Smoking behaviour and biological maturation in males and females: a 20-year longitudinal study. Analysis of data from the Amsterdam Growth and Health Longitudinal Study

Primary objective : (1) Describe the longitudinal smoking behaviour of boys and girls during adolescence in relation to calendar age, skeletal age, years from peak height velocity (PHV) and years from menarche (in girls). (2) and (3) Investigate the timing of biological maturation (early or late maturation) in relation to smoking behaviour in adolescence and in adulthood (i.e. calendar age 32/33). Hypothesis : We hypothesized skeletal age, years from PHV and years from menarche to be better predictors of smoking than calendar age. Research design : This study is part of the Amsterdam Growth and Health Longitudinal Study (AGAHLS) that was started in 1977 with 619 pupils from two secondary schools (mean age 13.0 SD 0.6). Methods and procedures : Smoking behaviour was assessed four times between 1977 and 1980 and once in 1996/1997. Calendar age and skeletal age were measured annually whereas height and menarche were measured every 4 months. Maturation rate (skeletal age minus calendar age), age at PHV and age at menarche were used to estimate timing of biological maturation. Generalized Estimating Equation (GEE) analysis was used to study maturation rate in relation to smoking during adolescence, whereas logistic regression analyses were used to study mean maturation rate, years from PHV and years from menarche in relation to smoking in adulthood. Outcomes and results : Skeletal age, years from PHV and years from menarche are no better predictors of smoking during adolescence than calendar age. The prevalence of smoking rises gradually with the increase in all four estimates of biological maturation. Timing of biological maturation was positively related to smoking but only at calendar age 13 (OR 3.34, CI 1.58, 7.07). None of the three measures to estimate timing of biological maturation was significantly related to smoking status in adulthood.     

The longitudinal development of running economy in males and females aged between 13 and 27 years: The Amsterdam Growth and Health Study

The purpose of this study was to describe the longitudinal development of running economy [defined as the oxygen uptake (V˙O₂) at a submaximal running speed] in males and females from teenage to young adult age using data from the Amsterdam Growth and Health Study. Submaximal V˙O₂ (in ml · kg^?1· min^?1) was measured in 84 males and 98 females while they ran on a treadmill at a constant speed of 8 km · h^?1 for 6 min at three different treadmill slopes (0%, 2.5% and 5%). This test was carried out six times, on the same subjects at the ages of 13, 14, 15, 16, 21, and 27 years. The longitudinal development of running economy in males and females was analysed using a two-way analysis of variance for repeated measurements. At all three slopes, a significant decrease in V˙O₂ with increasing age was found for both males and females, implying a significant increase in running economy for both sexes. Males showed significantly higher V˙O₂ values than females at all ages measured and for all three slopes, suggesting that females have a significantly higher running economy than males. In order to make a better comparison of the V˙O₂ of individuals of different sizes, allometric models were used; power function ratios were constructed in which body mass was expressed to an exponential power. Following this analysis the difference in submaximal V˙O₂ and running economy between males and females appeared even larger.     

Cigarette smoking and suicidal behaviour: results from a 25-year longitudinal study

BACKGROUND: This study examined the associations between cigarette smoking and suicidal ideation and suicide attempts, both before and after control for potentially confounding using fixed effects regression models. METHOD: Data were gathered during the Christchurch Health and Development Study, a 25-year longitudinal study of a birth cohort of New Zealand children (635 males, 630 females). The analysis was based on a sample of 1041 participants with available data on cigarette smoking and suicidal behaviour from ages 16 to 25 years. The main outcome measures were suicidal ideation and suicide attempts, ages 16-18, 18-21, and 21-25. RESULTS: There were significant bivariate associations between the frequency of cigarette smoking and both suicidal ideation and suicide attempts. Cohort members who smoked 20 or more cigarettes per day had odds of suicidal ideation that were 3.39 times (95% CI 2.06-5.59) those of non-smokers, and odds of suicide attempt that were 4.39 (95% CI 2.18-8.85) times those of non-smokers. Control for non-observed fixed confounding factors reduced the association between cigarette smoking and suicidal ideation and suicide attempts to statistical non-significance. After adjustment, those smoking more than 20 cigarettes per day had odds of suicidal ideation that were 1.00 times (95% CI 0.46-2.18) those of non-smokers, and odds of suicide attempt that were 1.84 (95% CI 0.81-4.18) times those of non-smokers. CONCLUSIONS: The findings suggest that the associations between frequency of cigarette smoking and suicidal behaviour may largely be explained by the non-observed background factors and life circumstances that are associated with both cigarette smoking and suicidal behaviour.     

