Prevalence and Determinants of Diagnosed Dementia: A Registry Linkage Study Linking Diagnosis of Dementia in the Population-Based HUNT Study to Registry Diagnosis of Dementia in Primary Care and Hospitals in Norway.

Background: A timely diagnosis of dementia can be beneficial for providing good support, treatment, and care, but the diagnostic rate remains unknown and is probably low. Objective: To determine the dementia diagnostic rate and to describe factors associated with diagnosed dementia. Methods: This registry linkage study linked information on research-based study diagnoses of all-cause dementia and subtypes of dementias, Alzheimer's disease, and related dementias, in 1,525 participants from a cross-sectional population-based study (HUNT4 70+) to dementia registry diagnoses in both primary-care and hospital registries. Factors associated with dementia were analyzed with multiple logistic regression. Results: Among those with research-based dementia study diagnoses in HUNT4 70+, 35.6% had a dementia registry diagnosis in the health registries. The diagnostic rate in registry diagnoses was 19.8% among home-dwellers and 66.0% among nursing home residents. Of those with a study diagnosis of Alzheimer's disease, 35.8% (95% confidence interval (CI) 32.6-39.0) had a registry diagnosis; for those with a study diagnosis of vascular dementia, the rate was 25.8% (95% CI 19.2-33.3) and for Lewy body dementias and frontotemporal dementia, the diagnosis rate was 63.0% (95% CI 48.7-75.7) and 60.0% (95% CI 43.3-75.1), respectively. Factors associated with having a registry diagnosis included dementia in the family, not being in the youngest or oldest age group, higher education, more severe cognitive decline, and greater need for help with activities of daily living. Conclusions: Undiagnosed dementia is common, as only one-third of those with dementia are diagnosed. Diagnoses appear to be made at a late stage of dementia.

Genetic associations with psychosis and affective disturbance in Alzheimer's disease.

INTRODUCTION: Individuals with Alzheimer's disease (AD) commonly experience neuropsychiatric symptoms of psychosis (AD+P) and/or affective disturbance (depression, anxiety, and/or irritability, AD+A). This study's goal was to identify the genetic architecture of AD+P and AD+A, as well as their genetically correlated phenotypes. METHODS: Genome-wide association meta-analysis of 9988 AD participants from six source studies with participants characterized for AD+P AD+A, and a joint phenotype (AD+A+P). RESULTS: AD+P and AD+A were genetically correlated. However, AD+P and AD+A diverged in their genetic correlations with psychiatric phenotypes in individuals without AD. AD+P was negatively genetically correlated with bipolar disorder and positively with depressive symptoms. AD+A was positively correlated with anxiety disorder and more strongly correlated than AD+P with depressive symptoms. AD+P and AD+A+P had significant estimated heritability, whereas AD+A did not. Examination of the loci most strongly associated with the three phenotypes revealed overlapping and unique associations. DISCUSSION: AD+P, AD+A, and AD+A+P have both shared and divergent genetic associations pointing to the importance of incorporating genetic insights into future treatment development. Highlights: It has long been known that psychotic and affective symptoms are often comorbid in individuals diagnosed with Alzheimer's disease. Here we examined for the first time the genetic architecture underlying this clinical observation, determining that psychotic and affective phenotypes in Alzheimer's disease are genetically correlated.Nevertheless, psychotic and affective phenotypes in Alzheimer's disease diverged in their genetic correlations with psychiatric phenotypes assessed in individuals without Alzheimer's disease. Psychosis in Alzheimer's disease was negatively genetically correlated with bipolar disorder and positively with depressive symptoms, whereas the affective phenotypes in Alzheimer's disease were positively correlated with anxiety disorder and more strongly correlated than psychosis with depressive symptoms.Psychosis in Alzheimer's disease, and the joint psychotic and affective phenotype, had significant estimated heritability, whereas the affective in AD did not.Examination of the loci most strongly associated with the psychotic, affective, or joint phenotypes revealed overlapping and unique associations.

Associations of Serum Vitamin D With Dental Caries and Periodontitis: The HUNT Study.

