IMPORTANCE In clinical guidelines, overt and subclinical thyroid dysfunction are mentioned as causal and treatable factors for cognitive decline. However, the scientific literature on these... Show moreIMPORTANCE In clinical guidelines, overt and subclinical thyroid dysfunction are mentioned as causal and treatable factors for cognitive decline. However, the scientific literature on these associations shows inconsistent findings.OBJECTIVE To assess cross-sectional and longitudinal associations of baseline thyroid dysfunction with cognitive function and dementia.DESIGN, SETTING, AND PARTICIPANTS This multicohort individual participant data analysis assessed 114 267 person-years (median, 1.7-11.3 years) of follow-up for cognitive function and 525 222 person-years (median, 3.8-15.3 years) for dementia between 1989 and 2017. Analyses on cognitive function included 21 cohorts comprising 38 144 participants. Analyses on dementia included eight cohorts with a total of 2033 cases with dementia and 44 573 controls. Data analysis was performed from December 2016 to January 2021.EXPOSURES Thyroid function was classified as overt hyperthyroidism, subclinical hyperthyroidism, euthyroidism, subclinical hypothyroidism, and overt hypothyroidism based on uniform thyrotropin cutoff values and study-specific free thyroxine values.MAIN OUTCOMES AND MEASURES The primary outcome was global cognitive function, mostly measured using the Mini-Mental State Examination. Executive function, memory, and dementia were secondary outcomes. Analyses were first performed at study level using multivariable linear regression and multivariable Cox regression, respectively. The studies were combined with restricted maximum likelihood meta-analysis. To overcome the use of different scales, results were transformed to standardized mean differences. For incident dementia, hazard ratios were calculated.RESULTS Among 74 565 total participants, 66 567 (89.3%) participants had normal thyroid function, 577 (0.8%) had overt hyperthyroidism, 2557 (3.4%) had subclinical hyperthyroidism, 4167 (5.6%) had subclinical hypothyroidism, and 697 (0.9%) had overt hypothyroidism. The study-specific median age at baseline varied from 57 to 93 years; 42 847 (57.5%) participants were women. Thyroid dysfunction was not associated with global cognitive function; the largest differences were observed between overt hypothyroidism and euthyroidism-cross-sectionally (-0.06 standardized mean difference in score; 95% CI, -0.20 to 0.08; P = .40) and longitudinally (0.11 standardized mean difference higher decline per year; 95% CI, -0.01 to 0.23; P = .09). No consistent associations were observed between thyroid dysfunction and executive function, memory, or risk of dementia.CONCLUSIONS AND RELEVANCE In this individual participant data analysis of more than 74 000 adults, subclinical hypothyroidism and hyperthyroidism were not associated with cognitive function, cognitive decline, or incident dementia. No rigorous conclusions can be drawn regarding the role of overt thyroid dysfunction in risk of dementia. These findings do not support the practice of screening for subclinical thyroid dysfunction in the context of cognitive decline in older adults as recommended in current guidelines. Show less
How long does the average person sleep? Here, Kocevska et al. conducted a meta-analysis including over 1.1 million people to produce age- and sex-specific population reference charts for sleep... Show moreHow long does the average person sleep? Here, Kocevska et al. conducted a meta-analysis including over 1.1 million people to produce age- and sex-specific population reference charts for sleep duration and efficiency.We aimed to obtain reliable reference charts for sleep duration, estimate the prevalence of sleep complaints across the lifespan and identify risk indicators of poor sleep. Studies were identified through systematic literature search in Embase, Medline and Web of Science (9 August 2019) and through personal contacts. Eligible studies had to be published between 2000 and 2017 with data on sleep assessed with questionnaires including >= 100 participants from the general population. We assembled individual participant data from 200,358 people (aged 1-100 years, 55% female) from 36 studies from the Netherlands, 471,759 people (40-69 years, 55.5% female) from the United Kingdom and 409,617 people (>= 18 years, 55.8% female) from the United States. One in four people slept less than age-specific recommendations, but only 5.8% slept outside of the 'acceptable' sleep duration. Among teenagers, 51.5% reported total sleep times (TST) of less than the recommended 8-10 h and 18% report daytime sleepiness. In adults (>= 18 years), poor sleep quality (13.3%) and insomnia symptoms (9.6-19.4%) were more prevalent than short sleep duration (6.5% with TST < 6 h). Insomnia symptoms were most frequent in people spending >= 9 h in bed, whereas poor sleep quality was more frequent in those spending <6 h in bed. TST was similar across countries, but insomnia symptoms were 1.5-2.9 times higher in the United States. Women (>= 41 years) reported sleeping shorter times or slightly less efficiently than men, whereas with actigraphy they were estimated to sleep longer and more efficiently than man. This study provides age- and sex-specific population reference charts for sleep duration and efficiency which can help guide personalized advice on sleep length and preventive practices. Show less
