Sequence Analysis of Cardiometabolic Multimorbidity and Association with Subsequent Dementia

Sequence analysis is used in the social sciences to examine patterns of events occurring across the life course, but there are few examples of its use in multimorbidity research among older adults. We used sequence analysis to identify longitudinal patterns of cardiometabolic multimorbidity over a five-year period among participants in the National Health and Aging Trends Study (N=5,218). Multimorbidity sequences were constructed using self-reported diagnosis of diabetes, heart disease, stroke, and myocardial infarction (MI) assessed annually. Death was included as an absorbing state, yielding a total of 281 distinct sequences. We calculated sequence dissimilarity using optimal matching then used hierarchical clustering to identify seven distinct sequence clusters. The largest cluster (46.2%) was characterized by no baseline cardiometabolic disease and minimal incident disease across the 5-year period. Three clusters were characterized by stable sequences: diabetes (13.1%), heart disease (7.5%), and MI or stroke (7.3%) across the 5-year period. Two clusters exhibited a high rate of incident cardiometabolic disease during the 5-year period, one among persons with no baseline disease (9.6%) and one with rapid accumulation of cardiometabolic multimorbidity (5.3%). Finally, one cluster largely contained persons who died during the study period (11.0%). Compared to those with no baseline and minimal incident cardiometabolic disease, the odds of subsequent dementia were significantly higher among the cluster without prior disease who developed incident cardiometabolic disease (OR= 1.61, 95% CI:1.07,2.43) and the cluster with high cardiometabolic multimorbidity (OR=2.77, 95% CI:1.84,4.18). These findings contribute to our understanding of the impact of cardiometabolic multimorbidity on cognitive health

Mental-Somatic Multimorbidity in Trajectories of Cognitive Function for Middle-Aged and Older Adults

Multimorbidity may confer higher risk for cognitive decline than any single constituent disease. This study aims to identify distinct trajectories of cognitive impairment probability among middle-aged and older adults, and to assess the effect of changes in mental-somatic multimorbidity on these distinct trajectories

Light Intensity Physical Activity and Sedentary Behavior in Relation to Body Mass Index and Grip Strength in Older Adults: Cross-Sectional Findings from the Lifestyle Interventions and Independence for Elders (LIFE) Study.

Background Identifying modifiable determinants of fat mass and muscle strength in older adults is important given their impact on physical functioning and health. Light intensity physical activity and sedentary behavior are potential determinants, but their relations to these outcomes are poorly understood. We evaluated associations of light intensity physical activity and sedentary time—assessed both objectively and by self-report—with body mass index (BMI) and grip strength in a large sample of older adults. Methods We used cross-sectional baseline data from 1130 participants of the Lifestyle Interventions and Independence for Elders (LIFE) study, a community-dwelling sample of relatively sedentary older adults (70-89 years) at heightened risk of mobility disability. Time spent sedentary and in light intensity activity were assessed using an accelerometer worn for 3–7 days (Actigraph GT3X) and by self-report. Associations between these exposures and measured BMI and grip strength were evaluated using linear regression. Results Greater time spent in light intensity activity and lower sedentary times were both associated with lower BMI. This was evident using objective measures of lower-light intensity, and both objective and self-reported measures of higher-light intensity activity. Time spent watching television was positively associated with BMI, while reading and computer use were not. Greater time spent in higher but not lower intensities of light activity (assessed objectively) was associated with greater grip strength in men but not women, while neither objectively assessed nor self-reported sedentary time was associated with grip strength. Conclusions In this cross-sectional study, greater time spent in light intensity activity and lower sedentary times were associated with lower BMI. These results are consistent with the hypothesis that replacing sedentary activities with light intensity activities could lead to lower BMI levels and obesity prevalence among the population of older adults. However, longitudinal and experimental studies are needed to strengthen causal inferences

Successful Aging and Obesity: Social and Developmental Heterogeneity in Trajectories of Body Weight from Middle to Older Age

