessee, and Pittsburgh, Pennsylvania. Health, Aging and Body Composition study participants aged 70 to 79 without mobility limitations at the Year 3 visit (N = 1,862). Vision was measured at the Year 3 visit, and VI was defined as distance visual acuity (VA) worse than 20/40, contrast sensitivity (CS) less than 1.55 log Contrast, and stereoacuity (SA) greater than 85 arcsec. Incident persistent walking and stair climbing limitation was defined as two consecutive 6-month reports of any difficulty walking one-quarter of a mile or walking up 10 steps after 1, 3, and 5 years of follow-up. At Year 3 (baseline for these analyses), 7.4% had impaired VA, 27.2% had impaired CS, and 29.2% had impaired SA. At all follow-up times, the incidence of walking and stair climbing limitations was higher in participants with VA, CS, or SA impairment. After 5 years, impaired CS and SA were independently associated with greater risk of walking limitation (hazard ratio (HR)CS = 1.3, 95% confidence interval (CI) = 1.1-1.7; HRSA = 1.3, 95% CI = 1.1-1.6) and stair climbing limitation (HRCS = 1.4, 95% CI = 1.1-1.8; HRSA = 1.3, 95% CI=1.1-1.7). Having impaired CS and SA was associated with greater risk of mobility limitations (HRwalking limitations = 2.0, 95% CI = 1.6-2.5; HRstair limitation = 2.1, 95% CI = 1.6-2.8). Multiple aspects of VI may contribute to mobility limitations in older adults. Addressing more than one component of vision may be needed to reduce the effect of vision impairment on functional decline. © 2014, Copyright the Authors Journal compilation © 2014, The American Geriatrics Society.
    Journal of the American Geriatrics Society 12/2014; · 4.22 Impact Factor
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    ABSTRACT: Inflammation may represent a common physiological pathway linking both short and long sleep duration to mortality. We evaluated inflammatory markers as mediators of the relationship between sleep duration and mortality in community-dwelling older adults.
    Sleep 10/2014; · 5.06 Impact Factor
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    ABSTRACT: Cross-sectional studies suggest that low 25-hydroxyvitamin D (25[OH]D) may be a risk factor for depression; however, there are few prospective studies. We examined the association between 25(OH)D and depressive symptoms in community-dwelling persons aged 70-79 years in the Health, Aging, and Body Composition (Health ABC) Study (n = 2598).
    The Journals of Gerontology Series A Biological Sciences and Medical Sciences 10/2014; · 4.31 Impact Factor
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    ABSTRACT: Low literacy is common among the elderly and possibly more reflective of educational attainment than years of school completed. We examined the association between literacy and risk of likely dementia in older adults. Participants were 2,458 black and white elders (aged 71-82) from the Health, Aging and Body Composition study, who completed the Rapid Estimate of Adult Literacy in Medicine and were followed for 8 years. Participants were free of dementia at baseline; incidence of likely dementia was defined by hospital records, prescription for dementia medication, or decline in Modified Mini-Mental State Examination score. We conducted Cox proportional hazard models to evaluate the association between literacy and incidence of likely dementia. Demographics, education, income, comorbidities, lifestyle variables, and apolipoprotein E (APOE) ε4 status were included in adjusted analyses. Twenty-three percent of participants had limited literacy (<9th-grade level). Limited literacy, as opposed to adequate literacy (≥9th-grade level), was associated with greater incidence of likely dementia (25.5% vs17.0%; unadjusted hazard ratio [HR] = 1.75, 95% confidence interval 1.44-2.13); this association remained significant after adjustment. There was a trend for an interaction between literacy and APOE ε4 status (p = .07); the association between limited literacy and greater incidence of likely dementia was strong among ε4 noncarriers (unadjusted HR = 1.85) but nonsignificant among ε4 carriers (unadjusted HR = 1.25). Limited literacy is an important risk factor for likely dementia, especially among APOE ε4-negative older adults, and may prove fruitful to target in interventions aimed at reducing dementia risk.
