Bjørn Heine Strand

Background: Physical activity is a key component in public health frameworks to maintain functional ability through ageing. In Norway, healthcare services such as home health nursing and long-term institutional stays for older adults account for a significant amount of healthcare expenditures, but little is known about the association between physical activity levels through adulthood and utilisation of these services later in life. To this end, we wanted to explore an association between physical activity and the use of these specific healthcare services. Methods: We used data from three waves of the Trøndelag Health Study, that surveyed physical activity levels through questions about physical activity frequency, duration and intensity (HUNT1, 3 and 4). These questions allowed the calculation of minutes per week of moderate intensity physical activity, in addition to assessment of weekly physical activity frequencies (low-high). We included all who were either ≥ 65 years in HUNT3 or took part in all three surveys. Time-series of home health nursing and long-term institutional stays was collected from the combined Individual-based Statistics for Nursing and Care Services (IPLOS) and the Norwegian Registry for Primary Health Care (NRPHC) between 2007 and 2022. Multiple Cox proportional hazard models were built to assess the association between time to healthcare utilisation and physical activity levels. Results: Of the 15,737 participants who took part in HUNT1 and HUNT3, 9318 also participated in HUNT4. Moderate-intensity physical activity could be calculated for 8882 participants aged ≥ 65 years in HUNT3 (53% women), of whom 42.7% achieved the recommended ≥ 150 min per week. Physical activity frequency analysis included all 15,737 participants (55.7% women), of whom 43.4% increased their physical activity frequency between their first and last HUNT survey. Of the 9318 participants who took part in all three surveys, 40.8% received home health nursing care during follow-up, and 16.3% received long-term institutional stays. For participants who did not take part in HUNT4, the corresponding proportions were 76.5% and 41.8%. A potential dose-response relationship was seen between physical activity levels and healthcare utilisation, although not all comparisons were statistically significant. Conclusion: Individuals who partake in higher levels of leisure time physical activity had lower utilisation of home health nursing and long-term institutional stays. As most of the participants in our study did not comply with the nationally recommended ≥ 150 min of moderate physical activity per week, understanding what enables physical activity throughout life could help enable healthy ageing and reduce need for healthcare. Clinical trial number: Not applicable. Trial registration: Not applicable.

Background: Key daily physical activities (e.g., standing and walking), postures (sitting and lying), and sleep constitute the 24-h day and have distinct health effects and functional implications. Traditionally studied separately, the distribution of these movement behaviours and sleep across the cognitive spectrum remains insufficiently characterised. We aimed to describe and compare the distribution of 24-h movement behaviours and sleep across the cognitive spectrum. Methods: We analysed cross-sectional, population-based data from 4,699 community-dwelling older adults (≥ 70 years) participating in the HUNT4 70 + study. Cognitive status was classified as mild cognitive impairment (MCI, n = 1,690) or dementia ( n = 360) according to DSM-5 criteria. Participants not classified with MCI or dementia were categorised as cognitively unimpaired. Accelerometers worn on the thigh and lower back (≤ 7 days) were used to assess standing, walking, sitting, lying awake, and sleep using validated machine-learning models. Inverse probability weighting and multiple imputation by chained equations were used to address selection bias. Group differences were examined using survey-weighted regression models adjusted for potential confounders including age, sex, education, marital status, self-rated health, obesity, depression, alcohol consumption, and smoking. Results: In fully adjusted models, older adults with MCI spent less time sitting (ß -12.4 [95% CI -20.0, -4.4] min/ 24 h) and more time lying awake (ß 10.3 [95% CI 2.7, 17.9]) and sleeping (ß 3.9 [95% CI 0.8, 7.0] min/24 h) than their cognitively unimpaired peers (all p < 0.05), while time spent standing and walking was similar between the two groups. In fully adjusted models, older adults with dementia spent less time standing (ß -29.0 [95% CI -41.3, -16.5] and ß -30.3 [95% CI -42.5, -18.2] min/24 h) and walking (ß -16.1 [95% CI -19.9, -12.4] and ß -17.2 [95% CI -20.9, -13.4] min/24 h), and more time lying awake (ß 36.3 [95% CI 17.1, 55.4] and ß 46.5 [95% CI 28.7, 64.5] min/24 h), than those with MCI and cognitively unimpaired peers (all p ≤ 0.001), and more time sleeping (ß 7.5 [95% CI 0.9, 14.9] min/24 h) than their cognitively unimpaired peers ( p = 0.04). Conclusion: Across the cognitive spectrum, older adults exhibit distinct distributions of 24-h movement behaviours and sleep. The clinical importance of the observed differences remains unknown, and future research on the independent and compositional effects of these behaviours is warranted.

