Genetic Regulation of Physical Fitness in Children: A Twin Study of 15 Tests from Eurofit and Fitnessgram Test Batteries.

PURPOSE: To analyze the shared genetic background of physical fitness tests in children. METHODS: Physical fitness was assessed in 198 Portuguese twin pairs (6-18 years old, 40% monozygotic) through 15 tests from the Eurofit and Fitnessgram test batteries. Genetic twin modeling was used to estimate the heritability of each test and the genetic correlations between them. RESULTS: Girls performed better than boys in flexibility, while boys performed better than girls in cardiorespiratory endurance and muscular strength. No sex differences were found in the influence of genetic factors on the physical fitness tests or their mutual correlations. Genetic factors explained 52% (standing long jump) to 79% (sit and reach) of the individual variation in motor performance, whereas individual-specific environmental factors explained the remaining variation. Most of the tests showed modest to moderate genetic correlations. Out of all 105 genetic correlations, 65% ranged from 0.2 to 0.6 indicating that they shared from 4% to 36% of genetic variation. The correlations between individual-specific environmental factors were mostly negligible. CONCLUSIONS: Tests measuring the strength of different muscle groups showed only modest correlations, but moderate correlations were found between tests measuring explosive strength, running speed/agility, and cardiorespiratory endurance. Genetic factors explained a major portion of the variation in tests included in the Eurofit and Fitnessgram test batteries and explained the correlations between them. The modest to moderate genetic correlations indicated that there is little redundancy of tests in either Eurofit or Fitnessgram test batteries.

Body size and three estimates of skeletal age: Relationships with strength and motor performance among male soccer players 9-12 and 13-16 years.

OBJECTIVE: To estimate the associations between height, weight, and three estimates of skeletal age (SA) and the strength and motor performance of male soccer players in two chronological age (CA) groups, 9-12 (n = 60) and 13-16 (n = 52) years. METHODS: Height, weight, strength (grip), speed (5 m, 20 m sprints), acceleration (time at crossing 10 m in 20 m sprint), agility (figure-of-eight run), power (vertical jump), and endurance (intermittent shuttle run) were measured. SA was assessed with the TW2 RUS, TW3 RUS, and Fels methods; each SA was expressed as the standardized residual of the regression of SA on CA (SAsr). Hierarchical multiple regression was used. RESULTS: Body size accounted for ≥50% of the variance in grip strength in both CA groups; the body size × SAsr for each method and SAsr alone added little to the explained variance. Body size, body size × SAsr interactions, and SAsr per se with each method accounted for small percentages of variance in motor tasks among players 9-12 years, while body size explained a larger proportion of variance in motor tasks (except the endurance run) among players 13-16 years; body size × SAsr interactions for TW2 and TW3 more so than Fels added to the explained variances. For the endurance run, only SAsr per se with each method accounted for significant portions of the variance. CONCLUSION: Body size and the three estimates of SA significantly influenced strength and motor performance, but the explained variance varied between CA groups and among SA methods and performance tasks.

Influence of body size and skeletal maturity status on strength and motor performances of soccer players 9-16 years.

The contributions of height, weight and skeletal age (SA) to strength and motor performances of male soccer players 9-12 (n = 60) and 13-16 (n = 52) years were estimated. SA was assessed with the Fels method, and was expressed as the standardized residual of the regression of SA on chronological age CA (SAsr). Static strength (right + left grip), speed (5 m, 20 m sprints), acceleration (10 to 20 m), agility (figure-of-eight run), explosive strength (vertical jump) and endurance (yo-yo intermittent shuttle run, 13-16 years only) were measured. Hierarchical multiple regression was used. The interaction of SAsr with body size (height and height x weight interaction) explained most of the variance in strength in both age groups, 9-12 years (51.6%) and 13-16 years (56.7%), and in speed (31.4%, 38.7%), acceleration (39.6%), and explosive strength (32.6%) among players 13-16 years. In contrast, SAsr alone explained limited amounts of variance in strength, speed, acceleration and vertical jump among players 9-12 years (1.4-4.5%) and 13-16 years (0-0.5%). Results for agility varied with CA group, while SAsr per se was the primary contributor to endurance among players 13-16 years (18.5% of the variance). Although the influence of body size and skeletal maturity status on performances was significant, the explained variance differed among tasks and between CA groups, and suggested a role for other factors affecting performances of the soccer players.

