Examining trends in dementia incidence and prevalence using an age-period-cohort framework

Dementia, a decline in memory and cognition leading to disability in daily function, is a common and feared geriatric condition. Over the past decade, dementia has been the focus of increasing attention from researchers, clinicians, and policymakers due to the projected significant increase in the number of dementia cases expected to result from the worldwide growth in the elderly population. Given the growing evidence that late-life dementia risk likely results from the summation of risk and protective factors that individuals experience across the life course from birth (even pre-birth) through old age, an ‘age-period-cohort’ perspective which clarifies trends in dementia using each of these different lenses may help in identifying potential causal pathways that affect dementia risk. In this chapter, we review recent literature on trends in dementia incidence and prevalence in countries around the world, discuss hypothesized causes for those trends, and present new data on recent trends in dementia incidence and prevalence in the USA.

Impact of physical activity, protein intake and social network and their combination on the development of frailty

Background Frailty is a geriatric condition associated with adverse health outcomes. As physical inactivity, low protein intake and poor social network are known risk factors, we aimed to assess the influence of these parameters and their interaction in an 11-year follow-up study on a Europe-wide level. Methods Data from the Study on Health, Ageing and Retirement in Europe were used, including 22 226 community-dwelling robust and prefrail persons aged ≥50 years, from 11 countries. Frailty was assessed with the ‘Frailty Instrument for Primary care of the Survey of Health, Ageing and Retirement in Europe’. Additionally, self-reported physical activity (PA), protein intake and satisfaction with social network were assessed. The impact of these parameters on the development of frailty was calculated using multivariate cox regressions. Results Performing no regular PA, was associated with higher hazards ratio (HRs) for frailty compared with performing regular PA [men: 1.90 (95%CI: 1.50–2.42); women: 1.65 (95%CI: 1.25–2.18)]; HRs for low protein intake were 1.16 (95%CI: 0.93–1.46) for men and 1.05 (95%CI: 0.80–1.37) for women. And HR for poor social network were 0.92 (95%CI: 0.74–1.15) for men and 1.72 (95%CI: 1.31–2.27)] for women. In general, persons with a combination of two of the assessed risk factors had a higher risk for frailty compared with those with no or only one of the risk factors. However, no significant synergy index could be found. Conclusion The results illustrate the importance of PA, but also of nutritional and social network to prevent frailty.