Sleep quality and duration are related to microvascular function: the Amsterdam Growth and Health Longitudinal Study

Sleep and sleep disorders are related to cardiovascular disease, and microvascular function is an early cardiovascular disease marker. Therefore, the relationship of sleep (measured in sleep quality and duration) with microvascular function was examined in healthy adults. Sleep quality was assessed with the validated Sleep Wake Experience List (SWEL) questionnaire. Duration of sleep was self‐reported in an additional question. Microvascular function was measured using nailfold capillaroscopy. Linear regression analyses were used to examine the relationship between sleep and microvascular function. Potential confounders included physical activity, smoking, blood pressure, body mass index and several biochemical parameters. Analyses were performed in 259 participants (116 men). For women reporting insufficient (<7 h) sleep duration, microvascular function (post‐ischaemic capillary recruitment) was significantly lower (b = ?11.17; P = 0.04) compared to women reporting sufficient sleep duration. There was no relationship between sleep quality and microvascular function in females. In males, a trend towards lower capillary recruitment was found in those reporting a combination of poor sleep quality and insufficient duration (b = ?7.54; P = 0.09), compared to those reporting good sleep quality as well as sufficient duration. This study suggests an association between sleep and microvascular function. Which aspects of sleep exactly affect microvascular function, and if indeed the association is different between males and females in other samples, needs further research.     

Emergence and persistence of late life depression: a 3-year follow-up of the Longitudinal Aging Study Amsterdam

BACKGROUND: The present study was designed to assess onset and persistence of late-life depression, systematically comparing the factors associated with prevalence, onset and prognosis. METHODS: The data were derived from a large (n=2200), random, age and sex stratified sample of the elderly (55-85 years) in The Netherlands. Using a 3-year, prospective longitudinal design, both the onset and the persistence of depression were assessed. Depression was measured using the Center for Epidemiologic Studies Depression Scale. Risk factors associated with prevalence, onset and persistence were compared using both bivariate and multivariate analyses. RESULTS: In those not depressed at index assessment, the onset of depression was 9.7%. Among those depressed at baseline, persistence occurred in 50.4%. Risk factors predicting onset were almost identical to those associated with prevalence. Persistence was predicted by very few factors (external locus of control and chronic physical illness). CONCLUSIONS: The data suggest that cross-sectional studies are biased due to their overrepresenting chronic depressive episodes. However, the risk factors derived from cross-sectional studies do seem to adequately reflect factors associated with onset. The prognosis is not adequately predicted by variables usually included in epidemiological studies of late life depression. It is speculated that including more biological correlates of depression and data concerning positive life-changes may improve our understanding of the prognosis of late life depression.     

