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SUMMARY: This study investigates the relationship between the second and fourth finger ratio (2D:4D), physicians' propensity to choose an internal or surgical branch, and sex differences. On a voluntary basis, 177 physicians working in Elazig, 122 men and 55 women were enrolled in the study. Their hands were measured for 2D and 4D lengths, and the 2D:4D ratio was computed. In female doctors, the left hand's 2D:4D ratio is 1.01, compared to the right hand's 1.00. Male doctors' right 2D:4D ratio is 0.99, while their left 2D:4D ratio is 1.00. Male physicians' 2D:4D ratios were different from those of men in the general population, whereas female physicians' 2D:4D ratios were comparable to those of women in the general population. As a result, this study was the first to examine the relationship between the ratio of the second and fourth fingers (2D:4D), physicians' tendency to choose an internal medicine or surgical branch, and sex differences. While the 2D:4D ratio was higher than 0.98 in all physicians, it was low in women who disliked their profession and branch. Since there aren't many studies on this subject, data from in-depth studies that will be conducted in the future will help physicians who choose internal medicine and surgery make more informed decisions.
Este estudio investiga la relación entre la proporción de los dedos segundo y cuarto (2D:4D), la propensión de los médicos a elegir una rama interna o quirúrgica y las diferencias de género. De forma voluntaria, se inscribieron en el estudio 177 médicos que trabajaban en Elazig, 122 hombres y 55 mujeres. Sus manos se midieron en longitudes 2D y 4D, y se calculó la relación 2D:4D. En las médicos mujeres, la relación 2D:4D de la mano izquierda es 1,01, en comparación con 1,00 de la mano derecha. La relación 2D:4D derecha de los médicos hombres fue 0,99, mientras que la relación 2D:4D izquierda fye 1,00. Las proporciones 2D:4D de los médicos hombres fueron diferentes de las de los hombres en la población general, mientras que las proporciones 2D:4D de las mujeres médicas fueron comparables a las de las mujeres en la población general. Como resultado, este estudio fue el primero en examinar la relación entre la proporción del segundo y cuarto dedo (2D:4D), la tendencia de los médicos a elegir una rama de medicina interna o quirúrgica y las diferencias de sexo. Mientras que la relación 2D:4D fue superior a 0,98 en todos los médicos, fue baja en las mujeres que no les gustaba su profesión y rama. Dado que no hay muchos estudios sobre este tema, los datos de estudios en profundidad que se realizarán en el futuro ayudarán a los médicos que eligen medicina interna y cirugía a tomar decisiones más informadas.
Subject(s)
Humans , Male , Female , Physicians/psychology , Choice Behavior , Fingers/anatomy & histology , Digit Ratios , General Surgery , Sex Factors , Anthropometry , Sex Characteristics , Internal MedicineABSTRACT
Background: The second to fourth digit ratio (2D:4D ratio) is derived by dividing the length of the index finger (2D) by the length of the ring finger (4D). It has been considered as an index of how much the fetus is exposed to testosterone in utero. Research has suggested that high levels of testosterone are associated with low 2D:4D ratio. The relationship between 2D:4D ratio and physical performance is still an unexplored field in badminton players. Aims and Objectives: This study intends to assess the digit ratio 2D:4D in non-elite male badminton players in comparison to their sedentary controls. Materials and Methods: The study included 30 male badminton players in the age group of 19–23 years who were practicing badminton for more than 3 years and 30 age, body mass index-matched sedentary controls. The second and fourth finger measurements were taken from scanned printouts using Vernier calipers. Results: The 2D:4D ratio was significantly lower in the left hand of badminton players when compared to their controls (P = 0.0001). There was no significant difference in 2D:4D ratios of the right hand and 2D:4D (? r–l) between badminton players and controls. Conclusion: There was significant difference in the ratio of 2nd–4th digit between badminton players and controls in the left hand but not in the right hand. The reason for no difference in 2D:4D ratio and controls in the right hand could be due to the fact that badminton is a moderate intensity sport, and also, the study participants were non-elite players.
