Cohort Profile: The 1934-66 Mysore Birth Records Cohort in South India

Babies of South Asian and European Ancestry Show Similar Associations With Genetic Risk Score for Birth Weight Despite the Smaller Size of South Asian Newborns

Size at birth is known to be influenced by various fetal and maternal factors, including genetic effects. South Asians have a high burden of low birth weight and cardiometabolic diseases, yet studies of common genetic variations underpinning these phenotypes are lacking. We generated independent, weighted fetal genetic scores (fGSs) and maternal genetic scores (mGSs) from 196 birth weight-associated variants identified in Europeans and conducted an association analysis with various fetal birth parameters and anthropometric and cardiometabolic traits measured at different follow-up stages (5-6-year intervals) from seven Indian and Bangladeshi cohorts of South Asian ancestry. The results from these cohorts were compared with South Asians in UK Biobank and the Exeter Family Study of Childhood Health, a European ancestry cohort. Birth weight increased by 50.7 g and 33.6 g per SD of fGS (P = 9.1 × 10-11) and mGS (P = 0.003), respectively, in South Asians. A relatively weaker mGS effect compared with Europeans indicates possible different intrauterine exposures between Europeans and South Asians. Birth weight was strongly associated with body size in both childhood and adolescence (P = 3 × 10-5 to 1.9 × 10-51); however, fGS was associated with body size in childhood only (P < 0.01) and with head circumference, fasting glucose, and triglycerides in adults (P < 0.01). The substantially smaller newborn size in South Asians with comparable fetal genetic effect to Europeans on birth weight suggests a significant role of factors related to fetal growth that were not captured by the present genetic scores. These factors may include different environmental exposures, maternal body size, health and nutritional status, etc. Persistent influence of genetic loci on size at birth and adult metabolic syndrome in our study supports a common genetic mechanism that partly explains associations between early development and later cardiometabolic health in various populations, despite marked differences in phenotypic and environmental factors in South Asians.

A lifecourse approach to the relationship between lung function and cognition function in late life: findings from the Mysore studies of Natal effect on Ageing and Health (MYNAH) in South India

Background: Emerging evidence from high income settings indicates that lung function may be an independent determinant of cognitive abilities in late life. Despite a high burden of chronic lung disorders and neurocognitive disorders, there are limited data exploring the relationship between lung and cognitive function in later life in low- and middle-income (LMIC) settings. Methods: Between 2013 and 2016, 721 men and women from the Mysore Birth Records Cohort in South India, aged 55-80 years, were retraced and underwent standardised assessments for sociodemographic characteristics, cardiometabolic risk factors, lung function, cognitive function and mental health. Approximately 20 years earlier, a subset of them had assessments for cardiometabolic risk factors (n=522) and lung function (n=143). Results: Forced Expiratory Volume at one second (FEV1) and six seconds (FEV6) were higher among men than women. Women had higher immediate and delayed recall scores compared to men. Multivariate models indicated that those with lower FEV1 (lts) and FEV1/FEV6 ratio in late life had lower composite cognitive score (SD, standard deviation), independent of growth and environment in early life and childhood, attained education, socioeconomic position, cardiometabolic disorders in mid-and late life and lifestyle factors (0.29 SD per litre 95% confidence interval [CI] (0.10, 0.50) p=0.006 for FEV1 and 1.32 SD (0.20, 2.50) p=0.02 for FEV1/FEV6 ratio). Lung function in midlife was unrelated to cognitive outcomes in late life. Conclusions: Causality cannot be inferred from cross sectional associations. Therefore, causality is best explored in longitudinal studies with serial, but contemporaneous measurements of both lung and cognitive function. Mechanistic studies that examine the role of shared risk factors like environmental pollutants and biomass exposure on this relationship are urgently required in LMICs.

