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Sorokowski P, Kowal M. Relationship between the 2D:4D and prenatal testosterone, adult level testosterone, and testosterone change: Meta-analysis of 54 studies. AMERICAN JOURNAL OF BIOLOGICAL ANTHROPOLOGY 2024; 183:20-38. [PMID: 37795916 DOI: 10.1002/ajpa.24852] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/06/2022] [Revised: 08/29/2023] [Accepted: 09/12/2023] [Indexed: 10/06/2023]
Abstract
The ratio between the hands' second to the fourth finger (2D:4D) is commonly hypothesized to result from prenatal testosterone. The 2D:4D has also been hypothesized to relate to adult-level testosterone and, more recently, to the testosterone response to a challenging situation. In the present work, we tested these core assumptions. Drawing from, in total, 54 studies and 8077 participants, we investigated whether the 2D:4D is related to adult level testosterone (44 studies), testosterone change (6 studies), and prenatal testosterone (10 studies). We found no evidence of the relationship between the above testosterone types and digit ratios. Furthermore, there was no relationship between testosterone and the right and left 2D:4D, male and female 2D:4D, and the 2D:4D and testosterone measurement (i.e., measured in blood or saliva). However, we found some evidence that prenatal testosterone measured in amniotic fluid (but not cord blood) might be related to the digit ratios-further studies are necessary to validate this observation. In summary, considering the current state of knowledge, any conclusions drawn from the assumption of the digit ratios as the proxy for testosterone (prenatal, adult level, or testosterone change under a challenging situation) warrant great caution.
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Affiliation(s)
| | - Marta Kowal
- IDN Being Human Lab, University of Wrocław, Wrocław, Poland
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2
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Klimek M, Entringer S, Matras A, Blukacz M, Nenko I, Galbarczyk A, Jasienska G. Early-life adversities and later-life reproductive patterns in women with fully traced reproductive history. Sci Rep 2023; 13:9328. [PMID: 37291139 PMCID: PMC10250381 DOI: 10.1038/s41598-023-36226-w] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/06/2023] [Accepted: 05/31/2023] [Indexed: 06/10/2023] Open
Abstract
One of the most crucial determinants of early-life development is the experience of childhood adversities. However, limited evidence is available for how these experiences shape later-life reproductive outcomes in women. Here we test the association between early-life adversities and reproductive parameters in women. Post-reproductive women (N = 105; mean age = 59.7; SD = 10.09) were recruited at the Mogielica Human Ecology Study Site in Poland within a traditional population with a low prevalence of birth control usage and fully traced reproductive histories. Reproductive parameters, as well as exposure to early-life abuse and neglect, were assessed using questionnaires. Childhood adversity was associated negatively with age at menarche (p = 0.009). Analyses on specific subtypes revealed that compared to women who did not experience any kind of early-life adversities in childhood, those who were exposed to emotional (p = 0.007) and physical (p = 0.023) neglect had an earlier age at menarche, those who experienced emotional abuse reported an earlier age at first birth (p = 0.035), and those who were exposed to physical abuse gave birth to fewer number of sons (p = 0.010). Our results suggest that women exposed to childhood adversities experience earlier physiological reproductive readiness and timing of the first birth, but their overall biological condition might be impaired as they bear fewer sons.
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Affiliation(s)
- Magdalena Klimek
- Department of Environmental Health, Faculty of Health Sciences, Jagiellonian University Medical College, Krakow, Poland.
| | - Sonja Entringer
- Institute of Medical Psychology, Charité - Universitätsmedizin Berlin, Corporate Member of Freie Universität Berlin and Humboldt-Universität Zu Berlin, Berlin, Germany
- Department of Pediatrics, University of California Irvine, Irvine, CA, USA
| | - Agnieszka Matras
- Department of Environmental Health, Faculty of Health Sciences, Jagiellonian University Medical College, Krakow, Poland
| | - Mateusz Blukacz
- Department of Environmental Health, Faculty of Health Sciences, Jagiellonian University Medical College, Krakow, Poland
- Institute of Psychology, Faculty of Social Sciences, University of Silesia, Katowice, Poland
| | - Ilona Nenko
- Department of Environmental Health, Faculty of Health Sciences, Jagiellonian University Medical College, Krakow, Poland
| | - Andrzej Galbarczyk
- Department of Environmental Health, Faculty of Health Sciences, Jagiellonian University Medical College, Krakow, Poland
| | - Grazyna Jasienska
- Department of Environmental Health, Faculty of Health Sciences, Jagiellonian University Medical College, Krakow, Poland
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Evcen R, Çölkesen F, Saygın DA, Aykan FS, Kılınç M, Ergün ÜY, Akkuş FA, Önalan T, Yıldız E, Arslan Ş. High digit ratio (2D:4D) is associated with attack frequency and severity in hereditary angioedema patients. Early Hum Dev 2023; 177-178:105724. [PMID: 36827749 DOI: 10.1016/j.earlhumdev.2023.105724] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/12/2023] [Revised: 02/03/2023] [Accepted: 02/03/2023] [Indexed: 02/11/2023]
Abstract
BACKGROUND Hereditary angioedema (HAE) caused by a deficiency or dysfunction of the plasma protease C1-inhibitor is a rare autosomal-dominant disorder. We explored a possible correlation between the ratio of the second and fourth finger lengths (2D:4D) and the frequency of HEA attacks, and whether the ratio might predict laryngeal attack. METHOD We evaluated 35 HEA patients aged 19 to 66 years; 3 were subsequently excluded. The 2D:4D ratio was calculated by dividing the length of the second finger by that of the fourth finger of both hands. A structured clinical questionnaire exploring HAE course and treatment over the prior year was administered. RESULTS Of the 32 participants, 56.25 % (n = 18) were female. Of them, those with high 2D:4D ratios suffered significantly more laryngeal attacks than others; 93.3% of patients with high 2D:4D ratios experienced ≥5 attacks annually, significantly more than those with low ratios. Among type 2 HEA patients, 75 % of those experiencing ≥5 attacks annually had high 2D:4D ratios; all patients with low 2D:4D ratios reported <5 attacks annually. These significant effects were found for right-hand 2D:4D ratios and not left-hand 2D:4D ratios. CONCLUSION The data suggest that intrauterine sex hormone exposure, which affects the 2D:4D ratio, is significantly associated with HEA attack frequency and severity, and laryngeal edema.
