28 research outputs found
Identification of a Hypothalamic Neural System That Can Reduce Body Weight and Adipose Mass in Diet-Induced Obesity
No full textIUIDynamic hypothalamic circuits balance energy intake with expenditure to protect individuals from obesity. Lasting negative energy balance, however, triggers a compensatory decrease in energy expenditure, hindering progressive weight loss. While we understand some key players underlying energy balance, the detailed neural underpinnings remain unclear. Here I will delineate the functional efferent circuitry from the ventromedial hypothalamic nucleus (VMN) that facilitates weight loss and prevents rebound weight gain.
VMN neurons have long been linked to a role in energy balance. Both vesicular communication by VMN steroidogenic factor 1 (SF1) neurons and pituitary adenylate cyclase activating peptide (PACAP) release from VMN neurons are essential for maintaining body weight and activating VMNSf1 neurons curbs diet-induced obesity without altering food intake. However, the exact pathway of this VMN signal is unclear because the VMN does not directly communicate with preganglionic sympathetic neurons, indicating signal transmission through an efferent node. Of the few brain sites they communicate with, VMNSf1 neurons sends the densest projections to the caudal preoptic area (POA) and the anterior bed nucleus of stria terminalis (BNST). Stimulating VMNPACAP axonal fibers in the caudal POA, but not anterior BNST, induced thermogenesis in brown and beige adipose tissues in both sexes of mice. To identify caudal POA populations in body weight regulation, I activated excitatory (glutamatergic) and inhibitory (GABAergic) caudal POA cells in diet-induced obese male mice and found that both glutamatergic and GABAergic caudal POA neurons can reduce diet-induced obesity through separate means. While there is intra-POA communication, my data supports efferent communication with separate downstream circuits by glutamate and GABA caudal POA cells in ameliorating diet-induced obesity.
Because the POA and BNST are extremely complex regions with diverse functions, I then employed deep transfer learning to pinpoint obesity and diabetes risk-associated cell subsets in the POA and BNST. Using single nuclei RNA sequencing on >200,000 nuclei from both sexes of mice, I identified 6 specialized sets of caudal POA and BNST neuronal subtypes that increased in obese and glucose-intolerant mice on a high-fat diet. Targeting these newly identified pathways and neuron subtypes could lead to future obesity and diabetes therapeutics
Delivery Long-Term Care Support Services and Care Recipients' Health Outcomes: Synthesis of Current Evidence
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Healthy lifestyle, disease prevention and health care utilization
Get PDFThis dissertation consists of three independent but related essays in the field of health economics. The two main focus areas of my dissertation include prevention through healthy lifestyle and dementia caregiving in the United States-implications for long-term care decisions. The first essay presents a theoretical characterization of individual investments in self-protection that mitigates the risk of future ill health and the interaction between market insurance and self-protection in reducing uncertain financial losses. It also examines the role of self-insurance (through saving) in offsetting future health costs. The results suggest that self-protection can be a substitute or complement for market insurance, and self- insurance and market insurance can coexist in lowering the severity of a potential future loss. The findings of this paper have implications for policymakers who want to encourage self-protective behavior to reduce the burdens of chronic and preventable illnesses. The second essay examines a set of lifestyle characteristics that are potential protective or risk factors for dementia and other cognitive impairments among older individuals in the U.S. The use of instrumental variables technique provides evidence in favor of a causal relationship between education and the risk of dementia. From a policy perspective the causality question is important for evaluation of the effectiveness of public expenditures on education. Some important lifestyle related risk factors are advancing age, an incidence of stroke, and a specific genetic make up. The final essay analyzes a sequence of individual characteristics of patients and family caregivers that jointly predict the optimal mix of informal and formal health care services utilized by dementia patients in this country. In addition, this study investigates the effect of a caregiver's satisfactions and gratifications on the provision of informal and formal care services. Results indicate that a measure of "altruism" is associated with an increased level of informal care and delays institutionalization. A patient's need for supervision help is an important predictor for both informal and all types of formal care services. These findings have profound social and health implications for extending publicly funded long-term care (LTC) resources and developing appropriate intervention policies to promote the well-being of patients and caregivers
Identification of a Hypothalamic Neural System That Can Reduce Body Weight and Adipose Mass in Diet-Induced Obesity
No full textIUIDynamic hypothalamic circuits balance energy intake with expenditure to protect individuals from obesity. Lasting negative energy balance, however, triggers a compensatory decrease in energy expenditure, hindering progressive weight loss. While we understand some key players underlying energy balance, the detailed neural underpinnings remain unclear. Here I will delineate the functional efferent circuitry from the ventromedial hypothalamic nucleus (VMN) that facilitates weight loss and prevents rebound weight gain.