The influence of dance training on growth and maturation of young females: a mixed longitudinal study

BACKGROUND: The effects of systematic sports training during childhood and adolescence on subsequent growth and sexual maturation remains in dispute. AIM: The study aimed to determine whether moderate-high volumes of dance training adversely influence linear growth and sexual maturation of young girls progressing through puberty. SUBJECTS AND METHODS: This 3-year mixed longitudinal study comprised 82 novice dancers and 61 controls, aged 8-11 years at baseline, who were assessed bi-annually for 3 consecutive years. A biological maturational age was determined by estimating attainment of age at peak height velocity (PHV). Body dimensions were measured by anthropometry, and exercise levels, nutritional intake and age at menarche by questionnaires. RESULTS: Controls had significantly greater unadjusted height velocity than dancers 1 year before PHV, however there was no difference between groups in age of attainment of PHV. When controlling for maturation, lean mass, fat mass and extracurricular sport (excluding dancing), there were no group differences in absolute growth or velocity of growth in height, sitting height or leg length. Within the dancers there were no effects of years of dancing (>6.5 years) or weekly dance hours (>7 h per week) on growth velocities. No association was found between age at menarche and years or hours of dance training. CONCLUSION: Results suggest that moderate-high levels of dance training do not affect linear growth and maturation. Thus, girls should not be discouraged from dance participation on the basis of potential growth delays.     

Posttraumatic intrusion, avoidance, and social functioning: a 20-year longitudinal study

The study assesses posttraumatic intrusion, avoidance, and social functioning among 214 Israeli combat veterans from the first Lebanon War with and without combat stress reaction (CSR) 1, 2, 3, and 20 years after the war. CSR veterans reported higher intrusion and avoidance than did non-CSR veterans. With time, there was a decline in these symptoms. In addition, intrusion and avoidance were associated with problems in social functioning on a given year, and they longitudinally predicted social dysfunction 2, 3, and 20 years after the war. CSR veterans presented stronger temporal covariations between intrusion-avoidance and social functioning. The findings suggest that CSR is a marker for future psychopathology and point to the role of avoidance in social dysfunction.     

A controlled study of longitudinal IQ changes in females and males with fragile X syndrome

The aim is this study is to compare the longitudinal changes in IQ scores of females and males with fragile X syndrome and controls and to assess the impact on IQ of molecular variations of the FMR-1 gene in males. Medical records from the child development unit at a university-affiliated children's hospital were retrospectively reviewed. Chart review yielded 35 males with fragile X (19 with a fully methylated full mutation, 9 with a mosaic pattern, and 7 with a partially unmethylated full mutation) 16 females with fragile X and a full mutation, 9 female controls, and 9 male controls who had repeated standardized IQ testing separated by 7 months to 13 years. The differences between the first and last IQ scores from the same IQ test were compared by t tests and subsequently by analysis of variance. Overall, a significant IQ decline was seen in 10/35 (28%) of fragile X males, 0/9 (0%) of control males, 6/16 (36%) of fragile X females, and 1/9 (11%) of control females. The initial t tests and analysis of variance showed a significant difference in IQ (p = 0.02) between fragile X males and control males but did not show a significant difference between males and females with fragile X syndrome or between fragile X and control females. When an analysis of covariance was carried out with the initial IQ as a covariable, a significant difference persisted between fragile X and control males, with a greater IQ decline in fragile X males. There were limitations in using the same IQ test. A comparison among the molecular subgroups of males yielded a significant IQ decline in 3/9 (33%) of mosaic males, 6/19 (32%) of fully methylated full mutation males, and 1/7 (14%) of partially methylated full mutation males. An analysis of covariance using the initial IQ and the intertest interval as covariables demonstrated significant differences between the fragile X molecular subgroups and the controls. Our findings show that a substantial percentage of both male and female fragile X patients and female control patients demonstrated significant IQ decline. There was a significant differences in the IQ change between fragile X and control males. There were no significant differences between fragile X and female controls. There were also significant differences in IQ decline among males with different molecular patterns compared with controls. Males with a mosaic pattern versus control males had the most significant decline of the molecular subtypes. Although the numbers were limited, there was no significant IQ decline in males with less than 50% methylation of the full mutation. This suggests that a small amount of FMR-1 protein production, which is often seen in males with less than 50% methylation, protects against significant IQ decline. © 1996 Wiley-Liss, Inc.     