Validation of EURO-D, a geriatric depression scale in South India: Findings from the Mysore study of Natal effects on Ageing and Health (MYNAH)

INTRODUCTION

Many of the assessment tools used to study depression amongst older people in low- and middle- income countries (LMICs) are adaptations of instruments developed in other cultural settings. There is a need to validate those instruments in LMICs.

METHODS

721 men and women aged 55-80 years from the Mysore Birth Records Cohort underwent standardised assessments for sociodemographic characteristics, cardiometabolic risk factors, cognitive function and mental health. Sensitivity, specificity and level of agreement of EURO-D diagnosis of depression with diagnosis of depression derived by the Geriatric Mental State (GMS) examination were calculated. To validate the EURO-D score against GMS depressive episode, we used maximum Youden's index as the criterion for each cut-off point. Concurrent validity was assessed by measuring correlations with the WHO Disability Assessment Schedule (WHO DAS II).

RESULTS

Of the 721 (408 men and 313 women) who participated in this study, 138 (54 men and 84 women) were diagnosed with depression. Women had higher depression scores on the EURO-D scale and disability on the WHO DAS II scale. A maximum Youden's Index of 0.60 was observed at a EURO-D cut-off of 6, which corresponded to 95% sensitivity, 64% specificity, kappa value of 0.6 and area under the curve (AUC) of 80%. There was significant and positive correlation between EURO-D and WHO DAS II scores.

LIMITATIONS

Future independent validation studies in other settings are required.

DISCUSSION

This study supports the use of the EURO-D scale for diagnosing depression amongst older adults in South India.

Size at birth, lifecourse factors, and cognitive function in late life: findings from the MYsore study of Natal effects on Ageing and Health (MYNAH) cohort in South India

OBJECTIVE

To examine if smaller size at birth, an indicator of growth restriction in utero, is associated with lower cognition in late life, and whether this may be mediated by impaired early life brain development and/or adverse cardiometabolic programming.

DESIGN

Longitudinal follow-up of a birth cohort.

SETTING

CSI Holdsworth Memorial Hospital (HMH), Mysore South India.

PARTICIPANTS

721 men and women (55-80 years) whose size at birth was recorded at HMH. Approximately 20 years earlier, a subset (n = 522) of them had assessments for cardiometabolic disorders in mid-life.

MEASUREMENTS

Standardized measurement of cognitive function, depression, sociodemographic, and lifestyle factors; blood tests and assessments for cardiometabolic disorders.

RESULTS

Participants who were heavier at birth had higher composite cognitive scores (0.12 SD per SD birth weight [95% CI 0.05, 0.19] p = 0.001) in late life. Other lifecourse factors independently positively related to cognition were maternal educational level and participants' own educational level, adult leg length, body mass index, and socioeconomic position, and negatively were diabetes in mid-life and current depression and stroke. The association of birth weight with cognition was independent cardiometabolic risk factors and was attenuated after adjustment for all lifecourse factors (0.08 SD per SD birth weight [95% CI -0.01, 0.18] p = 0.07).

CONCLUSIONS

The findings are consistent with positive effects of early life environmental factors (better fetal growth, education, and childhood socioeconomic status) on brain development resulting in greater long-term cognitive function. The results do not support a pathway linking poorer fetal development with reduced late life cognitive function through cardiometabolic programming.

A scientometric analysis of birth cohorts in South Asia: Way forward for Pakistan

