Effects of life history variation on size and growth in stream-dwelling Atlantic salmon

A large size variation amongst life histories for stream-dwelling Atlantic salmon Salmo salar was found and the relative effect of life histories on size varied over time. As early as December (age 0+ years), fish that later smolted at age 2+ years were significantly larger than fish that did not smolt at age 2+ years. In contrast, there were no mass differences at age 0+ years between fish that would mature or not at age 1+ years (October). The mass differences between smolts and non-smolts persisted until smolting, and differences between mature and immature fish first appeared in May (age 1+ years). Following September (age 1+ years), there was also a significant interaction between smolting and maturity. Previously mature and immature age 2+ year smolts were not significantly different in size, but immature age 2+ year non-smolts were much lighter than mature age 2+ year non-smolts. Based on mass differences, the apparent 'decision' to smolt occurred c . 5 months before (winter, age 0+ years) the decision to mature (late spring, age 1+ years). In addition to strong seasonal growth variation, sizes of freshwater Atlantic salmon were largely structured by the complex interaction between smolt-age and maturity.     

Growth curves of body weight and their relationship to sexual maturity in laboratory-bred male African green monkeys (Cercopithecus aethiops)

Nonlinear growth models having a three- or four-parameter family were applied to individual body weight data of 5 male African green monkeys for estimating their growth patterns. Body weight was measured from birth to six years of age and 58 to 114 data items per monkey were collected. The average body weight at birth was 360g with the standard deviation of +/- 25g, 4.54 +/- 0.29 kg at five years of age, and 4.50 +/- 0.12 kg at six years of age at which point body weight was judged to have reached a plateau. Five growth models (Gompertz, Logistic, Richards, Bertalanffy and Brody) were applied to the growth data in this study. As a result, two (Gompertz and Logistic) of the five models were found applicable to all data from the five monkeys. However, the coefficient of determination (R2) obtained by application of the two models were not so large (0.919 +/- 0.05 in Gompertz, 0.889 +/- 0.01 in Logistic). Therefore the data were divided into two groups according to monkey age: the first group being from monkeys between birth and 2 years 10 months of age and the second group was from monkeys older than 2 years 10 months of age. The Gompertz model fitted best the data of the first group in four of the five animals (R2 = 0.982 +/- 0.011). The age at the inflexion point in the Gompertz model nearly corresponded to the age of weaning. The Logistic model was most suitable for the date of the second group in all five animals (R2 = 0.955 +/- 0.038).(ABSTRACT TRUNCATED AT 250 WORDS)     

Influence of ageing on aerobic parameters determined from a ramp test

The purpose of this study was to examine the four parameters of aerobic function, the maximum oxygen uptake (VO2max), ventilation threshold (ThVE), efficiency, and the effective time constant for oxygen consumption (tau'VO2), across age. In particular, the study was designed to observe whether there may be accelerated declines in aerobic function beyond 60 years of age. Seventy-nine sedentary men aged 30-84 years were studied. Each subject performed two maximal cycle ramp function tests, and data were collected on a breath-by-breath basis. The VO2max, from a plateau in VO2, was achieved in 87% of the subjects using the ramp test. The VO2max showed a significant decrease with increasing age (from linear regression, r = -0.81) at a rate averaging 0.037 l.min-1.year-1. The ThVE also declined with increasing age, but at a slower rate (0.013 l.min-1.year-1). The tau'VO2 was significantly increased across the age groups from 69 s for those aged 30-40 years to 98 s for those aged 60 years or more. There was no evidence of accelerated decline in these aerobic parameters beyond age 60 years, and there were no differences in efficiency (27.5-29.9%) across age. Although other forcing functions should be used to confirm this characterization of the oxygen kinetics, this slowed response with age would result in greater oxygen deficit and possibly earlier fatigue in response to even light exercise in older individuals.     

Skeletal age determination by nandibular histomorphometry

50 undecalcified cross sections of mandible of 50 individuals of known sex and age (32 males and 18 females) were examined. The sample age range was 18–97 years. The avnumber of secondary osteons (X1) and average number of fragmented osteons (X2) were computed to correlate them with chronological age at death (Y). Linear regression analyses showed that in this age group, age at death could be estimated with a S.E. of ±6.42 years for the variable X1 and a S.E. of ±11.45 years for the variable X2. Some remarks about the reliability of bone methods for age at death estimation are also made.     