The influence of dance training on growth and maturation of young females: A mixed longitudinal study

Background: The effects of systematic sports training during childhood and adolescence on subsequent growth and sexual maturation remains in dispute.

Aim: The study aimed to determine whether moderate–high volumes of dance training adversely influence linear growth and sexual maturation of young girls progressing through puberty.

Subjects and methods: This 3-year mixed longitudinal study comprised 82 novice dancers and 61 controls, aged 8–11 years at baseline, who were assessed bi-annually for 3 consecutive years. A biological maturational age was determined by estimating attainment of age at peak height velocity (PHV). Body dimensions were measured by anthropometry, and exercise levels, nutritional intake and age at menarche by questionnaires.

Results: Controls had significantly greater unadjusted height velocity than dancers 1 year before PHV, however there was no difference between groups in age of attainment of PHV. When controlling for maturation, lean mass, fat mass and extracurricular sport (excluding dancing), there were no group differences in absolute growth or velocity of growth in height, sitting height or leg length. Within the dancers there were no effects of years of dancing (>6.5 years) or weekly dance hours (>7?h per week) on growth velocities. No association was found between age at menarche and years or hours of dance training.

Conclusion: Results suggest that moderate–high levels of dance training do not affect linear growth and maturation. Thus, girls should not be discouraged from dance participation on the basis of potential growth delays.

Résumé. Arrière plan: On reste partagé sur les effets que l’entraînement sportif systématique pendant l’enfance et l’adolescence, peut avoir sur la croissance et sur la maturation sexuelle.

Objectif: L’étude cherche à savoir si l’entraînement moyen ou intensif à la danse, influence négativement la croissance linéaire et la maturation sexuelle des filles en cours de puberté.

Sujets et méthodes: Cette étude semi longitunale de trois ans impliquait 82 danseuses novices et 61 contrôles, âgées de 8 à 11 ans au départ, qui ont été examinées deux fois par an pendant trois années consécutives. Un âge de maturation biologique a été déterminé en estimant à quel âge survenait la croissance staturale de pic (CSP). Les dimensions corporelles ont été mesurées par anthropométrie et les niveaux d’activité physique, ainsi que l’alimentation et l’âge aux premières règles, ont été renseignés par questionnaires.

Résultats: Les contrôles présentent une croissance staturale non ajustée significativement plus élevée que celle des danseuses, un an avant la CSP, mais il n’y a cependant pas de différence d’âge d’atteinte de la CSP entre les groupes. A maturation, masse maigre, masse grasse et sport non programmé constants (à l’exclusion de la danse), il n’y a pas de différences entre les groupes, ni en croissance absolue, ni en vélocité de croissance staturale, taille assis ou longueur de la jambe. Parmi les danseuses, on n’observe aucun effet du nombre d’années de danse (>6,5 ans) ou du nombre d’heures de danse hebdomadaire (>7h par semaine) sur les vitesses de croissance. On n’a pas trouvé d’association entre le nombre d’heures d’entraînement à la danse et l’âge aux premières règles.

Conclusion: Les résultats suggèrent que des niveaux d’entraînement à la danse de modérés à élevés n’affectent pas la croissance linéaire ni la maturation. Les filles ne doivent donc pas être dissuadées de pratiquer la danse sur la crainte d’un retard de croissance potentiel.

Zusammenfassung. Hintergrund: Die Wirkung systematischen sportlichen Trainings während Kindheit und Adoleszenz auf das folgende Wachstum und die sexuelle Reifung wird noch kontrovers diskutiert.

Ziel: Das Ziel der Untersuchung war die Bestimmung, ob mäßig bis sehr intensives Tanztraining einen nachteiligen Einfluss auf das lineare Wachstum und die sexuelle Reifung junger Mädchen während ihrer pubertären Entwicklung hat.