OBJECTIVE: To study the relationships of serum 25-hydroxyvitamin D [25(OH)D] with dental caries and periodontitis in a general Norwegian adult population. METHODS: We analysed a subsample of 1605 participants from the Trøndelag Health Study (HUNT) in Norway that had serum 25(OH)D levels measured in HUNT3 (2006-08) and oral health assessed in the HUNT4 Oral Health Study (2017-19). Negative binomial and Poisson regression models were used to estimate the ratios of means (RMs; for count oral outcomes) and prevalence ratios (PRs; for dichotomous oral outcomes). RESULTS: Serum 25(OH)D was inversely associated with the number of decayed teeth in a dose-response gradient (<30.0 nmol/L: RM 1.41, 95% CI 1.07-1.85; 30.0-49.9 nmol/L: 1.14, 0.98-1.32 and ≥75.0 nmol/L: 0.84, 0.67-1.04, as compared to the 50.0-74.9 nmol/L group, P for trend <.001). Each 25 nmol/L decrease in 25(OH)D level was associated with a 15% (RM 1.15, 95% CI 1.05-1.26) increase in the mean number of decayed teeth. Serum 25(OH)D <30.0 nmol/L was associated with a 35% higher prevalence of severe periodontitis (PR 1.35, 95% CI 1.00-1.83). No association was observed between 25(OH)D and the number of natural teeth. CONCLUSION: The present study suggested that serum 25(OH)D level had an inverse and dose-response association with the number of decayed teeth, and serum 25(OH)D <30 nmol/L was associated with a higher prevalence of severe periodontitis in this Norwegian adult population.

The association between age and long-term quality of life after curative treatment for prostate cancer: a cross-sectional study.

OBJECTIVE: We aimed to investigate the associations between age at radical prostate cancer treatment and long-term global quality of life (QoL), physical function (PF), and treatment-related side effects. MATERIAL AND METHODS: This single-center, cross-sectional study included men treated for localized prostate cancer with robotic-assisted radical prostatectomy (RARP) or external beam radiotherapy (EBRT) in 2014-2018. Global QoL and PF were assessed by the European Organisation of Research and Treatment in Cancer Quality of life Questionnaire-C30 (QLQ-C30), side effects by the Expanded Prostate Cancer Index Composite (EPIC-26). Adjusted linear regression models were estimated to assess associations between age (continuous variable) at treatment and outcomes. QLQ-C30 scores were compared to normative data after dividing the cohort in two groups, <70 years and ≥70 years at treatment. RESULTS: Of 654 men included, 516 (79%) had undergone RARP, and 138 (21%) had undergone EBRT combined with androgen deprivation therapy for 93%. Mean time since treatment was 57 months. Median age at treatment was 68 (min-max 44-84) years. We found no statistically significant independent association between age at treatment and global QoL, PF or side effects, except for sexual function (regression coefficient [RC] -0.77; p < 0.001) and hormonal/vitality (RC 0.30; p = 0.006) function. Mean QLQ-C30 scores were slightly poorer than age-adjusted normative scores, for men <70 years (n = 411) as well as for men ≥70 years (n = 243) at treatment, but the differences were not beyond clinical significance. CONCLUSIONS: In this cohort of prostate cancer survivors, age at treatment had little impact on long-term QoL and function. Due to the cross-sectional design, short term impact or variation over time cannot be ruled out.

Proteome Network Analysis Identifies Potential Biomarkers for Brain Aging.

BACKGROUND: Alzheimer's disease and related dementias (ADRD) involve biological processes that begin years to decades before onset of clinical symptoms. The plasma proteome can offer insight into brain aging and risk of incident dementia among cognitively healthy adults. OBJECTIVE: To identify biomarkers and biological pathways associated with neuroimaging measures and incident dementia in two large community-based cohorts by applying a correlation-based network analysis to the plasma proteome. METHODS: Weighted co-expression network analysis of 1,305 plasma proteins identified four modules of co-expressed proteins, which were related to MRI brain volumes and risk of incident dementia over a median 20-year follow-up in Framingham Heart Study (FHS) Offspring cohort participants (n = 1,861). Analyses were replicated in the Cardiovascular Health Study (CHS) (n = 2,117, mean 6-year follow-up). RESULTS: Two proteomic modules, one related to protein clearance and synaptic maintenance (M2) and a second to inflammation (M4), were associated with total brain volume in FHS (M2: p = 0.014; M4: p = 4.2×10-5). These modules were not significantly associated with hippocampal volume, white matter hyperintensities, or incident all-cause or AD dementia. Associations with TCBV did not replicate in CHS, an older cohort with a greater burden of comorbidities. CONCLUSIONS: Proteome networks implicate an early role for biological pathways involving inflammation and synaptic function in preclinical brain atrophy, with implications for clinical dementia.

