Comprehensive Study about Mobile Phone Radiation Effects on Body Weight and Body Composition

Introduction

Nowadays, the development of technological devices has dramatically affected the daily life of humanity. Electromagnetic waves or electromagnetic radiations (EMRs), which are emitted by many artificial sources such as x-rays, radio and television stations, and mobile phones, are invisible phenomena having a day effect on people worldwide (1-3).

Mobile phones are used near bodies, and the time of usage has been quickly increasing lately. Additionally, data showed the usage of mobile phones has increased not only in adulthood but also among the elderly and youth people, and young children. Thus, there is significant concern about the potential biological effects of electromagnetic radiation liberated from mobile phones. But, data are deficient on the feasible effects of electromagnetic radiation on organisms liberated from mobile phone usage.

Research shows that constant exposure to EMRs could affect human health, such as causing headaches, cancer, and other health hazards (4-7). Exposure to EMR from mobile phones could affect people's health (8). The previous document revealed the significant association between EMR and reproduction, cancer, and neurobehavioral diseases (9-11). Some studies evaluated the effect of EMRs on body weight and literature results are inconsistent (12, 13). These studies assessed only weight index and other anthropometric indices did not evaluate (14) , also it has not been considered the organs function such as thyroid, kidney, and pancreas that can directly or indirectly affect body weight that document shows the EMRs might have a harmful effect on these organs function (15-19). Therefore, no comprehensive study assesses the effects of exposure to mobile phone radiation on body composition and body weight and body composition by considering the indicators related to body mass.

So, the present comprehensive study assessed the effects of exposure to mobile phone radiation on body weight and body composition as well as assessing the critical indicators associated with body composition including thyroid, kidney function, and hormonal profiles.

Methods

All rats were cared for according to the principles guidelines of Animal Care and the Ethical Committee of Tehran University of Medical Sciences approved the study (IR.TUMS.SINAHOSPITAL.REC.1399.017). Twenty rats weighing 200+10g at 4 to 6 weeks of age were randomly divided into the following two groups of 10 animals each: the control group and the intervention group that underwent electromagnetic wave radiation for 4 hours once a day for five weeks. To make mobile phone waves radiation, we used a wave transmitter with a wavelength equal to a current mobile phone in the standard markets. At the time of wave transmission, the cages of rats were entered into an aluminum box that was located adjacent to the wave transmitter. The exposure was given by mobile phone having a specific absorption rate (SAR) of 0.90watts/kg. The amount of SAR used in the experiment was the mean of the mobile phone SARs in various mobile modes including calling, listening, airplane mode, and talking. All rats were given unrestricted access to a standard rodent chow. 

Anthropometrical parameters and food intake                  

The weight, length of the body (nose-to-anus), thoracic circumference (immediately behind the foreleg), and abdominal circumference (AC) (immediately anterior to the forefoot) were measured in all rats at the same time of the day at weekly intervals during the 5-week study period. Body mass index (BMI) was calculated as body weight in grams divided by the length in centimeters squared (g/cm2), and lee index was calculated as the cube root of body weight in grams divided by the length in centimeters. Anthropometric parameters were measured under intraperitoneal ketamine-xylazine anesthesia. Food intake was assessed every day at the same time.

Biochemical parameters 

The rats were fasted overnight (10–12 h), and whole blood was sampled directly from the heart of the rats. Fasting blood glucose (FBS) (Biorex, Iran), lipid profile (Biorex, Iran), and insulin (Raybiotech, USA) were assayed. The leptin (MOB00B, R&D, USA), adiponectin (MBS068220‎, MyBioSource, USA), and ghrelin (CSB-E09816r, cusabio, USA) were assessed using a mouse enzyme-linked immunosorbent assay. Uric acid (Biorex, Iran), creatinine (Biorex, Iran), and thyroid hormones including T3 (MyBioSource, USA), T4 (GenWay Biotech, Inc), and TSH (Creative Diagnostics, USA) were assessed.

Body composition by micro-CT

The three-body composition components, including lean mass, fat mass, and total mass, were measured by micro-CT scanner (LOTUS-inVivo, Advanced Medical Technologies & Equipment Institute, Tehran University of medical sciences, Tehran, Iran) (Figure 1). 

Figure 1.  The position of rat on the LOTUS-in Vivo Micro-CT table

Histopathological evaluation

All rats were sacrificed at the end of the period. Some internal organs such as the kidney and liver were prepared for histopathological examination. For this assessment, 10% neutral-buffered formalin was utilized as a fixative and tissue sections were immersed in it. After fixing the tissues, paraffin embedding in paraffin wax and slide preparation were done before H&E (Hematoxylin and Eosin) staining. Then, all slides were monitored under a light microscope in the comparative pathology laboratory.   

Statistical analysis

The continuous variables were reported using mean (standard deviation (SD)) or median (interquartile range (IQR)), depending on whether the distribution is concordant with the normal distribution or not, respectively. The T-test and Mann-Whitney test were used in these two scenarios, in turn. Moreover, the longitudinal mixed-effects models were fitted to measure the gradual changes in the response variables, over the replications. The statistical software Stata (ver. 13) was used to perform the analyses. The statistical significance was set at 0.05.