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SUMMARY: Digit ratio established in utero is positivelly correlated with intrauterine level of estrogen. Since the breast cancer is related to excessive and prolonged exposure to estrogen, digit ratio might be considered as useful marker in breast cancer risk assessment. The aim of the present study was to compare digit ratios in breast cancer patients and healthy controls. The study group consisted of 98 breast cancer patients aged between 29 to 84 years while the control group included 141 healthy women aged between 21 and 67 years. After collecting anamnestic data concerning menopausal status, the length of second and fourth fingers were measured and the digit ratios were calculated for both hands, as well as the difference between right and left digit ratio. Digit ratio was significantly higher on right hand in breast cancer patients compaired to healthy controls (1.003±0.05 vs. 0.990±0.03). Right digit ratio showed better predictive capacity for the breast cancer development then the left (AUC:0.609 vs. 0.541). Negative statistically significant correlation between right digit ratio and the age of breast cancer diagnosis was observed (r=-0.271). Higher values of right digit ratio in women with breast cancer when compared to healthy women suggest their higher prenatal estrogen exposure that confirms the importance of digit ratio determination in breast cancer risk assessment.
La proporción de dígitos establecida en el útero, se correlaciona positivamente con el nivel intrauterino de estrógeno. Dado que el cáncer de mama está relacionado con una exposición excesiva y prolongada a los estrógenos, la proporción de dígitos podría considerarse un marcador útil en la evaluación del riesgo de cáncer de mama. El objetivo del presente estudio fue comparar proporciones de dígitos en pacientes con cáncer de mama y controles sanos. El grupo de estudio consistió en 98 pacientes con cáncer de mama con edades comprendidas entre los 29 y los 84 años, mientras que el grupo de control incluyó a 141 mujeres sanas con edades comprendidas entre los 21 y los 67 años. Después de recopilar datos anamnésticos sobre el estado menopáusico, se midió la longitud de los dedos segundo y anular y se calcularon las proporciones de los dedos para ambas manos, así como la diferencia entre la proporción de los dedos derecho e izquierdo. La proporción de dígitos fue significativamente mayor en la mano derecha en pacientes con cáncer de mama en comparación con controles sanos (1,003 ± 0,05 frente a 0,990 ± 0,03). La proporción del dígito derecho mostró una mejor capacidad predictiva para el desarrollo de cáncer de mama que el izquierdo (AUC: 0.609 vs. 0.541). Se observó una correlación estadísticamente significativa negativa entre la proporción de dígitos derechos y la edad del diagnóstico de cáncer de mama (r=-0,271). Los valores más altos de la proporción de dígitos derechos en mujeres con cáncer de mama en comparación con mujeres sanas sugieren una mayor exposición prenatal a estrógenos que confirma la importancia de la determinación de la proporción de dígitos en la evaluación del riesgo de cáncer de mama.
Subject(s)
Humans , Female , Adult , Middle Aged , Aged , Aged, 80 and over , Young Adult , Breast Neoplasms/diagnosis , Breast Neoplasms/pathology , Fingers/anatomy & histology , ROC Curve , Sensitivity and Specificity , Age Factors , Digit RatiosABSTRACT
Objective: The etiology of bipolar disorder has yet to be fully elucidated, but differences in sex hormones have been suggested to play a role in its pathogenesis. An easily assessed marker of prenatal androgen exposure is the second-to-fourth-digit ratio (2D:4D) of the hand. In this study, we aimed to compare the 2D:4D ratio of patients with bipolar disorder to that of healthy controls. Methods: Seventy patients with bipolar disorder and 70 healthy controls, matched for age and sex, were included in the study. Finger lengths were measured from the palmar digital crease to the tip using a digital vernier caliper. Results: Patients with bipolar disorder had considerably higher right-hand 2D:4D ratios compared to controls. Both the right and left 2D:4D ratios of male patients were significantly greater than those of males in the control group. Female patients showed no differences in right or left 2D:4D ratio compared to healthy controls. Conclusion: These findings suggest that a high 2D:4D digit ratio of right hand is associated with the presence of bipolar disorder in males. Further large-scale, prospective studies are needed to explain the validity of this marker and its relationship with bipolar disorder.