Prevalence of malnutrition among older adults in a population-based study - the HUNT Study.

BACKGROUND: Malnutrition is common in older adults and is associated with increased morbidity and mortality rates. AIM: The aim of the study is to describe the prevalence of malnutrition based on low BMI, involuntary weight loss, and reduced food intake, in a Norwegian population of community-dwelling older adults and older adults living in nursing homes. METHODS: This population-based study is part of the fourth wave of the Trøndelag Health Study (HUNT4) and includes participants ≥70 years from the HUNT4 70+ cohort. The HUNT4 70+ cohort consist of 9930 (response rate 51.2%) participants. In the current study 8127 older people had complete dataset for inclusion in the analyses. Participants completed a self-report questionnaire and standardised interviews and clinical assessments at field stations, in participants' homes or at nursing homes. Malnutrition was defined using the following criteria: low BMI, involuntary weight loss and severely reduced food intake. The standardised prevalence of malnutrition was estimated using inverse probability weighting (IPW) with weights for sex, age and education of the total population in the catchment area of HUNT. RESULTS: Of the 8127 included participants, 7671 (94.4%) met at field stations, 356 (4.4%) were examined in their home, and 100 (1.2%) in nursing homes. In total, 14.3% of the population were malnourished based on either low BMI, weight loss, or reduced food intake, of which low BMI was the most frequently fulfilled criterion. The prevalence of malnutrition was less common among men than among women (10.1 vs 18.0%, p < 0.001), also after adjustment for age (OR 0.53, 95% confidence interval (CI) 0.46-0.61). The prevalence increased gradually with increasing age and the regression analysis adjusted for sex showed that for each year increase in age the prevalence of malnutrition increased with 4.0% (OR 1.04, 95% CI 1.03-1.05). The prevalence was higher both among older adults examined in their homes (26.4%) and residents in nursing home (23.6%), as compared to community-dwelling older adults who met at field stations (13.5%). CONCLUSION: The prevalence of malnutrition is high in the older population. Special attention on prevention and treatment of malnutrition should be given to older women, the oldest age groups, and care-dependent community-dwelling older adults and nursing home residents.

The Association between Coffee and Tea Consumption at Midlife and Risk of Dementia Later in Life: The HUNT Study.

BACKGROUND: Studies exploring the possible protective effect of coffee and tea consumption on dementia have shown inconsistent results so far. We aimed to investigate whether consumption of tea and different types of coffee at midlife are associated with dementia later in life and whether sex or ApoE4 influence such association. METHODS: We included 7381 participants from the Norwegian HUNT Study. Self-reported questionnaires assessed daily consumption of coffee and tea at baseline. After 22 years, individuals 70 years or older were screened for cognitive impairment. RESULTS: General coffee consumption and tea consumption was not associated with dementia risk. Compared to daily consumption of 0-1 cups of coffee, daily consumption of ≥8 cups of boiled coffee was associated with increased dementia risk in women (OR: 1.83, 95% CI: 1.10-3.04, p-value for trend = 0.03) and daily consumption of 4-5 cups of other types of coffee was associated with a decrease in dementia risk in men (OR: 0.48, 95% CI: 0.32-0.72, p-value for trend = 0.05). Furthermore, the association between boiled coffee and increased dementia risk was only found in ApoE4 non-carriers. Differences by sex or ApoE4 carrier status were not supported by strong statistical evidence for interaction. Tea consumption was not associated with dementia risk. CONCLUSION: type of coffee may play a role in the direction of the association between coffee-drinking habits and dementia later in life.

Dementia and mild cognitive impairment in older people in Trøndelag. / Demens og mild kognitiv svikt hos eldre personer i Trøndelag.

BACKGROUND: The number of people with dementia is expected to triple by 2050. We present figures showing the prevalence of dementia and mild cognitive impairment in Trondheim, and show how weighting for non-response and nursing home residency affects these figures when comparing Trondheim with Nord-Trøndelag. MATERIAL AND METHOD: In the fourth data collection in the Trøndelag Health Study (HUNT4) in the Norwegian county of Trøndelag, people aged 70 and over in Trondheim were invited to participate in HUNT4 Trondheim 70+. The participants were interviewed and underwent cognitive testing. A diagnostic team diagnosed dementia and mild cognitive impairment. Weights adjusting for non-response bias were used in the comparison of Trondheim and Nord-Trøndelag. RESULTS: The prevalence of dementia in Trondheim was estimated at 16.2 % for the age group 70 years and over, after weighting for non-response bias with regard to age, sex, education and proportion of nursing home residents. Unadjusted dementia prevalence was 21.0 % in Trondheim and 15.7 % in Nord-Trøndelag. After weighting, the prevalence was almost identical in the two samples. INTERPRETATION: Weighting for non-response is crucial for obtaining representative figures in prevalence studies of dementia.