The present study aims to: a) systematically map the of birth cohort studies from the South Asian region b) examine the major research foci and landmark contributions from these cohorts using reproducible scientometric techniques and c) offer recommendations on establishing new birth cohorts in Pakistan, building upon the strengths, weaknesses and gaps of previous cohorts. Bibliographic records for a total of 260 articles, published during through December 2018, were retrieved from the Web of Science (core database). All data were analysed using Microsoft Excel (2013), Web of Science platform and CiteSpace. A series of network analysis were then run for each time-period using the link reduction method and pathfinder network scaling. The co-cited articles were clustered into their homogeneous research clusters. The clusters were named using the Latent Semantic Indexing (LSI) method that utilized author keywords as source of names for these clusters. The scientometric analyses of original research output from these birth cohorts also paint a pessimistic landscape in Pakistan- where Pakistani sites for birth cohorts contributed only 31 publications; a majority of these utilized the MAL-ED birth cohort data. A majority of original studies were published from birth cohorts in India (156), Bangladesh (63), and Nepal (15). Out of these contributions, 31 studies reported data from multiple countries. The three major birth cohorts include prospective and multi-country MAL-ED birth cohort and The Pakistan Early Childhood Development Scale Up Trial, and a retrospective Maternal and infant nutrition intervention cohort. In addition to these, a few small-scale birth cohorts reported findings pertaining to neonatal sepsis, intrauterine growth retardation and its effects on linear growth of children and environmental enteropathy.

Consortium on Vulnerability to Externalizing Disorders and Addictions (cVEDA): A developmental cohort study protocol

BACKGROUND

Low and middle-income countries like India with a large youth population experience a different environment from that of high-income countries. The Consortium on Vulnerability to Externalizing Disorders and Addictions (cVEDA), based in India, aims to examine environmental influences on genomic variations, neurodevelopmental trajectories and vulnerability to psychopathology, with a focus on externalizing disorders.

METHODS

cVEDA is a longitudinal cohort study, with planned missingness design for yearly follow-up. Participants have been recruited from multi-site tertiary care mental health settings, local communities, schools and colleges. 10,000 individuals between 6 and 23 years of age, of all genders, representing five geographically, ethnically, and socio-culturally distinct regions in India, and exposures to variations in early life adversity (psychosocial, nutritional, toxic exposures, slum-habitats, socio-political conflicts, urban/rural living, mental illness in the family) have been assessed using age-appropriate instruments to capture socio-demographic information, temperament, environmental exposures, parenting, psychiatric morbidity, and neuropsychological functioning. Blood/saliva and urine samples have been collected for genetic, epigenetic and toxicological (heavy metals, volatile organic compounds) studies. Structural (T1, T2, DTI) and functional (resting state fMRI) MRI brain scans have been performed on approximately 15% of the individuals. All data and biological samples are maintained in a databank and biobank, respectively.

DISCUSSION

The cVEDA has established the largest neurodevelopmental database in India, comparable to global datasets, with detailed environmental characterization. This should permit identification of environmental and genetic vulnerabilities to psychopathology within a developmental framework. Neuroimaging and neuropsychological data from this study are already yielding insights on brain growth and maturation patterns.

Diagnosis of Dementia by Machine learning methods in Epidemiological studies: a pilot exploratory study from south India

BACKGROUND

There are limited data on the use of artificial intelligence methods for the diagnosis of dementia in epidemiological studies in low- and middle-income country (LMIC) settings. A culture and education fair battery of cognitive tests was developed and validated for population based studies in low- and middle-income countries including India by the 10/66 Dementia Research Group.

AIMS

We explored the machine learning methods based on the 10/66 battery of cognitive tests for the diagnosis of dementia based in a birth cohort study in South India.

METHODS

The data sets for 466 men and women for this study were obtained from the on-going Mysore Studies of Natal effect of Health and Ageing (MYNAH), in south India. The data sets included: demographics, performance on the 10/66 cognitive function tests, the 10/66 diagnosis of mental disorders and population based normative data for the 10/66 battery of cognitive function tests. Diagnosis of dementia from the rule based approach was compared against the 10/66 diagnosis of dementia. We have applied machine learning techniques to identify minimal number of the 10/66 cognitive function tests required for diagnosing dementia and derived an algorithm to improve the accuracy of dementia diagnosis.

RESULTS

Of 466 subjects, 27 had 10/66 diagnosis of dementia, 19 of whom were correctly identified as having dementia by Jrip classification with 100% accuracy.

