Home | About us | Editorial board | Search | Ahead of print | Current issue | Archives | Submit article | Instructions | Subscribe | Contacts | Advertise | Login 
 
Search Article 
  
Advanced search 
  Users Online: 323 Home Print this page Email this page Small font sizeDefault font sizeIncrease font size  

 
Table of Contents
ORIGINAL ARTICLE
Year : 2017  |  Volume : 21  |  Issue : 6  |  Page : 803-808

Neck circumference as a marker of overweight and obesity and cutoff values for Bangladeshi adults


1 Department of Endocrinologyand Diabetes, National Healthcare Network, Dhaka, Bangladesh
2 Department of Medicine, Green Life Medical College and Hospital, Dhaka, Bangladesh
3 Maternal and Child Health Division, ICDDR'B, Dhaka, Bangladesh
4 Department of Medicine, MARKS Medical College and Hospital, Dhaka, Bangladesh
5 Department of Medicine, Sapporo Dental College and General Hospital, Dhaka, Bangladesh
6 Department of Medicine, Ibrahim General Hospital, Dhaka, Bangladesh
7 Department of Endocrinology, Ibrahim Medical College and BIRDEM General Hospital, Dhaka, Bangladesh
8 Department of Endocrinology and BIRDEM Academy, Ibrahim Medical College and BIRDEM General Hospital, Dhaka, Bangladesh

Date of Web Publication27-Nov-2017

Correspondence Address:
Nazmul Kabir Qureshi
Department of Endocrinology and Diabetes, National Health Care Network, Dhaka
Bangladesh
Login to access the Email id

Source of Support: None, Conflict of Interest: None


DOI: 10.4103/ijem.IJEM_196_17

Rights and Permissions
   Abstract 

Objective: There are several methods of assessing overweight and obesity. Several studies conducted in different populations indicate that neck circumference (NC) can be used as a simple measure of overweight and obesity. This study was conducted to evaluate NC as a marker of overweight and obesity and to determine respective cutoff values for Bangladeshi male and female participants.
Research Design/Materials and Methods: This cross-sectional observational study was conducted with during July 2013–June 2014 among randomly selected 871 Bangladeshi participants (male = 496 [56.9%], female = 375 [43.1%], aged >18 years) who visited Outpatient Department of United Hospital, Bangladesh Institute of Research and Rehabilitation in Diabetes, Endocrine and Metabolic disorders, primary health-care centers located in Dhaka, Savar, Gazipur. NC of participants was taken in centimeter to the nearest 1 mm, using plastic tape measure. Main outcome included NC, waist circumferences (WC), body mass index (BMI), and waist: hip ratio (WHR). Results: Pearson's correlation coefficients indicated a significant association between NC and height (men, r = 0.33; women, r = 0.28; P < 0.0001), weight (men, r = 0.61; women, r = 0.55; P < 0.0001), BMI (men, r = 0.51; women, r = 0.41; P < 0.0001), WC (men, r = 0.61; women, r = 0.46; P < 0.0001), hip circumference (men, r = 0.61; women, r = 0.44; P < 0.0001), WHR (men, r = 0.22; women, r = 0.18; P < 0.0001). Receiver operating characteristic curve analysis showed that NC ≥34.75 cm in men (area under curve [AUC]: 0.77; P < 0.001) and ≥31.75 cm in women (AUC: 0.62; P < 0.001) were the best cutoff value for BMI ≥23 (overweight). NC ≥35.25 cm in men (AUC: 0.82; P < 0.001) and NC ≥34.25 cm in women (AUC: 0.76; P < 0.001) were the best cutoff value for BMI ≥27.5 (obesity). NC ≥35.25 cm in male (AUC: 0.83; P < 0.001) and NC ≥31.25 cm in women (AUC: 0.65; P < 0.001) were the best cutoff value for WC >90 cm in men and > 80 cm in women, respectively. NC ≥34.45 cm in male (AUC: 0.59; P= 0.001) and NC ≥31.25 cm in women (AUC: 0.66; P = 0.008) were the best cutoff value for WHR >0.9 in men and >0.8 in women, respectively. Conclusion: NC measurement is a simple, convenient, inexpensive screening measure to identify overweight and obese participants. Men with NC ≥34.75 cm and women with NC ≥31.75 cm are to be considered overweight while men with NC ≥35.25 cm and women with NC ≥34.25 cm are to be considered obese. NC ≥35.25 cm in male and NC ≥31.25 cm in women were the best cutoff value for abdominal obesity.