Wouters, H.; Hilmer, S.N.; Gnjidic, D.; Campen, J.P. van; Teichert, M.; Meer, H.G. van der; ... ; Taxis, K. 2020
Background: Anticholinergic and sedative medications are frequently prescribed to older individuals. These medications are associated with short-term cognitive and physical impairment, but less is... Show moreBackground: Anticholinergic and sedative medications are frequently prescribed to older individuals. These medications are associated with short-term cognitive and physical impairment, but less is known about long-term associations. We therefore examined whether over 20 years cumulative exposure to these medications was related to poorer cognitive and physical functioning.Methods: Older adult participants of the Longitudinal Aging Study Amsterdam (LASA) were followed from 1992 to 2012. On seven measurement occasions, cumulative exposure to anticholinergic and sedative medications was quantified with the drug burden index (DBI), a linear additive pharmacological dose-response model. Cognitive functioning was assessed with the Mini-Mental State Examination (MMSE), Alphabet Coding Task (ACT, three trials), Auditory Verbal Learning Test (AVLT, learning and retention condition), and Raven Colored Progressive Matrices (RCPM, two trials). Physical functioning was assessed with the Walking Test (WT), Cardigan Test (CT), Chair Stands Test (CST), Balance Test (BT), and self-reported Functional Independence (FI). Data were analyzed with linear mixed models adjusted for age, education, sex, living with a partner, BMI, depressive symptoms, comorbidities (cardiovascular disease, diabetes, cancer, COPD, osteoarthritis, CNS diseases), and prescribed medications.Results: Longitudinal associations were found of the DBI with poorer cognitive functioning (less items correct on the three ACT trials, AVLT learning condition, and the two RCPM trials) and with poorer physical functioning (longer completion time on the CT, CST, and lower self-reported FI).Conclusions: This longitudinal analysis of data collected over 20 years, showed that higher long-term cumulative exposure to anticholinergic and sedative medications was associated with poorer cognitive and physical functioning. Show less
Objectives Older age and major depressive disorder (MDD) are both risk factors for the development of cardiovascular diseases. Testosterone has been associated with MDD and metabolic syndrome (MetS... Show moreObjectives Older age and major depressive disorder (MDD) are both risk factors for the development of cardiovascular diseases. Testosterone has been associated with MDD and metabolic syndrome (MetS) in men, although associations in women are less clear. Therefore, we investigated whether testosterone is associated with MetS and whether this association is different for depressed and non-depressed older men and women. Methods In this prospective cohort study, 478 participants (349 patients with MDD and 129 controls) aged between 60 and 93 years from the Netherlands Study of Depression in Older Persons were included. Total testosterone (TT) and sex-hormone binding globulin levels were measured using a second-generation radioimmune assay. Free testosterone (FT) was calculated based on TT. MetS was defined according to the National Cholesterol Education Program Adult Treatment Panel III criteria. Results A higher risk for MetS was found in men with low FT and TT (odds ratio [OR]: 0.67, 95% confidence interval [95%CI]: 0.47-0.95 and OR: 0.51, 95%CI: 0.34-0.75), and in women with high FT (OR: 1.41, 95%CI: 1.08-1.82). Strong associations in the same direction were found with adiposity, glucose, and plasma lipid MetS components at baseline, but not with changes in these components at 2-year follow-up. The associations did not significantly differ between MDD patients and controls. Conclusions Independently of having MDD, low testosterone levels in men and, in contrast, high testosterone levels in women were significantly associated with MetS and its components. Show less
Neijenhof, R.J.G.P. van; Duijn, E. van; Comijs, H.C.; Berg, J.F. van den; Waal, M.W.M. de; Oude Voshaar, R.C.; Mast, R.C. van der 2018
