Cortisol concentration affects fat and muscle mass among Polish children aged 6-13 years.

BACKGROUND: Cortisol is a steroid hormone acting as a stress hormone, which is crucial in regulating homeostasis. Previous studies have linked cortisol concentration to body mass and body composition. METHODS: The investigations were carried out in 2016-2017. A total of 176 children aged 6-13 years in primary schools in central Poland were investigated. Three types of measurements were performed: anthropometric (body weight and height, waist and hip circumferences), body composition (fat mass FM (%), muscle mass - MM (%), body cellular mass - BCM (%), total body water - TBW (%)), and cortisol concentration using saliva of the investigated individuals. Information about standard of living, type of feeding after birth, parental education and maternal trauma during pregnancy was obtained with questionnaires. RESULTS: The results of regression models after removing the environmental factors (parental education, standard of living, type of feeding after birth, and maternal trauma during pregnancy) indicate a statistically significant association between the cortisol concentration and fat mass and muscle mass. The cortisol concentration was negatively associated with FM (%) (Beta=-0.171; p = 0.026), explaining 2.32 % of the fat mass variability and positively associated with MM (%) (Beta = 0.192; p = 0.012) explaining 3.09 % of the muscle mass variability. CONCLUSIONS: Cortisol concentration affects fat and muscle mass among Polish children. TRIAL REGISTRATION: The Ethical Commission at the University of Lodz (nr 19/KBBN-UL/II/2016).

Prenatal oestrogen-testosterone balance as a risk factor of migraine in adults.

BACKGROUND: Migraine is a common neurological disease with extremely debilitating, but fully reversible symptoms. Women suffer from migraine more often than men. It was assumed that fluctuation of oestrogen level during menstrual cycle is one of many factors responsible for more frequent migraine attacks. The second-to-fourth digit ratio (2D:4D) is considered as an indicator of prenatal sex steroids. Balance of prenatal androgens (testosterone) and oestrogen has been studied in numerous diseases that are affected by hormones. However, the relationship between migraine and the sex steroids balance in prenatal development is still unexplained. The aim of this paper is to provide an evidence of relationship between prenatal oestrogen and testosterone exposure following 2D:4D digit ratio, and migraine prevalence in adults. METHODS: We examined a group of 151 adults (33 males, 118 females) with migraine and a control group of 111 adults (45 males, 66 females). 2D:4D digit ratio of both hands was measured using sliding Vernier calliper. RESULTS: Significant differences were found in the right hand. Female migraineurs had lower value of 2D:4D ratio than the control group and the right 2D:4D was lower than left 2D:4D (Δ2D:4D), suggesting prenatal testosterone dominance. The opposite relationship was observed in males. Male migraineurs had higher value of 2D:4D ratio and Δ2D:4D was greater than the control group, suggesting prenatal oestrogen dominance. CONCLUSIONS: Our results suggest that depending on sex, different proportion of prenatal sex steroids might be a risk factor of migraine in adults. Women with migraine were presumably exposed in prenatal life to higher testosterone levels relative to oestrogen, while men with migraine were probably exposed in prenatal life to higher levels of oestrogen relative to testosterone.

Association of saliva 25(OH)D concentration with body composition and proportion among pre-pubertal and pubertal Polish children.