Probanden und Methoden: Diese dreijährige, gemischt longitudinale Studie umfasste 82 neu anfangende Tänzerinnen und 61 Kontrollen, die zu Beginn der Studie 8 bis 11 Jahre alt waren und hernach in 6-montigen Abständen für 3 weitere Jahre untersucht wurden. Ein biologisches Reifealter wurde durch Schätzung des Alters zum Zeitpunkt der maximalen Wachstumsgeschwindigkeit (peak height velocity, PHV) bestimmt. Körpermaße wurden mittels Anthropometrie bestimmt, sowie sportliche Leistung, Ernährung und Menarchealter mittels Fragebogen.

Ergebnisse: Unkorrigiert hatten Kontrollen eine signifikant größere Wachstumsgeschwindigkeit als Tänzerinnen ein Jahr vor PHV, allerdings gab es keinen Unterschied zwischen den Gruppen hinsichtlich des Alters bei Erreichen der PHV. Wenn für Reifestatus, fettfreie Körpermasse, Fettmasse und zusätzliche sportliche Aktivität (neben dem Tanzen) korrigiert wurde, gab es keine Gruppenunterschiede mehr hinsichtlich der absoluten Zunahme oder der Wachstumsgeschwindigkeit von Körperhöhe, Sitzhöhe oder Beinlänge. Unter den Tänzerinnen gab es keine Unterschiede hinsichtlich der Anzahl der Tanzjahre (>6,5?Jahre) oder der wöchentlichen Tanzstunden (>7?h?pro Woche) auf die Wachstumsgeschwindigkeit. Es wurden keine Beziehungen zwischen Menarchealter und der Anzahl der Tanzjahre oder der wöchentlichen Tanztrainingsstunden gefunden.

Zusammenfassung: Die Ergebnisse sprechen dafür, dass ein mäßig bis sehr intensives Tanztraining keinen Einfluss auf lineares Wachstum und körperliche Reifung hat. Aus diesem Grunde sollten Mädchen nicht von der Teilnahme am Tanzen abgeschreckt werden, nur weil eine mögliche Beeinträchtigung des Wachstums befürchtet wird.

Resumen. Antecedentes: Los efectos del entrenamiento deportivo sistemático durante la infancia y adolescencia sobre el crecimiento y la maduración sexual siguen siendo objeto de debate.

Objetivo: El estudio intenta determinar si los niveles moderados y/o altos de entrenamiento en danza influyen adversamente sobre el crecimiento lineal y la maduración sexual de las chicas jóvenes que están progresando hacia la pubertad.

Sujetos y métodos: Este estudio semi-longitudinal de 3 años de duración incluía a 82 bailarinas principiantes y 61 controles, de entre 8 y 11 años de edad como punto de comparación, que fueron estudiadas bianualmente durante tres años consecutivos. La edad biológica de maduración se determinó estimando la edad a la que se alcanzaba el pico de velocidad en el crecimiento estatural (PHV). Las dimensiones corporales fueron medidas por antropometría, y los niveles de ejercicio, la ingesta nutricional y la edad de menarquia mediante cuestionarios.

Resultados: Las chicas control tenían velocidades estaturales no ajustadas significativamente mayores que las bailarinas 1 año antes del PHV, aunque no había diferencias significativas entre los grupos en cuanto a la edad a la que se alcanzaba el PHV. Cuando se controlaba para la maduración, la masa magra, la masa grasa y el deporte extra-curricular (excluyendo la danza), no había diferencias entre los grupos en el crecimiento absoluto o en la velocidad de crecimiento en estatura, talla sentado o longitud de la pierna. Entre las bailarinas, no había efectos debidos a los años que llevaban bailando (> 6,5 años) o las horas de baile semanales (> 7 horas/semana ) sobre las velocidades de crecimiento. No se encontró ninguna asociación entre la edad de menarquia y los años u horas de entrenamiento en danza.