Keywords: Bangladeshi men and women, height, neck circumference, obesity, overweight, waist circumference, waist:hip ratio, weight


How to cite this article:
Qureshi NK, Hossain T, Hassan MI, Akter N, Rahman MM, Sultana MM, Ashrafuzzaman S M, Latif ZA. Neck circumference as a marker of overweight and obesity and cutoff values for Bangladeshi adults. Indian J Endocr Metab 2017;21:803-8

How to cite this URL:
Qureshi NK, Hossain T, Hassan MI, Akter N, Rahman MM, Sultana MM, Ashrafuzzaman S M, Latif ZA. Neck circumference as a marker of overweight and obesity and cutoff values for Bangladeshi adults. Indian J Endocr Metab [serial online] 2017 [cited 2017 Dec 18];21:803-8. Available from: http://www.ijem.in/text.asp?2017/21/6/803/219317


   Introduction Top


Overweight and obesity are the terms used to define weight- and height-related anthropometric measures above the cutoff values recommended for the age and sex that poses various metabolic derangements to body and subsequent increase in morbidities and mortality. Once considered as a health-related problem for developed countries, overweight and obesity have become common globally. In 1997, the World Health Organization (WHO) has declared this condition as a global epidemic.[1] According to the International Obesity Task Force report, in 2010, the number of overweight and obese people globally was estimated nearly 1.0 billion and 475 million, respectively. Using Asian cutoff value for body mass index (BMI), the number of obese people increased to 600 million.[2] Childhood obesity is increasing in the same trend and it has been estimated that near about 200 million school-going children are overweight or obese.[2]

To define nutritional status and grade overweight and obesity, there are several anthropometric measures. Among them, mostly used measures are BMI, waist circumference (WC), hip circumference (HC), and waist: hip ratio (WHR). Other procedures such as ultrasonography, computed tomography scan, and magnetic resonance imaging scan are expensive, less cost-effective and used for research purposes only.[3] Nowadays, neck circumference (NC) is deserving mentionable magnitude.[4],[5],[6],[7]

Vague, who was the first to describe that different body morphology and types of fat distribution are related to health-related risks, used neck skin-fold thickness as an index for assessing upper body fat distribution.[7] Through subsequent studies, it has been found that upper body obesity and fat distribution are more strongly associated with glucose intolerance, hyperinsulinemia, diabetes mellitus, hyperuricemia, gout, hypertriglyceridemia, uric calculus, etc., than lower body obesity and fat distribution.[3],[7]

Though BMI and WC have been adopted by most health-care professionals for defining and classifying overweight and obesity, they do not necessarily illustrate the body composition regarding upper body and lower body morphology and fat distribution. Hence, it has been suggested that NC can be a good index for defining upper body fat distribution, overweight, and obesity.[4] Moreover, in busy everyday primary care practice, NC can be used as a convenient tool to define and grade overweight and obesity.

Several studies have been conducted in different populations which indicate that NC can be used as a simple measure for overweight and obesity.[4],[6] Yet, no such study of this kind has been done in Bangladesh. This study has been designed to evaluate NC as a marker of overweight and obesity and to define respective cutoff values for Bangladeshi male and female.


   Materials and Methods Top


Study design and research ethics

This cross-sectional study was conducted between July 2013 and June 2014. Bangladeshi adult participants, aged more than 18 years, both male and female, who visited Outpatient Department of United Hospital, Bangladesh Institute of Research and Rehabilitation in Diabetes, Endocrine and Metabolic Disorders, primary health-care centers located in Dhaka, Savar, Gazipur, were randomly selected. Those having goiter, cervical lymphadenopathy, cystic or mass lesion in the neck or any anatomical abnormality of the neck region, ascites, intra-abdominal organomegaly or intra-or extra-abdominal mass lesion, kyphosis, scoliosis or any anatomical abnormality of the waist and hip region, pregnancy, and participants suffering from severe comorbid conditions were excluded from the study. After exclusion, a total of 871 participants were included in the study. The data were collected in a preformed standard printed data collection form after explaining the study purpose, procedure, and taking informed consent from the study participants. All coresearchers involved in data collection were briefed and trained before commencement of the study.

