Search

The association between second to fourth finger ratio and thyroid diseases is unexplained. There is a possible interaction between prenatal exposition to sex hormone and thyroid functions in the adulthood. The study included 175 adults investigated in Łódź in the central Poland. It consisted of two main parts: a survey including questions about occurrence of thyroid gland dysfunction and anthropometric measurements (body mass and height and length of the second and fourth finger, waist and hip circumferences). The women who had thyroid disease had higher 2D:4D digit ratio (left hand) (mean = 1.004; SD = 0.036) than healthy ones (mean = 0.989; SD = 0.030) (t = − 2105; p = 0.038; d = 0.707). The association between thyroid diseases occurrence and prenatal steroid hormone exposition is noticed. Only females who had thyroid diseases tend to have higher 2D:4D digit ratio, for left hand. [ABSTRACT FROM AUTHOR]

The 2D:4D digit ratio is formed as a result of genetic factors but also prenatal exposure to sex hormones. The higher index value the higher concentration of the prenatal oestrogen. It is commonly known that testosterone is a hormone connected with muscle mass growth and that oestrogen affects adipogenesis. The aim of this study was to find if the digit ratio can be an informative indicator of the fat mass and muscle mass and body proportions in prepubertal children. Material and methods The analysed cohort included 420 children (221 girls and 199 boys) aged 6-13 years. Pearson's and Spearman's tests were conducted to assess whether 2D:4D was significantly correlated with the body composition measurements. Multiple regression models and stepwise forward regression were applied to select the most important independent variables affecting fat mass (%) and muscle mass (%) as well as the BMI and the WHR. Results The study shows that the digit ratio is negatively correlated with muscle mass (MM%) among girls (p < 0.05).There was no similar relationship in the group of boys. The regression models showed a significant role in determining the body composition and body proportions played by maternal factors such as: maternal level of education and weight gain during pregnancy. Conclusions The 2D:4D digit ratio seems to be an informative indicator of the muscle mass development since girls' early childhood. Moreover, maternal environment is also important in forming the offspring's body composition and proportions. [ABSTRACT FROM AUTHOR]

Humans exhibit sex differences in competitiveness, sensation seeking and risk-taking attitude, which are required in sports. These attributes are often linked to prenatal testosterone (PT) exposure. The second-to-fourth digit length ratio (2D:4D) is an indicator of PT exposure. A lower 2D:4D indicates higher PT exposure and vice versa. Males generally have a lower 2D:4D than females. Sensation- and/or thrill-seeking behaviours have also been found to be negatively associated with 2D:4D. Boxing and judo are considered to be high-risk sports. Voluntary participation in judo/boxing in contrast to aerobics can be guided by such behaviours and thus have an association with lower 2D:4D. This cross-sectional study included 167 female students from a military academy in Wrocław, Poland. Of them, 119 had voluntarily chosen aerobic exercise, and 48 opted for judo/boxing. Height, weight and second and fourth digit lengths were measured. Physical fitness was assessed using Eurofit tests. The two groups showed similar physical fitness and body size. However, the judo/boxing group had significantly lower mean 2D:4D values than the aerobics group. It is proposed that voluntary choice of participation in a sport discipline by women could be linked to the ‘organizational’ effect of intrauterine testosterone exposure during prenatal growth. [ABSTRACT FROM PUBLISHER]

The second to fourth digit ratio (2D:4D) is claimed to be a biomarker of prenatal sex steroids. This study compared 2D:4D and waist–hip ratio (WHR) in men and women with nose deformity caused by injuries suggesting risky behaviour with those of unaffected controls. This kind of facial trauma was accepted as an indicator of risk-taking behaviour. The study involved 100 patients (50 women aged 30.74±8.09 years and 50 men aged 30.98±10.86 years) who underwent rhinoplasty due to nose trauma in a hospital in Łódź, Poland, in 2015. For comparison purposes, a control sample of 70 women (aged 23.03±3.36 years) and 70 men (aged 22.87±3.46 years) was recruited. In both groups the following measurements were taken: body height, waist and hip circumferences, II and IV digit lengths and body weight. The results showed that women and men who had suffered nose injury had significantly higher values of WHR than controls. The 2D:4D in women with post-traumatic nose deformity was significantly different than the ratio in control women (p<0.0001) and presented the male pattern. It is concluded that in women risky behaviours seem to be associated with prenatal sex hormone influence, while differences in WHR suggest that this tendency is also related to postnatal hormonal factors. Risky behaviours in men should be linked to postnatal hormonal changes rather than to increased prenatal androgen exposure. [ABSTRACT FROM PUBLISHER]