Normative Scores on the Norwegian Version of the Mini-Mental State Examination.

BACKGROUND: The Mini-Mental State Examination (MMSE), a simple test for measuring global cognitive function, is frequently used to evaluate cognition in older adults. To decide whether a score on the test indicates a significant deviation from the mean score, normative scores should be defined. Moreover, because the test may vary depending on its translation and cultural differences, normative scores should be established for national versions of the MMSE. OBJECTIVE: We aimed to examine normative scores for the third Norwegian version of the MMSE. METHODS: We used data from two sources: the Norwegian Registry of Persons Assessed for Cognitive Symptoms (NorCog) and the Trøndelag Health Study (HUNT). After persons with dementia, mild cognitive impairment, and disorders that may cause cognitive impairment were excluded, the sample contained 1,050 cognitively healthy persons, 860 from NorCog, and 190 from HUNT, whose data we subjected to regression analyses. RESULTS: The normative MMSE score varied from 25 to 29, depending on years of education and age. More years of education and younger age were associated with higher MMSE scores, and years of education was the strongest predictor. CONCLUSION: Mean normative MMSE scores depend on test takers' years of education and age, with level of education being the strongest predictor.

Prescription of potentially addictive medications after a multilevel community intervention in general practice.

OBJECTIVE: To evaluate the long-term effects of a multilevel community intervention to improve the quality of prescription practice of potentially addictive medications (PAMs). DESIGN: We conducted a retrospective study, using anonymized data from the Norwegian prescription registry. SETTING: Based on an initiative from the GPs in Molde Municipality in Norway, a multilevel community intervention was initiated by the municipal chief physician in 2018. The intervention targeted GPs, patients, and the public. SUBJECTS: We retrieved prescription data from 26 of 36 GPs. MAIN OUTCOME MEASURES: By using the standardized defined daily dose (DDD), we compared prescription of three groups of PAMs from before the intervention (2017) throughout the intervention in 2018, and through 2020 to determine long-term effects. RESULTS: Three years after the intervention, the GPs in our study sample prescribed 26% less opioids, 38% less benzodiazepines, and 16% less z-hypnotics. Overall prescription of PAMs decreased by 27%. The number of individuals receiving at least 90 DDD of benzodiazepines and z-hypnotics were reduced from 9 to 7 and 34 to 24 per 1000, respectively. Also, the number of individuals receiving two and three PAMs concomitantly were reduced. CONCLUSION: Addressing prescription practice among GPs in a community as a joint intervention, combined with addressing patients and the public may be a feasible method to obtain long-term reduction of PAM prescriptions.Key pointsNon-therapeutic prescriptions of potentially addictive medications (PAMs) are both a public health concern and a frequent challenge in general practice.A multilevel community intervention, targeting general practitioners, patients, and the public, led to 27% reduction in prescription of PAMs.Both the number of daily users and concomitant use of several PAMs were reduced.The reduction in prescription persisted for three years.

Physical performance in older age by sex and educational level: the HUNT Study.

BACKGROUND: Population-based studies on physical performance provide important information on older people's health but rarely include the oldest and least-healthy segment of the population. The aim of this study was to provide representative estimates of physical performance by age, sex, and educational level based on recent data from a population-based health study in Norway that includes older people with a wide range in age and function. METHODS: In the fourth wave of the Trøndelag Health Study (2017-2019), all participants aged 70 + were invited to an additional examination of physical performance assessed by the Short Physical Performance Battery (SPPB), either by attending a testing station or by visits from ambulatory teams. The distribution and variation in SPPB total and subscores, as well as gait speed, are presented by sex, age, and educational level. RESULTS: The SPPB was registered in 11,394 individuals; 54.8% were women; the age range was 70-105.4 years, with 1,891 persons aged 85 + . SPPB scores decreased by 0.27 points (men) and 0.33 points (women) for each year of age, and gait speed by 0.02 m/sec (men) and 0.03 m/sec (women). Using a frailty cut-off for gait speed at < 0.8 m/sec, the proportion of participants categorized as frail increased from 13.9% in the 70-74 years cohort to 73.9% in participants aged 85 + . Level of education [Formula: see text] 10 years corresponded to 6 years (men) and 4 years (women) earlier onset of frailty (SPPB [Formula: see text] 9) compared to education [Formula: see text] 14 years. CONCLUSION: We found that the SPPB captured a gradual decline and wide distribution in physical performance in old age. The results provide information about physical performance, health status, and risk profiles at a population level and can serve as reference data for clinicians, researchers, and healthcare planners.

