Leisure-time physical activity at midlife and the risk of dementia and Alzheimer's disease

BACKGROUND: Physical activity may help maintain cognitive function and decrease dementia risk, but epidemiological findings remain controversial. The aim of our study was to investigate the association between leisure-time physical activity at midlife and the subsequent development of dementia and Alzheimer's disease (AD). METHODS: Participants were randomly selected from the survivors of a population-based cohort previously surveyed in 1972, 1977, 1982, or 1987. 1449 persons (72.5%) age 65-79 years participated in the re-examination in 1998 (mean follow-up, 21 years). 117 persons had dementia and 76 had AD. Multiple logistic regression methods were used to analyse the association between leisure-time physical activity and dementia or AD. FINDINGS: Leisure-time physical activity at midlife at least twice a week was associated with a reduced risk of dementia and AD (odds ratio [OR] 0.48 [95% CI 0.25-0.91] and 0.38 [0.17-0.85], respectively), even after adjustments for age, sex, education, follow-up time, locomotor disorders, APOE genotype, vascular disorders, smoking, and alcohol drinking. The associations were more pronounced among the APOE epsilon4 carriers. INTERPRETATION: Leisure-time physical activity at midlife is associated with a decreased risk of dementia and AD later in life. Regular physical activity may reduce the risk or delay the onset of dementia and AD, especially among genetically susceptible individuals.     

Psoriasis susceptibility locus on 18p revealed by genome scan in Finnish families not associated with PSORS1

The major susceptibility locus for psoriasis, PSORS1, resides on chromosome 6p and includes the candidate genes HLA-C, HCR, and CDSN. Based on a nationwide collection of psoriasis patients and genotyping for the PSORS1 susceptibility haplotype, we selected for a genome scan nine families who do not show association with PSORS1 to more easily detect minor loci for psoriasis susceptibility. In the genome scan, five loci gave initial evidence of linkage and were studied with a denser marker map. After fine mapping, only one locus on 18p11.23 showed suggestive evidence of linkage (nonparametric multipoint linkage analysis score, 3.58; p = 0.0038). The bootstrapping analysis showed that one large family contributed the majority of the linkage (p = 0.0039), but was supported by other families. Haplotype sharing between the linked families and haplotype association analysis gave additional support for the locus. Further, the 18p locus has shown nominal evidence of linkage with psoriasis in the British population. Taken together, these findings confirm the presence of a minor susceptibility locus for psoriasis on 18p11.     

Variables associated with insulin production in persons with type 2 diabetes treated with multiple daily insulin injections

From the MDI-liraglutide study, we evaluated variables associated with endogenous insulin production in persons with multiple daily insulin injections-treated type 2 diabetes by relating C-peptide, proinsulin and proinsulin/C-peptide ratio at baseline to baseline variables. Lower insulin production was related to longer diabetes duration, shorter abdominal sagittal diameter and more glycaemic variability.     

The Circadian Syndrome Is a Significant and Stronger Predictor for Cardiovascular Disease than the Metabolic Syndrome—The NHANES Survey during 2005–2016

The study aimed to compare the predictive value of the Circadian Syndrome (CircS) and Metabolic Syndrome (MetS) for cardiovascular disease (CVD). We used data of 12,156 adults aged ≥20 years who attended National Health and Nutrition Examination Survey (NHANES) 2005–2016. Mortality was obtained from the registry updated to 2019. The CircS was defined based on components of the MetS, in addition to short sleep and depression. Both the MetS and CircS were directly associated with self-reported history of CVD. The odds ratios for prevalent CVD associated with the CircS and MetS, respectively, were 2.92 (95% confidence interval (CI) 2.21–3.86) and 3.20 (2.38–4.30) in men, and 3.27 (2.34–4.59) and 3.04 (2.15–4.30) in women. The CircS had a better predictive power for prevalent CVD than that of MetS, as indicated by the higher positive predictive value (PPV); in men, the PPV for prevalent CVD with CircS was 23.1% and with MetS 20.9%, and in women these were 17.9% vs. 16.4%, respectively. However, the PPV of the CircS and MetS did not differ for the CVD mortality prediction. Women with CircS alone had a higher risk for both prevalent CVD and CVD mortality than those with MetS alone. In conclusion, the CircS is a significant and stronger predictor for CVD than the MetS in US adults.     

Social factors and the gender difference in mortality

The effect of social factors on the male/female difference in mortality in Finland was studied by comparing age-adjusted mortality of males and females by social class and marital status. 44,548 death certificates (years 1969-1971) and 1970 census data for 25-64-years olds were analysed. The gender difference was 2.8-fold: 5.3-fold for violent causes and 2.3-fold for natural causes. The greatest gender difference from violent causes was found in accidental poisonings (18.7-fold) and drownings (12.8-fold), and from natural causes in mental disorders (mainly alcoholism; 5.7-fold) and in ischemic heart disease (4.5-fold). The gender difference was most prominent in unskilled workers, divorced and widowed and less prominent in married and upper professionals. The great variation of gender difference of mortality by social class and marital status seems to indicate that mortality difference between males and females is associated to external factors rather than biological differences between men and women. This conclusion is also supported by the progressive increase of gender difference of mortality from 1.4 to 2.8 during the last 80 years in working-aged Finns.