Study tools

  1. Participants were examined regarding height, weight, BMI, WC, HC, WHR, and NC
    1. Height (cm): Standing height was measured in centimeter (cm) using stadiometer and height rod (Detecto Scale Company, USA) with minimal clothes. The participant was positioned fully erect, with the head in the Frankfurt plane (with the line connecting the outer canthus of the eyes and the external auditory meatus perpendicular to the long axis of the trunk), the back of the head, thoracic spine, buttocks, and heels touched the vertical axis of the anthropometer, and the heels were together. Height was recorded to the nearest 1 mm. If the reading fell between two values, the lower reading was recorded
    2. Weight (kilogram [kg]): Standard weight measuring device was used that was placed on a hard flat surface and checked for zero balance before measurement. Each participant was placed in the center of the platform wearing light clothes without shoes, after emptying bladder. Weight was recorded to the nearest 0.5 kg
    3. BMI: BMI of participants were calculated by dividing weight in kg with the square of height in meter using formula kg/m 2
    4. WC: WC was measured in centimeter to within 1 mm that was taken horizontally in using plastic tape measure at midpoint between the costal margin and iliac crest in the midaxillary line, with the participant standing and at the end of a gentle expiration. Average of two readings was used for analysis
    5. HC: HC was measured in centimeter using a plastic tape measuring, at the horizontal level of greater trochanters, with the legs close together. Average of two readings was used for analysis
    6. WHR: WC was divided by HC to get the WHR
    7. NC: NC of participants was taken in centimeter to the nearest 1 mm, using plastic tape measure. It was taken in a plane as horizontal as possible, at a point just below the larynx (thyroid cartilage) and perpendicular to the long axis of the neck (the tape line in front of the neck at the same height as the tape line in the back of the neck). While taking this reading, the participant was asked to look straight ahead, with shoulders down, but not hunched. Care was taken not to involve the shoulder/neck muscles (trapezius) in the measurement. Average of two readings was used for analysis.


  1. Primary outcomes of this study were NC, BMI, WC, and WHR.
    1. BMI: As specified for the Asia-Pacific population by the Western Pacific Regional Office of the WHO, BMI was classified as following: BMI <18.50 kg/m 2: underweight; BMI 18.50–22.99 kg/m 2: Normal; BMI ≥23.00–27.49 kg/m 2: Overweight, and BMI ≥27.5.00 kg/m 2: Obesity [8],[9],[10]
    2. WC: WC > 90 cm in male and >80 cm for female were used for data analysis as cutoff values to define abdominal obesity [10],[11],[12]
    3. WHR: The data were analyzed using cutoff values >0.9 for male and >0.8 for female to define obesity.[10],[13]


Statistical analysis

Data were collected in preformed record form and were analyzed with IBM SPSS for Windows version 20 (IBM SPSS Statistics for Windows, Version 20.0. IBM Corp. Armonk, NY, USA). All data were analyzed and reported by sex. The means and standard deviations (SD) were used to describe continuous data. For categorical data, frequencies and percentages were estimated. The significance of differences in proportions was tested using Chi-square test. The associations between NC and anthropometric parameters of studied participants were assessed using Pearson's correlation analysis. Receiver operating characteristic (ROC) curve analysis was employed to determine optimal sex-specific cutoffs of NC in relation to BMI, WC, and WHR. Statistical significance was set at P < 0.05.


   Results Top


Among 871 studied participants, 496 (56.9%) were male and rest were female (43.1%) and their anthropometric and metabolic characteristics are presented in [Table 1]. Mean BMI (kg/m 2) was 22.71 ± 3.49 and female had higher BMI than male (female: 23.42 ± 3.70, male: 22.17 ± 3.23). According to BMI, totally 35.1% of participants were overweight and 9.2% were obese. Compared to male, female were more overweight (male = 31.9%, female = 39.5%) and obese (male = 6.3%, female = 13.1%) [Table 2]. As mean ± SD, WC (cm) of studied participants was as follows: total participants: 82.02 ± 8.47, in male: 82.32 ± 7.87 and in female: 81.62 ± 9.20. As per WC, 16.9% of men and 49.1% of women had abdominal obesity. As mean ± SD, HC (cm) of studied participants was as follows: Total participants: 90.30 ± 7.38, in male: 90.20 ± 6.90 and in female: 90.43 ± 7.98 and WHR was as follows: total participants: 0.91 ± 0.06, in male: 0.91 ± 0.05 and in female: 0.90 ± 0.06 [Table 1].
Table 1: Anthropometric and metabolic characteristics of studied participants