Interrelationships among skeletal age, growth status and motor performances in female athletes 10-15 years.

BACKGROUND: Motor performances of youth are related to growth and maturity status, among other factors. AIM: To estimate the contribution of skeletal maturity status per se to the motor performances of female athletes aged 10-15 years and the mediation effects of growth status on the relationships. SUBJECTS AND METHODS: Skeletal age (TW3 RUS SA), body size, proportions, estimated fat-free mass (FFM), motor performances, training history and participation motivation were assessed in 80 non-skeletally mature female participants in several sports. Hierarchical and regression-based statistical mediation analyses were used. RESULTS: SA per se explained a maximum of 1.8% and 5.8% of the variance in motor performances of athletes aged 10-12 and 13-15 years, respectively, over and above that explained by covariates. Body size, proportions, and hours per week of training and participation motivation explained, respectively, a maximum of 40.7%, 18.8%, and 22.6% of the variance in performances. Mediation analysis indicated specific indirect effects of SA through stature and body mass, alone or in conjunction with FFM on performances. CONCLUSION: SA per se accounted for small and non-significant amounts of variance in several motor performances of female youth athletes; rather, SA influenced performances indirectly through effects on stature, body mass and estimated FFM.

Pneumocephalus Secondary to Cerebral Air Embolism After Acute Bleeding in an Emphysema Bulla.

Pneumocephalus is the presence of air in the intracranial space and has multiple causes, including cerebral air embolism. Its presentation may range from asymptomatic to decrease mental status, coma, and seizures. We present a case of cerebral air embolism secondary to acute bleeding inside an emphysema bulla. A 69-year-old female was brought to the emergency room after suffering acute dyspnea, convulsions, and cardiac arrest during a commercial flight. The Head CT showed the presence of multiple small gas collections in the brain, and the Thoracic Angiotomography showed a thin-walled bulla surrounded with pulmonary venous vascular structures and signs of active bleeding. The patient had rapid neurological deterioration with evolution to brain death due to anoxic encephalopathy before the possibility of treatment with pulmonary lobectomy and hyperbaric oxygen therapy. It is important to identify the localization of pneumocephalus to determine its etiology and to deliver the best treatment. Cerebral air embolism may happen when air enters the arterial or venous system, which can cause brain damage due to capillary leak syndrome and local ischemia. Treatment of pneumocephalus includes treating the cause, bed rest, avoidance of Valsalva maneuvers, positive pressure, and hyperbaric oxygen therapy. Early recognition is essential to prevent complications such as irreversible brain lesions and to improve patient outcomes.

Genetic regulation of body size and morphology in children: a twin study of 22 anthropometric traits.

BACKGROUND: Anthropometric measures show high heritability, and genetic correlations have been found between obesity-related traits. However, we lack a comprehensive analysis of the genetic background of human body morphology using detailed anthropometric measures. METHODS: Height, weight, 7 skinfold thicknesses, 7 body circumferences and 4 body diameters (skeletal breaths) were measured in 214 pairs of twin children aged 3-18 years (87 monozygotic pairs) in the Autonomous Region of Madeira, Portugal. Factor analysis (Varimax rotation) was used to analyze the underlying structure of body physique. Genetic twin modeling was used to estimate genetic and environmental contributions to the variation and co-variation of the anthropometric traits. RESULTS: Together, two factors explained 80% of the variation of all 22 anthropometric traits in boys and 73% in girls. Obesity measures (body mass index, skinfold thickness measures, as well as waist and hip circumferences) and limb circumferences loaded most strongly on the first factor, whereas height and body diameters loaded especially on the second factor. These factors as well as all anthropometric measures showed high heritability (80% or more for most of the traits), whereas the rest of the variation was explained by environmental factors not shared by co-twins. Obesity measures showed high genetic correlations (0.75-0.98). Height showed the highest genetic correlations with body diameter measures (0.58-0.76). Correlations between environmental factors not shared by co-twins were weaker than the genetic correlations but still substantial. The correlation patterns were roughly similar in boys and girls. CONCLUSIONS: Our results show high genetic correlations underlying the human body physique, suggesting that there are sets of genes widely affecting anthropometric traits. Better knowledge of these genetic variants can help to understand the development of obesity and other features of the human physique.