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Affiliation(s)
- Recep Evcen
- Division of Clinical Immunology and Allergy, Department of Internal Medicine, Necmettin Erbakan University, Meram Faculty of Medicine, Konya, Turkey.
| | - Fatih Çölkesen
- Division of Clinical Immunology and Allergy, Department of Internal Medicine, Necmettin Erbakan University, Meram Faculty of Medicine, Konya, Turkey
| | - Duygu Akın Saygın
- Department of Anatomy, Necmettin Erbakan University, Meram Faculty of Medicine, Konya, Turkey
| | - Filiz Sadi Aykan
- Division of Clinical Immunology and Allergy, Department of Internal Medicine, Necmettin Erbakan University, Meram Faculty of Medicine, Konya, Turkey
| | - Mehmet Kılınç
- Division of Clinical Immunology and Allergy, Department of Internal Medicine, Necmettin Erbakan University, Meram Faculty of Medicine, Konya, Turkey
| | - Ümmügülsüm Yılmaz Ergün
- Division of Clinical Immunology and Allergy, Department of Internal Medicine, Necmettin Erbakan University, Meram Faculty of Medicine, Konya, Turkey
| | - Fatma Arzu Akkuş
- Division of Clinical Immunology and Allergy, Department of Internal Medicine, Necmettin Erbakan University, Meram Faculty of Medicine, Konya, Turkey
| | - Tuğba Önalan
- Division of Clinical Immunology and Allergy, Department of Internal Medicine, Necmettin Erbakan University, Meram Faculty of Medicine, Konya, Turkey
| | - Eray Yıldız
- Necip Fazıl City Hospital, Division of Clinical Immunology and Allergy, Kahramanmaraş, Turkey
| | - Şevket Arslan
- Division of Clinical Immunology and Allergy, Department of Internal Medicine, Necmettin Erbakan University, Meram Faculty of Medicine, Konya, Turkey
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Maternal Age and Behavior during Pregnancy Affect the 2D:4D Digit Ratio in Polish Children Aged 6–13 Years. BIOLOGY 2022; 11:biology11091286. [PMID: 36138765 PMCID: PMC9527011 DOI: 10.3390/biology11091286] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 07/28/2022] [Revised: 08/23/2022] [Accepted: 08/27/2022] [Indexed: 11/16/2022]
Abstract
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 (β = 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 (β = −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.
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Dinsdale N, Nepomnaschy P, Crespi B. The evolutionary biology of endometriosis. EVOLUTION MEDICINE AND PUBLIC HEALTH 2021; 9:174-191. [PMID: 33854783 PMCID: PMC8030264 DOI: 10.1093/emph/eoab008] [Citation(s) in RCA: 26] [Impact Index Per Article: 8.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 10/19/2020] [Accepted: 02/04/2021] [Indexed: 12/14/2022]
Abstract
We provide the first analysis and synthesis of the evolutionary and mechanistic bases for risk of endometriosis in humans, structured around Niko Tinbergen's four questions about phenotypes: phylogenetic history, development, mechanism and adaptive significance. Endometriosis, which is characterized by the proliferation of endometrial tissue outside of the uterus, has its phylogenetic roots in the evolution of three causally linked traits: (1) highly invasive placentation, (2) spontaneous rather than implantation-driven endometrial decidualization and (3) frequent extensive estrogen-driven endometrial proliferation and inflammation, followed by heavy menstrual bleeding. Endometriosis is potentiated by these traits and appears to be driven, proximately, by relatively low levels of prenatal and postnatal testosterone. Testosterone affects the developing hypothalamic-pituitary-ovarian (HPO) axis, and at low levels, it can result in an altered trajectory of reproductive and physiological phenotypes that in extreme cases can mediate the symptoms of endometriosis. Polycystic ovary syndrome, by contrast, is known from previous work to be caused primarily by high prenatal and postnatal testosterone, and it demonstrates a set of phenotypes opposite to those found in endometriosis. The hypothesis that endometriosis risk is driven by low prenatal testosterone, and involves extreme expression of some reproductive phenotypes, is supported by a suite of evidence from genetics, development, endocrinology, morphology and life history. The hypothesis also provides insights into why these two diametric, fitness-reducing disorders are maintained at such high frequencies in human populations. Finally, the hypotheses described and evaluated here lead to numerous testable predictions and have direct implications for the treatment and study of endometriosis. Lay summary: Endometriosis is caused by endometrial tissue outside of the uterus. We explain why and how humans are vulnerable to this disease, and new perspectives on understanding and treating it. Endometriosis shows evidence of being caused in part by relatively low testosterone during fetal development, that 'programs' female reproductive development. By contrast, polycystic ovary syndrome is associated with relatively high testosterone in prenatal development. These two disorders can thus be seen as 'opposite' to one another in their major causes and correlates. Important new insights regarding diagnosis, study and treatment of endometriosis follow from these considerations.