Geographic and social factors that affect the age of puberty

1866 girls aged 11-15 1/2 years in Northwest Slovakia were interviewed at their schools concerning the age at menarche, number of siblings, and altitude of their residence. 518 of the girls had undergone menarche. An angular transformation of the data was carried out, and an analysis of the variance of percentages of young girls who had attained puberty was performed. An increase in the number of girls attaining puberty with age was observed as expected, but decreases in the proportion attaining puberty at a given age corresponding with an increase in the number of siblings or of altitude were also observed. The age f pubety for those with 0-1 siblings was 14.32 years; for each additional 2 siblings, it increased by about .105 years, or about 5 weeks. The average age of puberty for girls whose homes were located at 450 m above sea level or less was 14.19 years, with each additional 100 meters of altitude adding about .253 years, or 3 months, to the age at menarche. The effects of both altitude and number of siblings were statistically significant.     

The effects of age, season and fertility status on plasma and intratesticular insulin-like growth factor I concentration in stallions

The purposes of this study were to establish the basal plasma and testicular insulin-like growth factor-I (IGF-I) values for stallions ranging in age from 6 months to 23 years and to determine if IGF-I could be used as a marker for declining fertility. Blood and testes were obtained from 28 light horse stallions and colts. Of the 28 stallions, 22 were considered fertile and were categorized by age (<2 y, 5 to 10 y, 11 to 15 y, and 16 to 23 y); 12 age-matched stallions were grouped as to fertility status (fertile, subfertile, infertile); and all 28 stallions were grouped as to season of castration (breeding season vs. non-breeding season). In colts less than 2 years of age, IGF-I concentrations in plasma and testicular extracts were higher (P < 0.01) than in the other age groups and were higher in the breeding season than in the non-breeding season (P < 0.01). No significant differences in plasma or testicular extract concentrations of IGF-I were found among fertility groups. The results of this study demonstrate that plasma and testicular IGF-I levels are high in stallions younger than 2 years of age and then decline and plateau in stallions older than 5 years of age, suggesting that IGF-I may be involved in testicular development. The results allude to a possible seasonal effect on IGF-I production. However, it is difficult to separate true seasonality and the effect of age as only those stallions less than 2 years old exhibited variation between seasons. The IGF-I does not appear to have a direct relationship with declined fertility in the stallions tested, suggesting that IGF-I may not be a reliable biomarker for the diagnosis of subfertility and infertility.     

Study of seroconversion of antibody to human T-cell lymphotropic virus type-I in children of Okinawa, Japan

From 1983 to 1986, 1,813 children in nursery schools in Ishigaki Island and 1,228 children under 15 years old in the rural area in the Yaeyama District of Okinawa, Japan, were tested for anti-HTLV-I; 18 children (1.0%) in Ishigaki Island and 39 children (3.2%) in the rural area were positive. In order to survey when anti-HTLV-I developed in these children, their older serum samples were investigated retrospectively for 1 to 5 years. Two cases of seroconversion from anti-HTLV-I negative to positive were found between the age of 2 and 4, and there were no cases of seroconversion over 4 years old. Among the children who suffered maternal transmission of HTLV-I and developed anti-HTLV-I before the age of 15, about 80% of the children were considered to have anti-HTLV-I before the age of 2, and the remainder developed anti-HTLV-I before the age of 4.     

Age-related changes in the expression of QTLs for growth in radiata pine seedlings

 Haploid megagametophytes from a full-sib cross of Pinus radiata were used to construct a genetic linkage map for radiata pine based on random amplified polymorphic DNA (RAPD) markers. The map, which was made from 222 markers, was used to carry out a QTL analysis of growth using measurements made on seedlings from which these megagametophytes were collected at an early germination stage. Trends in the expression of QTLs for stem diameter, volume and height were compared using measurements made at 5 months of age, and at 1, 2 and 3 years of age. None of the observed trends showed complete stability, i.e. none of the putative QTL positions detected at any one age was strongly expressed at all of the four stages of measurement. However, 45% of the trends showed partial stability, i.e. putative QTLs significant at one age were also detected at a subsequent age. Trends in QTL expression with age followed one of three patterns: (1) putative QTLs at some locations showed a gradual linear increase in influence from 5 months of age and were highest at 3 years of age; (2) QTLs detected at 5 months of age gradually became less significant with age; and (3) some putative QTLs showed a curvilinear increase in effect from 5 months of age, reaching their peak expression at 1 to 2 years, and sometimes were still detected at 3 years of age. Received: 10 July 1997 / Accepted: 31 March 1998     

Genetic study of the height and weight process during infancy.

