Biol Trace Elem Res (2014) 161:13–19 DOI 10.1007/s12011-014-0082-9
Hair Toxic Element Content in Adult Men and Women in Relation to Body Mass Index Margarita G. Skalnaya & Alexey A. Tinkov & Vasily A. Demidov & Eugeny P. Serebryansky & Alexandr A. Nikonorov & Anatoly V. Skalny
Received: 30 May 2014 / Accepted: 15 July 2014 / Published online: 23 July 2014 # Springer Science+Business Media New York 2014
Abstract The primary objective of the current study was to estimate the hair toxic metal content in adults in relation to body mass index. A total of 1,229 persons including 719 women and 510 men were examined. All subjects were divided into two age groups: 1 and 2 periods of adulthood. All men and women were also subdivided into groups in relation to their values of body mass index (BMI): underweight, normal weight, overweight and obese. Hair aluminium (Al), beryllium (Be), cadmium (Cd), mercury (Hg), lead (Pb) and tin (Sn) content was evaluated using mass spectrometry with inductively coupled plasma. It has been shown that increase in body weight is accompanied by elevated hair cadmium content in women. At the same time, no significant alteration of hair cadmium concentration was observed in males. Higher values of scalp hair mercury and lead content were observed in men and women with increased body mass index independently of their age. BMI-related elevation of hair tin content was registered only in men of the first period of adulthood. A significant correlation between hair metal content and the values of BMI was observed for mercury independently of the gender of the sub-
M. G. Skalnaya : V. A. Demidov : E. P. Serebryansky : A. V. Skalny Russian Society of Trace Elements in Medicine, ANO “Centre for Biotic Medicine”, Zemlyanoy Val St. 46, Moscow, Russia 105064 A. A. Tinkov (*) : A. A. Nikonorov Department of Biochemistry, Orenburg State Medical Academy, Sovetskaya St., 6, Orenburg, Russia 460000 e-mail: [email protected] A. V. Skalny Institute of Bioelementology (Russian Satellite Centre of Trace Element – Institute for UNESCO), Orenburg State University, Pobedy Ave. 13, Orenburg, Russia 460352
jects, whereas BMI values correlated significantly with hair cadmium levels in women and lead and tin levels in men. It has been also estimated that hair cadmium, mercury and lead levels in men exceed the respective values in women. Keywords Cadmium . Mercury . Lead . Tin . Body mass index
Introduction Nowadays, obesity and overweight is thought to be the one of the most common noninfectious diseases with the incidence of more than 10 % of people worldwide [1]. It occurs both in men and women. Particularly, in 2008, obesity was observed in 502 million of individuals (205 in men and 297 in women) [2]. Adults are the most economically active part of the population. Obesity in adults is accompanied by the development of early disability [3], leading to productivity losses due to decreased workforce participation and increased work limitations [4]. The latter results in increased indirect economic costs of obesity [5]. The role of endocrine disruptors in obesityassociated adipose tissue endocrine dysfunction is widely discussed in the last decades [6]. According to the current knowledge, toxic metals are supposed to possess endocrine-disrupting properties [7]. It has been shown that aluminium, cadmium, mercury and lead compounds induce alteration of a number of endocrine tissues and cells [8]. At the same time, data regarding interaction of toxic trace elements balance and obesity development seem to be inhomogeneous [9]. Therefore, the primary objective of the current study is to
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Skalnaya et al.
estimate the hair toxic metal (Al, Be, Cd, Hg, Pb, Sn) content in adults in relation to body mass index (BMI).
correlation. All statistical analyses were performed with Statistica 11.0 (Statsoft).