Sex Differences in Falls: The Mediating Role of Gait Stability Ratio and Body Balance in Vulnerable Older Adults.

This study, conducted on a large sample of older adults at elevated fall risk (1), aimed to verify statistical differences in gait stability ratio (GSR) and body balance (BB) according to sex, (2) to examine and compare GSR and BB performance between older adult fallers and non-fallers, (3) to determine an association between GSR and BB according to the history of falls, and (4) to explore whether GSR and BB mediate the association between sex and falls. We included 619 individuals (69.8 ± 5.6 years) living in the Autonomous Region of Madeira, Portugal. The frequency of falls was obtained by self-report. BB was determined by the Fullerton Advanced Balance scale, while GSR was established by dividing cadence by gait speed and data collected during the 50-foot walk test. Males indicated a lower prevalence of falls in the last 12 months (23.6%), while females had a higher score (48.7%), as well as a lower balance performance (p < 0.001) and higher GSR scores (p < 0.001). Lower BB control (p < 0.001), as well as higher GSR, were more expressive for fallers (p < 0.001). We found a large, negative and significant correlation between GSR and BB for historical falls (r = −0.560; p < 0.001), and between male and female cohorts (r = −0.507; p < 0.001). The total effect of sex on falls mediated by GSR and BB was 16.4%. Consequently, GSR and BB mediated this association by approximately 74.0% and 22.5%, respectively.

Exploring Mediation Effects of Gait Speed, Body Balance, and Falls in the Relationship between Physical Activity and Health-Related Quality of Life in Vulnerable Older Adults.

The present study aimed to examine whether gait speed (GS), body balance (BB), and falls mediated the relationship between physical activity (PA) and health-related quality of life (HRQoL) in community-dwelling older adults. This is a cross-sectional study that included 305 men and 314 women (69.5 ± 5.6 years), residing in the Autonomous Region of Madeira, Portugal. HRQoL and PA were assessed using the SF-36 and Baecke Questionnaires, respectively. While BB was obtained by the Fullerton Advance Balance (FAB) scale, GS by the 50-foot (15 m) walk test, and the frequency of falls was obtained by self-report. According to the analyses, when GS and BB were placed concomitantly as mediators, the direct effect revealed by the model revealed a non-significant relationship between PA and falls. Thus, in the context of falls, GS and BB partially mediated the association between PA and HRQoL in approximately 29.7%, 56%, and 49.2%, respectively. The total HRQoL model explained a variance of 36.4%. The results can help to understand the role that GS, BB, and falls play in the relationship between PA and HRQoL of the vulnerable older adult population.

Regional variation in growth status. The Peruvian health and optimist growth study.

OBJECTIVE: This study aims to (1) investigate differences in weight, body mass index (BMI), and waist circumference (WC) among Peruvian children and adolescents living in three areas located at different altitudes; (2) compare age- and sex-specific height, weight, and BMI within each site with US reference data. METHODS: We sampled 8753 subjects (4130 boys), aged 4 to 17 years from sea level, rainforest, and high-altitude. Height, weight, and WC were measured and BMI was calculated. Analysis of variance was used to compare variables across geographic regions, and the Hoff and Blackburn procedure was used to compare the Peruvian results with US reference data. RESULTS: Participants living at sea level were taller, heavier, had greater BMI and WC relative to those living at high-altitude and in the rainforest. Peruvian schoolchildren of both sexes from the three geographical areas were shorter and lighter than their American peers. Boys and girls living in the rainforest and at high-altitude had lower BMI, whereas WC values of American schoolchildren are higher than those of the Peruvian children by age and gender. CONCLUSIONS: Peruvians living at different altitudes differ in their growth indicators (height, weight, BMI, and WC), with significant differences between those living at sea level relative to their peers from other regions. Further, Peruvian schoolchildren of both sexes from the three geographical areas significantly differ from their US counterparts.

