Dermatoglyphical impressions are different between children and adolescents with normal weight, overweight and obesity: a cross-sectional study

Introduction

Obesity is a matter of constant concern for global health and is considered to be the second most common cause of preventable death (WHO, 2014). This condition has a multifactorial origin involving genetic and environmental factors (Martínez García et al., 2017) and is considered one of the major problems for public health around the world. By 2014, more than 1.9 million adults were overweight. Of these, 600 million were obese. From 1980 to 2013, the number of obese and overweight people increased by 27.5% among adults and 47.1% among children, which generated even more concern (Ng et al., 2014).

The predictive value of dermatoglyphic features (DGFs) in relation to a variety of diseases has been investigated for more than five decades, from the seminal work of Cummins and Midlo in 1961 (Bhat et al., 2012; Sharma & Sharma, 2012; Shetty et al., 2016). Dermatoglyphics is the scientific study of epidermal crescent patterns and several researchers from different fields, such as biology, anthropology, genetics, and medicine, are engaged in unraveling several unknown aspects of this field (Raniwala et al., 2017). In addition, dermatoglyphics has been used as a noninvasive diagnostic tool to detect or predict different medical conditions that have a fetal origin (Wijerathne et al., 2016).

The reason for the association between DGFs and health is the influence of epigenetics, which affects both (Yohannes, 2015). The formation of the former begins in the first trimester of pregnancy, during the 6th week, is completed after the 24th week of gestation and is formed according to the development and maturation of the central nervous system (Babler, 1991; King et al., 2009).

Although DGFs have no causal relationship with health (Mittal et al., 2012), they may be used as a marker of health problems when there are associations that are consistent with the diseases of interest, this condition being essential for effective screening (Gupta & Karjodkar, 2013). In the case of obesity, this is a multifactorial (polygenic and environmental) condition where epigenetic factors of obesity can influence DGF patterns; therefore, these can be used as markers of obesity throughout life (Bhardwaj et al., 2015).

Our aims were to determine the association between DGF characteristics and obesity in children and adolescents aged 10 to 19 years in the center-west region of the state of Santa Catarina, in the south of Brazil and investigate whether a dermatoglyphic marker can of obesity exists.

Methods

Statistical analysis

Statistical analyzes were performed using the STATA version 12.0. Analysis of variance (ANOVA) for DGF tested the null hypothesis that there was no difference in the number of finger lines between the weight groups. The differences were considered statistically significant at p <0.05. The chi-square test was used to test whether there was a difference between weight groups in the following variables: arch, radial loop, ulnar loop and whorl fingerprint patterns (Figure 1). The differences were considered statistically significant at p <0.05.

Figure 1. Examples of dermatoglyphic drawings.

Nodari Junior and Fin authorized the reproduction of this image (taken from Nodari-Júnior & Fin, 2016), both are authors of this article.

Results

The final sample for this study consisted of 2,172 students, of which 1,166 were female and 1,006 were male (Alberti, 2019). Students were aged between 10 and 19 years and enrolled in a public or private primary or secondary education in the municipality of Joaçaba, Santa Catarina-Brazil.

As for the quantitative fingerprint variables (the number of lines of each finger, the total number of lines on the fingers of the right hand, the total number of lines on the fingers of the left hand and the total number of lines on the fingers of both hands), it was observed that, on average, individuals who were of a healthy weight had a greater number of lines in relation to overweight and obese individuals in MET2 (left-hand finger two). (Table 1).

The results obtained may suggest the presence of predictive markers for BMI in the researched population. For left-hand finger two (MET2), participants of a healthy weight presented with a higher frequency the whorl pattern, while overweight and obese participants had a higher frequency of the ulnar loop pattern; for left-hand finger three (MET3), participants of a healthy weight presented a higher frequency of the radial loop pattern, while overweight and obese participants had a higher frequency of the ulnar loop pattern; for left-hand finger four (MET4), participants of a healthy weight presented a higher frequency of the whorl pattern, while the overweight group presented a higher frequency of the radial loop and the ulnar loop pattern; for left-hand finger five (MET5), participants of a healthy weight presented a higher frequency of the arch pattern, while the overweight group presented a higher frequency of the radial loop pattern and the obese group had a higher frequency of the ulnar loop pattern; for finger one of the right hand (MDT1), participants of a healthy weight presented a higher frequency of the arch pattern, the overweight group had a higher frequency of the radial loop pattern, and the obese group had a higher frequency of the ulnar loop pattern; for right-hand finger three (MDT3), participants of a healthy weight had a higher frequency of the whorl pattern, while overweight and obese groups had a higher frequency of the ulnar loop pattern; for right-hand finger four (MDT4), participants of a healthy weight had the highest frequency of the whorl pattern, while the overweight group presented a higher frequency of the radial loop pattern and the obese group presented a higher frequency of the figure ulnar loop; for right-hand finger five (MDT5), participants of a healthy weight presented a high frequency of the whorl pattern, while the overweight group presented a high frequency of the radial loop pattern and the obese group presented a high frequency of the ulnar loop pattern. (Table 2).