    The Journals of Gerontology Series A Biological Sciences and Medical Sciences 10/2013; · 4.31 Impact Factor
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    ABSTRACT: Context:Previous 25-hydroxyvitamin D [25(OH)D] and mortality studies have included mostly individuals of European descent. Whether the relationship is similar in Blacks and to what extent differences in 25(OH)D explain racial disparities in mortality is unclear.Objective:The objective of the study was to examine the relationship between 25(OH)D, PTH, and mortality in Black and white community-dwelling older adults over 8.5 yr of follow-up.Design and Setting:Health ABC is a prospective cohort study conducted in Memphis, TN, and Pittsburgh, PA.Participants:Well-functioning Blacks and whites aged 71-80 yr with measured 25(OH)D and PTH (n = 2638; 49% male, 39% Black) were included in the study.Main Outcome Measure:Multivariate-adjusted proportional hazards models estimated the hazard ratios (HR) for all-cause, cardiovascular, cancer, and noncancer, noncardiovascular mortality (n = 691 deaths).Results:Mean 25(OH)D concentrations were higher in whites than in Blacks [mean (sd): 29.0 (9.9) and 20.8 (8.7) ng/ml, respectively; P < 0.001]. Serum 25(OH)D by race interactions were not significant, however. Lower 25(OH)D concentrations were associated with higher mortality in Blacks and whites combined [HR (95% confidence interval [CI] 2.27 (1.59-3.24), 1.48 (1.20-1.84), and 1.25 (1.02-1.52) for < 10, 10 to < 20, and 20 to < 30 vs. ≥30 ng/ml]. In the multivariate model without 25(OH)D, Blacks had 22% higher mortality than whites [HR (95% CI) 1.22 (1.01, 1.48)]; after including 25(OH)D in the model, the association was attenuated [1.09 (0.90-1.33)]. The mortality population attributable risks (95% CI) for 25(OH)D concentrations less than 20 ng/ml and less than 30 ng/ml in Blacks were 16.4% (3.1-26.6%) and 37.7% (11.6-55.1%) and in whites were 8.9% (3.9-12.7%) and 11.1% (-2.7 to 22.0%), respectively. PTH was also associated with mortality [HR (95% CI) 1.80 (1.33-2.43) for ≥70 vs. <23 pg/ml].Conclusions:Low 25(OH)D and high PTH concentrations were associated with increased mortality in Black and white community-dwelling older adults. Because 25(OH)D concentrations were much lower in Blacks, the potential impact of remediating low 25(OH)D concentrations was greater in Blacks than whites.
    The Journal of Clinical Endocrinology and Metabolism 08/2012; · 6.31 Impact Factor
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    ABSTRACT: BACKGROUND:: The relationship between low socioeconomic status (SES) and depressive symptoms is well described, also in older persons. Although studies have found associations between low SES and unhealthy lifestyle factors, and between unhealthy lifestyle factors and depressive symptoms, not much is known about unhealthy lifestyles as a potential explanation of socioeconomic differences in depressive symptoms in older persons. METHODS:: To study the independent pathways between SES (education, income, perceived income, and financial assets), lifestyle factors (smoking, alcohol use, body mass index, and physical activity), and incident depressive symptoms (Center for Epidemiologic Studies--Depression [CES-D 10] and reported use of antidepressant medication), we used 9 years of follow-up data (1997-2007) from 2,694 American black and white participants aged 70-79 years from the Health, Aging, and Body Composition (Health ABC) study. At baseline, 12.1% of the study population showed prevalent depressive symptoms, use of antidepressant medication, or treatment of depression in the 5 years prior to baseline. These persons were excluded from the analyses. RESULTS:: Over a period of 9 years time, 860 participants (31.9%) developed depressive symptoms. Adjusted hazard ratios for incident depressive symptoms were higher in participants from lower SES groups compared with the highest SES group. The strongest relationships were found for black men. Although unhealthy lifestyle factors were consistently associated with low SES, they were weakly related to incident depressive symptoms. Lifestyle factors did not significantly reduce hazard ratios for depressive symptoms by SES. CONCLUSION:: In generally healthy persons aged 70-79 years, lifestyle factors do not explain the relationship between SES and depressive symptoms.
