Muscle cross-sectional area and structural bone strength share genetic and environmental effects in older women

The purpose of this study was to estimate to what extent muscle cross-sectional area of the lower leg (mCSA) and tibial structural strength are influenced by common and trait-specific genetic and environmental factors. pQCT scans were obtained from both members of 102 monozygotic (MZ) and 113 dizygotic (DZ) 63- to 76-yr-old female twin pairs to estimate the mCSA of the lower leg, structural bending strength of the tibial shaft (BSIbend), and compressive strength of the distal tibia (BSIcomp). Quantitative genetic models were used to decompose the phenotypic variances into common and trait-specific additive genetic (A), shared environmental (C), and individual environmental (E) effects. The …

Shared Genetic and Environmental Effects on Strength and Power in Older Female Twins

Purpose: This study examined the relative contribution of genetic and environmental effects on maximal leg extensor power and also investigated whether leg extensor power and maximum voluntary isometric knee extensor strength share a genetic component. Methods: Muscle functions were measured as part of the Finnish Twin Study on Aging in 101 monozygotic (MZ) and 116 dizygotic (DZ) female twin pairs aged 63–76 yr. Leg extensor power was measured using the Nottingham Leg Extensor Power Rig and maximum voluntary isometric knee extensor strength using an adjustable dynamometer chair. The analyses were carried out using the maximum likelihood method in Mx-program on the raw data set. Results: A b…

Contribution of genetic and environmental factors to individual differences in maximal walking speed with and without second task in older women

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…

Genetic effects in common on maximal walking speed and muscle performance in older women

The purpose was to examine whether maximal walking speed, maximal isometric knee extensor strength, and leg extensor power share genetic or environmental effects in common. The data was collected from 103 monozygotic and 114 dizygotic female twin pairs aged 63–76 years. Maximal walking speed over 10 m was measured in the laboratory corridor using photocells for timing. Isometric knee extensor strength and leg extensor power were measured using an adjustable dynamometer. The genetic models showed that strength, power, and walking speed had a genetic effect in common which accounted for 52% of the variance in strength, 36% in power, and 34% in walking speed. Strength and power had a non-share…

Catechol-O-Methyltransferase Gene Polymorphism Is Associated with Skeletal Muscle Properties in Older Women Alone and Together with Physical Activity

BackgroundMuscle strength declines on average by one percent annually from midlife on. In postmenopausal women this decrement coincides with a rapid decline in estrogen production. The genetics underlying the effects of estrogen on skeletal muscle remains unclear. In the present study, we examined whether polymorphisms within COMT and ESR1 are associated with muscle properties and assessed their interaction and their combined effects with physical activity.Methodology/principal findingsA cross-sectional data analysis was conducted with 434 63-76-year-old women from the population-based Finnish Twin Study on Aging. Body anthropometry, muscle cross-sectional area (mCSA), isometric hand grip a…

Fyysisen toimintakyvyn arviointi yli 75-vuotiailla : kahdeksan toimintatestin toistettavuustutkimus

Muscle Cross-Sectional Area and Structural Bone Strength Share Genetic and Environmental Effects in Older Women

The purpose of this study was to estimate to what extent muscle cross-sectional area of the lower leg (mCSA) and tibial structural strength are influenced by common and trait-specific genetic and environmental factors. pQCT scans were obtained from both members of 102 monozygotic (MZ) and 113 dizygotic (DZ) 63- to 76-yr-old female twin pairs to estimate the mCSA of the lower leg, structural bending strength of the tibial shaft (BSIbend), and compressive strength of the distal tibia (BSIcomp). Quantitative genetic models were used to decompose the phenotypic variances into common and trait-specific additive genetic (A), shared environmental (C), and individual environmental (E) effects. The …

Heritability of maximal isometric muscle strength in older female twins.