Conclusión: Los resultados sugieren que los niveles moderados y/o altos de entrenamiento en danza no afectan ni al crecimiento lineal ni a la maduración. Por tanto, las chicas no deberían renunciar a practicar danza basándose en supuestos retrasos de su potencial de crecimiento.     

Effects of health information in youth on adult physical activity: 20‐Year study results from the Amsterdam growth and health longitudinal study

In the Amsterdam Growth and Health Longitudinal Study (AGAHLS), a group of apparently healthy males and females (n = 200) were interviewed about their physical activities on eight separate occasions over a period of 20 years between 13 and 33 years of age (multi‐measured group: MM). Information about their health was given based on their personally measured lifestyle (activity, diet, smoking) and biological risk characteristics for chronic diseases (medical check‐ups). A comparable group of boys and girls (n = 200) was only measured on two occasions (bi‐measured group: BM): at 13 and 33 years. Physical activity was estimated with a structured interview. Total physical activity and sports activity were estimated in three intensity levels (light, moderate, and heavy). It was hypothesized that the eight repeated medical check‐ups with health information in the MM group would result in a healthier lifestyle with respect to the determinants and levels of habitual physical activity compared to the BM group. Contrary to the hypothesis, males and females in the BM group showed a significantly higher increase or a lower decrease in physical activities compared to the MM group. This negative effect on the physical activity pattern at 33 years in the MM group may have been caused by more underreporting of physical activities than in the BM group. In conclusion, there does not appear to be a significant effect of long‐term (multi‐measured) health information with medical check‐ups during adolescence and young adulthood on level of physical activity in males and females at 33 years of age. Am. J. Hum. Biol. 14:448–456, 2002. © 2002 Wiley‐Liss, Inc.     

Increasing incidence of candidemia: results from a 20-year nationwide study in Iceland

A nationwide study on candidemia was conducted in Iceland from 1980 to 1999. The annual incidence increased from 1.4 cases/100,000 inhabitants/year between 1980 and 1984 to 4.9 cases/100,000 inhabitants/year between 1995 and 1999 (P < 0.0001). Candidemia episodes at university hospitals increased from 0.15/1,000 admissions to 0.55/1,000 admissions (P < 0.0001). Candida albicans was the predominant species responsible (64.4%). The national import of fluconazole increased approximately fourfold during the second half of the study, but increased resistance to this agent was not observed.     

Frequent attenders in general practice: a retrospective 20-year follow-up study.

We describe a 20-year retrospective study of 58 patients with a cross-matched control group in one practice, who initially attended more than 12 times in 1975. The study establishes that frequent attendance is not consistent; the majority of high-attending patients in general practice revert over a short period of time to a normal consulting pattern. Diseases, rather than patients, appear to dictate high consulting rates. Consistent high attendance is largely owing to multiple pathology.     

Differences in three intercondylar notch geometry indices between males and females: a cadaver study

The primary purpose of this unique evaluation of cadaveric skeletal geometry was to compare intercondylar notch geometry between males and females. One hundred male skeletons and 100 female skeletons were evaluated. Three indices of notch geometry were calculated from digital photographs of the distal femur: notch width index, notch area index, and notch shape index. Notch shape index for males exceeded that for females (P<0.004). The intercondylar notch appears less round in females and may play a role in causing ACL injuries. Future studies are required to confirm any link between notch geometry and ACL injury.     

Self-concept, self-esteem and body weight in adolescent females: a three-year longitudinal study

Eighty girls aged 12.8 (0.6) years, completed self-concept, depression and anxiety scales over three years and had their height and weight measured. All nine self-concept domains were lower in the Highest BMI group, compared to the Lower BMI group and this trend was stable over three years. Highest BMI girls were substantially lower than population norms on all nine scales. Over three years, the Physical Appearance and Close Friendship scores of Highest BMI girls decreased compared to Lower BMI girls. This pattern was similar for all of the other self-concept domains. Several aspects of early adolescent girls' self-image may be adversely influenced by a heavy weight status.