VMN neurons have long been linked to a role in energy balance. Both vesicular communication by VMN steroidogenic factor 1 (SF1) neurons and pituitary adenylate cyclase activating peptide (PACAP) release from VMN neurons are essential for maintaining body weight and activating VMNSf1 neurons curbs diet-induced obesity without altering food intake. However, the exact pathway of this VMN signal is unclear because the VMN does not directly communicate with preganglionic sympathetic neurons, indicating signal transmission through an efferent node. Of the few brain sites they communicate with, VMNSf1 neurons sends the densest projections to the caudal preoptic area (POA) and the anterior bed nucleus of stria terminalis (BNST). Stimulating VMNPACAP axonal fibers in the caudal POA, but not anterior BNST, induced thermogenesis in brown and beige adipose tissues in both sexes of mice. To identify caudal POA populations in body weight regulation, I activated excitatory (glutamatergic) and inhibitory (GABAergic) caudal POA cells in diet-induced obese male mice and found that both glutamatergic and GABAergic caudal POA neurons can reduce diet-induced obesity through separate means. While there is intra-POA communication, my data supports efferent communication with separate downstream circuits by glutamate and GABA caudal POA cells in ameliorating diet-induced obesity.
Because the POA and BNST are extremely complex regions with diverse functions, I then employed deep transfer learning to pinpoint obesity and diabetes risk-associated cell subsets in the POA and BNST. Using single nuclei RNA sequencing on >200,000 nuclei from both sexes of mice, I identified 6 specialized sets of caudal POA and BNST neuronal subtypes that increased in obese and glucose-intolerant mice on a high-fat diet. Targeting these newly identified pathways and neuron subtypes could lead to future obesity and diabetes therapeutics
Effects of education and income on cognitive functioning among Indians aged 50 years and older: evidence from the Study on Global Ageing and Adult Health (SAGE) Wave 1 (2007-2010)
No full textAltruism and Informal Care for Dementia
Get PDFInformal care is an important source of care for persons with dementia. The primary objective of this study is to explore the factors that affect the choice to provide informal care and test if altruistic attitudes change the mix of formal and informal care given to patients with dementia. Using the Aging Demographic and Memory Study dataset, we analyze how patient and caregiver characteristics affect the use of informal and formal healthcare services by dementia patients, focusing on the role of altruism. Assuming that the total care provided is an unobserved mix of informal and formal care, we use a latent class model to test if direct altruism increases the probability that informal care is included in the care plan. Greater patient need, as measured by limitations in the number of activities of daily living, and having three or more comorbid conditions decreased the probability of having only informal care, while needing supervision increased the probability of having only informal care. The direct altruism has a positive and significant marginal effect on increasing the probability of providing only informal care and decreasing the probability of being in the mix category of informal and formal category. Our model suggests that altruism in the form of caregivers’ pleasure from providing care increases the amount of informal care used. Although not socially inefficient, it does raise the cost of care as part of the cost is “spent” on caregiver’s pleasure. We find empirical evidence in support of this theoretical implication
BMC Public Health
Get PDFBackgroundAmong the most studied evidence-based programs, the Chronic Disease Self-Management Program (CDSMP) has been shown to help participants improve their health behaviors, health outcomes, and reduce healthcare utilization. However, there is a lack of information on how CDSMP, when nationally disseminated, impacts healthcare utilization and averts healthcare costs. The purposes of this study were to: 1) document reductions in healthcare utilization among national CDSMP participants; 2) calculate potential cost savings associated with emergency room (ER) visits and hospitalizations; and 3) extrapolate the cost savings estimation to the American adults.MethodsThe national study of CDSMP surveyed 1,170 community-dwelling CDSMP participants at baseline, 6\ua0months, and 12\ua0months from 22 organizations in 17 states. The procedure used to estimate potential cost savings included: 1) examining the pattern of healthcare utilization among CDSMP participants from self-reported healthcare utilization assessed at baseline, 6\ua0months, and 12\ua0months; 2) calculating age-adjusted average costs for persons using the 2010 Medical Expenditure Panel Survey; 3) calculating costs saved from reductions in healthcare utilization; 4) estimating per participant program costs; 5) computing potential cost savings by deducting program costs from estimated healthcare savings; and 6) extrapolating savings to national populations using Census data combined with national health statistics.ResultsFindings from analyses showed significant reductions in ER visits (5%) at both the 6-month and 12-month assessments as well as hospitalizations (3%) at 6\ua0months among national CDSMP participants. This equates to potential net savings of 3.3 billion if 5% of adults with one or more chronic conditions were reached.ConclusionsFindings emphasize the value of public health tertiary prevention interventions and the need for policies to support widespread adoption of CDSMP.20131RC4AG038183-01/AG/NIA NIH HHS/United States1U48/DP001924/DP/NCCDPHP CDC HHS/United States24314032PMC3878965718