Blood pressure trajectories over 35 years and dementia risk: A retrospective study: The HUNT study.

High blood pressure is a well-established risk factor of dementia. However, the timing of the risk remains controversial. The aim of the present study was to compare trajectories of systolic blood pressure (SBP) over a 35-year follow-up period in the Health Survey in Trøndelag (HUNT) from study wave 1 to 4 in people with and without a dementia diagnosis at wave 4 (HUNT4). This is a retrospective cohort study of participants aged ≥ 70 years in HUNT4, where 9,720 participants were assessed for dementia. In the HUNT study all residents aged ≥ 20 years have been invited to four surveys: HUNT1 1984-86, HUNT2 1995-97, HUNT3 2006-08 and HUNT4 2017-19. The study sample was aged 70-102 years (mean 77.6, SD 6.0) at HUNT4, 54% were women and 15.5% had dementia, 8.8% had Alzheimer's disease (AD), 1.6% had vascular dementia (VaD) and 5.1% had other types of dementia. Compared to those without dementia at HUNT4, those with dementia at HUNT4 had higher SBP at HUNT1 and HUNT2, but lower SBP at HUNT4. These differences at HUNT1 and 2 were especially pronounced among women. Results did not differ across birth cohorts. For dementia subtypes at HUNT4, the VaD group had a higher SBP than the AD group at HUNT2 and 3. Age trajectories in SBP showed that the dementia group experienced a steady increase in SBP until 65 years of age and a decrease from 70 to 90 years. SBP in the no- dementia group increased until 80 years before it leveled off from 80 to 90 years. The present study confirms findings of higher midlife SBP and lower late-life SBP in people with dementia. This pattern may have several explanations and it highlights the need for close monitoring of BP treatment in older adults, with frequent reappraisal of treatment needs.

Temporal changes in personal activity intelligence and the risk of incident dementia and dementia related mortality: A prospective cohort study (HUNT).

Background: The Personal Activity Intelligence (PAI) translates heart rate during daily activity into a weekly score. Obtaining a weekly PAI score ≥100 is associated with reduced risk of premature morbidity and mortality from cardiovascular diseases. Here, we determined whether changes in PAI score are associated with changes in risk of incident dementia and dementia-related mortality. Methods: We conducted a prospective cohort study of 29,826 healthy individuals. Using data from the Trøndelag Health-Study (HUNT), PAI was estimated 10 years apart (HUNT1 1984-86 and HUNT2 1995-97). Adjusted hazard-ratios (aHR) and 95%-confidence intervals (CI) for incidence of and death from dementia were related to changes in PAI using Cox regression analyses. Findings: During a median follow-up time of 24.5 years (interquartile range [IQR]: 24.1-25.0) for dementia incidence and 23.6 years (IQR: 20.8-24.2) for dementia-related mortality, there were 1998 incident cases and 1033 dementia-related deaths. Individuals who increased their PAI score over time or maintained a high PAI score at both assessments had reduced risk of dementia incidence and dementia-related mortality. Compared with persistently inactive individuals (0 weekly PAI) at both time points, the aHRs for those with a PAI score ≥100 at both occasions were 0.75 (95% CI: 0.58-0.97) for incident dementia, and 0.62 (95% CI: 0.43-0.91) for dementia-related mortality. Using PAI score <100 at both assessments as the reference cohort, those who increased from <100 at HUNT1 to ≥100 at HUNT2 had aHR of 0.83 (95% CI: 0.72-0.96) for incident dementia, and gained 2.8 (95% CI: 1.3-4.2, P<0.0001) dementia-free years. For dementia-related mortality, the corresponding aHR was 0.74 (95% CI: 0.59-0.92) and years of life gained were 2.4 (95% CI: 1.0-3.8, P=0.001). Interpretation: Maintaining a high weekly PAI score and increases in PAI scores over time were associated with a reduced risk of incident dementia and dementia-related mortality. Our findings extend the scientific evidence regarding the protective role of PA for dementia prevention, and suggest that PAI may be a valuable tool in guiding research-based PA recommendations. Funding: The Norwegian Research Council, the Liaison Committee between the Central Norway Regional Health Authority and Norwegian University of Science and Technology (NTNU), Trondheim, Norway.

