Diabetes is one of the most common chronic diseases. Gestational Diabetes Mellitus (GDM) is a type of diabetes that starts during pregnancy.
To study the levels of chromium, iron, and copper in women with GDM compared with non-diabetic pregnant women.
Materials and Methods
In this case-control study that was performed in Amir Al Momenin Hospital (Zabol-IRAN) in 2016 (from may to October). Sixty pregnant women with GDM were included in the study group and 60 non-diabetic pregnant women were included in the control group. Seven millilitres of blood was taken from the study participants for serum separation. For measuring the levels of chromium, iron, and copper Atomic Absorption Spectrometry was used. Data analysis was performed by Student’s t-test using the Statistical Package for the Social Sciences (SPSS) software version 16.
Serum levels of chromium (7.76±2.83 vs 6.52±2.74 ng/dL), iron (0.60±0.10 vs 0.55±0.14 μg/dL) and copper (0.97±0.22 vs 0.83±0.22 μg/dL) were lower in the case group compared with the control group. Their difference was not statistically significant (p>0.05). The average age of participitants was 34.4±8.01 years. There was no significant difference in age between groups.
The present research showed that levels of Chromium, Iron and Copper in diabetic pregnant women were lower than that of non-diabetic pregnant women; but, these values did not had statistically significant difference.
Diabetes Mellitus (DM) is a common chronic metabolic disorder caused by complex interactions between genetic and environmental factors that may lead to various complications [1,2]. DM is the third most common cause of death in America .
Approximately 6% of the world’s population and 7.8% of Iran’s population is suffering from this disease [4,5]. GDM is defined as any degree of abnormal glucose tolerance during pregnancy . Prevalence of GDM in Iran is about 1.3-1.9% which indicates its high prevalence in iranian pregnant women . A 30-60% of GDM cases lead to type II diabetes during postpartum phase. Pregnancy is a stressful situation, since many physiological and metabolic functions significantly change during this period . In a healthy person, levels of free radicals and oxidants are in equilibrium normally, but they can be disturbed by stress and the oxidative stress respectively that damage tissue and cause various diseases [9-11].
Oxidative stress is involved in various complications such as preterm delivery, foetal growth restriction, pre-eclampsia, and abortion . Moreover, oxidative stress is increased in pregnant women with diabetes . GDM can stimulate oxidative stress, impaired antioxidant system, and various complications during pregnancy [13,14].
Latest evidence suggests that the metabolism of trace elements is changed in diabetes mellitus, and these metals may contribute to the pathogenesis and progression of the disease, due to various metabolic characteristics and their operations .
Chromium (Cr) is a micro-nutrient. It is an essential antioxidant and can be found in high levels in human body [16-18]. The most fundamental biological function of chromium is its effect on insulin and receptors . Chromium deficiency may be involved in the development of diabetes in animals and humans . Chromium could reduce lipid peroxidation through glucose-insulin system and chromium supplementation reduces blood glucose .
Copper (Cu) is known as an essential micronutrient, that is a component of many metalloenzymes which are involved in oxidation  and reduction processes .
In GDM cases, serum Cu level has been seen to be significantly higher, compared to healthy pregnant women .
Activating enzyme, Aminolevulinic Acid (ALA) synthase regulates heme synthesis. Copper is essential in the transport of iron from the gut into the plasma. On the other hand, transfer of trace elements in blood is supported by haemoglobin. Moreover, iron (Fe) is the most abundant trace element in metabolism associated with haemoglobin formation. About 75% of haemoglobin molecule contains iron .
Altered metabolism of Iron (Fe) has been reported in diabetes . Iron (Fe), as a strong pro-oxidant, catalyses several cellular reactions that result in the production of ROS with a subsequent increase in the level of oxidative stress. Therefore, high concentrations of free iron could be harmful. Increasing evidence now suggests a potential influence of Fe metabolism on type-2 DM . The relationship between Fe and insulin is bidirectional as Fe influences insulin activity by influencing glucose uptake and consumption, while insulin affects Fe uptake and storage by increasing the cell surface transferrin receptors .