    The American journal of geriatric psychiatry: official journal of the American Association for Geriatric Psychiatry 04/2012; · 3.35 Impact Factor
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    ABSTRACT: Little is known about the simultaneous effect of socioeconomic status (SES), psychosocial, and health-related factors on race differences in mortality in older adults. This study examined the association between race and mortality and the role of SES, health insurance, psychosocial factors, behavioral factors, and health-related factors in explaining these differences. Data consisted of 2,938 adults participating in the Health, Aging and Body Composition study. Mortality was assessed over 8 years. SES differences accounted for 60% of the racial differences in all-cause mortality; behavioral factors and self-rated health further reduced the disparity. The racial differences in coronary heart disease mortality were completely explained by SES. Health insurance and behavioral factors accounted for some, but not all, of the race differences in cancer mortality. Race-related risk factors for mortality may differ by the underlying cause of mortality.
    Annals of Behavioral Medicine 12/2011; 43(1):29-38. · 4.20 Impact Factor
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    ABSTRACT: Telomere shortening is a marker of cellular aging and has been associated with risk of Alzheimer's disease. Few studies have determined if telomere length is associated with cognitive decline in non-demented elders. We prospectively studied 2734 non-demented elders (mean age: 74 years). We measured cognition with the Modified Mini-Mental State Exam (3MS) and Digit Symbol Substitution Test (DSST) repeatedly over 7 years. Baseline telomere length was measured in blood leukocytes and classified by tertile as "short", "medium", or "long". At baseline, longer telomere length was associated with better DSST score (36.4, 34.9 and 34.4 points for long, medium and short, p<0.01) but not for change in score. However, 7-year 3MS change scores were less among those with longer telomere length (-1.7 points vs. -2.5 and -2.9, p=0.01). Findings were similar after multivariable adjustment for age, gender, race, education, assay batch, and baseline score. There was a borderline statistically significant interaction for telomere length and APOE e4 on 3MS change score (p=0.06). Thus, telomere length may serve as a biomarker for cognitive aging.
    Neurobiology of aging 11/2011; 32(11):2055-60. · 5.94 Impact Factor
  • 01/2011;
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    ABSTRACT: Leukocyte telomere length (LTL) is an emerging marker of biological age. Chronic inflammatory activity is commonly proposed as a promoter of biological aging in general, and of leukocyte telomere shortening in particular. In addition, senescent cells with critically short telomeres produce pro-inflammatory factors. However, in spite of the proposed causal links between inflammatory activity and LTL, there is little clinical evidence in support of their covariation and interaction. To address this issue, we examined if individuals with high levels of the systemic inflammatory markers interleukin-6 (IL-6), tumor necrosis factor-α (TNF-α) and C-reactive protein (CRP) had increased odds for short LTL. Our sample included 1,962 high-functioning adults who participated in the Health, Aging and Body Composition Study (age range: 70-79 years). Logistic regression analyses indicated that individuals with high levels of either IL-6 or TNF-α had significantly higher odds for short LTL. Furthermore, individuals with high levels of both IL-6 and TNF-α had significantly higher odds for short LTL compared with those who had neither high (OR = 0.52, CI = 0.37-0.72), only IL-6 high (OR = 0.57, CI = 0.39-0.83) or only TNF-α high (OR = 0.67, CI = 0.46-0.99), adjusting for a wide variety of established risk factors and potential confounds. In contrast, CRP was not associated with LTL. Results suggest that cumulative inflammatory load, as indexed by the combination of high levels of IL-6 and TNF-α, is associated with increased odds for short LTL. In contrast, high levels of CRP were not accompanied by short LTL in this cohort of older adults. These data provide the first large-scale demonstration of links between inflammatory markers and LTL in an older population.