Results

At the end of the study, the median serology variables in the exposure and control groups were shown in Table 1. The fbses were 125mg/dl and 154mg/dl in exposure and control groups, respectively and there was no significant difference between the two groups (P-value=0.1). Also, no significant differences were observed among exposure and control groups in lipid profiles. The median of T4, T3, and TSH  were 3.3µg/dl, 3.5ng/ml,  and 3.4ng/ml in the exposure group and 3.7µg/dl, 3.6ng/ml, and 3.7ng/ml in control groups, respectively and no significant differences found among groups (P-value<0.05).  Hormonal profiles including leptin, adiponectin, and ghrelin were 336pg/ml, 7.25ug/ml, and 7.15pg/ml, respectively in the exposure group at the end of the study, and were 316pg/ml, 8.7ug/ml, and 7.9pg/ml, respectively in the control group. The results show there were no significant differences between exposure and control groups in the hormonal profile (P-value<0.05). at the end of the study, there were no significant differences between the two groups in Cr, BUN, and Urea (P-value<0.05).

Table 1. Effect of cell phone radiation on serology variables

Numbers are expressed as median (IQR), p-values from the Mann-Whitney test

Table 2 showed the median of fat mass, lean mass, and total mass in exposure and control groups at the end of the study. in the exposure group, the fat mass, lean mass, and total mass were 19.34gr, 145.08gr, and 182.77gr, respectively, and were 13.56gr, 160.54gr, and 176.98gr in the control group, respectively. The findings showed no significant differences in fat mass (P-value=0.1), lean mass (P-value=0.9), and total mass (P-value=0.5) between control and exposure groups at the end of the study.

Table 2.  Effect of cell phone radiation on body composition

Numbers are expressed as median (IQR), p-values from the Mann-Whitney test

Table 3 showed the mean of anthropometric indices in exposure and control groups during the study. Significantly, the weight of rats in the exposure group increased from 145.2gr at baseline to 230.67gr in the 5th week and in the control group from 152.34gr to 227.78gr. But there was no significant gradual change between the two groups (P-value=0.133). The mean height increased significantly in exposure (from 16.2cm to 19.93cm) and control group (from 16.37cm to 19.87cm) but no significant difference was found in mean changes of height between the two groups (P-value=0.4). Significantly, the lee index rises from 2.07gr/cm to 2.25gr/cm in the exposure group and the control group from 2.9gr/cm to 2.25gr/cm. there was no significant difference in mean changes of the lee index between the two groups (P-value=0.2). Also, no significant differences were found in mean changes in chest and BMI between the two groups (P-value<0.05).

Table 3. Effect of cell phone radiation on anthropometric indices

Numbers are expressed as mean (SD);

+: t-test compared the baseline and week 5 of the exposure group;

++: t-test compared the baseline and week 5 of the control group;

+++: longitudinal model compared the gradual change between the two groups

Figures 2 and 3 showed histopathological sections of the kidney and liver in exposure and control groups. There were no significant differences in histopathology of the kidney and liver between exposure and control groups.

Figure 2. Histopathological sections of the kidney. Photomicrographs of the case group (A, B), and control group (C, D)

Figure 3. Histopathological sections of the liver. Photomicrographs of the case group (A, B), and control group (C, D)

Discussion

The present study assessed the effect of exposure to mobile phone radiation on body weight and body composition in rats by considering the critical indicators associated with body composition. Exposure to an 885-MHz mobile phone did not significantly change the body weight and body composition in five weeks. In addition, thyroid, kidney, and pancreas functions, and the level of adiponectin, leptin, and ghrelin are critical indicators in regulating glucose levels, the fatty acid breakdown and regulating appetite did not significantly change in the exposure group.

The findings of previous studies are inconsistent in assessing the effect of mobile phones on body weight. In this study, no significant differences were found in weight, BMI, or lee index between exposure and control groups; and the micro-CT indicated that the fat mass and lean mass did not significantly differ between exposure and control groups. These findings are consistent with previous studies (20-23). However, it was observed that body weight following exposure to mobile phone radiation decreased (24, 25). Alternatively, Gerardi et al., indicated an increase in body weight after long-term exposure (26). Differences in outcomes between the studies might be caused by differences in study design such as study duration, SAR rate, and sample size.

There were no significant differences in lipid profile and insulin level between the control and exposure groups in the present study. These findings agree with the results of previous studies (27, 28). However, some document shows that extremely low-frequency radiation increases the insulin level, which was associated with the increased size of pancreatic Langerhans islets (29). The primary variations in the methodology might explain these different results. In our study, 855 MHz GSM mobile phone radiation was used, and the duration of exposure was five weeks, but in the mentioned study, 50 Hz extremely frequency electromagnetic fields were used for 135 days. The mobile phone radiation did not change the thyroid and kidney function in the current study, and the TSH, T3, and T4 levels and creatinine, uric acid, and BUN were in the same range in the exposure and control groups. On the other hand, there were no significant differences between the levels of adiponectin, ghrelin, and leptin between the two groups. These factors are the indicators that directly or indirectly affect body composition such as fat mass and lean mass (30-33). Due to the no significant change in these indicators, it is to be expected that there was no significant change in anthropometric and body mass indices.

Conclusion

The current study showed that exposure to mobile phone radiations for 4 hours once a day for five weeks (SAR of 0.90Watt/kg) has no adverse effects on the thyroid, kidney functions, and hormonal profiles as well as body weight and body composition.

Authors’ contributions

All authors contributed equally.

Acknowledgments

Special thanks to the Urology Research Center, Tehran University of Medical Sciences, Tehran, Iran.  

Conflict of interest

All authors declare that there is no conflict of interest.

Funding

There was no funding.

Ethics statement

This study was approved by the  Ethical Committee of the Tehran University of Medical Sciences (IR.TUMS.SINAHOSPITAL.REC.1399.017).

Data availability

Data will be provided on request.

Abbreviations

AC         Abdominal circumference

BMI       Body mass index

EMR      Electromagnetic radiations

FBS        Fasting blood glucose

IQR        Interquartile range

SAR       Specific absorption rate

SD          Standard deviation