Longitudinal height and weight data from 4649 Dutch twin pairs between birth and 2.5 years of age were analyzed. The data were first summarized into parameters of a polynomial of degree 4 by a mixed-effects procedure. Next, the variation and covariation in the parameters of the growth curve (size at one year of age, growth velocity, deceleration of growth, rate of change in deceleration [i.e., jerk] and rate of change in jerk [i.e., snap]) were decomposed into genetic and nongenetic sources. Additionally, the variation in the estimated size at birth and at 2 years of age interpolated from the polynomial was decomposed into genetic and nongenetic components. Variation in growth was best characterized by a genetic model which included additive genetic, common environmental and specific environmental influences, plus effects of gestational age. The effect of gestational age was largest for size at birth, explaining 39% of the variance. The differences between monozygotic and dizygotic twin correlations were largest for size at 1 and 2 years of age and growth velocity of weight, which suggests that these parameters are more influenced by heritability than size at birth, deceleration and jerk. The percentage of variance explained by additive genetic influences for height at 2 years of age was 52% for females and 58% for males. For weight at 2 years of age, heritability was approximately 58% for both sexes. Variation in snap height for males was also mainly influenced by additive genetic factors, while snap for females was influenced by both additive genetic and common environmental factors. The correlations for the additive genetic and common environmental factors for deceleration and snap are large, indicating that these parameters are almost entirely under control of the same additive genetic and common environmental factors. Female jerk and snap, and also female height at birth and height at 2 years of age, are mostly under control of the same additive genetic factor.     

Parental age,birth order and tertiary sex ratio in the human population of Punjab,Pakistan

The data of this study, an extension of a previous study on secondary sex ratio in the human population of Muridke, Punjab, Pakistan, are based on the population of Muridke, 27 km north of Lahore, Punjab, Pakistan. Records of deaths of children, at later stages of birth, for different birth ranks, and that of maternal and paternal ages were made. 1000 families were scored for this study. Families providing the required information were included. Data for paternal age and maternal age combination consisted of 4807 total number of children of which 2586 were male. Paternal age and birth order combination was comprised of a total of 4405 children, containing 2316 males. Maternal age and birth order combination consisted of 4658 children, of which 2458 were males. The discrepancy in the number of children in the 3 types of combinations was due to the lack of required information in different groups. Sex ratio based on total number of males in relation to paternal age and maternal age was 0.54. Younger fathers (15-19 years) showed higher sex ratio (0.69). This dropped in paternal age groups 20-24 years (0.59) and 25-29 years (0.51). Younger mothers (15-19 years) showed higher sex ratio (0.62), declines in the age groups 20-24 years (0.52) and 25-29 years (0.51) and rise in age groups 35-39 years (0.55) and 40-44 years (0.54). Chi-square tests were carried out to compare the number of male and female offspring in the paternal age groups 15-19, 20-24, and 25-29 years. These showed highly significant deviation from the expected number. The higher age groups showed nonsignificant differences in the number of male and female offspring. Maternal age groups 15-19, 20-24, and 25-29 years showed highly significant differences in the male and female offspring and nonsignificant results in the higher age groups. Maternal age in relation to paternal age showed positive simple and partial correlations. Sex ratio for the total number of males based on paternal age and birth order was 0.52. 1st birth order showed higher sex ratio (0.55) and decreased in the 2nd (0.50) and 3rd birth orders (0.51), showed increase in the 4th birth order (0.53) and declines in the higher birth ranks. The number of male and female offspring in the birth orders 1, 2, and 3 showed significant differences, but in higher birth ranks the difference was insignificant. Paternal age and birth order indicated positive simple and partial correlations. Higher sex ratio (0.58) was seen in the 1st birth order and then it decreased in the 2nd (0.50) and 3rd (0.51) birth order. Chi-square tests carried out to compare the number of male and female offspring in borth orders 1, 2, and 3 showed highly significant differences but in higher birth ranks the difference was insignificant.     