Serum trace element measurement is a proper way to assess the nutritional status and health of individuals .
With regard to the importance of the complications of GDM such as possible role in the antioxidant system disturbance and important roles of trace elements on insulin physiology and antioxidant system activity , the aim of present research was to evaluate the levels of chromium, copper and iron in pregnant women suffering from diabetes and comparing with healthy pregnant controls.
Materials and Methods
This cross-sectional study was conducted in 2016 in Zabol (from may to October), on mothers who referred to the clinic of the hospital in the 20th to 40th weeks of pregnancy. During the study period, total of 120 pregnant women completed the consent form, 60 of them were diabetic pregnant women and 60 others were healthy pregnant women.
The sample size was calculated based on Formula ratios comparison in each group.
With Confidence level 95%, error possibility in diabetic pregnant women (α) up to 0.05, error possibility in healthy pregnant women (β) up to 0.1, possibility percent of diabetic pregnant women (p) 0.03 up to 0.05 and acceptable errors in ratio estimation in two groups (d) 0.13.
Healthy pregnant women as control group were confirmed with blood measurements. The diagnosis of diabetic pregnant women with high or medium risk was carried out in the second trimester of pregnancy. At first, Fasting Blood Sugar (FBS) was estimated in the diabetic pregnant women and then Glucose Challenge Test (GCT) was carried out after 50g glucose consumption, regardless of the time of the last meal. Blood sugar was 50-140 mg/dL one hour after consumption of glucose. Oral Glucose Tolerance Test (OGTT) was carried out by using 100g glucose. This test spanned three hours and the test results for the second hour showed that diabetic pregnant women had a glucose level above 130 mg/dL. In the present study, a blood glucose level above 130 mg/dL was considered as a criteria for pregnancy diabetes .
In this study, case group was compared with the control group in terms of age, Body Mass Index (BMI), problems during pregnancy. None of the participants had a history of smoking, consumption of drugs, immune system disorders, antibiotic use, neurotoxicity induced disease and discordance during the last 3 months. There was no history of hormonal disease and pre-eclampsia.
For blood glucose measurements and measuring chromium, iron, and copper in the pregnant women, 7 mL blood was taken and serum was immediately separated. Levels of FBS, challenge blood sugar (GCT), and GTT were measured using Bionik kit from Biotechnica (Italy) and with BT 3000 Plus Auto analyser.
After collecting all serum samples from the participants, 1 mL serum was diluted with 4mL deionised distilled water in order to measure iron and copper levels in pregnant women. Then, levels of iron and copper were measured in the diluted samples using Atomic Absorption Spectrometry (Rey Leight WFX-210 AA Spectrophotometer, China) and by addition standard method of flame technique . Levels of chromium in serum of pregnant women was also measured using standard addition method by Graphite furnace technique .
Statistical analysis was performed by SPSS software version 16. In the present research, we used independent student t-test to compare mean of values in the case and control groups and p-value less than 0.05 was considered as significant difference.
In the present investigation, 60 pregnant women with GDM and 60 healthy pregnant women participated with average age of 34.4±8.01 years (age range=19-47 years). The age difference between the two groups was not statistically significant (p=0.29). Means of BMI in the case and control groups were 29.7±3.53 kg/m2 and 29.61±3.49 kg/m2, respectively, which is statistically non-significant [Table/Fig-1].
Comparing mean age, BMI, and trace elements in diabetic and non-diabetic pregnant women in Zabol in 2016.
|Parameter||Non-diabetic n=60||Diabetic n=60||p-value|
*p<0.05 is statistically significant.
The Cr, Fe, and Cu plasma levels in the case and control groups were not statistically significant (p>0.05, [Table/Fig-1]).