Physical fitness spurts in pre-adolescent boys and girls: Timing, intensity and sequencing.

We aim to (1) estimate age of attainment of the peak mid-growth spurt in stature (age-at-peak MGS) in pre-adolescent boys and girls; (2) identify the timing, intensity, and sequences of physical fitness (PF) spurts aligned by the age-at-peak MGS; and (3) identify any sex differences in PF spurts aligned by age-at-peak MGS. The sample included 180 Portuguese children (90 girls) aged 6 to 10 years at study entry who were followed annually for 4 years. Height, health-, and performance-related PF were assessed. Age-at-peak MGS and PF spurts were estimated using a non-smooth mathematical procedure. Boys' and girls' age-at-peak MGS occurred at 7.8 ± 0.47 years and 8.0 ± 0.72 years, respectively. PF spurts' timing aligned by age-at-peak MGS were as follows: (1) before age-at-peak MGS: boys - static strength, aerobic capacity, explosive leg strength, and flexibility; girls - speed, agility, aerobic capacity, and upper body strength; (2) coincident with age-at-peak MGS: girls - explosive leg strength and flexibility; (3) after age-at-peak MGS: boys - abdominal strength, upper body strength, agility, and speed; girls - abdominal strength and static strength. Boys and girls attained their MGS at relatively similar ages. However, the timing and sequences of PF spurts, aligned on age-at-MGS, were different between boys and girls.

Physical fitness spurts in childhood: A study in boys.

This study aimed to (1) estimate age-at-mid-growth spurt (age-at-MGS) in Portuguese boys from two different regions-the Azores islands and Viana do Castelo, and (2) identify spurts in a variety of physical fitness (PF) components aligned by age-at-MGS in the two samples. A total of 176 (Azores, n = 91; Viana do Castelo, n = 85) boys aged 6 years old were followed annually to 10 years of age. Age-at-MGS and spurts in PF components (speed, explosive muscular strength, abdominal muscular strength, agility, and flexibility) were identified for each sample. The timing and intensities of the spurts were estimated using a non-smooth mathematical procedure. In Azorean boys, age-at-MGS occurred at 7.8 years (6.99 cm y-1 ), whereas in Viana do Castelo it occurred at 7.9 years (6.20 cm y-1 ). Spurt in speed was attained 12 months after the MGS in both samples (0.53 and 0.35 cm y-1 in Azores and Viana do Castelo, respectively), whereas spurts in explosive muscular strength and flexibility occurred 12 months before the MGS and at the MGS (Azores: 21.59 and 5.52 cm y-1 and Viana do Castelo: 14.12 and 2.5 cm y-1 , respectively). Agility and abdominal muscular strength peaked between 0 and 12 months after the MGS (Viana do Castelo: 0.37 m s-1  y-1 and 6.71 reps y-1 and Azores: 0.28 m s-1  y-1 and 19.36 reps y-1 , respectively). Results indicate that developmental spurts in explosive strength and flexibility occur before, or are coincident with, the mid-growth spurt in height, whereas spurts in speed, agility, and abdominal muscular strength occur after, or coincident with, the mid-growth spurt in height.

Genetics of somatotype and physical fitness in children and adolescents.