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Affiliation(s)
- Natalie Dinsdale
- Department of Biological Sciences, Simon Fraser University, Burnaby, BC, Canada
| | - Pablo Nepomnaschy
- Faculty of Health Sciences, Simon Fraser University, Burnaby, BC, Canada
| | - Bernard Crespi
- Department of Biological Sciences, Simon Fraser University, Burnaby, BC, Canada
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Richards G, Medland SE, Beaton AA. Digit ratio (2D:4D) and handedness: A meta-analysis of the available literature. Laterality 2021; 26:421-484. [PMID: 33517845 DOI: 10.1080/1357650x.2020.1862141] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Abstract
The Geschwind-Behan-Galaburda and sexual differentiation models predict an association between elevated foetal androgen exposure and left-handedness whereas the callosal hypothesis predicts the opposite. We present a meta-analysis of correlations between handedness and digit ratio (2D:4D), a putative marker of prenatal testosterone. Left-handedness predicted low (male-typical) right-hand digit ratio (R2D:4D), high (female-typical) left-hand digit ratio (L2D:4D), and low R2D:4D-L2D:4D directional asymmetry (D[R-L]). Effect sizes were extremely small and not moderated by sex or method of measuring handedness or 2D:4D. The same general pattern was observed after excluding the very large study (110,329 males, 90,412 females) of Manning and Peters ([2009]. Digit ratio (2D:4D) and hand preference for writing in the BBC Internet Study. Laterality: Asymmetries of Body, Brain and Cognition, 14(5), 528-540. doi:10.1080/13576500802637872); however, no significant effects for R2D:4D were observed once these samples were removed. The results do not confirm any theory linking prenatal androgens with handedness, so we speculate they instead reflect the mechanical action of writing causing subtle changes in the musculature and/or fat pads of the fingers. Gripping a pen/pencil might cause an increase in 2D relative to 4D (and/or decrease in 4D relative to 2D) resulting in higher ratios on the writing-hand; furthermore, this could differ between left- and right-handers due to writing in the left-to-right direction (as in English) having asymmetrical effects depending on which hand is used.
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Affiliation(s)
- Gareth Richards
- School of Psychology, Faculty of Medical Sciences, Newcastle University, Newcastle upon Tyne, UK.,Autism Research Centre, Department of Psychiatry, University of Cambridge, Cambridge, UK.,Centre for Research on Play in Education, Development & Learning, Faculty of Education, University of Cambridge, Cambridge, UK
| | - Sarah E Medland
- Psychiatric Genetics, QIMR Berghofer Medical Research Institute, Brisbane, Australia.,School of Psychology, University of Queensland, St Lucia, Australia.,School of Psychology and Counselling, Queensland University of Technology, Brisbane, Australia
| | - Alan A Beaton
- Department of Psychology, School of Human & Health Sciences, Swansea University, Swansea, UK.,Department of Psychology, Aberystwyth University, Aberystwyth, UK
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Association patterns between 2D:4D ratio and age at menarche: the impact of methodology. ANTHROPOLOGICAL REVIEW 2020. [DOI: 10.2478/anre-2020-0026] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Abstract
The ratio of index finger to ring finger length (2D:4D) is a sexually dimorphic feature and widely used as an indicator of prenatal androgen-estrogen exposure. Several studies have investigated the relationship between the 2D:4D ratio and the onset of the first menstrual period (menarche) in women.
The present study tested the association patterns between 2D:4D ratio and age at menarche. Furthermore, the impact of methods of measuring finger lengths was considered.
Two samples were used to conduct the study. One sample consisted of 110 women who self-measured their finger lengths. The finger length measurements in the second sample (88 women) were taken from one trained observer using the caliper-based technique. Age at menarche was determined using a retrospective method.
Women from the first sample reported an average age for the onset of the first menstrual bleeding at 12.9 (SD = 1.4) years of age. There was no significant association between the left and right 2D:4D ratio and the age at menarche. The second sample showed a mean age at menarche at 12.8 (SD = 1.3) years of age. Here, the right hand 2D:4D ratio and age at menarche were significantly correlated (p<0.001).
A more feminine 2D:4D ratio was significantly associated with an earlier menarcheal age only in the sample with direct finger length measurements by a trained investigator. The sample using self-measurements yielded no significant associations between menarcheal age and 2D:4D. The use of a reliable and well-founded methodology is essential for obtaining meaningful results.
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Richards G, Baron-Cohen S, van Steen T, Galvin J. Assortative mating and digit ratio (2D:4D): A pre-registered empirical study and meta-analysis. Early Hum Dev 2020; 151:105159. [PMID: 32942249 DOI: 10.1016/j.earlhumdev.2020.105159] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/02/2020] [Revised: 08/10/2020] [Accepted: 08/18/2020] [Indexed: 02/06/2023]
Abstract
BACKGROUND It has been hypothesised that the ratio of length between the second and fourth fingers (2D:4D), commonly employed as an indicator of foetal sex hormone exposure, may be positively correlated between heterosexual partners. AIMS As previous evidence has been conflicting, our study aimed to determine whether intra-couple correlations exist for digit ratio variables, and if so, to estimate the size and direction of these effects. STUDY DESIGN We present a preregistered (osf.io/6jg8p) correlational study and quantitative meta-analysis of the available literature, and attempted to locate further published and unpublished data (i.e. 'grey literature') by contacting n = 248 researchers in the 2D:4D and related fields. SUBJECTS n = 58 heterosexual dating couples from the UK took part in our empirical study, and the meta-analysis included data from k = 11 samples. OUTCOME MEASURES We measured digit ratio for the right hand (R2D:4D), left hand (L2D:4D), and average of both hands (M2D:4D), as well as the right-left-difference (D[R-L]). RESULTS We found no evidence of significant positive intra-couple correlations in our own data, but a significant (positive) meta-analytic effect size estimate emerged for R2D:4D (r = 0.072, p = 0.014). The meta-analytic effects for L2D:4D (r = 0.043, p = 0.303), M2D:4D (r = 0.070, p = 0.225), and D[R-L] (r = 0.028, p = 0.649) were all in the same direction but not statistically significant. However, if the sample from Klimek et al. (2014, 2016) were omitted, meta-analysis would also yield a significant positive correlation for M2D:4D (r = 0.128, p = 0.001). CONCLUSIONS Although our findings are based on a fairly small range of studies, which themselves provide a relatively small sample of participants, they do imply the intriguing possibility of small effects of positive assortment in relation to characteristics associated with the prenatal hormonal environment.