Click here to view
Table 2: Body mass index status of studied participants

Click here to view


Mean of NC (cm) of studied participants was 33.45 ± 2.22 and was higher in male than female participants (in male: 34.16 ± 1.95 and in female: 32.50 ± 2.20) [Table 1]. The Pearson's correlations between NC and studied parameters showed positive and significant correlation with weight (total participants: r = 0.59, P < 0.001; in male: r = 0.61, P < 0.001 and in female: r = 0.55, P < 0.001), BMI (total participants: r = 0.36, P < 0.001; in male: r = 0.51, P < 0.001 and in female: r = 0.41, P < 0.001), WC (total participants: r = 0.51, P < 0.001; in male: r = 0.61, P < 0.001 and in female: r = 0.46, P < 0.001), and HC (total participants: r = 0.48, P < 0.001; in male: r = 0.61, P < 0.001 and in female: r = 0.44, P < 0.001) of studied participants while WHR ratio was less positively correlated with NC (total participants: r = 0.23, P < 0.001; in male: r = 0.22, P < 0.001 and in female: r = 0.18, P < 0.001). NC was more correlated with weight, BMI, WC, and HC of male participants than that of female participants [Table 3].
Table 3: The Pearson's correlations between neck circumference and studied obesity parameters

Click here to view


ROC curve analysis was used to determine sex-specific the best cutoff values of NC in relation to BMI, WC, and WHR. In male, ROC curve analysis indicated that NC ≥34.75 cm (area under curve [AUC] = 0.77, 95% confidence interval [CI] = 0.73–0.82, P < 0.001) and ≥35.25 cm (AUC = 0.82, 95% CI = 0.73–0.89, P < 0.001) were the best cutoff levels to determine overweight (BMI ≥23) and obese (BMI 27.5) participants, respectively [Figure 1] and [Figure 2]. For defining abdominal obesity, ROC curve analysis suggested that NC ≥35.25 cm (AUC = 0.83, 95% CI = 0.78–0.88, P < 0.001) was the best cutoff value corresponding to WC >90 cm [Figure 3]. However, NC ≥34.45 cm (AUC: = 0.59, 95% CI = 0.54–0.64, P = 0.001) was the best cutoff value for WHR >0.9, which was less positively correlated [Figure 4].
Figure 1: Receiver operating characteristic curve for neck circumference in male overweight participants (body mass index ≥23). NB: Neck circumference cutoff value: ≥34.75 cm

Click here to view
Figure 2: Receiver operating characteristic curve for neck circumference in male obese participants (body mass index ≥27.5). NB: Neck circumference cutoff value: ≥35.25 cm

Click here to view
Figure 3: Receiver operating characteristic curve for neck circumference in male participants with abdominal obesity (waist circumference >90 cm). NB: Neck circumference cutoff value: ≥35.25 cm

Click here to view
Figure 4: Receiver operating characteristic curve for neck circumference in male subjects with abdominal obesity (Waist: Hip ratio >0.9). N.B.: NC cut-off value: ≥34.45 cm

Click here to view


In female, ROC curve analysis suggested that NC ≥31.75 cm (AUC = 0.62, 95% CI = 0.56–0.68, P < 0.001) and ≥34.25 cm (AUC = 0.76, 95% CI = 0.69–0.84, P < 0.001) were the best cutoff values to determine overweight (BMI ≥23) and obese (BMI ≥27.5) participants, respectively [Figure 5] and [Figure 6]. For defining abdominal obesity, ROC curve analysis suggested that NC ≥31.25 cm (AUC = 0.65, 95% CI = 0.59–0.70, P < 0.001) was the best cutoff value for corresponding to WC >80 cm [Figure 7]. NC ≥31.25 cm (AUC: = 0.65, 95% CI = 0.53–0.77, P = 0.008) was the best cutoff value for WHR >0.8 [Figure 8].
Figure 5: Receiver operating characteristic curve for neck circumference in female overweight participants (body mass index ≥23). NB: Neck circumference cutoff value: ≥31.75 cm

Click here to view
Figure 6: Receiver operating characteristic curve for neck circumference in female obese participants (body mass index ≥27.5). NB: Neck circumference cutoff value: ≥34.25 cm

Click here to view
Figure 7: Receiver operating characteristic curve for neck circumference in female participants with abdominal obesity (waist circumference >80 cm). NB: Neck circumference cutoff value: ≥31.25 cm