Human papillomavirus vaccination for adults aged 30 to 45 years in the United States: A cost-effectiveness analysis

BackgroundA nonavalent human papillomavirus (HPV) vaccine has been licensed for use in women and men up to age 45 years in the United States. The cost-effectiveness of HPV vaccination for women and men aged 30 to 45 years in the context of cervical cancer screening practice was evaluated to inform national guidelines.Methods and findingsWe utilized 2 independent HPV microsimulation models to evaluate the cost-effectiveness of extending the upper age limit of HPV vaccination in women (from age 26 years) and men (from age 21 years) up to age 30, 35, 40, or 45 years. The models were empirically calibrated to reflect the burden of HPV and related cancers in the US population and used standardized inputs regarding historical and future vaccination uptake, vaccine efficacy, cervical cancer screening, and costs. Disease outcomes included cervical, anal, oropharyngeal, vulvar, vaginal, and penile cancers, as well as genital warts. Both models projected higher costs and greater health benefits as the upper age limit of HPV vaccination increased. Strategies of vaccinating females and males up to ages 30, 35, and 40 years were found to be less cost-effective than vaccinating up to age 45 years, which had an incremental cost-effectiveness ratio (ICER) greater than a commonly accepted upper threshold of $200,000 per quality-adjusted life year (QALY) gained. When including all HPV-related outcomes, the ICER for vaccinating up to age 45 years ranged from $315,700 to $440,600 per QALY gained. Assumptions regarding cervical screening compliance, vaccine costs, and the natural history of noncervical HPV-related cancers had major impacts on the cost-effectiveness of the vaccination strategies. Key limitations of the study were related to uncertainties in the data used to inform the models, including the timing of vaccine impact on noncervical cancers and vaccine efficacy at older ages.ConclusionsOur results from 2 independent models suggest that HPV vaccination for adult women and men aged 30 to 45 years is unlikely to represent good value for money in the US.

Jane Kim and co-workers estimate the potential cost-effectiveness of papillomavirus vaccination for adults aged 30-45 years in the United States.     

Influence of age and gender on radiomorphometric indices of the mandible in removable denture wearers

The objective of this study was to measure and assess a number of radiomorphometric indices of the mandibular removable denture wearers taking into account age and gender. In a total of 136 dental panoramic radiographs (DPR) the following parameters were evaluated: MI = thickness of the mandibular cortex below the mental foramen, AI = thickness at the antegonion and GI = thickness at gonion; PMI = MI/distance between the low border of the mandible and the low border of the mental foramen, and MCI = mandibular cortical index, based on the assessment of the 3 categories of cortical appearance due to the resorptive changes. There were 40 male patients (mean age 72.7; range 56 to 84 years) and 96 female patients (mean age 69.7; range 48 to 86 years). Patients were grouped according to age into three age groups (1 = less than 65 years; 2 = 65-75 years; 3 = more than 75 years). The results revealed that MI, PMI, AI and GI showed a general downward trend with age for the both sexes until 75 years of age when the mean values of GI, AI and MI begun to fall down sharply for females compared to males. The difference was significant between age groups and gender for GI and AI. Only two categories (C2 and C3) of MCI have been recognized in our study sample, due to the relatively old age groups of patients with removable dentures. However, significantly higher incidence of C3 existed in the oldest group of females.     

乳腺癌患者的临床特征及其辅助治疗的影响因素分析

目的:探讨乳腺癌患者的临床病理特点及其辅助治疗的影响因素。方法:选取2009年1月~2012年2月我院收治的114例60岁以上的乳腺癌患者,按照年龄将其分为60~69岁组以及70岁以上组,对两组患者的临床特点、病例特点以及辅助治疗的模式进行对比分析。结果:两组患者在合并疾病、癌肿大小、病理学类型、受累淋巴结、以及雌孕激素受体阳性率、表皮生长因子2过度表达、肿瘤抑制基因P53阳性率以及Ki-67增殖指数等方面相比较,差异均无统计学意义(P0.05)。两组患者的手术治疗方式以及术后辅助化疗情况相比较,差异有统计学意义(P0.05)。多因素Logistic回归分析发现,年龄、淋巴结受累情况以及雌激素受体是否阳性成为术后辅助化疗主要考虑的因素。随诊2年,60~69岁组与70岁以上组患者的2年无复发生存率分别为88.89%(64/72)、92.86%(39/42),两组相比较,差异无统计学意义(P0.05)。结论:70岁以上的乳腺癌患者的临床特点与60~69岁的患者相比较无明显差异,目前,临床治疗采取的方法有所不同,但均能够达到较好的效果。年龄、淋巴结受累情况以及雌激素受体是否阳性成为医生考虑术后辅助化疗方案的主要因素。     