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Affiliation(s)
- Gareth Richards
- School of Psychology, Faculty of Medical Sciences, Newcastle University, UK; Autism Research Centre, Department of Psychiatry, University of Cambridge, UK.
| | - Simon Baron-Cohen
- Autism Research Centre, Department of Psychiatry, University of Cambridge, UK
| | - Tommy van Steen
- Institute of Security and Global Affairs, Universiteit Leiden, Netherlands
| | - John Galvin
- Department of Psychology, Birmingham City University, UK
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Miłkowska K, Nenko I, Klimek M, Galbarczyk A, Jasienska G. Season of birth and biomarkers of early-life environment. Am J Hum Biol 2020; 33:e23532. [PMID: 33166028 DOI: 10.1002/ajhb.23532] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/20/2020] [Revised: 08/21/2020] [Accepted: 10/22/2020] [Indexed: 11/05/2022] Open
Abstract
OBJECTIVE Early-life conditions play an important role in human development, affecting health status and survival. Conditions in utero partly depend on the external environment and thus vary in relation to the season of birth. The aim of this study was to investigate if people born in different seasons of the year differ in values of biomarkers that reflect conditions during fetal development. METHODS The study was conducted among Polish rural women recruited at the Mogielica Human Ecology Study Site. The participants were 234 women aged 45 to 92 (mean = 60.2; SD = 10.44). The indicators of early-life environment analyzed in the study were: Absolute Finger Ridge Count (AFRC), the difference between mean number of ridge counts in both thumbs and both little fingers (Md15), overall facial fluctuating asymmetry (OFA), central facial asymmetry (CFA), right and left hand 2D:4D. RESULTS Values of biomarkers of fetal development did not vary among groups of women born in different seasons of the year. CONCLUSIONS Lack of differences in values of biomarkers according to birth season may indicate that: (a) season of birth is not a good indicator of early-life conditions; (b) tested biomarkers do not reliably reflect the prenatal environment; (c) season of birth does not fully overlap with the sensitive periods of biomarker development and thus fails to capture differences in developmental conditions.
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Affiliation(s)
- Karolina Miłkowska
- Department of Environmental Health, Faculty of Health Sciences, Jagiellonian University Medical College, Krakow, Poland
| | - Ilona Nenko
- Department of Environmental Health, Faculty of Health Sciences, Jagiellonian University Medical College, Krakow, Poland
| | - Magdalena Klimek
- Department of Environmental Health, Faculty of Health Sciences, Jagiellonian University Medical College, Krakow, Poland
| | - Andrzej Galbarczyk
- Department of Environmental Health, Faculty of Health Sciences, Jagiellonian University Medical College, Krakow, Poland
| | - Grazyna Jasienska
- Department of Environmental Health, Faculty of Health Sciences, Jagiellonian University Medical College, Krakow, Poland
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10
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Klimek M, Galbarczyk A, Nenko I, Jasienska G. Biomarkers of fetal conditions: Finger ridge-counts, facial fluctuating asymmetry, and digit ratio (2D:4D)-are they correlated in women? AMERICAN JOURNAL OF PHYSICAL ANTHROPOLOGY 2020; 174:224-231. [PMID: 33098083 DOI: 10.1002/ajpa.24164] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/23/2020] [Revised: 08/01/2020] [Accepted: 10/10/2020] [Indexed: 11/08/2022]
Abstract
OBJECTIVES Fetal environmental conditions are crucial for life-long health. Direct measurements of developmental conditions are limited in humans; thus, several biomarkers of those conditions have been proposed: that is, finger ridge-counts, level of facial fluctuating asymmetry (FA), and digit ratio (2D:4D). Since all of these biomarkers share a similar gestational time of formation, we hypothesize that their values are significantly correlated. MATERIALS AND METHODS Data were collected at the Mogielica Human Ecology Study Site in southern Poland among 234 women. Finger ridge-counts, level of facial FA, and 2D:4D have been measured. The two-step analyses included Pearson's correlations of simple values of the biomarkers and correlations of composite variables calculated based on principal component analysis. RESULTS We did not find any statistically significant correlations between finger ridge-counts, FA, and 2D:4D in women. Similarly, we did not observe any correlations between three composites created from the biomarkers. DISCUSSION Our results indicate that there are no relationships between the biomarkers, suggested as proxies of the quality of prenatal conditions, in a single population. This is the first study analyzing three different markers simultaneously. The lack of correlations may indicate that the tested biomarkers reflect, in fact, different environmental conditions, occurring in separate "critical windows" of development, or that the biomarkers are not valid as proxies of developmental conditions.
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Affiliation(s)
- Magdalena Klimek
- Department of Environmental Health, Faculty of Health Sciences, Jagiellonian University Medical College, Krakow, Poland
| | - Andrzej Galbarczyk
- Department of Environmental Health, Faculty of Health Sciences, Jagiellonian University Medical College, Krakow, Poland
| | - Ilona Nenko
- Department of Environmental Health, Faculty of Health Sciences, Jagiellonian University Medical College, Krakow, Poland
| | - Grazyna Jasienska
- Department of Environmental Health, Faculty of Health Sciences, Jagiellonian University Medical College, Krakow, Poland
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11
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Jiang J, Young K, Pike CJ. Second to fourth digit ratio (2D:4D) is associated with dementia in women. Early Hum Dev 2020; 149:105152. [PMID: 32781308 PMCID: PMC7484057 DOI: 10.1016/j.earlhumdev.2020.105152] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/23/2020] [Revised: 08/03/2020] [Accepted: 08/04/2020] [Indexed: 02/08/2023]
Abstract
Alzheimer's disease is characterized by sex differences that may involve sex hormone exposure during development. Finger length ratios, an indirect measure of prenatal androgen exposure, were found to significantly differ in women with and without dementia. This finding links a relatively feminine in utero development with vulnerability to dementia in women.