    PLoS ONE 01/2011; 6(5):e19687. · 3.53 Impact Factor
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    ABSTRACT: To determine whether long-term maintenance of cognition is associated with health advantages such as lower mortality or incident disability in older adults. Longitudinal cohort study. Community clinics at two sites. Two thousand seven hundred thirty-three adults with a mean age of 74 at baseline and 80 at follow-up. Cognitive function was assessed using the Modified Mini-Mental State Examination (3MS), a test of global cognition, at least two times. Three cognitive groups were defined based on 4-year participant-specific slopes (maintainers, slopes of >or=0; minor decliners, slopes <0 but no more than 1 standard deviation (SD) below the mean; major decliners, slopes >1 SD below the mean). Whether the cognitive groups differed in mortality and incident disability during the subsequent 3 years was determined. Nine hundred eighty-four (36%) participants were maintainers, 1,314 (48%) were minor decliners, and 435 (16%) were major decliners. Maintainers had lower mortality (7% vs 14%, hazard ratio (HR)=0.48, 95% confidence interval (CI)=0.36-0.63) and incident disability (22% vs 29%, HR=0.74, 95% CI=0.62-0.89) than minor decliners. After adjustment for age, race, sex, education, apolipoprotein E epsilon4, depression, body mass index, stroke, hypertension, and diabetes mellitus, these differences remained. As expected, major decliners had greater mortality (20%) and incident disability (40%) than minor decliners. A substantial proportion of older adults maintain cognitive function in their eighth and ninth decades of life. These older adults demonstrate lower risk of death and functional decline than those with minor cognitive decline, supporting the concept of "successful" cognitive aging.
    Journal of the American Geriatrics Society 05/2010; 58(5):889-94. · 4.22 Impact Factor
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    ABSTRACT: The specific health benefits of meeting physical activity guidelines are unclear in older adults. We examined the association between meeting, not meeting, or change in status of meeting physical activity guidelines through walking and the 5-year incidence of metabolic syndrome in older adults. A total of 1,863 Health, Aging, and Body Composition (Health ABC) Study participants aged 70-79 were followed for 5 years (1997-1998 to 2002-2003). Four walking groups were created based on self-report during years 1 and 6: Sustained low (Year 1, <150 min/week, and year 6, <150 min/week), decreased (year 1, >150 min/week, and year 6, <150 min/week), increased (year 1, <150 min/week, and year 6, >150 min/week), and sustained high (year 1, >150 min/week, and year 6, >150 min/week). Based on the Adult Treatment Panel III (ATP III) panel guidelines, the metabolic syndrome criterion was having three of five factors: Large waist circumference, elevated blood pressure, triglycerides, blood glucose, and low high-density lipoprotein (HDL) levels. Compared to the sustained low group, the sustained high group had a 39% reduction in odds of incident metabolic syndrome [adjusted odds ratio (OR) = 0.61; 95% confidence interval (CI), 0.40-0.93], and a significantly lower likelihood of developing the number of metabolic syndrome risk factors that the sustained low group developed over 5 years (beta = -0.16, P = 0.04). Meeting or exceeding the physical activity guidelines via walking significantly reduced the odds of incident metabolic syndrome and onset of new metabolic syndrome components in older adults. This protective association was found only in individuals who sustained high levels of walking for physical activity.
    Metabolic syndrome and related disorders 04/2010; 8(4):317-22. · 1.92 Impact Factor
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    ABSTRACT: Weight change may be considered an effect of depression. In turn, depression may follow weight change. Deteriorations in health may mediate these associations. The objective was to examine reciprocal associations between depressed mood and weight change, and the potentially mediating role of deteriorations in health (interim hospitalizations and incident mobility imitation) in these associations. Data were from 2406 black and white men and women, aged 70-79 from Pittsburgh, Pennsylvania and Memphis, Tennessee participating in the Health, Aging and Body composition (Health ABC) study. Depressed mood at baseline (T1) and 3-year follow-up (T4) was measured with the CES-D scale. Three weight change groups (T1-T4) were created: loss (>or=5% loss), stable (within +/-5% loss or gain), and weight gain (>or=5% gain). At T1 and T4, respectively 4.4% and 9.5% of the analysis sample had depressed mood. T1 depressed mood was associated with weight gain over the 3-year period (OR:1.91; 95%CI:1.13-3.22). Weight loss over the 3-year period was associated with T4 depressed mood (OR:1.51; 95%CI:1.05-2.16). Accounting for deteriorations in health in the reciprocal associations between weight change and depressed mood reduced effect sizes between 16-27%. In this study, depressed mood predicted weight gain over three years, while weight loss over three years predicted depressed mood. These associations were partly mediated through deteriorations in health. Implications for clinical practice and prevention include increased awareness that depressed mood can cause weight change, but can also be preceded by deteriorations in health and weight change.
