Cognitive Activity and Onset Age of Incident Alzheimer Disease Dementia

Objective:To test the hypothesis that higher level of cognitive activity predicts older age of dementia onset in Alzheimer's disease (AD) dementia.Methods:As part of a longitudinal cohort study, 1,903 older persons without dementia at enrollment reported their frequency of participation in cognitively stimulating activities. They had annual clinical evaluations to diagnose dementia and AD, and the deceased underwent neuropathologic examination. In analyses, we assessed the relation of baseline cognitive activity to age at diagnosis of incident AD dementia and to postmortem markers of AD and other dementias.Results:During a mean of 6.8 years of follow-up, 457 individuals were diagnosed with incident AD at a mean age of 88.6 (SD = 6.4; range: 64.1-106.5). In an extended accelerated failure time model, higher level of baseline cognitive activity (mean 3.2, SD = 0.7) was associated with older age of AD dementia onset (estimate = 0.026; 95% confidence interval: 0.013. 0.039). Low cognitive activity (score = 2.1, 10th percentile) was associated with a mean onset age of 88.6 compared to a mean onset age of 93.6 associated with high cognitive activity (score = 4.0, 90th percentile). Results were comparable in subsequent analyses that adjusted for potentially confounding factors. In 695 participants who died and underwent a neuropathologic examination, cognitive activity was unrelated to postmortem markers of AD and other dementias.Conclusion:A cognitively active lifestyle in old age may delay the onset of dementia in AD by as much as 5 years.

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Improving Prediction of Age at Menopause Using Multiple Anti-Müllerian Hormone Measurements: the Tehran Lipid-Glucose Study

The Journal of Clinical Endocrinology & Metabolism ◽

10.1210/clinem/dgaa083 ◽

2020 ◽

Vol 105 (5) ◽

pp. 1589-1598 ◽

Cited By ~ 1

Author(s):

Fahimeh Ramezani Tehrani ◽

Razieh Bidhendi Yarandi ◽

Masoud Solaymani-Dodaran ◽

Maryam Tohidi ◽

Faezeh Firouzi ◽

...

Keyword(s):

Failure Time ◽

Reproductive Age ◽

Accelerated Failure Time Model ◽

Accelerated Failure Time ◽

Time Model ◽

Age At Menopause ◽

Decline Rate ◽

Accelerated Failure ◽

Failure Time Model

Abstract Context Several statistical models were introduced for the prediction of age at menopause using a single measurement of anti-müllerian hormone (AMH); however, individual prediction is challenging and needs to be improved. Objective The objective of this study was to determine whether multiple AMH measurements can improve the prediction of age at menopause. Design All eligible reproductive-age women (n = 959) were selected from the Tehran Lipid and Glucose Study. The serum concentration of AMH was measured at the time of recruitment and twice after that at an average of 6-year intervals. An accelerated failure-time model with Weibull distribution was used to predict age at menopause, using a single AMH value vs a model that included the annual AMH decline rate. The adequacy of these models was assessed using C statistics. Results The median follow-up period was 14 years, and 529 women reached menopause. Adding the annual decline rate to the model that included single AMH improved the model’s discrimination adequacy from 70% (95% CI: 67% to 71%) to 78% (95% CI: 75% to 80%) in terms of C statistics. The median of differences between actual and predicted age at menopause for the first model was –0.48 years and decreased to –0.21 in the model that included the decline rate. The predicted age at menopause for women with the same amount of age-specific AMH but an annual AMH decline rate of 95 percentiles was about one decade lower than in those with a decline rate of 5 percentiles. Conclusion Prediction of age at menopause could be improved by multiple AMH measurements; it will be useful in identifying women at risk of early menopause.

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