Genome-wide association identifies the first risk loci for psychosis in Alzheimer disease.

Psychotic symptoms, defined as the occurrence of delusions or hallucinations, are frequent in Alzheimer disease (AD with psychosis, AD + P). AD + P affects ~50% of individuals with AD, identifies a subgroup with poor outcomes, and is associated with a greater degree of cognitive impairment and depressive symptoms, compared to subjects without psychosis (AD - P). Although the estimated heritability of AD + P is 61%, genetic sources of risk are unknown. We report a genome-wide meta-analysis of 12,317 AD subjects, 5445 AD + P. Results showed common genetic variation accounted for a significant portion of heritability. Two loci, one in ENPP6 (rs9994623, O.R. (95%CI) 1.16 (1.10, 1.22), p = 1.26 × 10-8) and one spanning the 3'-UTR of an alternatively spliced transcript of SUMF1 (rs201109606, O.R. 0.65 (0.56-0.76), p = 3.24 × 10-8), had genome-wide significant associations with AD + P. Gene-based analysis identified a significant association with APOE, due to the APOE risk haplotype ε4. AD + P demonstrated negative genetic correlations with cognitive and educational attainment and positive genetic correlation with depressive symptoms. We previously observed a negative genetic correlation with schizophrenia; instead, we now found a stronger negative correlation with the related phenotype of bipolar disorder. Analysis of polygenic risk scores supported this genetic correlation and documented a positive genetic correlation with risk variation for AD, beyond the effect of ε4. We also document a small set of SNPs likely to affect risk for AD + P and AD or schizophrenia. These findings provide the first unbiased identification of the association of psychosis in AD with common genetic variation and provide insights into its genetic architecture.

Physical performance across the cognitive spectrum and between dementia subtypes in a population-based sample of older adults: The HUNT study.

BACKGROUND: Literature on physical performance in older adults across the cognitive spectrum remains inconclusive, and knowledge on differences between dementia subtypes is lacking. We aim to identify distinct physical-performance deficits across the cognitive spectrum and between dementia subtypes. METHODS: 11,466 persons were included from the 70-year-and-older cohort in the fourth wave of the Trøndelag Health Study (HUNT4 70+). Physical performance was assessed with the Short Physical Performance Battery (SPPB), 4-meter gait speed, five-times-sit-to-stand (FTSS), grip strength and one-leg-standing (OLS). Clinical experts diagnosed dementia per DSM-5 criteria. Multiple linear and logistic regression were performed to analyze differences between groups. Age, sex, education, somatic comorbidity, physical activity and smoking status were used as covariates. RESULTS: Gait speed declined across the cognitive spectrum, beginning in people with subjective cognitive decline (SCD). Participants with mild cognitive impairment (MCI) additionally showed reduced lower-limb muscle strength, balance and grip strength. Those with dementia scored lowest on all physical-performance measures. Participants with Alzheimer's disease (AD) had a higher SPPB sum score and faster gait speed than participants with vascular dementia (VaD) and Lewy body dementia (LBD); participants with VaD and LBD had lower odds of being able to perform FTSS and OLS than participants with AD. CONCLUSIONS: Physical performance declined across the spectrum from cognitively healthy to SCD to MCI and to dementia. Participants with AD performed better on all assessments except grip strength than participants with VaD and LBD. Stage of cognitive impairment and dementia subtype should guide exercise interventions to prevent mobility decline and dependency.

Current and Future Prevalence Estimates of Mild Cognitive Impairment, Dementia, and Its Subtypes in a Population-Based Sample of People 70 Years and Older in Norway: The HUNT Study.