OBJECTIVES: Due to increasing problems with obesity and vitamin D deficiency among children, studies that tackle both problems together are needed. METHODS: Data were collected from 182 randomly selected children aged 6-13 years in primary schools in central Poland. Measures included anthropometric dimensions, body composition, questionnaires completed by participants' parents, and saliva samples. The level of 25(OH)D was assessed from the saliva samples using an enzyme-linked immunosorbent assay kit. The children were divided into two groups: pre-pubertal (girls below 10 years and boys below 11 years) and pubertal individuals (girls above 10 years and boys above 11 years). RESULTS: The 25(OH)D concentrations were higher in late spring (June) among pre-pubertal children than in the autumn (November-December) among pubertal children. The level of 25(OH)D was positively correlated with body cell mass (BCM,%) among all children (pubertal: R = 0.20, P = .044; pre-pubertal: R = 0.23, P = .041) and inversely associated with waist-to-hip ratio (WHR) among pubertal children of both sexes (R = -0.25; P = .031). The stepwise regression analysis revealed that investigation in spring (June) and breastfeeding was associated with increased muscle mass (MM, %) (beta = 0.253, P = .003 and beta = 0.225, P = .005, respectively) and total body water (TBW, %) (beta = 0.276, P = .004 and beta = 0.246, P = .011, respectively) and was associated with decreased body mass index (BMI; beta = -0.222, P = .024 and beta = -0.269, P = .009, respectively) and fat mass (%) (beta = -0.288, P = .003 and beta = -0.266, P = .005, respectively). CONCLUSIONS: Season of salivary sampling and breastfeeding status were more strongly associated with body components, BMI and WHR, than 25(OH)D concentrations.

Parental smoking during pregnancy and head shape and size in school children.

BACKGROUND: Maternal smoking during pregnancy has been recognised as a detrimental factor associated with adverse perinatal outcomes; however, to date there is a dearth of information on how it affects post-natal head growth and shape. AIM: To assess the relationship between parental smoking exposure during pregnancy and head dimensions and shape at age 7-10 years in boys and girls. METHODS: Body height and head length, breadth and circumference were measured. Birth weight and gestational age were obtained from the children's medical record books. Parental smoking habits during pregnancy and maternal educational attainment were obtained by a questionnaire. The relationship between exposure to parental smoking during pregnancy and head dimensions was evaluated using analysis of covariance implemented in the Generalized Linear Model, separately for each sex. RESULTS: Maternal and parental smoking during pregnancy significantly altered head shape in boys by affecting head length, while neither head breadth nor circumference were affected. This phenomenon was not observed in girls. CONCLUSION: Smoking-induced chronic hypoxic effects on the growing foetus, indicated that both active and passive smoking during pregnancy seems to have persistent negative effects on children, going beyond foetal development and pre-natal growth restrictions.

Association between body height and month of birth among women of European origin in northern and southern hemispheres.

OBJECTIVES: The purpose of this study was to examine the potential association between month of birth and body height among women in northern and southern hemispheres. METHODS: Body heights of adult women of European origin born between 1935 and 1981 who lived in Poland (N = 3,933) and in Australia (N = 1,118) were examined in relation to month of birth by analysis of variance. RESULTS: No association between month of birth and body height was observed in either Polish or Australian women. For Polish women, a clear, statistically significant secular trend in body height was confirmed for the analyzed period (P < .0001). No such trend occurred among the Australian women. CONCLUSIONS: Results do not confirm a significant association between month of birth and adult body height in women. It is, however, important to see a difference in secular trends, which was large in Polish women and nonexistent in Australian females.

Skin color parameters and Fitzpatrick phototypes in estimating the risk of skin cancer: A case-control study in the Polish population.

BACKGROUND: Light skin pigmentation is a known risk factor for skin cancer. OBJECTIVE: Skin color parameters and Fitzpatrick phototypes were evaluated in terms of their usefulness in predicting the risk of skin cancer. METHODS: A case-control study involved 133 individuals with skin cancer (100 with basal cell carcinoma, 21 with squamous cell carcinoma, 12 with melanoma) and 156 healthy individuals. All of them had skin phototype determined and spectrophotometric skin color measurements were done on the inner surfaces of their arms and on the buttock. Using those data, prediction models were built and subjected to 17-fold stratified cross-validation. RESULTS: A model, based on skin phototypes, was characterized by area under the receiver operating characteristic curve = 0.576 and exhibited a lower predictive power than the models, which were mostly based on spectrophotometric variables describing pigmentation levels. The best predictors of skin cancer were R coordinate of RGB color space (area under the receiver operating characteristic curve 0.687) and melanin index (area under the receiver operating characteristic curve 0.683) for skin on the buttock. LIMITATIONS: A small number of patients were studied. Models were not externally validated. CONCLUSIONS: Skin color parameters are more accurate predictors of skin cancer occurrence than skin phototypes. Spectrophotometry is a quick, easy, and affordable method offering relatively good predictive power.