OBJECTIVES: To analyze the influence of genetic and environmental factors on the variation in somatotype, physical fitness, and their mutual associations. METHODS: Twins from 214 pairs (87 monozygotic) of the Autonomous Region of Madeira, Portugal, from 3 to 18 years of age (51% girls) were assessed in anthropometry and physical fitness tests. We estimated endomorphy, mesomorphy, and ectomorphy based on anthropometric measures and physical fitness using the Eurofit test battery. Two age categories were analyzed: children (3-11 years) and adolescents (12-18 years). Genetic and environmental variations were estimated using quantitative genetic twin modeling. RESULTS: No genetic sex differences were found, thus boys and girls were pooled in all genetic analyses. Heritability estimates were high for somatotype (a2  = 0.80-0.93), physical fitness traits (a2  = 0.67-0.83), and largely similar in children and adolescents. Positive correlations were found for ectomorphy with motor ability and cardiorespiratory endurance as well as for endomorphy and mesomorphy with muscular strength (r = 0.25-0.37). In contrast, negative associations were found for ectomorphy with muscular strength, as well as for endomorphy and mesomorphy with motor ability and cardiorespiratory endurance (-0.46 to -0.26). Twin modeling indicated that these associations were explained mostly by genetic factors in common to the two associated traits (84% or more). CONCLUSIONS: Associations between somatotype and physical fitness tests are mainly explained by common genetic background in children and adolescents. Therefore, interventions in youth should consider that a child's performance in physical fitness tests partly reflects their inherited physique.

Patterns of physical performance spurts during adolescence: a cross-cultural study of Canadian, Brazilian and Portuguese boys.

BACKGROUND: Data relating physical performance to the timing of the adolescent growth spurt are limited. Aim: This study identifies: (i) age-at-peak height velocity (APHV), (ii) physical performance spurt patterns aligned to APHV; and (iii) cross-cultural and time patterns in Canadian, Brazilian and Portuguese boys. Subjects and methods: A total of 512 boys (131 Canadian, 250 Portuguese and 131 Brazilian), 8-17 years of age were followed serially using longitudinal data. APHV was identified and five physical performance measures velocities [trunk extension (TE), trunk flexion (TF), standing long jump (SLJ), curl-ups (CU) and handgrip strength (HG)] were aligned at 6-month intervals, 4 years around the attainment of PHV. Velocities were estimated using a non-smooth mathematical procedure. Results: APHV was 13.9 ± 1.0, 13.4 ± 1.6 and 13.0 ± 0.8 years for Canadian, Brazilian and Portuguese boys, respectively. Maximal velocity in SLJ was attained between 12 and 6 months prior to PHV. For HG, peaks were attained 12-24 months after PHV. Maximal velocity in TE occurred between 12 and 0 months prior to PHV, while CU peaked between PHV and 6 months after PHV. Conclusion: Patterns of spurts in physical performance have remained relatively the same and do not appear to be influenced by cross-cultural differences.

Genetic and environmental influences on human height from infancy through adulthood at different levels of parental education.

Genetic factors explain a major proportion of human height variation, but differences in mean stature have also been found between socio-economic categories suggesting a possible effect of environment. By utilizing a classical twin design which allows decomposing the variation of height into genetic and environmental components, we tested the hypothesis that environmental variation in height is greater in offspring of lower educated parents. Twin data from 29 cohorts including 65,978 complete twin pairs with information on height at ages 1 to 69 years and on parental education were pooled allowing the analyses at different ages and in three geographic-cultural regions (Europe, North America and Australia, and East Asia). Parental education mostly showed a positive association with offspring height, with significant associations in mid-childhood and from adolescence onwards. In variance decomposition modeling, the genetic and environmental variance components of height did not show a consistent relation to parental education. A random-effects meta-regression analysis of the aggregate-level data showed a trend towards greater shared environmental variation of height in low parental education families. In conclusion, in our very large dataset from twin cohorts around the globe, these results provide only weak evidence for the study hypothesis.

Muscle Mass and Muscle Strength Relationships to Balance: The Role of Age and Physical Activity.

OBJECTIVE: To investigate the relations of balance to muscle mass (MM) and muscle strength (MS), depending on age and physical activity, which is of particular importance to functional independence in older people. METHODS: This cross-sectional study included 802 volunteers (69.82 ± 5.60 years). The Fullerton Advanced Balance scale was used to assess balance and a composite score, including arm curl and chair stand tests for assessing MS. MM was estimated by dual-energy X-ray absorptiometry and physical activity by questionnaire. RESULTS: Greater MM (r = .26, p < .001) and MS (r = .53, p < .001) were positively correlated to balance. The old-old adults and less active individuals attained lower balance. Notably, moderation and subsequent simple slope analyses revealed that the relations of balance, MM, and MS were larger in less active and the old-old adults. CONCLUSIONS: The old-old and less active adults were more prone to muscle weakness and balance impairments. Tailored interventions should particularly consider these vulnerable groups.