    The American journal of geriatric psychiatry: official journal of the American Association for Geriatric Psychiatry 03/2010; 18(3):236-44. · 3.35 Impact Factor
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    ABSTRACT: There is growing evidence that higher levels of inflammatory markers are associated with physical decline in older persons, possibly through the catabolic effects of inflammatory markers on muscle. The aim of this study was to investigate the association between serum levels of inflammatory markers and loss of muscle mass and strength in older persons. Using data on 2,177 men and women in the Health, Aging, and Body Composition Study, we examined 5-year change in thigh muscle area estimated by computed tomography and grip and knee extensor strength in relation to serum levels of interleukin-6 (IL-6), C-reactive protein, tumor necrosis factor-alpha (TNF-alpha), and soluble receptors (measured in a subsample) at baseline. Higher levels of inflammatory markers were generally associated with greater 5-year decline in thigh muscle area. Most associations, with the exception of soluble receptors, were attenuated by adjustment for 5-year change in weight. Higher TNF-alpha and interleukin-6 soluble receptor levels remained associated with greater decline in grip strength in men. Analyses in a subgroup of weight-stable persons showed that higher levels of TNF-alpha and its soluble receptors were associated with 5-year decline in thigh muscle area and that higher levels of TNF-alpha were associated with decline in grip strength. TNF-alpha and its soluble receptors showed the most consistent associations with decline in muscle mass and strength. The results suggest a weight-associated pathway for inflammation in sarcopenia.
    The Journals of Gerontology Series A Biological Sciences and Medical Sciences 08/2009; 64(11):1183-9. · 4.31 Impact Factor
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    ABSTRACT: To examine the association between dietary factors to daily activity energy expenditure (DAEE) and mortality among older adults. A sub-study of Health, Aging, and Body Composition study. 298 older participants (aged 70-82 years) in the Health, Aging, and Body Composition Energy Expenditure sub-study. Dietary factors, DAEE, and all-cause mortality were measured in 298 older participants. Dietary factors include dietary intake assessed by the Block Food Frequency Questionnaire (FFQ), Healthy Eating Index (HEI), and self-reported appetite and enjoyment of eating. DAEE was assessed using doubly labeled water. All-cause mortality was evaluated over a 9 year period. Participants in the highest tertile of DAEE were more likely to be men and to report having a 'good' appetite; BMI among men, proportion married, IL-6 and CRP levels and energy intake were also higher. Fewer black participants were in the 'good' HEI category. Participants in the 'good' HEI category had higher cognitive scores and a higher education level. Participants who reported improvement in their appetite as well as participants who reported a 'good' appetite were at lower risk for mortality (HR (95% CI): 0.42 (0.24-0.74) and 0.50 (0.26-0.88), respectively) even after adjusting for DAEE, demographic, nutritional and health indices. We showed an association between DAEE and appetite and mortality among well-functioning, community-dwelling older adults. These findings may have some practical use for the health providers. Inclusion of a question regarding appetite of an elderly patient may provide important information regarding risk for health deterioration and mortality.
    The Journal of Nutrition Health and Aging 06/2009; 13(5):414-20. · 2.66 Impact Factor
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    ABSTRACT: Although several risk factors for cognitive decline have been identified, much less is known about factors that predict maintenance of cognitive function in advanced age. We studied 2,509 well-functioning black and white elders enrolled in a prospective study. Cognitive function was measured using the Modified Mini-Mental State Examination at baseline and years 3, 5, and 8. Random effects models were used to classify participants as cognitive maintainers (cognitive change slope > or = 0), minor decliners (slope < 0 and > 1 SD below mean), or major decliners (slope < or = 1 SD below mean). Logistic regression was used to identify domain-specific factors associated with being a maintainer vs a minor decliner. Over 8 years, 30% of the participants maintained cognitive function, 53% showed minor decline, and 16% had major cognitive decline. In the multivariate model, baseline variables significantly associated with being a maintainer vs a minor decliner were age (odds ratio [OR] = 0.65, 95% confidence interval [CI] 0.55-0.77 per 5 years), white race (OR = 1.72, 95% CI 1.30-2.28), high school education level or greater (OR = 2.75, 95% CI 1.78-4.26), ninth grade literacy level or greater (OR = 4.85, 95% CI 3.00-7.87), weekly moderate/vigorous exercise (OR = 1.31, 95% CI 1.06-1.62), and not smoking (OR = 1.84, 95% CI 1.14-2.97). Variables associated with major cognitive decline compared to minor cognitive decline are reported. Elders who maintain cognitive function have a unique profile that differentiates them from those with minor decline. Importantly, some of these factors are modifiable and thus may be implemented in prevention programs to promote successful cognitive aging. Further, factors associated with maintenance may differ from factors associated with major cognitive decline, which may impact prevention vs treatment strategies.