Relationship between pre-natal factors, the perinatal environment, motor development in the first year of life and the timing of first deciduous tooth emergence.

BACKGROUND: The emergence of deciduous teeth, despite being genetically determined, shows significant correlation with the pre-natal environment, maternal factors, method of infant feeding and also family socioeconomic status. However, reported results are often contradictory and rarely concern healthy, full-term children. AIM: The objective of this study was to evaluate the influence of pre-natal and maternal factors as well as the method of infant feeding on the timing of first deciduous tooth emergence in healthy, full-term infants and to examine the relationship between the psychomotor development rate and the age at first tooth. SUBJECTS AND METHODS: The database contained 480 records for healthy, term-born children (272 boys and 208 girls born at 37-42 weeks of gestation) aged 9-54 months. Multiple regression analysis and multi-factor analysis of variance were used to identify significant explanatory variables for the age at first tooth. RESULTS: The onset of deciduous tooth emergence is negatively correlated with birth weight and maternal smoking during pregnancy and positively correlated with breastfeeding and the age at which the child begins to sit up unaided. These factors have an additive effect on the age at first tooth. CONCLUSION: An earlier onset of tooth emergence in children exposed to maternal smoking during pregnancy seems to provide further evidence for disturbed foetal development in a smoke-induced hypoxic environment.

Accentuated lines in the enamel of primary incisors from skeletal remains: A contribution to the explanation of early childhood mortality in a medieval population from Poland.

Physiological disruptions resulting from an impoverished environment during the first years of life are of key importance for the health and biological status of individuals and populations. Studies of growth processes in archaeological populations point to the fact that the main causes of childhood mortality in the past are to be sought among extrinsic factors. Based on this assumption, one would expect random mortality of children, with the deceased individuals representing the entire subadult population. The purpose of this study is to explore whether differences in early childhood survival are reflected in differences in deciduous tooth enamel, which can provide an insight into the development of an individual during prenatal and perinatal ontogeny. Deciduous incisors were taken from 83 individuals aged 2.0-6.5 years from a medieval inhumation cemetery dated AD 1300-1600. Prenatal and postnatal enamel formation time, neonatal line width, and the number of accentuated lines were measured using an optical microscope. The significantly wider neonatal line and the higher frequency of accentuated lines in the enamel of the incisors of children who died at the age of 2-3 years suggest the occurrence of stronger or more frequent stress events in this group. These results indicate that in skeletal populations mortality was not exclusively determined by random external factors. Individuals predisposed by an unfavorable course of prenatal and perinatal growth were more likely to die in early childhood.

Caries Experience and Distribution by Tooth Surfaces in Primary Molars in the Pre-school Child Population of Lodz, Poland.

PURPOSE: To evaluate caries experience in primary molars as well as the differences in caries prevalence and caries lesion location on individual tooth surfaces between first and second primary molars in pre-school children. MATERIALS AND METHODS: A cross-sectional study was conducted on 307 children, aged 3 to 5 years, from randomly chosen kindergartens in Lodz, Poland. Caries experience was scored according to WHO recommendations. The caries intensity (dmft, dmfts) for first and second primary molars was calculated. In addition, the percentage of particular surfaces with caries was counted for each molar separately. RESULTS: The mean dmft for primary molars was 1.84 (dmfts=2.47) and dmft>0 was seen in 53.09% of the study subjects. While in the entire examined population dmft and dmfts for first and second molars did not differ significantly, in 5-year-old children, the left mandibular first molar was associated with a higher caries intensity than the left mandibular second molar (dmfts=0.465 vs 0.344, Z=-1.98, p=0.04). However, in 5-year-olds, higher caries occurrence was seen for occlusal surfaces of the tooth 85 than 84 (33.62% vs 20.68%, χ2=4.09, p=0.03). The distal surface was more frequently affected in first molars than in second molars in children aged 4 (85 vs 84, χ2=17.1, p<0.001; 75 vs 74, χ2=11.5, p=0.007, 55 vs 54; χ2=4.6, p=0.03) and 5 years (54 vs 55, χ2=20.09; 64 vs 65, χ2=16.75; 74 vs 75, χ2=21.6; 84 vs 85, χ2=31.07; all comparisons p<0.001). In contrast, the mesial surfaces of mandibular second molars demonstrated more caries than the homologous surfaces of first molars, both in 4-year-olds (85 vs 84, χ2=6.15, p=0.01) and 5-year-olds (75 vs 74, χ2=3.9, p=0.04). CONCLUSION: In 5-year-old children, caries of occlusal and mesial surfaces was more common in primary second molars. However, distal surfaces were affected more in first than second molars.

