Cognitive Ageing in Healthy Adults in India: A Cross-Sectional Multimodal Study Protocol

Introduction

The population of older adults in India is projected to exceed 230 million within the next decade. With increasing life expectancy, maintaining cognitive and neurobiological health becomes essential for ensuring a good quality of life. This study is a comprehensive multimodal investigation of aging and cognition in a healthy Indian cohort. The aim is to characterize cognitive, neurobiological, physiological, psychological, and molecular trajectories and their associations across the adult lifespan in India.

Methods and Analysis

Data will be collected cross-sectionally from healthy young (19–35 years, n = 100), middle-aged (40–55 years, n = 100), and older adults (60–75 years, n = 100) with regional nativity and residence in Telangana or Andhra Pradesh. Individuals with cognitive impairment or any chronic health condition will be excluded. Assessments will include standardized cognitive tests, mental health questionnaires, brain imaging, heart rate variability, and serum samples for standard blood tests and epigenetic analyses. Hair cortisol and serum inflammatory markers will also be collected to profile stress and systemic inflammation, respectively. Data from this study will help to profile healthy aging in an Indian cohort, thereby addressing critical gaps in clinical research and health policy.

Ethics and Dissemination

This study was approved by the Institutional Review Board at IIIT Hyderabad (IIITH-IRB-PRO-2023-11). All participants will give written consent. Results from this study will be presented at conferences and published in peer-reviewed journals. Data will also be curated for an interactive web-portal to enable researchers, clinicians, and policy makers to understand the data in meaningful ways.

Strengths and Limitations

• Most studies in aging focus on risk factors and progression of degenerative conditions. What healthy aging really means is not well understood.

• This study will recruit healthy Indian adults free from any chronic health problem and with regional nativity and residence to minimize geo-climatic effects and genetic heterogeneity.

• Hair cortisol and serum-inflammation levels may provide unique insights in healthy aging.

• The comprehensive data from this study will provide a profile of healthy aging in an Indian cohort that is highly vulnerable to metabolic disorders. It will enable clinicians, researchers, and policy makers to plan and promote healthy aging.

• The restricted native sample population and sample size may not capture the divergent trajectories in aging across other demographic populations within and outside India.

• Though cross-sectional data will not capture the changes that longitudinal data can, it will offer an opportunity to compare psychosocial and physiological measures across different age groups.