Background: Subjective memory impairment (SMI) is used as a proxy for objective memory, although their relationship remains unclear. Moreover, SMI is suggested to be a risk factor for dementia. This study investigated associations between SMI and (1) concurrent objective memory performance, (2) early‐life general cognitive abilities (GCA), and (3) if SMI and objective memory scores were associated with distinct or overlapping sociodemographic, health, and lifestyle risk factors for dementia. Material and Methods: 2690 participants between 30 and 90 years from the general, geographical population study HUNT4 were included. SMI scores were from the Meta‐Memory‐Questionnaire. Verbal, spatial, and ability to differentiate between similar representations (pattern separation) were tested concurrently. GCA was from conscription at age 18. We implemented multiple imputation and inverse probability weighting from the entire population to account for selection bias. Results: Higher SMI scores were associated with verbal memory and GCA, but not spatial or pattern separation memory. There was an interaction between sex and verbal memory on SMI, with men reporting higher SMI than women at similar lower verbal memory performance. Higher SMI scores were associated with higher age, blood pressure, depression, sleep, fatigue, and chronic pain, but not APOE4 or lifestyle variables. All memory tests were positively associated with each other and negatively with age. Diabetes was associated with verbal memory. Conclusion: In the general population, SMI was weakly linked to concurrent verbal memory and GCA in adolescence. Health, in particular mental health, was highly associated with SMI but not objective memory performance. Thus, SMI is a complement to memory testing, not a proxy.

Background: Parental socioeconomic status is associated with health outcomes across age. However, the specific age-, gender-, and disease-related patterns linking parental income during early childhood to healthcare utilization across age remain poorly characterized. Enhanced understanding of these associations is essential to inform targeted interventions and improve health equity. Methods: This cross-sectional study analyzed primary care consultations for all Norwegian residents aged 10–59 in 2018 ( N = 2,882,669), merged with parental income records from 1958 up until 2017. The analysis was restricted to GP consultations for diseases or disorders, excluding consultations for symptoms and complaints. Analyses were stratified by sex, age, and type of health problem. We also examined how adult income and education mitigate socioeconomic disparities in healthcare utilization. Results: Individuals from low parental income backgrounds had higher primary care utilization. In the lowest parental income quintile, females averaged 1.89 (SD 3.30) and males 1.24 (SD 2.65) consultations per year, compared to 1.60 (SD 2.94) and 1.00 (SD 2.21), respectively, in the highest quintile. Socioeconomic differences varied by age and disease type. Among females, the largest inequality occurred at age 24, with 1.97 (95% CI 1.89–2.05) consultations in the lowest quintile versus 1.17 (95% CI 1.11–1.23) in the highest. For males, inequality was largest at age 31, with 1.22 (95% CI 1.15–1.30) versus 0.78 (95% CI 0.74–0.83) consultations. Disease-specific differences showed the largest odds ratios for psychological (females: OR 1.54, 95% CI 1.51–1.57; males: OR 1.64, 95% CI 1.60–1.68) and endocrine/nutritional issues (females: OR 1.34, 95% CI 1.32–1.37; males: OR 1.35, 95% CI 1.31–1.38). Adjusting for adult education and income eliminated most disparities, except for musculoskeletal and endocrine/nutritional health problems. Conclusions: Lower parental income in childhood was associated with higher adult primary care use, particularly for psychological, musculoskeletal, and endocrine conditions, with heterogeneity by age and sex. These associations were attenuated when accounting for individuals’ own education and income, suggesting that policies that enhance educational attainment and economic opportunity can help reduce health inequalities.