Age- and sex-related changes in vertebral trabecular bone architecture in Neolithic and Mediaeval populations from Poland.

This paper investigates trabecular bone ontogenetic changes in two different Polish populations, one prehistoric and the other historical. The studied populations are from the Brzesc Kujawski region in Kujawy (north-central Poland), one from the Neolithic Period (4500-4000 BC) and one from the Middle Ages (twelfth-sixteenth centuries AD), in total 62 vertebral specimens (32 males, 30 females). Eight morphometric parameters acquired from microCT scan images were analysed. Two-way ANOVA after Box-Cox transformation and multifactorial regression model were calculated. A significant decrease in percentage bone volume fraction (BV/TV; [%]) with age at death was observed in the studied sample; Tb.N (trabecular number) was also significantly decreased with age; trabecular separation (Tb.Sp) increased with advancing age; connectivity density (Conn.D) was negatively correlated with biological age and higher in the Neolithic population. These data are found to be compatible with data from the current biomedical literature, while no loss of horizontal trabeculae was recorded as would be expected based on modern osteoporosis.

Pre-natal and perinatal factors affecting body mass index in pre-pubertal Polish children.

BACKGROUND: An increased prevalence of body mass deficit among children has been reported in developing countries, including Eastern European states which have undergone political transformation. However, there are few studies evaluating risk factors for body mass deficit in schoolchildren and adolescents. AIM: To assess selected familial, pre-natal and early life factors in terms of risk associated with the prevalence of body mass deficit in children aged 7-10 years. SUBJECTS AND METHODS: Logistic regression models based on 812 records for children aged 7-10 years were applied for the evaluation of familial, pre-natal and perinatal risk factors affecting the height-to-weight ratio. RESULTS: The risk of underweight in 7-10-year-old children is significantly higher for girls (OR = 1.70) and for children whose mothers reported a traumatic experience during pregnancy (OR = 2.77). The effect of reported stress during pregnancy differed as regards the child's sex. Mother's trauma increased the risk of body weight deficit only in boys (OR = 2.74), while in girls it significantly decreased this risk (OR = 0.35). Low birth weight significantly increased the risk of underweight only in boys (OR = 2.99) and mother's occupational activity decreased the risk of underweight only in girls (OR = 0.57). CONCLUSION: Low birth weight and mother's trauma during pregnancy are risk factors for underweight in Polish schoolchildren, particularly in boys.

The impact of exposure to tobacco smoking and maternal trauma in fetal life on risk of migraine.

