Insomnia Impairs Both the Pro-BDNF and the BDNF Levels Similarly to Older Adults with Cognitive Decline: An Exploratory Study.

Sleep disorders, including insomnia, are common during aging, and these conditions have been associated with cognitive decline in older adults. Moreover, during the aging process, neurotransmitters, neurohormones, and neurotrophins decrease significantly, leading to the impairment of cognitive functions. In this sense, BDNF, the most abundant neurotrophic factor in the human brain, has been suggested as a potential target for the prevention and improvement of cognitive decline during aging; however, the current evidence demonstrates that the exogenous administration of BDNF does not improve cognitive function. Hence, in the present study, we quantified pro-BDNF (inactive) and BDNF (active) concentrations in serum samples derived from older individuals with insomnia and/or cognitive decline. We used linear regression to analyze whether clinical or sociodemographic variables impacted the levels of BNDF concentration. We observed that insomnia, rather than cognitive decline, is significantly associated with BDNF concentration, and these effects are independent of other variables. To our knowledge, this is the first study that points to the impact of insomnia on improving the levels of BDNF during aging and suggests that opportune treatment of insomnia may be more beneficial to prevent cognitive decline during aging.

Telomere shortening and frailty in Mexican older adults.

AIM: Telomere shortening has been associated with several age-related diseases, in addition to being considered a hallmark of aging. Frailty is a clinical syndrome characterized by an accentuated physiological and functional decline that might be a predictor of an adverse condition in older age. The present study evaluated the relationship between frailty and telomere shortening in older adults from Mexico City, Mexico. METHODS: This was a cross-sectional study. Data were collected from 323 frail older adults, including physical and environmental factors, such as body mass index, comorbidities, physical activity and tobacco consumption. Telomere length was measured by real-time polymerase chain reaction. The frailty syndrome was diagnosed using the Fried criteria. RESULTS: An association between frailty and telomere shortening was found in both sexes. Telomere length decreased from 6.05 kb (5.54-6.48 kb) to 4.20 kb (3.80-4.54 kb; P < 0.001). It was also observed that tobacco consumption could be a significant modifying factor in the association between these two variables. Previous reports are contradictory, suggesting that there is no relationship between telomere length and frailty; however, it is possible that there are genetic and/or environmental variables to be elucidated, that might influence this association, particularly in the studied population. CONCLUSIONS: Telomere length is inversely related to frailty in Mexican frail older adults, and tobacco consumption is the main environmental modifying factor. Geriatr Gerontol Int 2018; 18: 1286-1292.