Materials and Methods
Results
A total of 1,229 persons (719 women and 510 men) living in the Orenburg region (Russia) took part in the current survey. The research was approved by the Local Ethics Committee of the Orenburg State University (Institute of Bioelementology). All examinees gave their informed consent prior to the inclusion in the study. All subjects were divided into two age groups according to the periods of adulthood [10]. In particular, in men, the first period of the adulthood started at 22 and ended at 35 years old, whereas the second period ended at the age of 60. The same periods of the adulthood in women were limited to 21–35 and 35–55 years old, respectively. The exclusion criteria in the current study were (i) occupational exposure to toxic metals; (ii) habitation in the zone of influence of metal processing industries; (iii) smoking (both current and former smokers); (iv) acute infectious, surgical and traumatic diseases; (v) metallic implants; (vi) pregnancy and lactation; (vii) vegetarian diet; and (viii) menopause. Potential participants with one or more criteria were excluded from the current study. The participants were also subdivided into four subgroups depending on the body mass index values. Particularly, we have used the simplified gradation of BMI values suggested by WHO [11]. The first group of subjects with BMI values less than 18.5 were considered to be underweight, the second group was characterized by normal body weight (BMI= 18.5–25), the third group of examinees with BMI values from 25 to 30 were classified as overweight, whereas persons with values of BMI higher than 30 were graded as obese. Occipital scalp hair was collected. All participants have washed their hair on the day of sample collection. Toxic metal Al, Be, Cd, Hg, Pb and Sn content (μg/g) was assessed by inductively coupled plasma mass spectrometry using Elan 9000 (Perkin-Elmer, USA).
Hair Toxic Trace Element Content in Persons of the First Period of Adulthood
Statistical Analysis Data distribution was evaluated by the Shapiro-Wilk test. Since the distribution was not Gaussian, the obtained data were reported as median and the respective 25 and 75 % quartiles (Me (Q25– Q75)). Nonparametric Mann-Whitney U test was used for comparison of two groups. Global differences in hair toxic metal concentration were assessed by Kruskal-Wallis test (KWP). The level of significance was set as p < 0.05 for all analyses. Correlation analysis was performed using Spearman’s coefficient of rank
The data obtained (Table 1) show that obesity in women resulted in 44, 36 and 92 % decrease in hair aluminium content when compared to the underweight, normal weight and overweight groups, respectively. The tendency was also observed in men. However, the changes were not significant. It is important to note that hair aluminium content in males significantly exceeded the respective values observed in females. No universal tendency in beryllium hair dynamics was observed. Increased BMI values in women were accompanied by a significant decrease in hair beryllium content. The reverse tendency was observed in men. In particular, hair Be content values in obese males significantly exceeded the ones obtained for underweight persons. At the same time, hair beryllium concentration in obese men did not differ from the respective values in the normal-weight group. Obese females were characterized by a twofold increase in hair Cd when compared to the normal-weight ones. However, no difference in hair cadmium values was observed between male weight groups. Simultaneously, the concentration of cadmium in men’s hair significantly exceeded the one observed in women. It is estimated that hair mercury content in women with normal and excessive weight exceeded the respective values obtained for underweight persons by 78 and 41 %, respectively. At the same time, obesity resulted in a significant increase in hair Hg values by 248, 39 and 76 % in comparison to the values observed in underweight, normal-weight and overweight subjects. Such tendency was observed in men. Thus, in normal and overweight males, a nonsignificant 58 and 62 % increase in hair mercury content compared to the underweight group was detected. At the same time, a 157 and 63 % increase in hair Hg content was observed in obese men when compared to underweight and normal-weight subjects. It is important to note that hair mercury values in males exceeded the ones observed in females. Moreover, the Kruskal-Wallis test indicated significant dependence of hair mercury content on BMI values both in men and women. Hair lead content in women had a tendency to increase with BMI. However, these changes were not significant. At the same time, such tendency was more expressed in men. Particularly, hair lead concentration in obese men significantly exceeded the respective values observed for underweight and normal-weight subjects by 36 and 27 %, respectively. The