Introduction: Prenatal period is the key time in human development. Many prenatal factors are well-known and increase the risk of developing diseases' after birth. Few studies indicated the link between the prenatal period and the prevalence of migraine in childhood and adolescence so far. We decided to broaden current knowledge and investigate whether the prenatal factors influence the prevalence of migraine in adulthood. The objective of this study is to provide evidence of relationship between in utero environment and risk of migraine. Methods: In total 266 females (136 in the migraine group, 130 in the control group) and 80 males (35 in the migraine group, 45 in the control group), aged 18-65 participated in the study. The quality of prenatal environment was characterized on the basis of mother's and father's education, tobacco smoke exposure, alcohol consumption, and traumatic event during pregnancy, which are considered as prenatal factors and affect on fetal development. Results: Migraine occurrence in adulthood was significantly associated with maternal tobacco smoking during pregnancy (OR 3.42, 95% CI 1.54-7.61, p = 0.036) and traumatic event during pregnancy (OR 2.27, 95% CI 1.24-4.13, p = 0.020). Discussion: Our study suggests that the fetal programming effect of tobacco smoking exposure and maternal trauma is not limited to prenatal life and is suggested as having a role in adulthood. Our findings support evidence that migraine adulthood can be partly influenced by early life conditions.

Biometric characteristics of the pelvis in female-to-male transsexuals.

The objective of the study was to evaluate the metric features of pelvises of 24 female-to-male (FtM) transsexuals as compared to control groups of 24 healthy males and 24 healthy females. The participants had their pelvises X-rayed with the same X-ray apparatus and in the same position. Seventeen measurements were taken on the basis of X-ray pictures of FtM transsexuals' pelvises and both comparison groups. Additionally, their body height was compared. The results showed that FtM transsexuals having female body height represent an intermediate size of three pelvic features and male values of five variables. In order to develop a model based on metric variables of the pelvis that would best discriminate the FtM transsexuals, the control females, and the control males, a discriminant analysis was applied. The model included four variables out of 17 metric features: the height of the pubic symphysis, the greatest pelvic breadth, the interischial distance, and the acetabular diameter. The model was found to be the best in discriminating males from females and FtM transsexuals, but considerably less effective in discriminating transsexuals from the two control groups. The results demonstrate that a number of FtM transsexuals' pelvic measurements reveal "masculinization," which confirms current results demonstrating a shift in the somatometric traits of transsexual females towards male traits. A discriminant analysis based only on pelvic metric features shows some differences between the size of the pelvis and chromosomal sex in FtM transsexuals, which might indicate a biological basis for gender identity disorder.

Auxology of small samples: A method to describe child growth when restrictions prevent surveys.

BACKGROUND: Child growth in populations is commonly characterised by cross-sectional surveys. These require data collection from large samples of individuals across age ranges spanning 1-20 years. Such surveys are expensive and impossible in restrictive situations, such as, e.g. the COVID pandemic or limited size of isolated communities. A method allowing description of child growth based on small samples is needed. METHODS: Small samples of data (N~50) for boys and girls 6-20 years old from different socio-economic situations in Africa and Europe were randomly extracted from surveys of thousands of children. Data included arm circumference, hip width, grip strength, height and weight. Polynomial regressions of these measurements on age were explored. FINDINGS: Polynomial curves based on small samples correlated well (r = 0.97 to 1.00) with results of surveys of thousands of children from same communities and correctly reflected sexual dimorphism and socio-economic differences. CONCLUSIONS: Fitting of curvilinear regressions to small data samples allows expeditious assessment of child growth in a number of characteristics when situations change rapidly, resources are limited and access to children is restricted.

Primary Headaches and Physical Performance: A Professional Youth Female Soccer Team Study.

The vast majority of the research on acute post-traumatic incidents in athletes focuses on migraines. Physical exercise might reduce the frequency of migraines as well as trigger a migraine attack. The objectives of the study were to evaluate primary headache prevalence in professional young female soccer players and to assess whether headaches are related to physical performance. To the best of our knowledge, this is the first study that has considered the relationship between primary headaches and physical performance assessment. The research was conducted in 19 females aged 12-17 from a professional youth soccer academy. Players completed a questionnaire about health status and then performed laboratory physical tests (e.g., cardiopulmonary tests, countermovement and squat jumps, handgrip, sit-and-reach tests). Subsequently, players were separated into a headache group and a headache-free control group. In the analysed group, eight female players (42%) suffered from primary headaches. Among the performance parameters, a significant result was found in terms of flexibility. Females from the headache group had higher results in the sit-and-reach test than females from the control group (p = 0.029). Flexibility as well as mobility in migraine patients is an area with significant potential for further investigation, as little research has been conducted to date.