Development of Physical Performance Tasks during Rapid Growth in Brazilian Children: The Cariri Healthy Growth Study.

Growth and physical performance scores were studied around three years of attainment of peak height velocity (PHV). We aimed to estimate the age at peak velocity, or at peak rate, in physical performance tasks, and sex-differences when aligned by biological age. A total of 131 boys and 123 girls, 8 to 14 years of age were recruited from the Cariri region of Brazil. A mixed longitudinal design was used with four overlapping age cohorts: 8, 10, 12, and 14 years, followed for three years, with measurements performed at 6 month intervals. Height, 12 min run (12mR), handgrip strength (HG), standing long jump (SLJ), and shuttle run (SR) velocities were estimated using a non-smooth mathematical procedure. Age at PHV was 13.4 ± 1.6 years in boys compared with 12.2 ± 2.3 years in girls. Maximal velocity in SLJ was attained 6 and 3 months prior to PHV in boys and girls, respectively. For HG, peaks were attained 9 months after PHV in boys and 15 months after PHV in girls. Maximal velocity in 12mR was attained 6 months before PHV in boys and at PHV in girls, whereas a peak in SR occurred 12 months after PHV in both sexes. In conclusion, dynamic changes in physical performance relative to PHV appear similar in both sexes, although sex differences were evident in some motor tests.

Growth velocity curves and pubertal spurt parameters of Peruvian children and adolescents living at different altitudes. The Peruvian health and optimist growth study.

OBJETIVE: To estimate the growth parameters of Peruvian children and adolescents living at different altitudes. METHODS: The sample comprised 10 795 Peruvian children and adolescents (5781 girls, aged 6-7 years) from sea level, the Amazon region, and high altitude. Height was measured with standardized techniques. Mathematical and biological growth parameters were estimated using the Preece-Baines growth model I. RESULTS: Sea-level children and adolescents experienced peak height velocity (PHV) at an earlier age (girls, 8.56 ± 2.37 years; boys, 12.03 ± 0.58 years) were taller at the time of PHV (girls, 144.1 ± 1.9 cm; boys, 154.3 ± 1.4 cm), had higher PHV (girls, 6.23 ± 3.87 cm/year; boys, 7.52 ± 2.31 cm/year), and had a taller estimated final height (girls, 154.2 ± 0.3 cm; boys, 166.3 ± 1.0 cm) compared to those living at high altitude (girls, 152.7 ± 0.7 cm; boys, 162.8 ± 0.8 cm) or in the Amazon region (152.1 ± 0.4 cm; boys, 162.2 ± 0.6 cm). Across all geographical areas, PHV occurred approximately 2 years earlier in girls (9.68 ± 0.99 years) than in boys (12.61 ± 0.42 years), their estimated PHV was 5.88 ± 1.92 cm/year vs 6.45 ± 1.09 cm/year, their size at PHV was 142.2 ± 1.4 cm vs 152.8 ± 0.7 cm, and their final adult height was estimated to be 153.1 ± 0.3 cm vs 164.2 ± 0.7 cm. CONCLUSIONS: Peruvian children and adolescents' physical growth timing and tempo were influenced by their living altitudes. Those living at sea level experienced an earlier age at PHV were taller at time of PHV, had a higher PHV, and had a taller estimated final height compared to those living at higher altitudes. Girls and boys also differed significantly in their growth parameters.

Are there gross motor coordination spurts during mid-childhood?

