Search results for "twin"
showing 10 items of 435 documents
Satisfaction With Present Life Predicts Survival in Octogenarians
2006
We examined the effect of life satisfaction on survival over 10 years among 80-year-old and older same-sex twins of whom 320 individuals responded to the Life Satisfaction Index Z questionnaire in connection with the OCTO-Twin study. We treated participants as individuals in semiparametric Cox regression mixed-effects models (frailty) by adjusting the similarity of mortality risk within twin pairs by modeling it as a random variable. An exploratory factor analysis yielded three factors: Zest and Mood represented satisfaction with present life and Congruence represented satisfaction with past life. Those in the lowest quartile of factors of satisfaction with present life had an almost twofol…
Biological clocks and physical functioning in monozygotic female twins
2018
Background Biomarkers of biological aging – DNA methylation age (DNAm age) and leukocyte telomere length (LTL)– correlate strongly with chronological age across the life course. It is, however, unclear how these measures of cellular wear and tear are associated with muscle strength and functional capacity, which are known to decline with older age and are associated with mortality. We investigated if DNAm age and LTL were associated with body composition and physical functioning by examining 48 monozygotic twin sisters. Methods White blood cell DNAm age (predicted years) was calculated from Illumina 450 k BeadChip methylation data using an online calculator. DNAm age acceleration was define…
Genetic and environmental influences on hearing at different frequencies separately for the better and worse hearing ear in older women
2007
The purpose of the present study was to examine the relative contribution of genetic and environmental effects on the air-conducted hearing threshold levels at low (0.125-0.5 kHz), mid (1-2 kHz), and high (4-8 kHz) frequencies separately for the better and worse hearing ear in older women. We also examined the distribution of audiogram configurations. Data was analysed using quantitative genetic modelling. As part of the Finnish twin study on aging (FITSA), hearing was measured in 103 monozygotic and 114 dizygotic female twin pairs aged 63-76 years. Approximately every third subject had a flat type, and two-thirds a descending type of audiogram configuration. No significant difference was o…
A twin study on the heritability of walking ability among older women
2006
BACKGROUND This study examined the role of genetic and environmental factors explaining individual differences in women's walking ability in old age. METHODS A maximal walking speed test over 10 meters and a 6-minute walking endurance test were done under standard conditions among 92 monozygotic and 105 dizygotic pairs of twin sisters reared together, aged 63-75 years. RESULTS The mean maximum walking speed was 1.73 +/- 0.32 m/s and the mean distance covered in the 6-minute walking test was 525.6 +/- 77.3 m. Multivariate genetic modeling showed that a minor part of the variances in walking speed (16%, 95% confidence interval [CI]: 0%-54%) and endurance (20%, 95% CI: 0%-56%) were accounted f…
Body Fat and Mobility Are Explained by Common Genetic and Environmental Influences in Older Women
2008
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, walkin…
Hearing as a Predictor of Falls and Postural Balance in Older Female Twins
2009
BACKGROUND: The purpose of the present study was to examine, first, whether hearing acuity predicts falls and whether the potential association is explained by postural balance and, second, to examine whether shared genetic or environmental effects underlie these associations. METHODS: Hearing was measured using a clinical audiometer as a part of the Finnish Twin Study on Aging in 103 monozygotic and 114 dizygotic female twin pairs aged 63-76 years. Postural balance was indicated as a center of pressure (COP) movement in semitandem stance, and participants filled in a fall-calendar daily for an average of 345 days after the baseline. RESULTS: Mean hearing acuity (better ear hearing threshol…
Genetic and environmental influences on hearing in older women.
2007
Background. This study examined the relative contribution of genetic and environmental effects on the air-conducted hearing threshold level (0.5‐4 kHz) and speech recognition threshold level of the better ear as well as self-reported hearing in older women. Methods. Hearing was measured as a part of the Finnish Twin Study on Aging in 103 monozygotic (MZ) and 114 dizygotic (DZ) female twin pairs aged 63‐76 years. Audiometric measured hearing was tested using standardized methods in soundproof conditions. Self-reported hearing was assessed by a structured question. Quantitative genetic modeling was used for data analyses. Results. No significant differences in age, exposure to noise, hearing-…
Genetic and environmental contribution to postural balance of older women in single and dual task situations
2005
Abstract The purpose of the present study was to examine the effect of a second task on postural balance and to determine the role of genetic influences on postural balance when dual tasking among 206 monozygotic and 227 dizygotic female twins, aged 63–76 years. Balance was measured as medio-lateral and antero-posterior velocity of the centre of pressure (COP) (mm/s) and velocity moment (mm2/s) while standing on a force platform. Doing an arithmetic task increased movement of the COP while the hand motor task had no effect on movement of the COP. The genetic contribution to balance in the single task situation was minor (14%, 95% confidence interval, CI: 11–35%) whereas in the dual task sit…
Contribution of genetic and environmental factors to individual differences in maximal walking speed with and without second task in older women
2005
Background. Among older people, distraction while walking may increase the risk of falls. Factors underlying individual differences in dual tasking are not fully understood. Our aim was to study the effect of a second task on maximal walking speed and to examine whether individual differences in walking speed measured with and without a second task are accounted for by genetic and environmental influences shared across tasks or specific to each task. Methods. The data were collected from the 101 monozygotic and 116 dizygotic twin pairs aged 63–76 years recruited from the Finnish Twin Cohort. Maximal walking speed (MWS) over 10 m was measured on a laboratory corridor and timed with photocell…
Contribution of genetic and environmental effects to postural balance in older female twins
2003
The aim of the present study was to determine the relative roles of genetic and environmental influences on postural balance in older women. The participants were 97 monozygotic (MZ) and 102 dizygotic (DZ) female twins, aged 64–76 yr. Postural sway was measured during side-by-side stance with eyes open and eyes closed, and during semitandem stance with eyes open on a force platform. Sway data were condensed into four first-order and one second-order latent factors. The second-order factor, named balance, incorporates sway data from multiple tests and thus best describes the phenotype of postural balance. The contribution of genetic and environmental influences on the variability of the lat…