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Background The association between the extremely low-frequency magnetic field generated by overhead power lines and neurodegenerative disease is still a matter of debate. Methods A population-based case-control study was carried out on the residents in the Milan metropolitan area between 2011 and 2016 to evaluate the possible association between exposure to extremely low-frequency magnetic fields generated by high-voltage overhead power lines and Alzheimer's dementia and Parkinson's disease. A statistical analysis was performed on cases and controls matched by sex, year of birth and municipality of residence (with a case to controls ratio of 1 : 4) using conditional logistic regression models adjusted for socio-economic deprivation and distance from the major road network as potential confounders. Results Odds ratios for residents Conclusions The finding of a weak association between exposure to the extremely low-frequency magnetic field and neurodegenerative diseases suggests the continuation of research on this topic. Moreover, the low consistency between the results of the already existing studies emphasises the importance of increasingly refined study designs.

Background Work has been associated with cognitive health. We examined whether retirement from work is associated with a decrease in episodic memory and whether this effect differs when considering workers’ occupational class. Methods In this prospective study using the English Longitudinal Study of Ageing (ELSA), we examined 1629 persons aged 50–75 years who were in paid work at baseline. A two-slope random effects linear regression centred at retirement was used to study the effect of retirement on episodic memory. The potential effect modification by occupational class was examined. Results While memory trajectories show slightly decreasing memory scores before and afterretirement, the decreasing rates for both periods were similar [episodic memory β2b−β2a= −0.03, 95% confidence interval (CI) −0.08, 0.02]. When stratifying by occupational class, there was also no substantial difference in episodic memory trajectories before and after retirement. However, the lower occupational class showed a clear decline in episodic memory with time (pre-retirement β2a = −0.11, 95% CI −0.19, −0.03; post-retirement β2b = −0.13, 95% CI −0.19, −0.07) which was not evident for the higher occupational classes. Conclusions Our results show no observable difference in trajectories of change in episodic memory before and after retirement. However, the steeper memory decline in workers belonging to the lower occupational class may limit their prospect of prolonging their working lives. Hence enrichment programmes for the prevention of memory decline for these workers should be considered.

Background Whether worldwide increases in life expectancy are accompanied by a better health status is still a debate. People age differently, and there is a need to disentangle whether healthy-ageing pathways can be shaped by cohort effects. This study aims to analyse trends in health status in two large nationally representative samples of older adults from England and the USA. Methods The sample comprised 55 684 participants from the first seven waves of the English Longitudinal Study of Ageing (ELSA), and the first 11 waves of the Health and Retirement Study (HRS). A common latent health score based on Bayesian multilevel item response theory was used. Two Bayesian mixed-effects multilevel models were used to assess cohort effects on health in ELSA and HRS separately, controlling for the effect of household wealth and educational attainment. Results Similar ageing trends were found in ELSA (β = –0.311; p Conclusions Health inequalities have increased in recent cohorts, with the wealthiest participants presenting a better health status in both the USA and English populations. Actions to promote health in the ageing population should consider the increasing inequality scenario, not only by applying highly effective interventions, but also by making them accessible to all members of society.

Background As the population ages, cognitive decline and dementia have become major health concerns in the UK. Loneliness has been linked to cognitive decline, but the reverse causality of this association remains unclear. This study aims to examine whether there is a bidirectional relationship between loneliness and cognitive function in older English adults (age 50 years and over) over a 10-year follow-up. Methods Data came from a nationally representative sample of 5885 participants in the English Longitudinal Study of Ageing (ELSA), free of stroke or dementia and followed every 2 years up to wave 7 (2014–15). At each wave, cognitive function was measured with word recall and verbal fluency tests, and loneliness was measured with the abridged version of the revised UCLA Loneliness Scale. Bivariate dual change score models were used to assess the multivariate associations between loneliness and cognitive function, used interchangeably as exposures and outcomes. Results Greater loneliness at baseline was associated with poorer memory [β intercept = −0.03, standard error (SE) = 0.01, P = 0.016] and verbal fluency (β intercept = −0.01, SE = 001, P = 0.027) at baseline, and with a stronger linear rate of decline in both memory (β linear slope = −0.07, SE = 001, P ≤ 0.001) and verbal fluency (β linear slope = −0.09, SE = 0.03, P = 0.003) over a 10-year follow-up period, although the performance on verbal fluency did not change substantially on average over this period. We also found that higher baseline memory, but not verbal fluency, predicted a slower change in loneliness (β linear slope = −0.01, SE = 001, P = 0.004) and that a linear decline in memory was associated with an acceleration in loneliness (β quadratic slope = −0.02, SE = 001, P ≤ 0.001) during follow-up. Conclusions Higher loneliness is associated with poorer cognitive function at baseline and contributes to a worsening in memory and verbal fluency over a decade. These factors seem, however, to be partially intertwined, since baseline memory and its rate of decline also contribute to an increase in loneliness over time.

Objective Several studies report a polygenic component of risk for Alzheimer’s disease. Understanding whether this polygenic signal is associated with educational, cognitive and behavioural outcomes in children could provide an earlier window for intervention. Methods We examined whether polygenic risk scores (PRS) at varying P-value thresholds in children from the Avon Longitudinal Study of Parents and Children were associated with academic achievement, cognitive and behavioural measures in childhood and adolescence. Results We did not detect any evidence that the genome-wide significant PRS (5x10-8) were associated with these outcomes. PRS at the highest P-value threshold examined (P ≤ 5x10-1) were associated with lower academic achievement in adolescents (Key Stage 3; β: -0.03; 95% confidence interval: -0.05, -0.003) but the effect was attenuated when single nucleotide polymorphisms (SNPs) associated with educational attainment were removed. These PRS were associated with lower IQ (β: -0.04; 95% CI: -0.07, -0.02) at age 8 years with the effect remaining after removing SNPs associated with educational attainment. Conclusions SNPs mediating the biological effects of Alzheimer’s disease are unlikely to operate early in life. The evidence of association between PRS for Alzheimer’s disease at liberal thresholds and cognitive measures suggest shared genetic pathways between Alzheimer’s disease, academic achievement and cognition.

BACKGROUND AND PURPOSE The clinical differentiation between parkinsonism in idiopathic normal pressure hydrocephalus (iNPH) and Parkinson's disease (PD) remains challenging in the initial phase. Whether an early cognitive profiling might support the differential diagnosis of early iNPH and PD was addressed. METHODS Neuropsychological tests of 40 iNPH subjects with early symptoms resembling parkinsonism were retrospectively evaluated together with 47 de novoPD patients (dnPD). Only neuropsychological tests performed within 1 year from the first motor symptom were included. The cognitive spectrum of iNPH and dnPD was also compared with a sample of 70 normal controls. RESULTS A clear difference in the cognitive profile of iNPH, dnPD patients and normal controls was shown. 65% of iNPH subjects showed a diffuse cognitive impairment, including memory, visuospatial abilities, fronto-executive functioning and attention, whereas only 25.5% of the dnPD patients presented an executive dysfunction. 35% of iNPH and 74.5% of PD patients performed within the normal range (P < 0.05). CONCLUSION Subjects with iNPH showed an early and diffuse alteration of cognition with respect to dnPD patients. Performing a prompt and accurate neuropsychological evaluation might support the differential diagnosis of these two conditions of parkinsonism.