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Affiliation(s)
| | | | - Christian J. Pike
- Corresponding Author: Christian J. Pike, Ph.D., Leonard Davis School of Gerontology, University of Southern California, 3715 McClintock Avenue, Los Angeles, CA 90089-0191 USA, Tel: 213-740-4205,
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12
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Lee KMN, Rogers-LaVanne MP, Galbarczyk A, Jasienska G, Clancy KBH. Bone density and frame size in adult women: Effects of body size, habitual use, and life history. Am J Hum Biol 2020; 33:e23502. [PMID: 32935454 DOI: 10.1002/ajhb.23502] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/11/2020] [Revised: 07/31/2020] [Accepted: 08/09/2020] [Indexed: 12/31/2022] Open
Abstract
OBJECTIVE Bone mineral density (BMD) and frame size are important predictors of future bone health, with smaller frame size and lower BMD associated with higher risk of later fragility fractures. We test the effects of body size, habitual use, and life history on frame size and cortical BMD of the radius and tibia in sample of healthy adult premenopausal women. METHODS We used anthropometry and life history data from 123 women (age 18-46) from rural Poland. Standard techniques were used to measure height, weight, and body fat. Life history factors were recorded using surveys. Grip strength was measured as a proxy for habitual activity, wrist breadth for skeletal frame size. Cortical BMD was measured at the one-third distal point of the radius and mid-point of the tibia using quantitative ultrasound (reported as speed of sound, SoS). RESULTS Radial SoS was high (mean t-score 3.2 ± 1.6), but tibia SoS was average (mean t-score 0.35 ± 1.17). SoS was not associated with age, although wrist breadth was positively associated with age after adjusting for height. Radius SoS was not associated with measures of body size, habitual use, or life history factors. Wrist breadth was associated with body size (p < .05 for all), lean mass, and grip strength. Tibia SoS was associated with height. Life history factors were not associated with frame size or cortical SoS. CONCLUSIONS Habitual use and overall body size are more strongly associated with frame size and cortical SoS than life history factors in this sample of healthy adult women.
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Affiliation(s)
- Katharine M N Lee
- Department of Anthropology, University of Illinois Urbana-Champaign, Urbana, Illinois, USA
| | - Mary P Rogers-LaVanne
- Department of Anthropology, University of Illinois Urbana-Champaign, Urbana, Illinois, USA
| | - Andrzej Galbarczyk
- Department of Environmental Health, Faculty of Health Sciences, Jagiellonian University Medical College, Krakow, Poland
| | - Grazyna Jasienska
- Department of Environmental Health, Faculty of Health Sciences, Jagiellonian University Medical College, Krakow, Poland
| | - Kathryn B H Clancy
- Department of Anthropology, University of Illinois Urbana-Champaign, Urbana, Illinois, USA.,Beckman Institute of Advanced Science & Technology, University of Illinois Urbana-Champaign, Urbana, Illinois, USA
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Lofeu L, Brandt R, Kohlsdorf T. Digit identity matters: origin and evolution of sexual dimorphism in the digit lengths of tropidurid lizards. Biol J Linn Soc Lond 2020. [DOI: 10.1093/biolinnean/blaa088] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022]
Abstract
Abstract
Sexual dimorphism in digit lengths reflects phenotypic evolution mediated by developmental steroids. Differences in the identity of the sexually-dimorphic digit may evolve if the concentrations of sex-steroid receptors in the digit are easily modified and the initial changes have low impact on fitness. Accordingly, sexual dimorphism in digit lengths might initially originate under neutral selective regimes, being subsequently co-opted by embryonic hormonal effects on sensitive traits that are more likely to be targeted by selection. Correlated variation among sexually-dimorphic traits might therefore reflect pleiotropic hormonal modulation during development. Moreover, the identity and trend of the sexually-dimorphic digit might be evolutionarily labile even among closely-related species. We evaluated this model by assessing the identity of sexually-dimorphic digits among 11 Tropiduridae lizard species and inferring evolutionary patterns of sexual dimorphism. Assuming that digit lengths can be used as a proxy for hormonal modulation of steroid-sensitive traits during development, we tested for evolutionary associations among sexual dimorphism of digit lengths, body size and other traits that may be direct targets of sexual selection in the Tropiduridae. Sexual dimorphism in digit lengths is evolutionarily labile in the Tropiduridae, and diversity, instead of conservatism, seems to rule developmental mechanisms underlying the evolution of sexual dimorphism in digit ratios.
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Affiliation(s)
- Leandro Lofeu
- Department of Biology, FFCLRP, University of São Paulo, Ribeirão Preto, São Paulo, Brazil
| | - Renata Brandt
- Department of Biology, FFCLRP, University of São Paulo, Ribeirão Preto, São Paulo, Brazil
- Science North, Sudbury, ON, Canada
| | - Tiana Kohlsdorf
- Department of Biology, FFCLRP, University of São Paulo, Ribeirão Preto, São Paulo, Brazil
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Kirchengast S, Dottolo E, Praxmarer E, Huber J. Low digit ratio (2D:4D) is associated with early natural menopause. Am J Hum Biol 2019; 32:e23374. [PMID: 31837082 PMCID: PMC7317431 DOI: 10.1002/ajhb.23374] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/20/2019] [Revised: 12/02/2019] [Accepted: 12/05/2019] [Indexed: 11/09/2022] Open
Abstract
Objectives Intrauterine environmental conditions may affect the number of primordial follicles and in this way the timing of menopause. The aim of the present study was to investigate association patterns between right hand digit ratio, that is, 2D:4D ‐ as an indicator of prenatal androgen and estrogen exposure, and age at menopause. Methods One hundred sixty‐nine women, who had experienced natural menopause, were enrolled in the study. Length of second and fourth finger were measured directly from the palmar side and digit ratios of both hands were calculated. For further analyses the digit ratio of the right hand was used only. Additionally, smoking habits, body weight and body height, body mass index and the number of children were determined. Multiple regression analyses were used to test association patterns between digit ratio and age at menopause, body height, BMI, nicotine consumption as well as number of births and age at menopause. Results Age at menopause correlated significantly positively with the digit ratio. A more feminine digit ratio is associated with a higher age at menopause, while a low digit ratio, interpreted as a hint of a higher androgen exposure during prenatal phase was associated with a lower age at menopause. Conclusions Low digit ratio is associated with an earlier onset of natural menopause.