Variation in age at first reproduction of male Japanese fluvial sculpin induced by the timing of parental reproduction

The relationships between age and size at reproduction and lifetime reproductive output of male Japanese fluvial sculpin Cottus pollux were estimated by a mark-recapture study. Although all males were physiologically capable of breeding at age 2 years, age at first successful reproduction varied amongst individuals. Males with delayed reproduction had lower net reproductive rate than males that bred at age 2 years on average suggesting that age at first reproduction was a conditional strategy. Males that delayed reproduction were significantly smaller at age 1 and 2 years than males that bred at age 2 years. Despite no significant difference in body size of hatched yolk-sac larvae between the early and late phase of the breeding season, by May of the first year of life, progeny from nests in the early phase had hatched earlier and were larger than those from the nests in the late phase. The results suggested an important effect of timing of reproduction of parents on the growth and subsequent age at first reproduction of their progeny.     

The growth of charr, Salvelinus willughbii Günther, in Windermere

The growth of charr ( Salvelinus willughbii Günther ) caught in Windermere from 1941–1952 has been studied. Scales were used for determination of age and back-calculation of length for age. Autumn and spring spawners, males and females, and charr of normal and dwarf growth were treated separately. In fish of normal growth, the spring spawners were significantly smaller than the autumn spawners at ages 1 and 2 years, and significantly larger from age 4 years onwards. There was little difference in growth between males and females within the two spawning populations. Charr of lengths of less than 200 mm at age 4 years were considered to be dwarfs. Mean lengths at capture of male charr were: autumn spawners normal growth 272 mm, dwarf 218 mm; spring spawners normal growth 327 mm, dwarf 194 mm. The oldest recorded age was 8 years.     

Plasma androgens in children and adolescents. Part I: control subjects

In this cross-sectional study, plasma levels of dehydroepiandrosterone sulfate (DHEA-S), dehydroepiandrosterone (DHEA), delta 4-androstenedione (delta 4) and testosterone (T) were measured by RIA in 232 normal subjects of both sexes, aged 2 weeks to 20 years. The results were analyzed in relation to chronological age, body surface and pubertal stage. High levels of plasma androgens were found in newborn infants of both sexes. After 3 months of age, androgen levels were uniformly low and rose with increasing chronological age and body surface. The first significant increase in mean androgen levels was found for DHEA-S. It occurred after 6 years of age in girls and after 8 years in boys. DHEA and T rose in both sexes after 8 years of age. delta 4 increased steadily with chronological age and body surface in both sexes. When androgen levels were related to body surface, a first significant increase was observed above 1.00 m2 for the four androgens, in both boys and girls. Above 1.20 m2 and 12 years of age, girls had higher mean levels of DHEA-S, DHEA and delta 4, but lower mean T levels than boys of the same body surface and chronological age. Before puberty, a positive correlation was found in both sexes between the plasma androgen levels on the one hand, and both chronological age and body surface on the other. Plasma androgen levels markedly increased at stage P2 in both sexes, and further increased with pubertal development. During puberty, girls had higher plasma delta 4, but lower plasma T levels than boys of the same pubertal stage. Plasma DHEA-S and DHEA levels were similar in both sexes. In contrast to the plasma androgens, plasma cortisol levels did not show any change in relation either to chronological age or to body surface or pubertal development. Body surface appears to be as good a discriminating factor as chronological age, at least in young children. It also appears from this study that DHEA-S is a good guide for the clinical evaluation of adrenal maturation and may be very useful in evaluating patients with growth or pubertal disturbances.     

Observations related to chronologic and gynecologic age in pregnant adolescents.

A low chronologic age (less than or equal to 15 years) and low gynecologic age (less than or equal to 2 years) have been considered factors that increase medical complications among adolescent pregnant women. Gynecologic age (GA) is defined in this study as age in years at conception minus age at menarche. Two hundred twelve consecutive pregnant teenagers were followed prospectively in the Teen OB Clinic at the University of California, San Diego Medical Center, between August 1978 and July 1981. The clinic population consisted of 37.3 percent Whites, 35.8 percent Hispanics, 20.8 percent Blacks, and 6.1 percent other (mostly Indochinese). Sixty-eight percent of the patients were funded by MediCal. The patient population was divided by chronological age (CA) at conception into those 15 years or less or 16 years or older. A low chronological age was found to be a significant risk factor for premature rupture of membranes. Teenagers with a low gynecologic age (less than or equal to 2) had a lower mean pre-pregnancy weight and body mass index (Kg/M2) than teenagers with a higher gynecologic age. In this study, we did not find that a low CA or GA was correlated with a higher frequency of pregnancy-induced hypertension, prenatal medical problems, obstetrical problems at labor or delivery, or an excessive number of low-birthweight infants.     