d
c
b
a
25.19±4.98 9.275 (5.260–10.890) 0.002 (0.002–0.007) 0.029 (0.015–0.052) 0.287 a (0.175–0.796) 0.399 (0.240–0.759) 0.110 (0.058–0.161)
25.0–30.0 (n=42) 28.28±5.52 4.829 abc (3.298–9.360) 0.002 a (0.002–0.008) 0.041 b (0.018–0.113) 0.506 abc (0.364–0.880) 0.431 (0.200–0.727) 0.111 (0.053–0.224)
>30 (n=18)
Significant difference in comparison to the respective women weight group values
Significant difference in comparison to the weight group with BMI=25.0–30.0
Significant difference in comparison to the weight group with BMI=18.5–25.0
Significant difference in comparison to the weight group with BMI
Hair Toxic Element Content in Adult Men and Women in Relation to Body Mass Index Margarita G. Skalnaya & Alexey A. Tinkov & Vasily A. Demidov & Eugeny P. Serebryansky & Alexandr A. Nikonorov & Anatoly V. Skalny
Received: 30 May 2014 / Accepted: 15 July 2014 / Published online: 23 July 2014 # Springer Science+Business Media New York 2014
Abstract The primary objective of the current study was to estimate the hair toxic metal content in adults in relation to body mass index. A total of 1,229 persons including 719 women and 510 men were examined. All subjects were divided into two age groups: 1 and 2 periods of adulthood. All men and women were also subdivided into groups in relation to their values of body mass index (BMI): underweight, normal weight, overweight and obese. Hair aluminium (Al), beryllium (Be), cadmium (Cd), mercury (Hg), lead (Pb) and tin (Sn) content was evaluated using mass spectrometry with inductively coupled plasma. It has been shown that increase in body weight is accompanied by elevated hair cadmium content in women. At the same time, no significant alteration of hair cadmium concentration was observed in males. Higher values of scalp hair mercury and lead content were observed in men and women with increased body mass index independently of their age. BMI-related elevation of hair tin content was registered only in men of the first period of adulthood. A significant correlation between hair metal content and the values of BMI was observed for mercury independently of the gender of the sub-
M. G. Skalnaya : V. A. Demidov : E. P. Serebryansky : A. V. Skalny Russian Society of Trace Elements in Medicine, ANO “Centre for Biotic Medicine”, Zemlyanoy Val St. 46, Moscow, Russia 105064 A. A. Tinkov (*) : A. A. Nikonorov Department of Biochemistry, Orenburg State Medical Academy, Sovetskaya St., 6, Orenburg, Russia 460000 e-mail: [email protected] A. V. Skalny Institute of Bioelementology (Russian Satellite Centre of Trace Element – Institute for UNESCO), Orenburg State University, Pobedy Ave. 13, Orenburg, Russia 460352
jects, whereas BMI values correlated significantly with hair cadmium levels in women and lead and tin levels in men. It has been also estimated that hair cadmium, mercury and lead levels in men exceed the respective values in women. Keywords Cadmium . Mercury . Lead . Tin . Body mass index
Introduction Nowadays, obesity and overweight is thought to be the one of the most common noninfectious diseases with the incidence of more than 10 % of people worldwide [1]. It occurs both in men and women. Particularly, in 2008, obesity was observed in 502 million of individuals (205 in men and 297 in women) [2]. Adults are the most economically active part of the population. Obesity in adults is accompanied by the development of early disability [3], leading to productivity losses due to decreased workforce participation and increased work limitations [4]. The latter results in increased indirect economic costs of obesity [5]. The role of endocrine disruptors in obesityassociated adipose tissue endocrine dysfunction is widely discussed in the last decades [6]. According to the current knowledge, toxic metals are supposed to possess endocrine-disrupting properties [7]. It has been shown that aluminium, cadmium, mercury and lead compounds induce alteration of a number of endocrine tissues and cells [8]. At the same time, data regarding interaction of toxic trace elements balance and obesity development seem to be inhomogeneous [9]. Therefore, the primary objective of the current study is to
14
Skalnaya et al.
estimate the hair toxic metal (Al, Be, Cd, Hg, Pb, Sn) content in adults in relation to body mass index (BMI).
correlation. All statistical analyses were performed with Statistica 11.0 (Statsoft).