Assessment of the Predictive Value of Spectrophotometric Skin Color Parameters and Environmental and Behavioral Factors in Estimating the Risk of Skin Cancer: A Case-Control Study.

Keratinocyte carcinomas are the most common cancers with different etiological risk factors. The aim of this study was to assess the predictive value of spectrophotometric parameters of skin color in correlation with environmental/behavioral factors to estimate the risk of skin cancer. The case-control study involved 389 patients. The analysis was performed on the training group to build a predictive model and on the testing group to check the quality of the designed model. Area under the curve based on the spectrophotometric skin parameters varied from 0.536 to 0.674. A statistically significant improvement of the area under curve was achieved by adding the number of sunburns for some models. The best single spectrophotometric measurement for estimating skin cancer is the skin melanin index measured on the arm or buttock. Spectrophotometric skin parameters are not very strong but are essential elements of models for estimating the risk of skin cancer. The most important environmental/behavioral factor seems to be the number of sunburns, but not the total exposure to ultraviolet radiation or usage of photoprotectors. Some other pigmentation predictors should be taken into account when creating new models, especially those that can be easily measured in objective and repeatable way. Spectrophotometric measurements can be employed as quick screening skin examination method.

Maternal Age and Behavior during Pregnancy Affect the 2D:4D Digit Ratio in Polish Children Aged 6-13 Years.

BACKGROUND: The length of the second and fourth finger calculated as a ratio (2D:4D) is a marker of prenatal exposure to sex hormones. Higher exposure to testosterone is related to a lower 2D:4D digit ratio, and inversely, higher exposure to estrogen is related to a higher 2D:4D. The digit ratio in humans (prenatally determined by sex hormone levels and androgen receptor activity) is associated with multiple biological, cognitive, and behavioral traits, as well as health in later life. The aim of this study was to verify if maternal traits during pregnancy are associated with 2D:4D among their children. METHODS: We investigated 537 boys, 646 girls, and their mothers. The investigation consisted of a questionnaire and a measurement part. In the questionnaire, we included questions about maternal traits during pregnancy such as: illnesses, active and passive smoking, work activity, psychological trauma (death or serious illness of a loved one, divorce, job loss), and age. We performed length measurements of the second and fourth fingers on both hands for both study groups. RESULTS: The GLM analysis showed that children of smoking mothers were characterized by a higher 2D:4D R as compared to their peers whose mothers did not smoke (ß = 0.10, p = 0.0008). In turn, the offspring of women who worked during pregnancy exhibited lower 2D:4D R values than the children of women who did not work (ß = -0.07, p = 0.0233). It should be noted, however, that the effects of those maternal factors were small, as each of them explained less than 1% of 2D:4D R in the population, adjusted for child age and sex. Pearson's linear correlation revealed that maternal age was negatively correlated with 2D:4D R in daughters (r = -0.11, p = 0.0137), but not in sons (r = 0.02, p = 0.6908). The negative correlation of 2D:4D R with maternal age indicates that the daughters of older mothers exhibited lower values of that ratio relative to the same-age daughters of younger mothers. CONCLUSIONS: For both study groups, the right-hand digit ratio was positively correlated with maternal smoking and negatively with maternal work during pregnancy. Maternal age during pregnancy was negatively related to right hand 2D:4D only among girls.

Risk of Migraine in Europeans with Low Melanin Levels-A Population Based Case-Control Study.