The lowest and highest blood sugar levels in the diabetic pregnant women were 70 mg/dL and 223 mg/dL, respectively; its mean was 122.4 mg/dL. Also, the average of blood suger level in healthy pregnant women was 95.5 mg/dL with the lowest level of it as 65 mg/dL and the highest level 126 mg/dL.
Body needs more quantity of trace elements in pregnancy not only due to increased demand, but also increased loss . Women with GDM are exposed to considerable type 2 diabetes risks, even in the coming years after the delivery [1,8]. Moreover, the damage caused to the mother and the embryo cannot be properly elucidated [14,32]. Among the most important factors which are significantly associated with GDM are high age and obesity . In the present study, the age of participants in both group had no significant difference.
In GDM, there is an excessive nutrient loss that may be due to glucosuria . In the present research, according to the results; chromium (Cr), iron (Fe), and copper (Cu) levels in the pregnant women with GDM were lower than those of the healthy pregnant women, but the difference was not statistically significant. Results of this study were similar to those of Woods S et al., . In the study done by Shindea U et al., Cr level in the control group was significantly more than that of the case group . Some studies including that of Babalola O et al., could not find any relationship between serum chromium levels and type 2 diabetes . In the study by Akhlaghi F et al., Fe level in the control group was more than that in the case group. but amount of other elements in the case group was higher than the control group . In the study by Ugwuja EI et al., Cu level in the control group was higher than that in the case group .
In the present study, GDM was not associated with low levels of Cr; however its low consumption in pregnant women can behave as a possible underlying factor in inducing GDM. With this assumption, in some studies including that of Balk E et al., chromium supplementation in patients with diabetes led to satisfactory results . In an animal experiment by Shindea U et al., this beneficial effect was observed . In Rajendran K et al., study, chromium levels in type 2 diabetic patients were lower than normal and this deficiency was greater in older patient and their results indicated to essential role of chromium for insulin function . Choi R et al., in a study conducted in 2016 inferred that increased risk of gestational diabetes was associated with higher levels of ferritin and serum iron and dietary heme iron intakes that warrants further investigation. They also found Cu absorption rises during pregnancy due to the increased need for maternal Cu-containing enzymes such as cytochrome c oxidase and superoxide dismutases .
In a study in Bangladesh, 172 pregnant women in the second and third trimester were selected, of which 86 were diabetic. The result showed that serum Cu levels in GDM cases were significantly higher in both trimesters compared to those of non-diabetic women. They suggested that the possible causes of high serum Cu concentration in GDM cases could be due to the hormonal, metabolic and enzymatic changes in pregnancy and also decreased insulin sensitivity in GDM .
It is documented in the study by Atari-Hajipirloo S et al., that Fe affects glucose metabolism and it has been shown that free iron concentrations in the patients with T2DM are higher than healthy people, which could contribute to tissue damage that may potentially lead to complications associated with T2DM .
Previous studies have also demonstrated that impaired trace element metabolism is an additional risk factor in the development and progress of disease and they contribute to the pathogenesis of T2DM. Trace elements plays an important role in various metabolic processes and are crucial for many physiological processes . Since diabetes is a multi-factorial disease and various factors including race, nutrition, and environment plays a role in it, more research with a higher sample size should be carried out in this field. As confirmed by the findings of this research, it is recommended to pregnant women to use chromium supplement in their diet and avoid the environment with pollutants and consumption of food produced in these polluted areas as far as possible.
One of the limitations of this study was insufficient funds for conducting experiments on a larger number of samples. It was also difficult to find mothers who had study conditions.
The assessment of mothers with the history of some diseases was done via self-report in the questionnaires; therefore, a misclassification is probable.
Reults of this study showed no significant difference in serum levels of chromium, copper and iron between pregnant diabetic and healthy mothers although some studies have shown that deficiency of these trace elements can disturb glucose metabolism.