The ratio of second-to-fourth digit length (2D:4D), which is generally higher in women compared with men, is a putative marker of prenatal testosterone (PT) exposure. Lower 2D:4D is linked with greater physical ability and strength, better sporting performance and a propensity towards jobs demanding greater physical ability. The objectives of this paper were to examine the sexual dimorphism in 2D:4D in both hands 1and compare this dimorphism in the students of military and civil courses at the General Kuściuszko Military Academy of Land Forces in Wrocław. The cross-sectional study compared 59 female and 118 male students from the military courses and 53 females and 64 male students from the civil courses. Besides calculating 2D:4D (2D/4D) for each hand, height and weight were also recorded. Physical fitness and endurance were assessed using Eurofit tests. Handgrip strength was measured using a standardized isometric dynamometer. In almost all physical tests, students in the military cohort showed highly significant greater physical ability and strength (e.g. handgrip strength) when compared with the civil cohort. Male participants had a significantly lower 2D:4D than females for each hand, as well as for the average value for both hands. The sexual dimorphism was, however, a little more pronounced in the right hand than in the left. Both sex and course type were significant predictors of 2D:4D. There were significant interactions between sex and the student type. Among females, but not in males, the military cohort had a significantly lower, i.e. more 'masculine', 2D:4D for the left hand and right hand and average for both hands (t=3.290, p<0.001) than the civil cohort. This was not the case in males. However, the sex difference in 2D:4D was only significant among the civil students, and not among the military cadets. In conclusion, higher PT exposure, as represented by a lower 2D:4D, among the Polish females might be an indicator of relatively increased physical ability and motivation to choose professions that require higher strength and endurance. [ABSTRACT FROM AUTHOR]

The aim of the retrospective study was to assess the influence of parity on the skeletal status in 760 postmenopausal women. Women with factors affecting their bone status, or those treated for osteoporosis, were not included. Quantitative ultrasound measurements were performed at the heel (Achilles, n = 465) or at hand phalanges (DBM Sonic 1200, n = 295). Regarding hand phalanges, Z score values were significantly lower in women with three, four, and five or six deliveries in comparison to nonparous women and in women with four deliveries versus women with one or two deliveries. Calcaneus ultrasound variables did not differ in regard to the number of deliveries. Stepwise multiple regression analysis has shown that the main factors, affecting the bone status, were postmenopause duration and body weight. We concluded the increasing number of deliveries negatively influences ultrasound measurements at hand phalanges, which suggests their role as a qualitative feature factor of cortical non-weight-bearing bone. [ABSTRACT FROM AUTHOR]

Background: Tattoos bring risks yet no obvious evolutionary benefit. Koziel et al. (2010) reported increased fluctuating symmetry (a proxy for low developmental instability) in tattooed men, suggesting they could serve as fitness indicators.Aims: We replicate and extend the findings of Koziel et al. by examining fluctuating asymmetry of finger lengths and digit ratio (2D:4D) (a putative indicator of prenatal testosterone exposure) as predictors of adult tattoo prevalence.Study Design: We used an online survey with a correlational design.Subjects: Participants were recruited from the UK and Poland via university participant pools and social media. Data were available for presence/absence of tattoos and at least one predictor variable (composite Fluctuating Asymmetry [cFA], right-hand digit ratio [R2D:4D] and left-hand digit ratio [L2D:4D]) for n = 186 males and n = 997 females.Outcome Measures: We firstly assessed presence/absence of tattoos; when at least one tattoo was present, we also examined overall number and highest visibility.Results: Greater cFA was associated with lower likelihood of having tattoos in males, though in females greater cFA was associated with higher numbers of tattoos. R2D:4D and L2D:4D correlated negatively with number of tattoos in males, and a positive correlation between L2D:4D and number of tattoos was observed in females. However, these latter findings did not remain significant after controlling for covariates.Conclusions: Tattoos may act as fitness indicators in males, though this explanation appears not to extend to females. Prenatal testosterone may also play a role, though doubt is cast on this premise because 2D:4D effects did not remain statistically significant after controlling for covariates. [ABSTRACT FROM AUTHOR]