BACKGROUND: Having accurate, up-to-date information on the epidemiology of mild cognitive impairment (MCI) and dementia is imperative. OBJECTIVE: To determine the prevalence of MCI and dementia in Norway using data from a large population-based study. METHODS: All people 70 + years of age, n = 19,403, in the fourth wave of the Trøndelag Health Study (HUNT4) were invited to participate in the study HUNT4 70 + . Trained health personnel assessed participants using cognitive tests at a field station, at homes, or at their nursing home. Interviewers also completed a structured carer questionnaire in regard to participants suspected of having dementia. Clinical experts made diagnoses according to DSM-5 criteria. We calculated prevalence weighing the data to ensure population representativeness. RESULTS: A total of 9,930 (51.2%) of the possible 19,403 people participated, and 9,663 of these had sufficient information for analysis. Standardized prevalence of dementia and MCI was 14.6% (95% confidence interval (CI) 13.9-15.4) and 35.3% (95% CI 34.3-36.4), respectively. Dementia was more prevalent in women and MCI more prevalent in men. The most prevalent dementia subtype was Alzheimer's disease (57%). By adding data collected from a study of persons < 70 years in the same region, we estimate that there are 101,118 persons with dementia in Norway in 2020, and this is projected to increase to 236,789 and 380,134 in 2050 and 2100, respectively. CONCLUSION: We found a higher prevalence of dementia and MCI than most previous studies. The present prevalence and future projections are vital for preparing for future challenges to the healthcare system and the entire society.

Temporal changes in cardiorespiratory fitness and risk of dementia incidence and mortality: a population-based prospective cohort study.

BACKGROUND: Cardiorespiratory fitness is associated with risk of dementia, but whether temporal changes in cardiorespiratory fitness influence the risk of dementia incidence and mortality is still unknown. We aimed to study whether change in estimated cardiorespiratory fitness over time is associated with change in risk of incident dementia, dementia-related mortality, time of onset dementia, and longevity after diagnosis in healthy men and women at baseline. METHODS: We linked data from the prospective Nord-Trøndelag Health Study (HUNT) done in Nord-Trøndelag, Norway with dementia data from the Health and Memory Study and cause of death registries (n=30 375). Included participants were apparently healthy individuals for whom data were available on estimated cardiorespiratory fitness and important confounding factors. Datasets were matched to each participant through their 11-digit personal identification number. Cardiorespiratory fitness was estimated on two occasions 10 years apart, during HUNT1 (1984-86) and HUNT2 (1995-97). HUNT2 was used as the baseline for follow-up. Participants were classified into two sex-specific estimated cardiorespiratory fitness groups according to their age (10-year categories): unfit (least fit 20% of participants) and fit (most fit 80% of participants). To assess the association between change in estimated cardiorespiratory fitness and dementia, we used four categories of change: unfit at both HUNT1 and HUNT2, unfit at HUNT1 and fit at HUNT2, fit at HUNT1 and unfit at HUNT2, fit at both HUNT1 and HUNT2. Using Cox proportional hazard analyses, we estimated adjusted hazard ratios (AHR) for dementia incidence and mortality related to temporal changes in estimated cardiorespiratory fitness. FINDINGS: During a median follow-up of 19·6 years for mortality, and 7·6 years for incidence, there were 814 dementia-related deaths, and 320 incident dementia cases. Compared with participants who were unfit at both assessments, participants who sustained high estimated cardiorespiratory fitness had a reduced risk of incident dementia (AHR 0·60, 95% CI 0·36-0·99) and a reduced risk of dementia mortality (0·56, 0·43-0·75). Participants who had an increased estimated cardiorespiratory fitness over time had a reduced risk of incident dementia (AHR 0·52, 95% CI 0·30-0·90) and dementia mortality (0·72, 0·52-0·99) when compared with those who remained unfit at both assessments. Each metabolic equivalent of task increase in estimated cardiorespiratory fitness was associated with a risk reduction of incident dementia (adjusted HR 0·84, 95% CI 0·75-0·93) and dementia mortality (0·90, 0·84-0·97). Participants who increased their estimated cardiorespiratory fitness over time gained 2·2 (95% CI 1·0-3·5) dementia-free years, and 2·7 (0·4-5·8) years of life when compared with those who remained unfit at both assessments. INTERPRETATION: Change in estimated cardiorespiratory fitness is an independent risk factor for incidence dementia and dementia mortality. Maintaining or improving cardiorespiratory fitness over time may be a target to reduce risk of dementia incidence and mortality, delay onset, and increase longevity after diagnosis. Our data highlight the importance of assessing cardiorespiratory fitness in health risk assessment for people at risk of dementia. FUNDING: The KG Jebsen Foundation, the Norwegian Research Council, the Liaison Committee between the Central Norway Regional Health Authority, and the Norwegian University of Science and Technology.