Vivian Isaac - Academia.edu (original) (raw)

Papers by Vivian Isaac

Research paper thumbnail of Cognitive function and brain structure correlations in healthy elderly East Asians

Research paper thumbnail of Adverse Associations between Visceral Adiposity, Brain Structure, and Cognitive Performance in Healthy Elderly

Frontiers in aging neuroscience, 2011

Research paper thumbnail of Associations between elevated homocysteine, cognitive impairment, and reduced white matter volume in healthy old adults

The American journal of geriatric psychiatry : official journal of the American Association for Geriatric Psychiatry, 2013

Research paper thumbnail of The influence of rural clinical school experiences on medical students’ levels of interest in rural careers

Human Resources for Health, 2014

Research paper thumbnail of Social activity and improvement in depressive symptoms in older people: a prospective community cohort study

The American journal of geriatric psychiatry : official journal of the American Association for Geriatric Psychiatry, 2009

Research paper thumbnail of Caregiver Burden and Quality of Life of Older Persons With Stroke: A Community Hospital Study in South India

Journal of Applied Gerontology, 2011

This article reports a preliminary investigation in India of the association between caregiver bu... more This article reports a preliminary investigation in India of the association between caregiver burden and quality of life (QOL) in older persons with stroke after controlling for disability, depression, and sociodemographic factors. A cross-sectional analysis was carried out with 46 stroke patients attending a community hospital in India. The primary outcome variable was patient QOL assessed using the World Health

Research paper thumbnail of Cognitive function and brain structure correlations in healthy elderly East Asians

Research paper thumbnail of Adverse associations between visceral adiposity, brain structure, and cognitive performance in healthy elderly

Frontiers in aging neuroscience, 2011

The link between central adiposity and cognition has been established by indirect measures such a... more The link between central adiposity and cognition has been established by indirect measures such as body mass index (BMI) or waist–hip ratio. Magnetic resonance imaging (MRI) quantification of central abdominal fat has been linked to elevated risk of cardiovascular and cerebro-vascular disease. However it is not known how quantification of visceral fat correlates with cognitive performance and measures of brain structure. We filled this gap by characterizing the relationships between MRI measures of abdominal adiposity, brain morphometry, and cognition, in healthy elderly. Methods: A total of 184 healthy community dwelling elderly subjects without cognitive impairment participated in this study. Anthropometric and biochemical markers of cardiovascular risk, neuropsychological measurements as well as MRI of the brain and abdomen fat were obtained. Abdominal images were segmented into subcutaneous adipose tissue and visceral adipose tissue (VAT) adipose tissue compartments. Brain MRI measures were analyzed quantitatively to determine total brain volume, hippocampal volume, ventricular volume, and cortical thickness. Results: VAT showed negative association with verbal memory (r = 0.21, p = 0.005) and attention (r = 0.18, p = 0.01). Higher VAT was associated with lower hippocampal volume (F = 5.39, p = 0.02) and larger ventricular volume (F = 6.07, p = 0.02). The participants in the upper quartile of VAT had the lowest hippocampal volume even after adjusting for age, gender, hypertension, and BMI (b = −0.28, p = 0.005). There was a significant age by VAT interaction for cortical thickness in the left prefrontal region. Conclusion: In healthy older adults, elevated VAT is associated with negative effects on cognition, and brain morphometry.

Research paper thumbnail of Cognitive function and brain structure correlations in healthy elderly East Asians

Research paper thumbnail of Adverse Associations between Visceral Adiposity, Brain Structure, and Cognitive Performance in Healthy Elderly

Frontiers in aging neuroscience, 2011

Research paper thumbnail of Associations between elevated homocysteine, cognitive impairment, and reduced white matter volume in healthy old adults

The American journal of geriatric psychiatry : official journal of the American Association for Geriatric Psychiatry, 2013

Research paper thumbnail of The influence of rural clinical school experiences on medical students’ levels of interest in rural careers

Human Resources for Health, 2014

Research paper thumbnail of Social activity and improvement in depressive symptoms in older people: a prospective community cohort study

The American journal of geriatric psychiatry : official journal of the American Association for Geriatric Psychiatry, 2009

Research paper thumbnail of Caregiver Burden and Quality of Life of Older Persons With Stroke: A Community Hospital Study in South India

Journal of Applied Gerontology, 2011

This article reports a preliminary investigation in India of the association between caregiver bu... more This article reports a preliminary investigation in India of the association between caregiver burden and quality of life (QOL) in older persons with stroke after controlling for disability, depression, and sociodemographic factors. A cross-sectional analysis was carried out with 46 stroke patients attending a community hospital in India. The primary outcome variable was patient QOL assessed using the World Health

Research paper thumbnail of Cognitive function and brain structure correlations in healthy elderly East Asians

Research paper thumbnail of Adverse associations between visceral adiposity, brain structure, and cognitive performance in healthy elderly

Frontiers in aging neuroscience, 2011

The link between central adiposity and cognition has been established by indirect measures such a... more The link between central adiposity and cognition has been established by indirect measures such as body mass index (BMI) or waist–hip ratio. Magnetic resonance imaging (MRI) quantification of central abdominal fat has been linked to elevated risk of cardiovascular and cerebro-vascular disease. However it is not known how quantification of visceral fat correlates with cognitive performance and measures of brain structure. We filled this gap by characterizing the relationships between MRI measures of abdominal adiposity, brain morphometry, and cognition, in healthy elderly. Methods: A total of 184 healthy community dwelling elderly subjects without cognitive impairment participated in this study. Anthropometric and biochemical markers of cardiovascular risk, neuropsychological measurements as well as MRI of the brain and abdomen fat were obtained. Abdominal images were segmented into subcutaneous adipose tissue and visceral adipose tissue (VAT) adipose tissue compartments. Brain MRI measures were analyzed quantitatively to determine total brain volume, hippocampal volume, ventricular volume, and cortical thickness. Results: VAT showed negative association with verbal memory (r = 0.21, p = 0.005) and attention (r = 0.18, p = 0.01). Higher VAT was associated with lower hippocampal volume (F = 5.39, p = 0.02) and larger ventricular volume (F = 6.07, p = 0.02). The participants in the upper quartile of VAT had the lowest hippocampal volume even after adjusting for age, gender, hypertension, and BMI (b = −0.28, p = 0.005). There was a significant age by VAT interaction for cortical thickness in the left prefrontal region. Conclusion: In healthy older adults, elevated VAT is associated with negative effects on cognition, and brain morphometry.