    Neurology 06/2009; 72(23):2029-35. · 8.30 Impact Factor
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    ABSTRACT: A growing body of evidence has consistently shown a correlation between obesity and chronic subclinical inflammation. It is unclear whether the size of specific adipose depots is more closely associated with concentrations of inflammatory markers than overall adiposity. This study investigated the relationship between inflammatory markers and computerized tomography-derived abdominal visceral and subcutaneous fat and thigh intermuscular and subcutaneous fat in older white and black adults. Data were from 2,651 black and white men and women aged 70-79 years participating in the Health, Aging, and Body Composition (Health ABC) study. Inflammatory markers, interleukin-6 (IL-6), C-reactive protein (CRP), and tumor necrosis factor-alpha (TNF-alpha) were obtained from serum samples. Abdominal visceral and subcutaneous fat and thigh intermuscular and subcutaneous fat were quantified on computerized tomography images. Linear regression analysis was used to evaluate the cross-sectional relationship between specific adipose depots and inflammatory markers in four race/gender groups. As expected, blacks have less visceral fat than whites and women less visceral fat than men. However, abdominal visceral adiposity was most consistently associated with significantly higher IL-6 and CRP concentrations in all race/gender groups (P < 0.05), even after controlling for general adiposity. Thigh intermuscular fat had an inconsistent but significant association with inflammation, and there was a trend toward lower inflammatory marker concentration with increasing thigh subcutaneous fat in white and black women. Despite the previously established differences in abdominal fat distribution across gender and race, visceral fat remained a significant predictor of inflammatory marker concentration across all four subgroups examined.
    Obesity 05/2009; 17(5):1062-9. · 4.39 Impact Factor
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    ABSTRACT: Obesity in middle and old age predicts mobility limitation; however, the cumulative effect of overweight and/or obesity over the adult life course is unknown. The association between overweight and/or obesity in young, middle, and late adulthood and its cumulative effect on incident mobility limitation was examined among community-dwelling US adults aged 70-79 years at baseline (1997-1998) in the Health, Aging and Body Composition Study (n = 2,845). Body mass index was calculated by using recalled weight at ages 25 and 50 years and measured weight at ages 70-79 years. Mobility limitation (difficulty walking 1/4 mile (0.4 km) or climbing 10 steps) was assessed semiannually over 7 years of follow-up and was reported by 43.0% of men and 53.7% of women. Men and women who were overweight or obese at all 3 time points had an increased risk of mobility limitation (hazard ratio = 1.61, 95% confidence interval: 1.25, 2.06 and hazard ratio = 2.85, 95% confidence interval: 2.15, 3.78, respectively) compared with those who were normal weight throughout. Furthermore, there was a significant graded response (P < 0.0001) on risk of mobility limitation for the cumulative effect of obesity in men and overweight and/or obesity in women. Onset of overweight and obesity in earlier life contributes to an increased risk of mobility limitation in old age.
    American journal of epidemiology 04/2009; 169(8):927-36. · 4.98 Impact Factor
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    ABSTRACT: To determine how three different physical performance measures (PPMs) combine for added utility in predicting adverse health events in elders. Prospective cohort study. Health, Aging and Body Composition Study. Three thousand twenty-four well-functioning older persons (mean age 73.6). Timed gait, repeated chair stands, and balance (semi- and full-tandem, and single leg stands each held for 30 seconds) tests were administered at baseline. Usual gait speed was categorized to distinguish high- and low-risk participants using the previously established 1-m/s cutpoint. The same population-percentile (21.3%) was used to identify cutpoints for the repeated chair stands (17.1 seconds) and balance (53.0 seconds) tests. Cox proportional hazard analyses were performed to evaluate the added value of PPMs in predicting mortality, hospitalization, and (severe) mobility limitation events over 6.9 years of follow-up. Risk estimates for developing adverse health-related events were similarly large for each of the three high-risk groups considered separately. Having more PPM scores at the high-risk level was associated with a greater risk of developing adverse health-related events. When all three PPMs were considered, having only one poor performance was sufficient to indicate a highly significantly higher risk of (severe) lower extremity and mortality events. Although gait speed is considered to be the most important predictor of adverse health events, these findings demonstrate that poor performance on other tests of lower extremity function are equally prognostic. This suggests that chair stand and standing balance performance may be adequate substitutes when gait speed is unavailable.