Populations with a relatively low concentration of melanin, e.g., inhabitants of Europe, North America, and Australia, are the most vulnerable to the harmful effects of UV radiation. Individuals with fair phototype are at greatest risk of developing skin cancer. Several neurological studies present that light skin may modify the risk of Alzheimer's and Parkinson's diseases. However, the relationship between migraine and skin pigmentation has not been investigated yet. The objective of this study is to provide evidence of the relationship between skin pigmentation and migraine prevalence in adults. We examined a group of 148 adults (33 men, 115 women) with migraine and a control group of 107 adults (43 men, 64 women). Parameters of skin pigmentation (melanin index, erythema index, CIElab, and RGB scales) were measured using a DSM II Cortex Technology dermospectrophotometer. Risk of migraine in lightly pigmented adults was elevated. Individuals with a low melanin index had over 3-fold increased risk of migraine (women: OR 3.53, men: OR 3.73). Fair phototype, which results from lightly pigmented skin, was associated with migraine prevalence. Migraineurs should take extra care to protect their skin from the negative effects of solar radiation.

Association studies between chromosomal regions 1q21.3, 5q21.3, 14q21.2 and 17q21.31 and numbers of children in Poland.

Number of children is an important human trait and studies have indicated associations with single-nucleotide polymorphisms (SNPs). Aim: to give further evidence for four associations using a large sample of Polish subjects. Data from the POPULOUS genetic database was provided from anonymous, healthy, unrelated, Polish volunteers of both sexes (N = 5760). SNPs (n = 173) studied: (a) 69 from the chromosome 17 H1/H2 inversion; (b) six from 1q21.3, 5q21.3 and 14q21.2; and (c) 98 random negative controls. Zero-inflated negative-binomial regression (z.i.) was performed (0-3 numbers of children per individual (NCI) set as non-events; adjustors: year of birth, sex). Significance level p = 0.05 with Bonferroni correction. Statistically-significant differences (with data from both sexes combined) were obtained from highly-linked inversion SNPs: representative rs12373123 gave means: homozygotes TT: 2.31 NCI (n = 1418); heterozygotes CT: 2.35 NCI (n = 554); homozygotes CC: 2.44 NCI (n = 43) (genotype p = 0.01; TTvs.CC p = 0.004; CTvs.CC p = 0.009). (Male data alone gave similar results.) Recessive modeling indicated that H2-homozygotes had 0.118 more children than H1-homozygotes + heterozygotes (z.i.-count estimates ± standard errors: CT, - 0.508 ± 0.194; TT, - 0.557 ± 0.191). The non-over-dispersed count model detected no interactions: of importance there was no significant interaction with age. No positive results were obtained from negative-control SNPs or (b). Conclusions: association between the H1/H2 inversion and numbers of children (previously reported in Iceland) has been confirmed, albeit using a different statistical model. One limitation is the small amount of data, despite initially ~ 6000 subjects. Causal studies require further investigation.

Association of prenatal sex steroid exposure estimated by the digit ratio (2D:4D) with birth weight, BMI and muscle strength in 6- to 13-year-old Polish children.

OBJECTIVES: The aim of this paper was to provide evidence for the impact of prenatal sex steroid exposure on prenatal and postnatal body size parameters, and muscle strength in children. METHODS: The following anthropometric data were studied in a group of 1148 children (536 boys and 612 girls) aged 6-13 years: the 2D:4D digit ratio, birth weight and length, and birth head and chest circumference. Postnatal parameters (6-13 years) included body weight and height, BMI, waist and hip circumference, WHR, as well as grip strength in both hands. All parameters that required it were adjusted for sex and gestational or chronological age. A general linear model, Pearson's correlation, t-statistics and Cohen's Δ were used in statistical analysis. RESULTS: Among birth size parameters, only birth weight was significantly negatively correlated with the 2D:4D digit ratio in children. Higher (feminized) digit ratios were significantly correlated with postnatal parameters such as body weight, BMI, and waist and hip circumference (positively), as well as hand grip strength-a proxy for muscular strength (negatively). CONCLUSION: Problems with maintaining adequate body size parameters and muscle strength may be programmed in fetal life and predicted on the basis of the 2D:4D digit ratio. Body weight at birth and in early ontogenesis are additive correlates of the 2D:4D ratio. The present findings suggest that the 2D:4D digit ratio is related to postnatal phenotypes such as birth weight, overweight, and obesity as well as muscle strength in 6-13-year-old children of both sexes.