CORRELATION BETWEEN BODY MASS INDEX AND CARRYING ANGLE AMONG ADOLESCENTS IN ABRAKA NIGERIA

Access this article online For the last 30 years, obesity has been primarily diagnosed by using the BMI.2 Excess adipose tissue (obesity) is deleterious for multiple body organ systems through thrombogenic, atherogenic, oncogenic, hemodynamic and neurohumoral mechanisms and is linked to multiple medical conditions, such as diabetes, heart disease and several types of cancer. 3–7 Obesity is presently the number one killer worldwide replacing smoking.8 Carrying angle is defined as the acute angle made by the median axis of the arm and that of fully extended and supinated forearm and thus Context: Carrying angle and body mass index (BMI) varies among individuals and therefore significant in forensic medicine and anthropology. Aim: The purpose of this study was to determine whether the BMI of healthy adolescents from Abraka had an impact on the carrying angle of the elbow joint. This research was also aimed at determining the variation of carrying angle among male and female adolescents from Abraka in Nigeria. Settings and Design: The multi-stage sampling technique was employed in this cross sectional study. Methods and Materials: Three hundred and eighty-four volunteers between the ages of 10 to 19 years (mean 14years) were investigated. Statistical analysis used: The data were analyzed using the Statistical Package for the Social Sciences (SPSS 20). Pearson correlation coefficient was used to establish the relationship between carrying angle and body mass index among the adolescents. The independent t test was used to determine gender differences in carrying angle among the participants. Results: Gender had no significant effect on the mean carrying angle irrespective of the side (p>0.05). There was a weak positive correlation between right carrying angle (M=12.411, SD=1.719) and BMI (M=18.730, SD=2.613), with r=0.144 and p<0.05. It was also observed that there was a weak positive correlation between left carrying angle (M=12.480, SD=1.787) and BMI (M=18.730, SD=2.613), with r=0.017 and p<0.05. Conclusion: The BMI of adolescents in Delta State has an impact on the carrying angle of the elbow joint.


INTRODUCTION
Body mass index (BMI) is a measure of weight adjusted for height.It is calculated as weight in kilograms divided by the square of height in meters. 1

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][5][6][7] Obesity is presently the number one killer worldwide replacing smoking. 8arrying angle is defined as the acute angle made by the median axis of the arm and that of fully extended and supinated forearm and thus it measures the lateral obliquity of the forearm.Most studies have focused on the question of cause of formation of carrying angle.Variation in carrying angle among age groups, gender and race has been reported in literature.The average value of the carrying angle is 12.5 ±0.57degrees in male and 15.26 ±0.45 degrees in females.Females had higher values than males except in 3-5yrs age group in whom the carrying angle is greater in males. 9Researchers observed that carrying angle demonstrated no correlation with BMI.It was also suggested that carrying angle was not affected by increased tissue mass around the elbow joint, but rather by changes in the bony anatomy of the elbow joint during maturation. 10here is dearth of data on the correlation between BMI and carrying angle among adolescents from Abraka in Nigeria.The purpose of this study was to determine whether the BMI of healthy adolescents from Abraka had an impact on the carrying angle of the elbow joint.This research was also aimed at determining the variation of carrying angle among male and female adolescents from Abraka in Nigeria.This study will provide information that will be useful in forensic medicine and anthropology.

SUBJECTS AND METHODS:
This cross sectional study of 384 adolescents (768 elbows) aged 10 to 19 years was conducted in Abraka, Nigeria in 2015.The multi-stage sampling technique was employed in this study.
The participants were without previous trauma or disease process affecting the elbow.BMI (kg/m 2 ) was calculated as weight (kg) divided by height (m 2 ).Height and weight were measured for the individuals.Age was self-reported.Carrying angle was measured on both upper limbs.Each person stood or sat with a fully extended arm, a supinated forearm, and a flexed and adducted shoulder.The goniometer was placed on the anterior surface of the upper limb and was aligned with the ulna distally, the goniometer's hinge was with the cubital fossa, and the humerus proximally.Two readings were taken in a measurement of the carrying angle of each elbow joint to minimize error.Height was measured with a locally constructed stadiometer and weight was measured with a weighing scale.All participants stood in anatomical position at all times throughout the measurement of height.Approval was obtained from the Research and Ethics Committee of the Faculty of Basic Medical Sciences in the Delta State University, Nigeria prior to the commencement of this study.Consent was obtained from each participant as only voluntary subjects were allowed to participate in the exercise.The data were analyzed using the Statistical Package for the Social Sciences (SPSS 20).Pearson's correlation coefficient was used to establish the relationship between carrying angle and BMI among the adolescents.Independent t-test was used to determine gender differences in carrying angle among participants.The gender distribution as depicted in table 1 showed that the male and female gender were equally represented.

RESULTS
Table 2: Independent sample t-test for gender difference in carrying angle and BMI Gender had no significant effect on the mean carrying angle irrespective of the side (p>0.05) as shown in table 2. Female right and left carrying angles were higher than the values obtained for male right and left carrying angles (Table3).

DISCUSSION
The carrying angle of the elbow is defined as the angle between the long axis of the extended forearm as it lies lateral to the long axis of the arm.Anatomically, the carrying angle in human adults is approximately 10 0 in men and 13 0 in women. 11It may change with skeletal growth. 12Body mass index [BMI, weight kg/height m 2 ] is presently the most often used and widely satisfactory methods of distribution of body weight and classification of medical risk. 13he present study determined the relationship between BMI and carrying angle among adolescents in Abraka, Delta State.The present study revealed a BMI of 18.73 ± 2.61 which falls in the normal weight category.This is consistent with the reports of other researchers. 14,15 he female right and left carrying angles were higher than the values obtained for male right and left carrying angles.This concurs with the findings of other researchers.
12 9, The present study revealed that there is no significant gender difference in the carrying angle.This finding is in accordance with that of other researchers. 10he present study revealed a weak positive correlation between carrying angle and BMI.This did not concur with researchers who noted that carrying angle demonstrated no correlation with BMI. 10 The disagreement may be due to differences in ethnicity and sample sizes.The present study revealed values of the carrying angle which did not concur with another which involved young adult participants within the age group of 18-22 years of age. 9The different age spread of the subjects employed in the two studies may be responsible for the differences seen.The limitation encountered in the course of the present study was due to the cross-sectional nature of this study.The implication is that one cannot conclude that BMI is a direct cause of increased carrying angle.

CONCLUSION
The BMI of adolescents in Delta State has an impact on the carrying angle of the elbow joint.

Figure 1 :
Figure 1: Correlation between right carrying angle and BMI irrespective of gender In Figure 1, it was shown that there was a weak positive correlation between right carrying angle (M=12.411,SD=1.719) and BMI (M=18.730,SD=2.613), with r=0.144 and p<0.05.

Figure 2 :
Figure 2: Correlation between left carrying angle and BMI irrespective of gender

Table 1 :
Frequency distribution of participants by gender.

Table 3 :
Descriptive statistics for mean height, weight, body mass index (BMI) and right and left carrying angles.