The purpose of the present study was to examine genetic and environmental effects on maximal isometric handgrip, knee extension, and ankle plantar flexion strength. In addition, we wanted to investigate whether the strength of these three muscle groups shares a genetic component or whether the genetic effect is specific for each muscle group. Muscle strength was measured as part of the Finnish Twin Study on Aging in 97 monozygotic (MZ) and 102 dizygotic (DZ) female twin pairs, aged 63-76 yr. The MZ and DZ individuals did not differ from each other in age, body height, weight, or self-related health. The age-adjusted pairwise (intraclass) correlations of the MZ and DZ twins were, respective…

Contribution of genetic and environmental effects to postural balance in older female twins

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…

Association of Body Mass Index and Waist Circumference With Physical Functioning: The Vitality 90+ Study

BACKGROUND Both obesity and underweight are associated with impaired physical functioning, but related information on the oldest old population is scarce. Our purpose was to examine whether body mass index, waist circumference (WC), and their combination are associated with physical performance and activities of daily living (ADL) disability in 90-year-old women and men. METHODS Data are from the Vitality 90+ Study, which is a population-based study of persons with age ≥90 years living in the area of Tampere, Finland. Altogether 416 women and 153 men, aged 90-91 years, provided data on body mass index, WC, chair stand, and Barthel Index. Comorbidity, physical exercise, smoking history, livi…

Are body mass index, waist circumference and waist-to-hip ratio associated with leptin in 90-year-old people?

Data on how body mass index (BMI), waist circumference (WC) and waist-to-hip ratio (WHR) are associated with body fat in the oldest-old people are scarce. The purpose of this study was to examine if BMI, WC or WHR are associated with leptin, a biological surrogate measure of body fat in 90-year-old people. The data comes from the Vitality 90+ Study, a prospective population-based study of people living in Tampere, Finland. BMI, WC, WHR and plasma concentration of leptin were available for 160 women and 54 men aged 90 years. BMI and WC had a strong significant positive association with leptin both in women and in men, but WHR was associated with leptin only in men. In conclusion, based on th…

Long-Term Determinants of Muscle Strength Decline: Prospective Evidence from the 22-Year Mini-Finland Follow-Up Survey

Objectives: To examine long-term changes in handgrip strength and the factors predicting handgrip strength decline. Design: Longitudinal cohort study with 22 years of follow-up. Setting: Population-based Mini-Finland Health Examination Survey in Finland. Participants: Nine hundred sixty-three men and women aged 30 to 73 at baseline. Measurements: Handgrip strength was measured using a handheld dynamometer at baseline and follow-up. Information on potential risk factors, namely lifestyle and chronic conditions, and their changes throughout the follow-up were based on health interviews. Results: Based on linear mixed-effect models, midlife physically strenuous work, excess body weight, smokin…

Genetics of Skeletal Muscle Characteristics and Maximal Walking Speed among Older Female Twins

The purpose of this study was to examine the contribution of genetic and environmental effects on individual differences in skeletal muscle characteristics and maximal walking speed. The aim was also to identify chromosomal areas that account for skeletal muscle characteristics and maximal walking speed and to study whether the regions are same for these traits.Maximal isometric muscle strength of different muscle groups (hand grip, knee extensor, and ankle plantar flexion), leg extensor power, lower leg muscle cross-sectional area (CSA) and maximal walking speed were measured in the laboratory from 103 monozygotic and 114 dizygotic female twin pairs 63-76 years of age and without severe di…

Uutta tutkimustietoa iäkkäiden sosiaalisesta hyvinvoinnista – SoWell-tutkimushankkeen laaja kyselyaineisto on valmistunut

publishedVersion Non peer reviewed

Genetics of maximal walking speed and skeletal muscle characteristics in older women.