Hypothalamic Neural Circuits Regulating Energy Expenditure
No full textThe hypothalamus plays a central role in regulating energy expenditure and maintaining energy homeostasis, crucial for an organism's survival. Located in the ventral diencephalon, it is a dynamic and adaptable brain region capable of rapid responses to environmental changes, exhibiting high anatomical and cellular plasticity and integrates a myriad of sensory information, internal physiological cues, and humoral factors to accurately interpret the nutritional state and adjust food intake, thermogenesis, and energy homeostasis. Key hypothalamic nuclei contain distinct neuron populations that respond to hormonal, nutrient, and neural inputs and communicate extensively with peripheral organs like the gastrointestinal tract, liver, pancreas, and adipose tissues to regulate energy production, storage, mobilization, and utilization. The hypothalamus has evolved to enhance energy storage for survival in famine and scarce environments but contribute to obesity in modern contexts of caloric abundance. It acts as a master regulator of whole-body energy homeostasis, rapidly adapting to ensure energy supplies for cellular functions. Understanding hypothalamic function, pertaining to energy expenditure, is crucial for developing targeted interventions to address metabolic disorders, offering new insights into the neural control of metabolic states and potential therapeutic strategies
Lasting Impacts of Childhood Health and Socioeconomic Circumstances on Adult Health Problems: Analysis of a Longitudinal Count Regression Model
No full textAbstract Objectives. This study examines the lasting impacts of childhood health and circumstances, in addition to adult socioeconomic status on trajectories of chronic health problems in later life and how these associations vary across race/ethnicity as well as gender. Methods. Employing a longitudinal dataset from the Health and Retirement Study (HRS), this study utilizes a random intercept count regression model to examine how circumstances associated with early life may influence chronic health trajectories in later life. Results. The results demonstrate that poor childhood health and disadvantaged socioeconomic status (SES) are associated with the higher incidence rates of chronic health problems over time. The associations are net of adult socioeconomic status and baseline health status. The adverse effects of poor childhood health and disadvantaged socioeconomic conditions are higher for women than men. While both childhood health and SES have significant impacts on chronic health trajectories for both African American and White, no such effects have been observed among Hispanic. Discussion. Trajectories of chronic health problems in late life continue to be shaped by childhood health and socioeconomic circumstances. The patterns of associations vary across race/ethnicity as well as gender
Exploring NCCARE360's Role in Addressing Food Insecurity: Onboarding Successes, Challenges, and Referral Outcomes Among Community-Based Organizations in the Piedmont Triad Region
Get PDFGiven the integral role community-based organizations (CBOs) play in connecting individuals to essential resources and services, understanding how CBOs engage with NCCARE360 is essential to enhancing adoption, sustainability, and impact of the platform. This study explored how CBOs in the Piedmont Triad Region use NCCARE360, North Carolina’s statewide coordinated care referral platform, to address food insecurity. A mixed methods approach was used to address the study’s objectives. Focus groups explored the barriers to onboarding and retention that CBOs experience as well as the facilitators that keep CBOs active and engaged with NCCARE360. Aggregated CBO-level referral data from July 2023 – June 2024 was analyzed using logistic and negative binomial regression components to evaluate and interpret trends in referral patterns, workflows, service subtypes, and acceptance rates across CBOs to understand referral success. Training and capacity building and resource constraints were commonly reported onboarding and retention barriers of NCCARE360. Facilitators of onboarding and retention emphasized increased exposure for CBOs and the value of using NCCARE360 to connect patients to resources, improve coordinated care, and strengthen care management. The number of referrals received and accepted increased for certain service types, such as emergency food, food pantries, and prepared meals. County-level differences were also noted, with Alamance County showing significant variations in referral acceptance rates, offering insights for best practices to improve NCCARE360 utilization in other counties. Results indicated that CBOs with consistent referral intake also accepted referrals more effectively, and that different CBOs and service subtypes played a crucial role in improving referral acceptance. Further research is needed to understand the specific challenges lower-performing CBOs face in delivering food security services through NCCARE360