Subject(s)
Humans , Male , Female , Pregnancy , Bipolar Disorder , Biomarkers , Prospective Studies , FingersABSTRACT
The 2D:4D is thought as a biomarker for prenatal androgen exposure. Some studies have reported a significant difference between the sexes. Earlier studies reported variations in different ethnic and geographic groups. 2D:4D is related to several medical conditions including cardiovascular diseases (CVD) and metabolic syndrome (MetS). The present study investigated the relationships between hand preference, ratio of the index finger (2nd digit: 2D) and ring finger (4th digit: 4D) lengths (2D:4D), height, waist-to-height ratio (WHtR), waist circumference (WC) and weight, body mass index (BMI) in a Turkish population. The study comprised 118 healthy subjects (68 males and 50 females). 2D and 4D finger lengths and some anthropometric traits (height, weight, WC) were measured. The BMI and WHtR were calculated. Hand preference was determined by using a questionnaire (Edinburgh handedness inventory). Geschwind scores were calculated to evaluate the degree of hand preference. The mean age was 26.74 (female 27.86, male 25.89). The right hand 2D:4D was found significantly lower in males (0.9797) than in females (0.9922) (p< 0.001), but the left hand 2D:4D was insignificant. Significant correlations (negative) were observed between the 2D:4D (both left and right) and WHtR; the 2D:4D ratio (both left and right) and WC in males. However, in females, these correlations were insignificant. The R2D:4D was sexually dimorphic in a Turkish population. There were significant differences between strong right (SR) and weak left (WL) in terms of the R2D:4D. However only 5 subject's hand preference was found WL. Therefore, further studies are needed to determine the relationships between hand preference and R2D:4D in Turkish population. Further studies are needed to determine whether a larger sample population alters these possible associations between the ratio of 2D:4D and other investigated traits in a Turkish population.
El 2D:4D está pensado como un biomarcador para la exposición prenatal de andrógenos. Algunos estudios han reportado una diferencia significativa entre sexos. Estudios anteriores informaron variaciones en diferentes grupos étnicos y geográficos. 2D:4D está relacionado con varias afecciones médicas que incluyen enfermedades cardiovasculares (ECV) y síndrome metabólico (MetS). El presente estudio investigó las relaciones entre la preferencia de la mano, la proporción del dedo índice (2º dígito: 2D) y el dedo anular (4º dígito: 4D), longitudes (2D:4D), altura, relación cintura-altura (WHtR), circunferencia de cintura y peso (WC), e índice de masa corporal (IMC), en una población de Turquía. El estudio incluyó 118 sujetos sanos (68 hombres y 50 mujeres). Se midieron longitudes de dedos 2D y 4D y algunos rasgos antropométricos (altura, peso, WC). Se calcularon el IMC y el WHtR. La preferencia de la mano se determinó mediante el uso de una escala (Edinburgh Handedness Inventory). Las puntuaciones de Geschwind se calcularon para evaluar el grado de preferencia de la mano. La edad media fue de 26,74 años (femenino 27,86; masculino 25,89). La mano derecha 2D: 4D se encontró significativamente más baja en los hombres (0,9797) que en las mujeres (0,9922) (p <0,001), pero la mano izquierda 2D: 4D fue no significante. Se observaron correlaciones significativas (negativas) entre la 2D: 4D (izquierda y derecha) y WHtR y la relación 2D: 4D (izquierda y derecha) y WC en hombres. Sin embargo, en las mujeres, estas correlaciones fueron no significantes. El R2D: 4D fue sexualmente dimorfo en una población de Turquía. Hubo diferencias significativas entre la mano derecha fuerte (SR) y la mano izquierda débil (WL) en términos de R2D: 4D. Sin embargo, sólo se encontraron 5 preferencias de mano en el sujeto con WL. Por lo tanto, se necesitan más estudios para determinar las relaciones entre la preferencia de mano y R2D: 4D en la población de Turquía. Se necesitan más estudios para determinar si una muestra mayor altera estas posibles asociaciones entre la proporción de 2D: 4D y otros rasgos investigados en una población de Turquía.
