Using grip strength to compute physical health-adjusted old age dependency ratios

Longitudinal Studies of Aging in Sub-Saharan Africa: Review, Limitations, and Recommendations in Preparation of Projected Aging Population

Background and Objectives

The United Nations has projected a 218% increase in older people in Sub-Saharan Africa (SSA) between 2019 and 2050, underscoring the need to explore changes that would occur over this time. Longitudinal studies are ideal for studying and proffering solutions to these changes. This review aims to understand the breadth and use of longitudinal studies on aging in the SSA regions, proffering recommendations in preparation for the projected aging population.

Research Design and Methods

This paper is the third of a four-part series paper of a previous systematic mapping review of aging studies in SSA. We updated the search (between 2021 and 2023) and screened the titles/abstracts and full-text articles by a pair of independent reviewers. Data were extracted using a standardized data-charting form, identifying longitudinal studies in SSA.

Results

We identified 193 studies leveraging 24 longitudinal study data sets conducted at 28 unique sites. The World Health Organization's Study on Global AGEing and Adult Health (WHO-SAGE) (n = 59, 30.5%) and Health and Aging in Africa: A Longitudinal Study of an INDEPTH Community in South Africa (HAALSI) (n = 51, 26.4%) were the most used longitudinal data sets. Four studies used more than one longitudinal study data set. Eighteen of the longitudinal study data sets were used only in 1-4 studies. Most (n = 150, 77.7%) of the studies used a cross-sectional analytical approach.

Discussion and Implications

Longitudinal studies on aging are sparingly being utilized in SSA. Most analyses conducted across the longitudinal data set were cross-sectional, which hindered the understanding of aging changes that occurred over time that could better inform aging policy and interventions. We call for funding bodies, such as WHO-SAGE, to develop funding competitions that focus on conducting longitudinal analyses, such as structural equation modeling, highlighting changes occurring among the aging population in SSA.

Resilience, Accelerated Aging and Persistently Poor Health: Diverse Trajectories of Health in Malawi

Individuals age at vastly different rates resulting in significant within-population heterogeneity in health and aging outcomes. This diversity in health and aging trajectories has rarely been investigated among low-income aging populations that have experienced substantial hardships throughout their lifecourses. Utilizing 2006-2018 data from the Malawi Longitudinal Study of Families and Health (MLSFH) and estimating group-based trajectory models (GBTM), our analyses identified three distinct lifecourse health trajectories: (1) comparatively good initial mental and physical health that persisted throughout the lifecourse ("resilient aging"); (2) relatively good initial mental and physical health that started to deteriorate during mid-adulthood ("accelerated aging"); and (3) poor initial mental and physical health that further declined over the lifecourse ("aging with persistently poor health"). For both physical and mental health, men were more likely to enjoy resilient aging than women. Predictors other than gender of trajectory membership sometimes confirmed, and sometimes contradicted, hypotheses derived from high-income country studies. Our analyses highlight the long arm of early life conditions and gender in determining aging trajectories and show that a non-trivial sub-population is characterized by aging with persistently poor health. The study uncovers widening gaps in health outcomes between those who age with resilience and those who experience accelerated aging.

Warm-Up and Handgrip Strength in Physically Inactive Chilean Older Females According to Baseline Nutritional Status

This study aims to analyze the effect of different types of warm-ups on handgrip strength (HGS) in physically inactive older females. Secondarily, it aims to compare HGS according to their baseline nutritional status. A randomized crossover trial study was conducted with 44 physically inactive older females distributed into normal weight (n = 12, BMI = 23.9 ± 3.2 kg/m²), overweight (n =16, BMI = 27 ± 4.7 kg/m²) and obese (n = 16, BMI = 31.6 ± 5.3 kg/m²), who participated in three warm-up conditions (static stretching condition, SSC; elastic band condition, EBC; and therapeutic compression ball condition, TCBC) and one control condition (CC, no warm-up). All participants performed the four randomized conditions with recovery within 72 h. A significant decrease (p < 0.05) in HGS for the dominant and non-dominant hands was observed when comparing SSC vs. CC. In contrast, comparing the warm-up conditions according to the baseline nutritional status, statistically significant differences (p < 0.05) were only reported in the obese group in the dominant and non-dominant hand in favor of CC concerning SSC. In conclusion, warm-up with static flexibility led to a decrease in HGS in physically inactive older females. Only the obese group exhibited this result when analyzed by nutritional status.

Cohort profile: the mature adults cohort of the Malawi longitudinal study of families and health (MLSFH-MAC)

PURPOSE

The Mature Adults Cohort of the Malawi Longitudinal Study of Families and Health (MLSFH-MAC) contributes to global ageing studies by providing a rare opportunity to study the processes of individual and population ageing, the public health and social challenges associated with ageing and the coincident shifts in disease burdens, in a low-income, high HIV prevalence, sub-Saharan African (SSA) context.

PARTICIPANTS

The MLSFH-MAC is an open population-based cohort study of mature adults aged 45+ years living in rural communities in three districts in Malawi. Enrolment at baseline is 1266 individuals in 2012. Follow-ups were in 2013, 2017 and 2018 when the cohort size reached 1626 participants in 2018.

FINDINGS TO DATE

Survey instruments cover ageing-related topics such as cognitive and mental health, non-communicable diseases (NCDs) and related health literacy, subjective survival expectations, measured biomarkers including HIV, grip strength, hypertension, fasting glucose, body mass index (BMI), broad individual-level and household-level social and economic information, a 2018 qualitative survey of mature adults and community officials, 2019 surveys of village heads, healthcare facilities and healthcare providers in the MLSFH-MAC study areas. Across many domains, MLSFH-MAC allows for comparative research with global ageing studies through harmonised measures and instruments. Key findings to date include a high prevalence of depression and anxiety among older adults, evidence for rapid declines in cognitive health with age, a low incidence of HIV among mature adults, rising prevalence of HIV due to increased survival of HIV-positive individuals and poor physical health with high NCD prevalence.

FUTURE PLANS

An additional wave of MLSFH-MAC is forthcoming in 2021, and future expansions of the cohort are planned. MLSFH-MAC data will also be publicly released and will provide a wealth of information unprecedented for ageing studies in a low-income SSA context that broadly represents the socioeconomic environment of millions of individuals in south-eastern Africa.