Discussion

This study suggests that a higher number of the total number of lines in Mesql2 may be a predictive marker of obesity and that a higher frequency of the whorl pattern may be found in people of a healthy weight, a higher frequency of the radial loop pattern may be found in overweight people and a higher frequency of the ulnar loop pattern may be found in obese people.

An increase in weight in children and adolescents can occur rapidly, causing, for example, low levels of cardiorespiratory and musculoskeletal aptitude and impairing the quality of life of these individuals (García-Hermoso et al., 2018). Several studies have begun to recognize epigenetic factors in obesity and, despite a relatively high heritability of non-syndromic common obesity (40–70%), the search for genetic variants that contribute to susceptibility has been a challenging task. Genome-wide association studies have dramatically changed the pace of detection of common variants involved in genetic susceptibility. By the year 2011, more than 40 genetic variants were associated with obesity. However, since these variants do not fully explain the heritability of obesity, other forms of variation, such as epigenetic markers, should be considered (Herrera et al., 2011).

Every organism is unique and has epigenetic traits that are inherited and generated in the womb. Studies have been conducted that are aimed at highlighting the influence of the gestation period and fetal environment for the development of diseases and conditions over a lifetime, such as obesity (Martínez García et al., 2017). The fetal development phase begins at the 9th week of gestation and goes through to the baby’s birth, the human gestation lasting on average 38 weeks (Dipietro, 2008). There are studies that reinforce that epigenetic influences have a strong association with the development of obesity (Ornellas et al., 2017).

Dermatoglyphics has its fundamental basis in this premise, being an epigenetic marker related to the period of fetal development (Yohannes, 2015). In addition to the fact that the fingerprints are intrinsically related to the central nervous system and can therefore reflect motor capacities inherited genetically and epigenetically for conditions that may have a marker expressed during this period of fetal development, fingerprint evaluation is a simple and practical method (King et al., 2009).

In one sample of 370 obese children, in a study to identify dermatoglyphic patterns in obese individuals and to discover the association between standard dermatoglyphics and obesity, a high frequency of the arch pattern was observed in the right thumb (Bhardwaj et al., 2015).

In another study, the authors (Oladipo et al., 2010) sought to determine the dermatoglyphic characteristics of obese Nigerian patients by comparing a group of 50 obese individuals (25 men and 25 women) with a group of 50 normal weight subjects (25 men and 25 women). The arch pattern was observed in the first digits of the right hand in 54.5% of obese men and 42.33% of obese women, whereas individuals with normal weight presented the figure more frequently.

In the city of São Paulo, Brazil, a survey (Pasetti et al., 2012) with 30 obese Brazilian women with a mean age of 46.1 ± 07.87 years, all with a BMI equal to or greater than 30, observed that participants presented a high frequency of the arch pattern, low frequencies of the ulnar loop pattern and a high frequency of the whorl pattern. These results corroborate the findings of several other authors (Bhardwaj et al., 2015; Oladipo et al., 2010) who also presented a predominance of the arch pattern in the obese group.

The present study utilized a sample of 2,172 individuals and the computerized method developed by Nodari Júnior, Heberle, Ferreira-Emygdio and Irany-Knackfuss in 2008, providing greater precision in the dermatoglyphic analysis. This method allows optimization of the analysis and greater reliability in the counting and marking of lines and designs. It allowed differentiation of the ulnar loop and radial loop patterns, which other studies in dermatoglyphics and obesity have not done.

The results showed the presence of different dermatoglyphic characteristics for different nutritional statuses of children and adolescents, indicating a higher number of the total number of lines in Mesql2 and a higher frequency of the whorl pattern may be found in people of a healthy weight, a higher frequency of the radial loop pattern may be found in overweight people and a higher frequency of the ulnar loop pattern may be found in obese people.

This data may contribute to this field of research and allow better and more adequate referrals possible for people that have a predictive marker of fetal origin of obesity.

As a limitation, because it was a cross-sectional study, it was not possible to associate the results with important factors, such as prenatal and family history, and it is recommended in future studies that a cohort-type follow-up should be performed to verify a possible association between these factors and the level of physical activity, along with fingerprints.

Data availability