Subject(s)
Humans , Male , Female , Adolescent , Adult , Middle Aged , Young Adult , Anthropometry/methods , Fingers/anatomy & histology , Functional Laterality , Turkey , Body Height , Body Weight , Body Mass Index , Waist CircumferenceABSTRACT
Background: Second to fourth digit (2D:4D) ratio is the ratio of index to ring fingers length. It reflects prenatal androgen exposure and sensitivity. Androgens are important in the pathogenesis of acne vulgaris, This ratio may therefore be of significance in determining the expression of androgen receptors. Aim: To investigate the relationship between second to fourth digit ratio and androgen receptor expression in female patients with acne vulgaris and to assess its association with clinical aspects of acne vulgaris. Methods: Females patients (n = 352) with different degrees of acne vulgaris severity and 168 age-matched females were enrolled. Right, left and total second to fourth digit ratios were calculated. Biopsies from all participants were processed for androgen receptor expression by immunohistochemical method. Results: Right, left and total second to fourth digit ratios were significantly lower in acne vulgaris patients than controls (P < 0.001 for all), and each of them had a significant negative correlation with duration of acne vulgaris (P < 0.001; P = 0.013; P < 0.001, respectively). Androgen receptors were detected in epidermal keratinocytes, hair follicles, sebaceous glands and fibroblasts. Right second to fourth digit ratio showed a negative correlation with androgen receptor H score of keratinocytes (r = −0.28;P = 0.02), hair follicles (r = −0.22; P = 0.05) and fibroblasts (r= −0.37;P = 0.001), while left second to fourth digit ratio demonstrated negative correlation with androgen receptor H score of sebocytes (r = −0.397; P < 0.000) only. Limitations: Lack of follow-up and absence of male participants were the main limitations of this study. Conclusion: A masculine second to fourth digit ratio in female patients could anticipate acne vulgaris development, its duration and severity. Moreover, this ratio is associated with an upregulation of cutaneous androgen receptors. Taken together, second to fourth digit ratio could help in designing plans for treatment of acne vulgaris.
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Background: Specific learning disorder in general called as dyslexia is a neuro developmental disorder,which occurs more commonly in males (Male:Female ratio is 4:1), there are evidence to suggest role ofprenatal gonadal hormone exposure in neurodevelopment. However, studies on association between 2nd to4th digit ratio and dyslexia are mixed. Objective: To compare the 2nd and 4th digit ratio (2D:4D) of bothhands between children with dyslexia and children without dyslexia.Methodology: A case control study, recruited 30 children with dyslexia and 30 age and education matchednormal controls, after getting informed consent from their parents. Collected socio demographic details,applied CARS, Schonell’s reading and spelling test, followed by detailed evaluation by psychiatrist andclinical psychologist, including psychological testing to confirm the diagnosis of dyslexia. The digit lengthof index and ring finger on both hands of all children were measured using Vernier Calliper by direct method.Results: In both the hands 2D:4D ratio was more in children with dyslexia than normal children, but thedifference was not significant (p – 0.146). Analysis of only male samples showed digit ratio is higher indyslexic children than normal children; which were significant (p – 0.03).Conclusion: Our study does not support an association between digit ratios and dyslexia; however, trendtowards higher ratio in dyslexia especially in male children are interesting and needs further exploration.Need more studies in this area to form a definite conclusion.
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The aim of this study is to provide basic data to prevent adolescent crime or violence by analyzing aggression according to second digit to fourth digit ratio (2D : 4D). Index and ring finger length on both hands by photocopy was measured using Callipers from ventral proximal crease to finger tip. This study was done on 187 elementary school students (98 males, 89 females). Data were collected by measuring index and ring finger length on both hands by photocopy and by completing self-reported questionnaire. The data were analyzed using SPSS win 21.0. This study showed that the 2D : 4D of males was significantly lower than female, and the aggression score of males was significantly higher than female. Especially, there was significantly differences between 0.900 or less than 0.900 digit ratio group and 1.000 or more than 1.000 digit ratio group only left hand of males. The results of this study suggest that left digit ratio of males in elementary school students are able to be used as one of physical markers to evaluate aggression.