OBJECTIVES: The aims of this study were (1) to identify the timing of the mid-growth spurt (MGS) in stature in children and (2) to identify gross motor coordination (GMC) spurts when aligned by the age of attainment of the MGS (aMGS). METHODS: Stature, weight, and GMC were measured in 245 Portuguese children followed annually from 6 to 10 years. GMC was assessed and to estimate children's MGS in stature as well as GMC spurts in each of the four tests aligned by aMGS, we used a nonsmoothed polynomial methodology. RESULTS: In boys, the aMGS was attained at 7.8 years, whereas in girls it was 8.0 years. In boys, the peak MGS was 6.2 cm∙yr-1 and in girls it was 6.4 cm∙yr-1 . In boys, the peak for walking backwards (WB) occurred 18 months before aMGS (14.9-points∙yr-1 ), jumping sideways (JS) was 12 months after aMGS (13.5-points∙yr-1 ), hopping on one leg (HO) was 18 months before aMGS (11.7-points∙yr-1 ), and shifting platform (SP) was 12 months before aMGS (6.8-points∙yr-1 ). In girls, WB spurts occurred 12 months after aMGS (13.3-points∙yr-1 ), JS was 12 months before aMGS (10.5-points∙yr-1 ), HO was coincident with aMGS (10.4-points∙yr-1 ), and SP was 18 as well as 12 months before aMGS (7.2-points∙yr-1 ). No differences were observed in the mean peak spurts between sexes in the GMC tests. CONCLUSIONS: Boys and girls reached their MGS in stature at about the same chronological age. Spurts in GMC did not express themselves in the same biological timing relative to aMGS in stature, and there are sex differences.

Parental Education and Genetics of BMI from Infancy to Old Age: A Pooled Analysis of 29 Twin Cohorts.

OBJECTIVE: The objective of this study was to analyze how parental education modifies the genetic and environmental variances of BMI from infancy to old age in three geographic-cultural regions. METHODS: A pooled sample of 29 cohorts including 143,499 twin individuals with information on parental education and BMI from age 1 to 79 years (299,201 BMI measures) was analyzed by genetic twin modeling. RESULTS: Until 4 years of age, parental education was not consistently associated with BMI. Thereafter, higher parental education level was associated with lower BMI in males and females. Total and additive genetic variances of BMI were smaller in the offspring of highly educated parents than in those whose parents had low education levels. Especially in North American and Australian children, environmental factors shared by co-twins also contributed to the higher BMI variation in the low education level category. In Europe and East Asia, the associations of parental education with mean BMI and BMI variance were weaker than in North America and Australia. CONCLUSIONS: Lower parental education level is associated with higher mean BMI and larger genetic variance of BMI after early childhood, especially in the obesogenic macro-environment. The interplay among genetic predisposition, childhood social environment, and macro-social context is important for socioeconomic differences in BMI.

Balance and mobility relationships in older adults: A representative population-based cross-sectional study in Madeira, Portugal.

BACKGROUND: Balance and mobility impairments are important modifiable risk factors associated with falls in older people. PURPOSE: To investigate how different functional fitness components relate to balance and mobility, after controlling for age, sex, body mass index (BMI), and different physical activity (PA) domains. METHODS: This representative cross-sectional study included 802 individuals, 401 males and 401 females (69.8 ± 5.6 years) from Madeira, Portugal. The Fullerton Advance Balance (FAB) scale was used to assess balance. Mobility in terms of gait velocity, cadence, stride length, and gait stability ratio (GSR) were assessed using the 50-foot Walk test. PA was assessed through a face-to-face interview using the Baecke questionnaire, and functional fitness was assessed with Senior Fitness tests (strength, flexibility, and aerobic endurance). RESULTS: Balance and mobility were negatively associated with age and BMI, and positively related to PA and functional fitness. Moreover, male presented better performance in balance and mobility. Hierarchical multiple regression analyses showed that functional fitness explained the highest amount of variance in balance and all mobility parameters (over and above age, sex, BMI, and PA). Specifically, entering functional fitness components significantly increased explained variance in FAB (+19%), gait velocity (+25%), cadence (+15%), stride length (+9%), and GSR (+ 31%). In these models, aerobic endurance consistently had the strongest contribution. CONCLUSION: Strength, flexibility, and especially aerobic endurance, over and above non-modifiable variables like age and sex, are crucial for maintaining or improving balance and mobility and, thereby, prevent falls in older people.