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Affiliation(s)
- Sylvia Kirchengast
- Department of Evolutionary Anthropology, University of Vienna, Vienna, Austria
| | - Elisabeth Dottolo
- Department of Evolutionary Anthropology, University of Vienna, Vienna, Austria
| | - Elisa Praxmarer
- Department of Evolutionary Anthropology, University of Vienna, Vienna, Austria
| | - Johannes Huber
- Medical University of Vienna, University Clinic for Gynecology and Obstetrics, Vienna, Austria
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15
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Pearce E, Wlodarski R, Machin A, Dunbar RIM. Associations between neurochemical receptor genes, 2D:4D, impulsivity and relationship quality. Biol Lett 2018; 14:20180642. [PMID: 30518641 PMCID: PMC6303519 DOI: 10.1098/rsbl.2018.0642] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/10/2018] [Accepted: 11/06/2018] [Indexed: 01/05/2023] Open
Abstract
The ratio between the second and fourth digits (2D:4D) has been widely used as a proxy for fetal exposure to androgens and has been linked to a number of sociosexual traits in humans. However, the role of genes in this equation remains unknown. Here (N = 474), we test, firstly, for associations between 2D:4D and single-nucleotide polymorphisms (SNPs) in nine neurochemical receptor genes (AR, OXTR, AVPR1A, OPRM1, DRD1/2, ANKK1, 5HTR1A/2A), and secondly, whether digit ratios mediate the relationship between genetic variation and sociosexuality. We demonstrate significant associations between AR, OPRM1 and AVPR1A and 2D:4D. Moreover, mediation analysis indicates that, in women, AR and OPRM1 variation drives digit ratios, which are related positively to impulsivity and, for OPRM1, negatively to romantic relationship quality. Although these findings are subject to multiple testing issues, this study provides preliminary evidence that in women genetic factors may affect both impulsivity and perceived relationship quality through influencing factors indexed by digit ratios.
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Affiliation(s)
- Eiluned Pearce
- Social and Evolutionary Neuroscience Research Group, Department of Experimental Psychology, University of Oxford, Anna Watts Building, Radcliffe Observatory, Woodstock Road, Quarter, Oxford OX2 6GG, UK
| | - Rafael Wlodarski
- Social and Evolutionary Neuroscience Research Group, Department of Experimental Psychology, University of Oxford, Anna Watts Building, Radcliffe Observatory, Woodstock Road, Quarter, Oxford OX2 6GG, UK
| | - Anna Machin
- Social and Evolutionary Neuroscience Research Group, Department of Experimental Psychology, University of Oxford, Anna Watts Building, Radcliffe Observatory, Woodstock Road, Quarter, Oxford OX2 6GG, UK
| | - Robin I M Dunbar
- Social and Evolutionary Neuroscience Research Group, Department of Experimental Psychology, University of Oxford, Anna Watts Building, Radcliffe Observatory, Woodstock Road, Quarter, Oxford OX2 6GG, UK
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Bakholdina VY, Movsesian AA, Negasheva MA. Association between the digit ratio (2D:4D) and body fat distribution in Mordovian students. Ann Hum Biol 2018; 45:414-418. [PMID: 30328710 DOI: 10.1080/03014460.2018.1495264] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/30/2023]
Abstract
BACKGROUND The length ratio of the second to the fourth finger (2D:4D) is a possible biomarker of prenatal sex hormone levels, which play a significant role in determining sex-related body traits. AIMS To evaluate the value of the 2D:4D ratio in a Mordovian sample and to test the associations between the 2D:4D ratio and sexually dimorphic morphological traits, such as height and body weight, body mass index, waist and hip circumference, the waist-to-hip ratio, handgrip strength and the skinfold thickness. SUBJECTS AND METHODS The sample studied included 106 individuals of Mordovian ethnicity: 58 males and 48 females, 16-23 years old. The associations between the 2D:4D ratio and morphological traits were evaluated by multivariate regression analysis and correlation analysis. RESULTS The 2D:4D ratio in males was significantly lower than in females. Most of the associations of the 2D:4D ratio with morphological traits were statistically insignificant. The 2D:4D ratio is only significantly correlated with skinfold thickness of the forearm and the abdomen in females. CONCLUSION The association between the 2D:4D ratio and skinfold thickness is indicative of the role of prenatal sex hormones in shaping the body fat distribution in females, along with the significant impact of sex hormones at puberty.