Subject(s)
Adolescent , Female , Humans , Male , Aggression , Crime , Fingers , Hand , ViolenceABSTRACT
The 2nd to 4th digit ratio (2D : 4D) reflects exposure level of sex hormones in fetal period. The aim of this study is to identify a change of digit ratio according to age and a critical age showing gender difference in Korean children. This study was done on 1,182 children (588 males, 594 females). Data were collected by measuring index and ring finger length on both hands by photocopy. The data were analyzed using SPSS win 21.0. This study showed that the 2nd and 4th finger length and digit ratio of both hands increased with age both male and female. There was no differences in 2nd to 4th digit ratio between males and females until they were 3 years old. However, there were significant differences in 2nd to 4th digit ratio between males and females from the age of four. The results suggest that digit ratio in Korean children increases with age and a critical age showing gender difference is from the age of four.
Subject(s)
Child , Female , Humans , Male , Fingers , Gonadal Steroid Hormones , HandABSTRACT
The 2nd to 4th digit ratio (2D : 4D) reflects exposure level of sex hormones in fetal period and there are various methods for finger length measurement. The aim of this study is to identify an accurate and effective method for finger length measurement. This study was done on 272 individuals (115 males, 157 females). Data were collected by measuring index and ring finger length on both hands by calipers, ruler, photocopy, and radiography. The data were analyzed through independent t-test, paired t-test, Pearson correlation analysis using SPSS win 19.0. This study showed that the 2nd and 4th finger measured by radiography were the longest finger both of males and females and revealed the largest length difference between 2nd and 4th finger. There were significant sex differences all of 4 measurement methods in 2D : 4D, especially remarkable sex difference by radiography and photography. The 2D : 4D by indirect measurement was lower than that of direct measurement. Correlation between digit ratio by radiography and by photocopy was 0.590 and correlation between digit ratio by radiography and by calipers was 0.586. The results of this study suggest that indirect measurement by radiography can be alternated by photocopy primarily and by calipers secondarily.
Subject(s)
Female , Humans , Male , Fingers , Gonadal Steroid Hormones , Hand , Photography , Sex CharacteristicsABSTRACT
The 2nd to 4th digit ratio (2D : 4D) as a predictor of the degree of expression of sexually dimorphic and other sex-hormone-mediated traits differs between the sexes, ethnics and race. The aim of this study is to identify characteristics and role of 2nd to 4th digit ratio as a sex determinant in Korean. This study was done on 664 individuals (332 males, 332 females). Data were collected by measuring index and ring finger length on both hands with digital callipers. The data were analyzed through the frequency, descriptive statistics, X2 test, independent t-test, paired t-test, Pearson correlation analysis using SPSS win 19.0. This study showed that the 2nd to 4th digit ratio (2D : 4D) in Korean men (0.96) was significantly lower than that of women (0.97). There was a significant difference in the types of 2nd and 4th finger length according to sex. There was a significant difference between right 2D : 4D and left 2D : 4D both of Korean men and women. Correlation between right and left hand digit ratio was .530 in men and .556 in women. The 2nd to 4th digit ratio accurately determinated sex in 89.1% males and 89.2% females for the left hand, and in 91.8% males and 91.9% females for the right hand. The results of this study suggest that 2nd to 4th digit ratio in Korean differs between males and females, moreover, it will be able to perform a role as a sex determinant.