Background: With increasing population longevity, Alzheimer's disease and dementia have become a health priority, and high-quality incidence estimates are needed. Objective: To provide reliable and precise incidence estimates of dementia applying a population-based sample of individuals aged 70+. Methods: A longitudinal cohort design was used, with baseline assessment in the Norwegian HUNT4 70+ study (2017–19) and at follow-up four years later (2021–23). Age-specific dementia incidence rates, standardized for the Norwegian population, were calculated as the number of new dementia cases per 1000 person-years assuming onset midway between study waves with inverse probability weights based on baseline factors associated with non-participation or death. Results: Among 5229 dementia-free individuals at baseline, 749 developed dementia over a 4.2-year period, resulting in a cumulative incidence proportion of 14.3%. At follow-up, 33.8% of new dementia cases showed no baseline cognitive impairment, while the rest had mild cognitive impairment (MCI). Of those with baseline MCI, 25.5% reverted to normal cognition, 48.2% remained MCI, and 26.2% developed dementia. The dementia incidence per 1000 person-years, was 43.9 (95% confidence interval (CI) 40.8, 47.1) (weighted for non-response and standardized to the dementia-free Norwegian population). Conclusions: Our study found higher dementia incidence rates in the 70+ population than hospital records indicate. Most individuals had preceding MCI, with similar numbers reverting to normal cognition as developing dementia. The projected incident dementia cases suggest a near doubling between 2023 and 2050, significantly impacting families and healthcare planning, including early detection and interventions.

INTRODUCTION: Loneliness is postulated to be a risk factor for dementia. However, the findings are inconsistent, and long‐term studies on this association remain scarce.METHODS: In all, 9389 participants self‐reported loneliness in the Trøndelag Health Study (HUNT) in HUNT1 (1984–1986), HUNT2 (1995–1997), and/or HUNT3 (2006–2008) and underwent cognitive assessment in HUNT4 (2017–2019) at age 70 years or older. Logistic regression was employed to analyze the association between the course of loneliness and dementia, with those never lonely as a reference.RESULTS: In the fully adjusted model, the odds ratio (OR) for persistent loneliness was 1.47 (95% confidence interval [CI] 1.10, 1.95). This attenuated when adjusting for depression (OR 1.28, 95% CI 0.95, 1.72).DISCUSSION: Persistent loneliness from midlife into older age, as well as becoming lonely, were associated with increased odds of dementia, whereas transient loneliness in midlife was not. These findings underscore the importance of reducing loneliness.Clinical trial registration: The study was registered with ClinicalTrials.gov (NCT04786561) and is available online .Highlights: Persistent and incident loneliness was associated with a higher risk of dementia. Transient loneliness was not associated with a higher risk of dementia. Loneliness 11 years before to the cognitive assessment was associated with dementia. Reducing the sense of loneliness might reduce or delay the onset of dementia.

We examined associations between body mass index (BMI), waist circumference (WC), and dementia risk, and differences in BMI and WC trajectories before dementia diagnosis. We included 9,739 participants (54% women) aged 70+ from the Trøndelag Health Study (HUNT4 70+). BMI was measured four times (1984–2019) and WC three times (1995–2019). Dementia diagnoses were clinically assessed at HUNT4 70+ . Women and men with dementia had higher midlife BMI and WC than those without dementia. These differences diminished closer to diagnosis, especially in women. Midlife obesity in both sexes and midlife overweight, high WC, and overweight/obesity with high WC in men were linked to higher dementia risk. Lower dementia risk was observed with late-life overweight for both sexes, late-life high WC in women, late-life overweight/obesity with normal WC in men or high WC in women. Adiposity measures and their changes influence dementia risk differently in women and men.