In older adults, mobility limitations often coexist with overweight or obesity, suggesting that similar factors may underlie both traits. This study examined the extent to which genetic and environmental influences explain the association between adiposity and mobility in older women. Body fat percentage (bioimpedance test), walking speed over 10 m, and distance walked in a 6-min test were evaluated in 92 monozygotic (MZ) and 104 dizygotic (DZ) pairs of twin sisters reared together, aged 63-76 years. Genetic and environmental influences on each trait were estimated using age-adjusted multivariate genetic modeling. The analyses showed that the means (and s.d.) for body fat percentage, walking speed, and walking endurance were 33.2+/-7.3%, 1.7+/-0.3 m/s and 529.7+/-75.4 m, respectively. The phenotypic correlation between adiposity and walking speed was -0.32 and between adiposity and endurance it was -0.33. Genetic influences explained 80% of the association between adiposity and speed, and 65% of adiposity and walking endurance. Cross-trait genetic influences accounted for 12% of the variability in adiposity, 56% in walking speed, and 34% in endurance. Trait-specific genetic influences were also detected for adiposity (54%) and walking endurance (13%), but not speed. In conclusion, among community-living older women, an inverse association was found between adiposity and mobility that was mostly due to the effect of shared genes. This result suggests that the identification of genetic variants for body fat metabolism may also provide understanding of the development of mobility limitations in older women.
To study which individual characteristics and environmental factors correlate with fear of moving outdoors and whether fear of moving outdoors predicts development of mobility limitation.
Observational prospective cohort study and cross-sectional analyses.
Community and research center.
Seven hundred twenty-seven community-living people aged 75 to 81 were interviewed at baseline, of whom 314 took part in a 3.5-year follow-up.
Fear of moving outdoors and its potential individual and environmental correlates were assessed at baseline. Perceived difficulties in walking 0.5 km and 2 km were assessed twice a year over a 3.5-year period.
At baseline, 65% of the women and 29% of the men reported fear of moving outdoors. Poor socioeconomic status; musculoskeletal diseases; slow walking speed; and the presence of poor street conditions, hills in the nearby environment, and noisy traffic correlated with fear of moving outdoors. At the first 6-month follow-up, participants with fear of moving outdoors had more than four times the adjusted risk (odds ratio (OR)=4.6, 95% confidence interval (CI)=1.92-11.00) of developing difficulties in walking 0.5 km and a three times greater adjusted risk (OR=3.10, 95% CI=1.49-6.46) for developing difficulty in walking 2 km compared with those without fear. The difference in the prevalence of walking difficulties remained statistically significant over the 3.5-year follow-up (P=.02 and P=.009, respectively).
Fear of moving outdoors is common in older adults and increases the risk of developing self-reported difficulties in walking 0.5 km and 2 km. Knowledge about individual and environmental factors underlying fear of moving outdoors and finding ways to alleviate fear of moving outdoors are important for community planning and prevention of disability.
The aim of the present study was to examine the contribution of genetic and environmental factors to depressive symptoms among older women. The participants were 102 monozygotic and 115 dizygotic female twin pairs aged 64 to 76 years. Depressive symptoms were assessed by the Center for the Epidemiologic Studies Depression Scale. The contribution of genetic and environmental effects was estimated for the constructed depressiveness factor and for the subscales which were depressed mood, psychomotor retardation, lack of wellbeing and interpersonal difficulties. Of the variance in depressiveness, shared environmental influences accounted for 39% and nonshared environmental influences 61%. For the subscales, 24% to 62% of the variance was explained by individual, and 13% to 23% by shared, environmental factors. Lack of wellbeing had its own moderate additive genetic effect explaining 30% of the variance. This study showed that in older women predominantly environmental factors underlay individual differences in depressiveness; however, the factors varied to some extent between dimensions measured by the subscales.
Stress has damaging effects on individual's health. However, information about the long-term consequences of mental stress is scarce.
This 28-year prospective cohort study examined on the associations between midlife stress and old age disability among 2,994 Finnish municipal professionals aged 44-58 years at baseline. Self-reported stress symptoms were assessed at baseline in 1981 and 4 years later in 1985 and perceived disability in 2009. For the baseline data, principal component analysis was used for differentiation into stress symptom profiles. The regression coefficient estimates for self-care disability (activities of daily living) and instrumental activities of daily living disability were estimated using left-censored regression. The odds ratios for mobility limitation were estimated using logistic regression.
Four midlife stress profiles were identified: negative reactions to work and depressiveness, perceived decrease in cognition, sleep disturbances, and somatic symptoms. We saw a clear gradient of increasing disability severity in old age for increasing intensity of midlife stress symptoms. In comparison with the participants with no stress symptoms, the extensively adjusted left-censored and logistic regression models showed that in old age, disability scores were almost 2-4 units higher and risk for mobility limitation was 2-3 times higher for those with constant stress symptoms in midlife.
Among occupationally active 44- to 58-year-old men and women, perceived stress symptoms in midlife correlated with disability 28 years later. Stress symptoms may be the first signs of decompensation of individual functioning relative to environmental demands, which may later manifest in disabilities.