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Affiliation(s)
| | - Alla A Movsesian
- a Department of Anthropology , Lomonosov State University , Moscow , Russian
| | - Marina A Negasheva
- a Department of Anthropology , Lomonosov State University , Moscow , Russian
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Zurawiecka M, Wronka I. Association of primary dysmenorrhea with anthropometrical and socio-economic factors in Polish university students. J Obstet Gynaecol Res 2018; 44:1259-1267. [PMID: 29673014 DOI: 10.1111/jog.13645] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/02/2017] [Accepted: 02/21/2018] [Indexed: 01/19/2023]
Abstract
AIMS To examine the prevalence and factors correlated with primary dysmenorrhea in young female subjects. METHODS Cross-sectional research was conducted among 1305 female university students aged 19-25 years. The following measurements were taken: height, body mass, waist circumference, hip circumference, the length of index and ring finger. A questionnaire was used to obtain information on menstrual pains, the characteristics of the menstrual cycles (regularity, duration), the number of the days of menstrual bleeding, age at menarche, overall health and socio-economic status of the subjects. RESULTS The prevalence of primary dysmenorrhea (PD) in the group was 64.85%, of which 69.60% reported mild pain, and 30.40% moderate and severe pain. PD occurs more frequently both in women with excess and insufficient level of abdominal adiposity. PD occurred more frequently in women who experience first menstruation at earlier age than in women with average and late age at menarche. The prevalence of PD grew along with mother's education and fell along with father's education. Painful menstruations occurred most commonly in women from large families. The impact of the age at menarche and the presence of abnormal body mass and abnormal level of abdominal adiposity on the prevalence of painful menstruation was also confirmed by the results of logistic regression analysis. The risk of PD is the highest in women whose finger 4 is longer than finger 2. CONCLUSION The results suggest that healthy body mass and lack of abdominal obesity may reduce the risk of PD.
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Affiliation(s)
- Martyna Zurawiecka
- Department of Anthropology, Institute of Zoology and Biomedical Research, Jagiellonian University in Krakow, Krakow, Poland
| | - Iwona Wronka
- Department of Anthropology, Institute of Zoology and Biomedical Research, Jagiellonian University in Krakow, Krakow, Poland
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18
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Wang L, Huo Z, Lu H, Bai C, Li K, Ma W. Digit ratio (2D:4D) and coronary artery disease in north Chinese women. Early Hum Dev 2018; 116:64-67. [PMID: 29179057 DOI: 10.1016/j.earlhumdev.2017.11.007] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/05/2017] [Revised: 11/19/2017] [Accepted: 11/21/2017] [Indexed: 01/23/2023]
Abstract
BACKGROUND Digit ratio (2D:4D) is fixed in utero and affected by fetal sex steroids. It has been proposed as a putative biomarker of certain hormone- related adult life traits and diseases. Several evidence suggest that 2D:4D ratio may correlate with cardiovascular disease risk (e.g., coronary artery disease). AIMS To investigate whether there is a possible relationship between digit ratio (especially 2D:4D ratio) and coronary artery disease (CAD), and age at CAD in north Chinese women. METHODS Photographs of the two hands of 303 females (controls: 194; patients: 109) were collected. Left hand, right hand and right minus left hand (Dr-l) digit ratio were analyzed and compared. RESULTS The mean values of digit ratio in patients with CAD were lower than controls for each hand. Significant differences of 2D:4D (left and right hand: P<0.01), 2D:5D (left hand: P<0.01; right hand: P<0.05) and 3D:4D (left hand: P<0.01) were found between two groups. There were no associations between 2D:4D ratio and age at CAD on both hands. CONCLUSION Decreased digit ratio (especially 2D:4D ratio) may suggest a higher prenatal testosterone (lower prenatal oestrogen) exposure in north Chinese women with coronary artery disease.
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Affiliation(s)
- Lu Wang
- Peking University Health Science Center, Beijing 100191, PR China
| | - Zhenghao Huo
- Ningxia Medical University, Key Laboratory of Fertility Preservation and Maintenance of Ministry of Education/Key Laboratory of Reproduction and Genetics/Basic Medical College, Yinchuan 750004, PR China
| | - Hong Lu
- Ningxia Medical University, Key Laboratory of Fertility Preservation and Maintenance of Ministry of Education/Key Laboratory of Reproduction and Genetics/Basic Medical College, Yinchuan 750004, PR China.
| | - Chunyue Bai
- Ningxia Medical University, Key Laboratory of Fertility Preservation and Maintenance of Ministry of Education/Key Laboratory of Reproduction and Genetics/Basic Medical College, Yinchuan 750004, PR China
| | - Keke Li
- Ningxia Medical University, Key Laboratory of Fertility Preservation and Maintenance of Ministry of Education/Key Laboratory of Reproduction and Genetics/Basic Medical College, Yinchuan 750004, PR China
| | - Wenqian Ma
- Ningxia Medical University, Key Laboratory of Fertility Preservation and Maintenance of Ministry of Education/Key Laboratory of Reproduction and Genetics/Basic Medical College, Yinchuan 750004, PR China
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Kaneoke Y, Donishi T, Iwahara A, Shimokawa T. Severity of Premenstrual Symptoms Predicted by Second to Fourth Digit Ratio. Front Med (Lausanne) 2017; 4:144. [PMID: 28936432 PMCID: PMC5595152 DOI: 10.3389/fmed.2017.00144] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2017] [Accepted: 08/14/2017] [Indexed: 12/25/2022] Open
Abstract
Women of reproductive age often experience a variety of unpleasant symptoms prior to the onset of menstruation. While genetics may influence the variability of these symptoms and their severity among women, the exact causes remain unknown. We hypothesized that symptom variability originates from differences in the embryonic environment and thus development caused by variation in exposure to sex hormones. We measured the second to fourth digit ratios (2D:4D) in 402 young women and investigated the potential relationships of this ratio premenstrual symptoms using a generalized linear model. We found that two models (one with two predictors such as both hands' digit ratios and the other with the difference between the two digit ratios, Dr-l) were significantly different from the constant model as assessed by chi-square test. The right digit ratio and Dr-l were negatively related to the symptom scores, and the left digit ratio was related to the scores. When premenstrual symptoms were classified into eight categories, five categories, including pain, concentration, autonomic reaction, negative affect, and control were associated with the digit ratios and Dr-l. Behavioral changes and water retention were not predicted by them. Arousal was predicted by Dr-l. The right 2D:4D is thought to be determined by the balance of testosterone and estrogen levels during early embryogenesis and is not affected by postpartum levels of sex hormones, while the left 2D:4D might be affected by the other prenatal environmental factors. We conclude that the embryonic environment, including the relative concentration of sex hormones an embryo is exposed to, is associated with the severity of premenstrual symptoms once menarche is reached.