Greater efficiency of human growth hormone therapy in children below five years of age with growth hormone deficiency. A 5-year follow-up study

The effect of human growth hormone (hGH) therapy was studied in 39 prepubertal children with growth hormone deficiency (24 with isolated growth hormone deficiency; 15 with multiple pituitary hormone deficiencies) who had been treated for 2-5 years. They were divided into two groups according to age at the initiation of therapy: group A (n = 21), 0.7-4.8 years (mean chronological age, 2.9 +/- 1.4 years, and bone age, 1.2 +/- 0.9 years); group B (n = 18), 5.2-9.9 years (mean chronological age, 7.4 +/- 1.3 years, and bone age, 4.0 +/- 1.5 years). hGH was given at an initial dose of 2-4 IU 3 times/week, raised to 4-6 IU 3 times/week when growth velocity slowed. In the first year, the mean height SDS gain was 1.7 for group A and 0.8 for group B, and in the second year, 1.1 and 0.1, respectively. Subsequently this remained consistent. Bone age advancement was significantly slower in the younger group (3.8 vs. 5.8 years during 5 years) although this group had a greater catch-up response to therapy. It is concluded that hGH therapy is significantly more effective in achieving normalization of height when treatment is initiated at an early age.     

Influence of female age, body size and environmental conditions on annual egg production of the bullhead

A population of bullhead Cottus gobio inhabiting a mountainous river network, was examined for the influence of maternal condition (total length, L _T, and age class in years) and environmental factors (water temperature and fish density) on fecundity, egg size and net annual reproductive effort ( E _R, defined as the ratio of total egg production mass to body mass) within several stocks. Regardless of location within the drainage network, bullhead reproduction was synchronous, with only a single batch and fecundity ranging from 69 to 896 eggs per female. As with L _T fecundity increased with age, although the difference between age classes 5 and 6 years was smaller than between other age classes. Egg diameter also increased with age from age classes 2 to 4 years, but then tended to decrease for age classes 5–6 years. Multiple stepwise regression was used to examine the effect of female L _T, water temperature and fish densities on bullhead egg production for each of the four age classes (2, 3, 4 and 5–6 years) separately. When statistically significant, water temperature always had a positive effect and fish densities a negative effect, on fecundity and egg size. The L _T always had a positive effect on fecundity for all the age classes. In contrast, L _T had a positive effect on egg size and E _R only for female reaching maturity (2 years), whereas intermediate aged females (3–4 years) were insensitive and the oldest fish showed a negative response.     

The effect of primary lack of estrogens and the influence of the age at the beginning of estrogen therapy on bone mineral density in patients with Turner's syndrome

Lumbar spine bone mineral density (BMD) values were measured in women with Turner's syndrome (TS) and the influence of primary ovarian failure as well as the age at the start of estroprogestins (EP) therapy were considered. EP treatment with 2mg of estradiol (E2) and BMD monitoring were started in 72 and finally continued for 5 years in 34 patients with TS, aged 12-38 years, previously not treated with growth hormone or anabolic steroids. The mean total BMD gain (deltaBMD) was 20% and the most significant increase was observed after the first (7.5%) and the second (6.6%) year of the therapy. Before the start and during EP treatment E2 levels were evaluated: they increased from 9.2pg/ml to the values observed in the controls (C) but positive correlation with BMD was not observed. Analysis of TS patients in age brackets (<15 years, 15-20 years, 21-25 years, >25 years) showed that only in the group that started EP treatment before the age of 15 every year significant deltaBMD was observed. The group that started EP therapy after the age of 20 didn't achieve significant deltaBMD. Patients wit TS had significantly higher levels of bone metabolism markers (Ntx and BALP) than the controls and in both groups negative correlation with age was found. On the basis of the results the conclusion was made that in hypoestrogenic women, not exclusively TS, the age when estrogen therapy is started may determine the effects in relation to bone mass. The administered E2 doses may also be important.