Click here to view
Figure 8: Receiver operating characteristic curve for neck circumference in female participants with abdominal obesity (waist: hip ratio >0.8). NB: Neck circumference cutoff value: ≥31.25 cm

Click here to view



   Discussion Top


Upper body fat distribution has been considered as risk factor of cardiovascular disease.[7] It has been reported that free fatty acids are released in larger proportion from upper body subcutaneous fat than lower body subcutaneous fat.[14] Moreover, NC has been used as an index for such an adverse risk profile.[15],[16]

This study evaluated NC as a marker of overweight and obesity and suggestive respective cutoff values have been determined. Of 871 studied participants, mean of NC was 33.45 ± 2.22 cm. Male had higher NC than that of female participants (as mean ± SD, in male: 34.16 ± 1.95 cm and in female: 32.50 ± 2.20 cm). NC showed positive and significant correlation with BMI, WC, and HC of studied participants. With ROC curve analysis, sex-specific the best cutoff values of NC in relation to BMI, WC, and WHR were determined. NC ≥34.75 cm in men (AUC: 0.77; P < 0.001) and ≥31.75 cm in women (AUC: 0.62; P < 0.001) were the best cutoff values corresponding to BMI ≥23 (overweight). For obesity (BMI ≥27.5), NC ≥35.25 cm in men (AUC: 0.82; P < 0.001) and ≥ 34.25 cm in women (AUC: 0.76; P < 0.001) were the best cutoff values. For abdominal obesity, NC ≥35.25 cm in male (AUC: 0.83; P < 0.001) and ≥31.25 cm in women (AUC: 0.65; P < 0.001) were the best cutoff values corresponding to WC >90 cm in men and >80 cm in women, respectively. For WHR >0.9 in men and >0.8 in women, NC ≥34.45 cm in male (AUC: 0.59; P = 0.001) and ≥31.25 cm in women (AUC: 0.66; P = 0.008) were the best cutoff values.

In a similar study but smaller sample size conducted in this region (41 male and 109 female, aged 18–20 years) also reported, NC was found higher in males than in females (35.56 ± 2.77 cm vs. 31.52 ± 1.96 cm, P < 0.001). NC had a strong and positive correlation (P< 0.001) with BMI (r = 0.861, P < 0.0001 in males; r = 0.704, P < 0.0001 in females) and WC (r = 0.858, P < 0.0001 in males; r = 0.623, P < 0.0001 in females). At BMI of 23.0 and 25.0, males had NC 35.7 cm and 37.5 cm while females had it at of 32.2 cm and 33.5 cm respectively.[6]

In another study (979 Israeli participants, 460 men and 519 women), significant association was found between NC and BMI (men, r = 0.83; women, r = 0.71; each, P = 0.0001), WC (men, r = 0.86; women, r = 0.85; each, P= 0.0001), HC (men, r = 0.62; women, r = 5 0.56; each, P= 0.0001), and WHR (men, r = 5 0.66; women, r = 0.87; each, P = 0.0001). NC ≥37 cm for men and ≥34 cm for women were the best cutoff levels for determining the participants with BMI ≥25.0 kg/m 2 using ROC analysis, and NC ≥39.5 cm for men and ≥36.5 cm for women were the best cutoff levels for determining the participants with BMI ≥30 kg/m 2.[4]

The study has several limitations. Sample size was small, selected from few health-care facilities that cannot be generalized over the whole population. Age group-specific cutoff points were not determined. Urban and rural stratification was not done. NC was not studied in relation to metabolic components as well. Despite the limitations, the study has important implications that points that in detection of overweight/obesity in adults NC can be a practical and an easier alternative tool.


   Conclusion Top


NC measurement as a simple and time-saving screening measure could be used to identify overweight and obese population. It is a straightforward, easy, and inexpensive tool that can be performed in any situation with a tape measure. This study, conducted among Bangladeshi participants, has suggested that men with NC ≥34.75 cm and women with NC ≥31.75 cm are to be considered overweight while men with NC ≥35.25 cm and women with NC ≥34.25 cm are to be considered obese. NC ≥ 35.25 cm in male and NC ≥ 31.25 cm in women were the best cutoff value for abdominal obesity. Further studies with age-grouped, urban-rural stratified in larger sample are required for validation of this tool.

Financial support and sponsorship

Nil.

Conflicts of interest

There are no conflicts of interest.