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Affiliation(s)
- Yoshiki Kaneoke
- Department of System Neurophysiology, Wakayama Medical University, Wakayama, Japan
| | - Tomohiro Donishi
- Department of System Neurophysiology, Wakayama Medical University, Wakayama, Japan
| | - Akihiko Iwahara
- School of Health and Nursing Science, Wakayama Medical University, Wakayama, Japan
| | - Toshio Shimokawa
- Clinical Research Center, Wakayama Medical University, Wakayama, Japan
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Lofeu L, Brandt R, Kohlsdorf T. Phenotypic integration mediated by hormones: associations among digit ratios, body size and testosterone during tadpole development. BMC Evol Biol 2017; 17:175. [PMID: 28768472 PMCID: PMC5541650 DOI: 10.1186/s12862-017-1021-0] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/25/2017] [Accepted: 07/26/2017] [Indexed: 12/21/2022] Open
Abstract
BACKGROUND Developmental associations often explain phenotypic integration. The intersected hormonal regulation of ontogenetic processes fosters predictions of steroid-mediated phenotypic integration among sexually dimorphic traits, a statement defied by associations between classical dimorphism predictors (e.g. body size) and traits that apparently lack sex-specific functions (e.g. ratios between the lengths of Digits II and IV - 2D:4D). Developmental bases of female-biased 2D:4D have been identified, but these remain unclear for taxa presenting male-biased 2D:4D (e.g. anura). Here we propose two alternative hypotheses to investigate evolution of male-biased 2D:4D associated with sexually dimorphic body size using Leptodactylus frogs: I)'hypothesis of sex-specific digit responses' - Digit IV would be reactive to testosterone but exhibit responses in the opposite direction of those observed in female-biased 2D:4D lineages, so that Digit IV turns shorter in males; II) 'hypothesis of identity of the dimorphic digit'- Digit II would be the dimorphic digit. RESULTS We compiled the following databases using Leptodactylus frogs: 1) adults of two species from natural populations and 2) testosterone-treated L. fuscus at post-metamorphic stage. Studied traits seem monomorphic in L. fuscus; L. podicipinus exhibits male-biased 2D:4D. When present, 2D:4D dimorphism was male-biased and associated with dimorphic body size; sex differences resided on Digit II instead of IV, corroborating our 'hypothesis of identity of the dimorphic digit'. Developmental steroid roles were validated: testosterone-treated L. fuscus frogs were smaller and exhibited masculinized 2D:4D, and Digit II was the digit that responded to testosterone. CONCLUSION We propose a model where evolution of sexual dimorphism in 2D:4D first originates from the advent, in a given digit, of increased tissue sensitivity to steroids. Phenotypic integration with other sexually dimorphic traits would then occur through multi-trait hormonal effects during development. Such process of phenotypic integration seems fitness-independent in its origin and might explain several cases of steroid-mediated integration among sexually dimorphic traits.
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Affiliation(s)
- Leandro Lofeu
- Departamento de Biologia, Faculdade de Filosofia, Ciências e Letras de Ribeirão Preto, Universidade de São Paulo, Ribeirão Preto, SP, 14040-901, Brazil
| | - Renata Brandt
- Departamento de Biologia, Faculdade de Filosofia, Ciências e Letras de Ribeirão Preto, Universidade de São Paulo, Ribeirão Preto, SP, 14040-901, Brazil
| | - Tiana Kohlsdorf
- Departamento de Biologia, Faculdade de Filosofia, Ciências e Letras de Ribeirão Preto, Universidade de São Paulo, Ribeirão Preto, SP, 14040-901, Brazil.
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Klimek M, Marcinkowska UM, Jasienska G. Value of digit ratio 2D:4D, a biomarker of prenatal hormone exposure, is stable across the menstrual cycle. Early Hum Dev 2017; 110:21-24. [PMID: 28499133 DOI: 10.1016/j.earlhumdev.2017.04.014] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/31/2017] [Revised: 04/21/2017] [Accepted: 04/25/2017] [Indexed: 12/14/2022]
Abstract
Digit ratio (2D:4D) is used as a marker of prenatal hormone exposure and, consequently, as a predictor of many characteristics throughout a woman's lifespan. A previous study has suggested that values of 2D:4D vary across menstrual cycles and further questioned the reliability of a single measurement of 2D:4D among cycling women, while another study failed to confirm these results. However, these studies estimated the timing of cycle phases based on a date of menstruation reported by participants and also had small sample sizes. For our study, we evaluated potential changes in 2D:4D values across a menstrual cycle in a group of women among whom the phases of the menstrual cycle were determined by hormonal (luteinizing hormone based) ovulation tests. We studied 32 naturally cycling women aged 22-37 from rural Poland. Lengths of second and fourth digits were measured based on scans of both hands taken three times (i.e. in the follicular phase, peri-ovulatory phase and luteal phase of the cycle) for each participant. No differences in 2D:4D value across the menstrual cycle were detected either when right-hand, left-hand, and mean 2D:4D for both hands were analysed, nor when difference in the 2D:4D value between hands (Dleft-right) was evaluated. We documented that 2D:4D is independent of the phase of the menstrual cycle and these findings suggest that among naturally cycling women, a value of 2D:4D can be reliably obtained from measurements taken during any day of the menstrual cycle.
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Affiliation(s)
- Magdalena Klimek
- Department of Environmental Health, Faculty of Health Sciences, Jagiellonian University Medical College, Grzegorzecka 20, 31-531 Krakow, Poland.
| | - Urszula M Marcinkowska
- Department of Environmental Health, Faculty of Health Sciences, Jagiellonian University Medical College, Grzegorzecka 20, 31-531 Krakow, Poland.
| | - Grazyna Jasienska
- Department of Environmental Health, Faculty of Health Sciences, Jagiellonian University Medical College, Grzegorzecka 20, 31-531 Krakow, Poland.
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