AbstractThe aim of this study was to examine whether maximal walking speed, maximal isometric muscle strength, leg extensor power and lower leg muscle cross-sectional area (CSA) shared a genetic effect in common. In addition, we wanted to identify the chromosomal areas linked to maximal walking speed and these muscle characteristics and also investigate whether maximal walking speed and these three skeletal muscle characteristics are regulated by the same chromosomal areas. We studied 217 monozygotic (MZ) and dizygotic (DZ) female twin pairs aged 66 to 75 years in the Finnish Twin Study on Aging study. The DZ pairs (94) were genotyped for 397 microsatellite markers in 22 autosomes and X-chr…

Mikä muuttui vai muuttuiko mikään? Yli 65-vuotiaiden arki korona-aikana

Koronapandemian leviämisen estämiseksi asetetut rajoitukset ovat kohdistuneet erityisesti ikäihmisiin, joille tauti on vaarallisin. Miten korona-aika rajoituksineen on näkynyt ikääntyneiden elämässä ja hyvinvoinnissa? Tutkimuksemme aineistona on 31 kesällä 2020 tehtyä puhelinhaastattelua. Korona-aika rajoituksineen oli vaikuttanut haastateltujen arkeen ja hyvinvointiin eri tavoin. Suuri osa koki arkensa muuttuneen vain vähän tai ei ollenkaan, osa taas koki hyvinvointinsa huonontuneen merkittävästi. Jotkut kokivat arkensa jopa parantuneen. Niillä, joilla arki ei ollut juuri muuttunut, elämä oli saattanut olla jo ennestään rajoittunutta huonon toimintakyvyn ja vähäisten sosiaalisten kontaktie…

Body Mass Index and Waist Circumference as Predictors of Disability in Nonagenarians : The Vitality 90+ Study

Background Only scarce data exist on the association between obesity and disability in the oldest old. The purpose of this prospective study is to examine if body mass index and waist circumference (WC) are associated with incident mobility and activities of daily living (ADL) disability in nonagenarians. Methods We used longitudinal data from the Vitality 90+ Study, which is a population-based study conducted at the area of Tampere, Finland. Altogether 291 women and 134 men, aged 90–91 years, had measured data on body mass index and/or WC and did not have self-reported mobility or ADL disability at baseline. Incident mobility and ADL disability was followed-up on median 3.6 years (range 0.…

Leg extension power asymmetry and mobility limitation in healthy older women

Objective To investigate the association of asymmetry in leg extension power (LEP) with walking and standing balance. Design Cross-sectional analysis. Setting Research laboratory. Participants Healthy female twins (N=419), ages 63 to 75 years. Interventions Not applicable. Main Outcome Measures The LEP difference between the stronger and the weaker leg, measured with the Nottingham power rig, was calculated. Ten-meter maximal walking velocity was assessed in a laboratory corridor on a wide (170cm) and narrow (35cm) track, and the ability to maintain tandem stance for 20 seconds was recorded. Results The mean LEP difference ± standard deviation between the legs was 15%±9% (P<.001). Those wit…

A Polygenic Risk Score for Hand Grip Strength Predicts Muscle Strength and Proximal and Distal Functional Outcomes among Older Women

Purpose Hand grip strength (HGS) is a widely used indicator of overall muscle strength and general health. We computed a polygenic risk score (PRS) for HGS, and examined, whether it predicted muscle strength, functional capacity and disability outcomes. Methods Genome-wide association study summary statistics for HGS from the Pan-UK Biobank was utilized. PRSs were calculated in the Finnish Twin Study on Aging (N = 429 women, 63–76 years). Strength tests included HGS, isometric knee extension, and ankle plantar flexion strength. Functional capacity was examined with the Timed Up and Go, six-minute and 10-meter walk tests, and dual-task tests. Disabilities in the basic (ADL) and instrumental …

Body Mass Index and Waist Circumference as Predictors of Disability in Nonagenarians: The Vitality 90+ Study.

Background Only scarce data exist on the association between obesity and disability in the oldest old. The purpose of this prospective study is to examine if body mass index and waist circumference (WC) are associated with incident mobility and activities of daily living (ADL) disability in nonagenarians. Methods We used longitudinal data from the Vitality 90+ Study, which is a population-based study conducted at the area of Tampere, Finland. Altogether 291 women and 134 men, aged 90-91 years, had measured data on body mass index and/or WC and did not have self-reported mobility or ADL disability at baseline. Incident mobility and ADL disability was followed-up on median 3.6 years (range 0.…