 
   References Top

1.
Caballero B. The global epidemic of obesity: An overview. Epidemiol Rev 2007;29:1-5.  Back to cited text no. 1
[PUBMED]    
2.
International Obesity Taskforce (IOTF). The Global Epidemic. Available from: http://www.iaso.org/iotf/obesity/obesitytheglobalepidemic. [Last cited on 2011 Jan 26].  Back to cited text no. 2
    
3.
Kissebah AH, Vydelingum N, Murray R, Evans DJ, Hartz AJ, Kalkhoff RK, et al. Relation of body fat distribution to metabolic complications of obesity. J Clin Endocrinol Metab 1982;54:254-60.  Back to cited text no. 3
[PUBMED]    
4.
Ben-Noun L, Sohar E, Laor A. Neck circumference as a simple screening measure for identifying overweight and obese patients. Obes Res 2001;9:470-7.  Back to cited text no. 4
[PUBMED]    
5.
Yang GR, Yuan SY, Fu HJ, Wan G, Zhu LX, Bu XL, et al. Neck circumference positively related with central obesity, overweight, and metabolic syndrome in Chinese subjects with type 2 diabetes: Beijing Community Diabetes Study 4. Diabetes Care 2010;33:2465-7.  Back to cited text no. 5
[PUBMED]    
6.
Hingorjo MR, Qureshi MA, Mehdi A. Neck circumference as a useful marker of obesity: A comparison with body mass index and waist circumference. J Pak Med Assoc 2012;62:36-40.  Back to cited text no. 6
[PUBMED]    
7.
Vague J. The degree of masculine differentiation of obesities: A factor determining predisposition to diabetes, atherosclerosis, gout, and uric calculous disease. Am J Clin Nutr 1956;4:20-34.  Back to cited text no. 7
[PUBMED]    
8.
World Health Organization, Western Pacific Region. International Association for the Study of Obesity (IASO) and the International Obesity Task Force (IOTF). The Asia-Pacific perspective: Redefining obesity and its treatment. Crows Nest, NSW, Australia: Health Communications Australia; 2000.  Back to cited text no. 8
    
9.
WHO Expert Consultation. Appropriate body-mass index for Asian populations and its implications for policy and intervention strategies. Lancet 2004;363:157-63.  Back to cited text no. 9
[PUBMED]    
10.
Ahmad N, Adam SI, Nawi AM, Hassan MR, Ghazi HF. Abdominal obesity indicators: Waist circumference or waist-to-hip ratio in Malaysian adults population. Int J Prev Med 2016;7:82.  Back to cited text no. 10
[PUBMED]  [Full text]  
11.
Zimmet PZ, Alberti KG. Introduction: Globalization and the non-communicable disease epidemic. Obesity (Silver Spring) 2006;14:1-3.  Back to cited text no. 11
[PUBMED]    
12.
IDF. The IDF consensus worldwide definition of the metabolic syndrome. Brussels, Belgium: International Diabetes Federation (IDF); 2006.  Back to cited text no. 12
    
13.
WHO. Waist Circumference and Waist-hip Ration: Report of a WHO Expert Consultation. Geneva: WHO; 2008.  Back to cited text no. 13
    
14.
Jensen MD. Lipolysis: Contribution from regional fat. Annu Rev Nutr 1997;17:127-39.  Back to cited text no. 14
[PUBMED]    
15.
Sjöström CD, Håkangård AC, Lissner L, Sjöström L. Body compartment and subcutaneous adipose tissue distribution – Risk factor patterns in obese subjects. Obes Res 1995;3:9-22.  Back to cited text no. 15
    
16.
Sjostrom CD, Lissner L, Sjostrom L. Relationship between changes in body composition and changes in cardiovascular risk factors: The SOS intervention study: Swedish obese subjects. Obes Res 1997;5:519-30.  Back to cited text no. 16
    


    Figures

  [Figure 1], [Figure 2], [Figure 3], [Figure 4], [Figure 5], [Figure 6], [Figure 7], [Figure 8]
 
 
    Tables

  [Table 1], [Table 2], [Table 3]



 

Top
 
  Search
 
    Similar in PUBMED
   Search Pubmed for
   Search in Google Scholar for
 Related articles
    Access Statistics
    Email Alert *
    Add to My List *
* Registration required (free)  

   Abstract Introduction Materials and Me... Results Discussion Conclusion Article Figures Article Tables
  In this article
 References

 Article Access Statistics
    Viewed186    
    Printed1    
    Emailed0    
    PDF Downloaded64    
    Comments [Add]    

Recommend this journal