Obesity is increasingly prevalent among older adults, yet little is known about the distribution of long-term trajectories of body-weight in this age group. The three essays included in this dissertation aim to depict the trajectories of body-mass index (BMI) from middle to old age and to examine social and behavioral variations in these trajectories. Eight waves (1992-2006) of the Health and Retirement Study involving a nationally representative cohort of Americans aged 51 to 61 years at baseline were used. Changes in BMI were analyzed using alternatively hierarchical linear modeling or semiparametric mixture modeling, with adjustment for time-constant and time-varying covariates. First study finds that over 14 years, respondents followed a linearly increasing BMI trajectory. Compared with Caucasians, African- Americans had higher BMI levels, while Hispanics had similar BMI levels, but lower rates of increase over time. Higher education predicted lower BMI levels and was not associated with the rate of change. Older age-at-baseline predicted lower BMI levels and lower rates of increase. No gender differences were found. The second study shows that smoking and vigorous physical activity (user status and initiation) were associated with significantly lower BMI trajectories over time. Cessation of smoking and physical activity resulted in higher BMI trajectories over time. The weight-gaining effect of smoking cessation increased during the study period, while the strength of association between BMI trajectories and PA or alcohol use were constant. In the third study, five distinct BMI trajectories are identified, differing primarily in their intercept: normal BMI trajectory (19.9% of sample), overweight (43.8%), borderline-obese (25.4%), obese (8.9%), and morbidly-obese (2.1%). Each trajectory showed an upward trend over the study period, although the rate-of-increase varied between trajectories. Compared with Whites, Blacks and Hispanics had greater probabilities of membership in the higher BMI trajectory groups. Females had approximately half the risk of following the overweight and obese BMI trajectories compared with males. In conclusion, significant racial/ethnic, gender and educational heterogeneity in BMI trajectories exists in older adults. Health behaviors provide beneficial modifications in BMI trajectories. Tailoring of public health and clinical interventions to trajectory group characteristics may reduce obesity-related health disparities in aging.Ph.D.Health Services Organization & PolicyUniversity of Michigan, Horace H. Rackham School of Graduate Studieshttp://deepblue.lib.umich.edu/bitstream/2027.42/86419/1/andabm_1.pd

Tracking Multimorbidity Changes in Diverse Racial/Ethnic Populations Over Time: Issues and Considerations

Multimorbidity is widely recognized as having adverse effects on health and wellbeing and may threaten the ability of older adults to live independently. Much of what is known about multimorbidity rests on research that has largely focused on one point in time, or from a static perspective. Given that there remains a lack of agreement in the field on how to standardize multimorbidity definitions and measurement, it is not surprising that analyzing and predicting multimorbidity development, progression over time, and its impact are still largely unaddressed. As a result, there are important gaps and challenges to measuring and studying multimorbidity in a longitudinal context. This Research Practice perspective summarizes pressing challenges and offers practical steps to move the field forward

The Role of Law in Public Health Preparedness: Opportunities and Challenges

We report the results of a study designed to assess and evaluate how the law shapes the public health system's preparedness activities. Based on 144 qualitative interviews conducted in nine states, we used a model that compared the objective legal environment with how practitioners perceived the laws. Most local public health and emergency management professionals relied on what they perceived the legal environment to be rather than on an adequate understanding of the objective legal requirements. Major reasons for the gap include the lack of legal training for local practitioners and the difficulty of obtaining clarification and consistent legal advice regarding public health preparedness. Narrowing the gap would most likely improve preparedness outcomes. We conclude that there are serious deficiencies in legal preparedness that can undermine effective responses to public health emergencies. Correcting the lack of legal knowledge, coupled with eliminating delays in resolving legal issues and questions during public health emergencies, could have measurable consequences on reducing morbidity and mortality.http://jhppl.dukejournals.org/content/37/2/297.lon