Materials and Methods
Results
A total of 1,229 persons (719 women and 510 men) living in the Orenburg region (Russia) took part in the current survey. The research was approved by the Local Ethics Committee of the Orenburg State University (Institute of Bioelementology). All examinees gave their informed consent prior to the inclusion in the study. All subjects were divided into two age groups according to the periods of adulthood [10]. In particular, in men, the first period of the adulthood started at 22 and ended at 35 years old, whereas the second period ended at the age of 60. The same periods of the adulthood in women were limited to 21–35 and 35–55 years old, respectively. The exclusion criteria in the current study were (i) occupational exposure to toxic metals; (ii) habitation in the zone of influence of metal processing industries; (iii) smoking (both current and former smokers); (iv) acute infectious, surgical and traumatic diseases; (v) metallic implants; (vi) pregnancy and lactation; (vii) vegetarian diet; and (viii) menopause. Potential participants with one or more criteria were excluded from the current study. The participants were also subdivided into four subgroups depending on the body mass index values. Particularly, we have used the simplified gradation of BMI values suggested by WHO [11]. The first group of subjects with BMI values less than 18.5 were considered to be underweight, the second group was characterized by normal body weight (BMI= 18.5–25), the third group of examinees with BMI values from 25 to 30 were classified as overweight, whereas persons with values of BMI higher than 30 were graded as obese. Occipital scalp hair was collected. All participants have washed their hair on the day of sample collection. Toxic metal Al, Be, Cd, Hg, Pb and Sn content (μg/g) was assessed by inductively coupled plasma mass spectrometry using Elan 9000 (Perkin-Elmer, USA).
Hair Toxic Trace Element Content in Persons of the First Period of Adulthood
Statistical Analysis Data distribution was evaluated by the Shapiro-Wilk test. Since the distribution was not Gaussian, the obtained data were reported as median and the respective 25 and 75 % quartiles (Me (Q25– Q75)). Nonparametric Mann-Whitney U test was used for comparison of two groups. Global differences in hair toxic metal concentration were assessed by Kruskal-Wallis test (KWP). The level of significance was set as p < 0.05 for all analyses. Correlation analysis was performed using Spearman’s coefficient of rank
The data obtained (Table 1) show that obesity in women resulted in 44, 36 and 92 % decrease in hair aluminium content when compared to the underweight, normal weight and overweight groups, respectively. The tendency was also observed in men. However, the changes were not significant. It is important to note that hair aluminium content in males significantly exceeded the respective values observed in females. No universal tendency in beryllium hair dynamics was observed. Increased BMI values in women were accompanied by a significant decrease in hair beryllium content. The reverse tendency was observed in men. In particular, hair Be content values in obese males significantly exceeded the ones obtained for underweight persons. At the same time, hair beryllium concentration in obese men did not differ from the respective values in the normal-weight group. Obese females were characterized by a twofold increase in hair Cd when compared to the normal-weight ones. However, no difference in hair cadmium values was observed between male weight groups. Simultaneously, the concentration of cadmium in men’s hair significantly exceeded the one observed in women. It is estimated that hair mercury content in women with normal and excessive weight exceeded the respective values obtained for underweight persons by 78 and 41 %, respectively. At the same time, obesity resulted in a significant increase in hair Hg values by 248, 39 and 76 % in comparison to the values observed in underweight, normal-weight and overweight subjects. Such tendency was observed in men. Thus, in normal and overweight males, a nonsignificant 58 and 62 % increase in hair mercury content compared to the underweight group was detected. At the same time, a 157 and 63 % increase in hair Hg content was observed in obese men when compared to underweight and normal-weight subjects. It is important to note that hair mercury values in males exceeded the ones observed in females. Moreover, the Kruskal-Wallis test indicated significant dependence of hair mercury content on BMI values both in men and women. Hair lead content in women had a tendency to increase with BMI. However, these changes were not significant. At the same time, such tendency was more expressed in men. Particularly, hair lead concentration in obese men significantly exceeded the respective values observed for underweight and normal-weight subjects by 36 and 27 %, respectively. The
d
c
b
a
25.19±4.98 9.275 (5.260–10.890) 0.002 (0.002–0.007) 0.029 (0.015–0.052) 0.287 a (0.175–0.796) 0.399 (0.240–0.759) 0.110 (0.058–0.161)
25.0–30.0 (n=42) 28.28±5.52 4.829 abc (3.298–9.360) 0.002 a (0.002–0.008) 0.041 b (0.018–0.113) 0.506 abc (0.364–0.880) 0.431 (0.200–0.727) 0.111 (0.053–0.224)
>30 (n=18)
Significant difference in comparison to the respective women weight group values
Significant difference in comparison to the weight group with BMI=25.0–30.0
Significant difference in comparison to the weight group with BMI=18.5–25.0
Significant difference in comparison to the weight group with BMI