CONCLUSIONS

This pilot exploratory study indicates that machine learning methods can help identify community dwelling older adults with 10/66 criterion diagnosis of dementia with good accuracy in a LMIC setting such as India. This should reduce the duration of the diagnostic assessment and make the process easier and quicker for clinicians, patients and will be useful for 'case' ascertainment in population based epidemiological studies.

Birth size, risk factors across life and cognition in late life: protocol of prospective longitudinal follow-up of the MYNAH (MYsore studies of Natal effects on Ageing and Health) cohort

INTRODUCTION

For late-life neurocognitive disorders, as for other late-life chronic diseases, much recent interest has focused on the possible relevance of Developmental Origins of Health and Disease (DOHaD). Programming by undernutrition in utero, followed by overnutrition in adult life may lead to an increased risk, possibly mediated through cardiovascular and metabolic pathways. This study will specifically examine, if lower birth weight is associated with poorer cognitive functioning in late life in a south Indian population.

METHODS AND ANALYSIS

From 1934 onwards, the birth weight, length and head circumference of all babies born in the CSI Holdsworth Memorial Hospital, Mysore, India, were recorded in obstetric notes. Approximately 800 men and women from the Mysore Birth Records Cohort aged above 55 years, and a reliable informant for each, will be asked to participate in a single cross-sectional baseline assessment for cognitive function, mental health and cardiometabolic disorders. Participants will be assessed for hypertension, type-2 diabetes and coronary heart disease, nutritional status, health behaviours and lifestyles, family living arrangements, economic status, social support and social networks. Additional investigations include blood tests (for diabetes, insulin resistance, dyslipidaemia, anaemia, vitamin B12 and folate deficiency, hyperhomocysteinemia, renal impairment, thyroid disease and Apolipoprotein E genotype), anthropometry, ECG, blood pressure, spirometry and body composition (bioimpedance). We will develop an analysis plan, first using traditional univariate and multivariable analytical paradigms with independent, dependent and mediating/confounding/interacting variables to test the main hypotheses.

ETHICS AND DISSEMINATION

This study has been approved by the research ethics committee of CSI Holdsworth Memorial Hospital. The findings will be disseminated locally and at international meetings, and will be published in open access peer reviewed journals.

An interpretative phenomenological analysis (IPA) of coercion towards community dwelling older adults with dementia: findings from Mysore studies of natal effects on ageing and health (MYNAH)

PURPOSE

Limited availability of specialist services places a considerable burden on caregivers of Persons with Dementia (PwD) in Low- and Middle-Income Countries (LMICs). There are limited qualitative data on coercive behavior towards PwD in an LMIC setting.

AIM

The aim of this study was to find relevant themes of the lived experience of relatives as caregivers for PwD in view of their use of coercive measures in community setting in South India.

METHOD

Primary caregivers (n = 13) of PwDs from the Mysore study of Natal effects on Ageing and Health (MYNAH) in South India were interviewed to explore the nature and impact of coercion towards community dwelling older adults with dementia. The narrative data were coded using an Interpretative Phenomenological Analysis (IPA) approach for thematic analysis and theory formation.

RESULTS

Caregivers reported feeling physical and emotional burn-out, a lack of respite care, an absence of shared caregiving arrangements, limited knowledge of dementia, and a complete lack of community support services. They reported restrictions on their lives through not being able take employment, a poor social life, reduced income and job opportunities, and restricted movement that impacted on their physical and emotional well-being. Inappropriate use of sedatives, seclusion and environmental restraint, and restricted dietary intake, access to finances and participation in social events, was commonly reported methods of coercion used by caregivers towards PwD. Reasons given by caregivers for employing these coercive measures included safeguarding of the PwD and for the management of behavioral problems and physical health.

CONCLUSION

There is an urgent need for training health and social care professionals to better understand the use of coercive measures and their impact on persons with dementia in India. It is feasible to conduct qualitative research using IPA in South India.