Subject(s)
Female , Humans , Male , Racial Groups , Fingers , HandABSTRACT
OBJECTIVES: Cerebral laterality is thought to be an important marker for neurodevelopment. Prenatal testosterone could influence both cerebral laterality and 2nd to 4th finger length ratio(2D:4D). EEG coherence and 2D:4D were examined to investigate the relationship between prenatal testosterone level and cerebral laterality. METHODS: EEG was recorded in 24 healthy subjects in the eyes closed resting state. Differences in 2D:4D finger ratio were used to discriminate "masculine finger type" and "feminine finger type" groups. The 2D:4D ratio was lower and greater than one for the "masculine finger type" group and "feminine finger type" group, respectively. We used coherence analysis to estimate the cortical functional connectivity. RESULTS: There were statistically meaningful relationships among cerebral functional connectivity, sex and finger ratio. Man and masculine finger type group showed higher intra-hemispheric coherence than those of woman and feminine finger type group. Woman and feminine finger type group showed higher inter-hemispheric coherence than those of man and masculine finger type group. CONCLUSIONS: These results imply that prenatal testosterone might act as important determinants of cerebral laterality. Further examination of the relationship between 2D:4D and EEG coherence in schizophrenia could give some clues for the neurodevelopmental hypothesis of schizophrenia genesis.
Subject(s)
Female , Humans , Electroencephalography , Eye , Fingers , Schizophrenia , TestosteroneABSTRACT
Objective To explore the relationship between digit ratio and personality among male college students of Han nationality. Methods 162 male college students of Han nationality were surveyed with Eysenck Personality Questionnaire. Measurements were taken from the middle of the basal crease to the tip of the finger by electronic vernier caliper. Personality factors scores were compared between male college students of Han nationality and normal. Finger length and digit ratio of the left hand and the right hand were compared among male college students of Han nationality. Correlation coefficient between digit ratio and personality was calculated.Results The male college students of Han nationality showed significantly lower psychoticism (4.53 ± 2. 55 ) and lie (9.64 ± 3. 55 ) than normal ( 5. 96 ± 2.84,12. 17 ± 3.57; t = - 7. 135, - 9. 085 ) , but higher neuroticism ( 12.67 ±3.94) than normal ( 10.63 ±4.44, t=6.573). The length of index finger(2D) & ring finger(4D) and ently higher than those of the right hand (71.74 ± 4. 01 ,74.85 ± 4.41,0. 8973 ± 0. 0306; P ＜ 0.05 ). There was an association of psychoticism with index finger(2D), middle finger(3D), ring finger(4D) and little finger(5D)among male college students of Han nationality ( r=0. 263,0.254,0.248,0.287,0.235,0.243,0.246,0. 283; P＜ 0. 01 ). There was an association of lie with index finger( 2D ), middle finger( 3D), the right ring finger( 4D ) & little finger(5D) among male college students of Han nationality ( r= -0. 208, -0. 213, -0. 185, -0. 226,-0.165, -0. 185; P＜ 0. 05 ). There was an association of neuroticism with the left second to fourth digit ratio ratio is found among male introvert college students of Han nationality. Digit ratio may be correlated with personality among male college students of Han nationality.
ABSTRACT
The ratio of index finger length to ring finger length is called the “2D:4D digit ratio,” or more simply, the “digit ratio”. This study was to investigate if there are ignificant differences in the digit ratio (2D:4D) of infertile men attending an infertility clinic and men drawn from the general population in Akure Nigeria; to generate data locally to serve as a source for future referencing in anthropometry as it relates to male fertility assessment. A total of 84 participants were involved in this study. They include men attending an infertility clinic (n=42), and those drawn randomly from the general population (n=42) with regards to their fertility. Information on 2D:4D and the seminal fluid data from two samples were obtained. Direct digit estimates was done using digital calipers and indirectly by taking measurements from a digital image of the hand. The digit ratios were obtained by dividing the lengths, of the index finger by the ring finger. Semen was collected from each participant by masturbation and examined for count and motility to ascertain their fertility status. There was a statistically significant (p < 0.05) increase in the length of the fourth digit compared to the second digit in fertile men. The 2D:4D ratio in fertile men was significantly lower (p < 0.05) compared to infertile men. This study demonstrates an association between 2D:4D ratio and the fertility status in adult men in Akure metropolis Nigeria.