    Journal of the American Geriatrics Society 03/2009; 57(2):251-9. · 4.22 Impact Factor
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    ABSTRACT: It is unclear if physical activity (PA) can prevent or reverse frailty. We examined different doses and types of PA and their association with the onset and severity of frailty. Health, Aging and Body Composition (Health ABC) study participants (N = 2,964) were followed for 5 years, with frailty defined as a gait speed of less than 0.60 m/s and/or inability to rise from a chair without using one's arms. Individuals with one impairment were considered moderately frail and those with both severely frail. We examined PA doses of volume and intensity, activity types (eg, lifestyle vs exercise activities), and their associations with incident frailty and transition to severe frailty in those who became frail. Adjusted models indicated that sedentary individuals had significantly increased odds of developing frailty compared with the exercise active group (adjusted odds ratio [OR] = 1.45; 95% confidence interval [CI]: 1.04-2.01), whereas the lifestyle active did not. Number of diagnoses was the strongest predictor of incident frailty. In those who became frail during follow-up (n = 410), there was evidence that the sedentary (adjusted OR = 2.80; 95% CI: 0.98-8.02) and lifestyle active (adjusted OR = 2.81; 95% CI: 1.22-6.43) groups were more likely to have worsening frailty over time. Despite the strong relationship seen between comorbid conditions and onset of frailty, this observational study suggests that participation in self-selected exercise activities is independently associated with delaying the onset and the progression of frailty. Regular exercise should be further examined as a potential factor in frailty prevention for older adults.
    The Journals of Gerontology Series A Biological Sciences and Medical Sciences 02/2009; 64(1):61-8. · 4.31 Impact Factor

Publication Stats

5k Citations
404.82 Total Impact Points


  • 2003–2014
    • University of California, San Francisco
      • • Department of Epidemiology and Biostatistics
      • • Department of Psychiatry
      • • Division of Hospital Medicine
      • • Division of Geriatrics
      San Francisco, California, United States
    • University of Leuven
      Louvain, Flanders, Belgium
  • 2013
    • San Francisco VA Medical Center
      San Francisco, California, United States
  • 2011
    • Johns Hopkins Bloomberg School of Public Health
      • Department of Health Policy and Management
      Baltimore, MD, United States
  • 2004–2010
    • National Institute on Aging
      • • Laboratory of Epidemiology, Demography and Biometry (LEDB)
      • • Clinical Research Branch (CRB)
      Baltimore, MD, United States
    • The Catholic University of America
      Washington, Washington, D.C., United States
  • 2009
    • Ben-Gurion University of the Negev
      Be'er Sheva`, Southern District, Israel
  • 2005–2009
    • University of Florida
      • Department of Aging and Geriatric Research
      Gainesville, FL, United States
    • University of Tennessee
      • Department of Periodontology
      Knoxville, TN, United States
    • The Prevention Group
      Omaha, Nebraska, United States
  • 2003–2009
    • Wake Forest School of Medicine
      • • Sticht Center on Aging
      • • Department of Internal Medicine
      Winston-Salem, NC, United States
  • 2006–2008
    • Vanderbilt University
      • • Department of Neurology
      • • Division of Cardiovascular Medicine
      Nashville, MI, United States
    • Canadian Society for Epidemiology and Biostatistics 
  • 2005–2007
    • Maastricht University
      Maestricht, Limburg, Netherlands
    • VU University Medical Center
      • Department of Psychiatry
      Amsterdam, North Holland, Netherlands
  • 2003–2006
    • University of Pittsburgh
      • • Department of Epidemiology
      • • Division of Geriatric Medicine
      Pittsburgh, PA, United States