Racial/Ethnic Differences in Multimorbidity Development and Chronic Disease Accumulation for Middle-aged Adults

Multimorbidity–having two or more coexisting chronic conditions–is highly prevalent, costly, and disabling to older adults. Questions remain regarding chronic diseases accumulation over time and whether this differs by racial and ethnic background. Answering this knowledge gap, this study identifies differences in rates of chronic disease accumulation and multimorbidity development among non-Hispanic white, non-Hispanic black, and Hispanic study participants starting in middle-age and followed up to 16 years. We analyzed data from the Health and Retirement Study (HRS), a biennial, ongoing, publicly- available, longitudinal nationally-representative study of middle-aged and older adults in the United States. We assessed the change in chronic disease burden among 8,872 non- Hispanic black, non-Hispanic white, and Hispanic participants who were 51–55 years of age at their first interview any time during the study period (1998–2014) and all subsequent follow- up observations until 2014. Multimorbidity was defined as having two or more of seven somatic chronic diseases: arthritis, cancer, heart disease (myocardial infarction, coronary heart disease, angina, congestive heart failure, or other heart problems), diabetes, hypertension, lung disease, and stroke. We used negative binomial generalized estimating equation models to assess the trajectories of multimorbidity burden over time for non-Hispanic black, non-Hispanic white, and Hispanic participants. In covariate-adjusted models non-Hispanic black respondents had initial chronic disease counts that were 28% higher than non- Hispanic white respondents (IRR 1.279, 95% CI 1.201, 1.361), while Hispanic respondents had initial chronic disease counts that were 15% lower than non-Hispanic white respondents (IRR 0.852, 95% CI 0.775, 0.938). Non-Hispanic black respondents had rates of chronic disease accumulation that were 1.1% slower than non-Hispanic whites (IRR 0.989, 95% CI 0.981, 0.998) and Hispanic respondents had rates of chronic disease accumulation that were 1.5% faster than non-Hispanic white respondents (IRR 1.015, 95% CI 1.002, 1.028). Using marginal effects commands, this translates to predicted values of chronic disease for white respondents who begin the study period with 0.98 chronic diseases and end with 2.8 chronic diseases; black respondents who begin the study period with 1.3 chronic diseases and end with 3.3 chronic diseases; and Hispanic respondents who begin the study period with 0.84 chronic diseases and end with 2.7 chronic diseases. Middle-aged non-Hispanic black adults start at a higher level of chronic disease burden and develop multimorbidity at an earlier age, on average, than their non-Hispanic white counterparts. Hispanics, on the other hand, accumulate chronic disease at a faster rate relative to non-Hispanic white adults. Our findings have important implications for improving primary and secondary chronic disease prevention efforts among non-Hispanic black and Hispanic Americans to stave off greater multimorbidity-related health impacts

Physical Activity As a Mediator Between Race/ethnicity and Changes in Multimorbidity.

Studies report racial/ethnic disparities in multimorbidity (≥2 chronic conditions) and their rate of accumulation over time as well as differences in physical activity. Our study aimed to investigate whether racial/ethnic differences in the accumulation of multimorbidity were mediated by physical activity among middle-aged and older adults

Multimorbidity Accumulation Among Middle-Aged Americans: Differences by Race/ethnicity and Body-Mass Index.

Obesity and multimorbidity are more prevalent among U.S. racial/ethnic minority groups. Evaluating racial/ethnic disparities in disease accumulation according to body-mass index (BMI) may guide interventions to reduce multimorbidity burden in vulnerable racial/ethnic groups

Revised Recommendations on Methods for Assessing Multimorbidity Changes over Time: Aligning the Method to the Purpose

The rapidly growing field of multimorbidity research demonstrates that changes in multimorbidity in mid- and late-life have far reaching effects on important person-centered outcomes, such as health-related quality of life. However, there are few organizing frameworks and comparatively little work weighing the merits and limitations of various quantitative methods applied to the longitudinal study of multimorbidity