Also, it is better for the future work, to compare the levels of chromium, iron, copper and other trace elements in diabetic individuals with conditions and different types of diabetes. With regard to the point that pregnancy causes changes in the quantity of elements, it is natural for both groups to experience some changes. In further future research, it is better to compare healthy non-pregnant women and diabetic non-pregnant women.*p<0.05 is statistically significant.
. Fauci AS, Braunwald E, Ksper DL, Harrison’s Principles of Internal Medicine, 2008, Vol. II USAMcGraw-Hill companies:46-47. [Google Scholar]
. Althuis MD, Jordan NE, Ludington EA, Wittes JT, Glucose and insulin responses to dietary chromium supplements: a meta-analysis The American journal of clinical nutrition 2002 76(1):148-55. [Google Scholar]
. Little J, Falace D, Miller C, Rhodus N, Dental management of the medically compromised patient 2008 7th edSt. LouisMosby [Google Scholar]
. Wang Y, Tan M, Huang Z, Sheng L, Ge Y, Zhang H, Elemental contents in serum of pregnant women with gestational diabetes mellitus Biological Trace Element Research 2002 88(2):113-18. [Google Scholar]
. Esteghamati A, Meysamie A, Khalilzadeh O, Rashidi A, Haghazali M, Asgari F, Third national Surveillance of Risk Factors of Non-Communicable Diseases (SuRFNCD-2007) in Iran: methods and results on prevalence of diabetes, hypertension, obesity, central obesity, and dyslipidemia BMC Public Health 2009 9(1):167 [Google Scholar]
. Harrison J, Fauci A, Braunwald E, Kasper D, Houser S, Jameson J, HARRISON’S principles of internal medicine 2008 17th edUSA [Google Scholar]
. Janghorbani M, Enjezab B, Review of Epidemiology of Gestational Diabetes in Iran Journal of Isfahan Medical School 2010 28(110) [Google Scholar]
. Bellamy L, Casas JP, Hingorani AD, Williams D, Type 2 diabetes mellitus after gestational diabetes: a systematic review and meta-analysis The Lancet 2009 373(9677):1773-79. [Google Scholar]
. Ginter E, Simko V, Panakova V, Antioxidants in health and disease Bratisl Lek Listy 2014 115(10):603-06. [Google Scholar]
. Smirnakis K, Plati A, Wolf M, Thadhani R, Ecker J, Predicting gestational diabetes: choosing the optimal serum marker Am J Obstet Gynecol 2007 196:410-e1-6. [Google Scholar]
. Sharma J, Sharma A, Bahadur A, Vimala N, Satyam A, Mittal S, Oxidative stress markers and antioxidant levels in normal pregnancy and pre-eclampsia Int J Gynaecol Obstet 2006 94:23-7. [Google Scholar]
. Myatt L, Cui X, Oxidative stress in the placenta Histochem Cell Biol 2004 122:369-82. [Google Scholar]
. Toescu V, Nuttall S, Martin U, Nightingale P, Kendall M, Brydon P, Changes in plasma lipids and markers of oxidative stress in normal pregnancy and pregnancies complicated by diabetes Clin Sci (Lond) 2004 106:93-98. [Google Scholar]
. Bo S, Lezo A, Menato G, Gallo M, Bardelli C, Signorile A, Gestational hyperglycemia, zinc, selenium, and antioxidant vitamines Nutrition 2005 21:186-91. [Google Scholar]
. Ajibola RS, Ogundahunsi OA, Soyinka OO, Ogunyemi EO, Odewabi AO, Serum chromium, molybdenum, zinc and magnesium levels in diabetes mellitus patients in Sagamu, South West Nigeria Asian J of Med Sciences 2014 6(2):15-19. [Google Scholar]
. Patil S, Kodliwadmath M, Kodliwadmath SM, Study of oxidative stress and enzymatic antioxidants in normal pregnancy Indian Journal of Clinical Biochemistry 2007 22(1):135-37. [Google Scholar]
. Hummel M, Standl E, Schnell O, Chromium in metabolic and cardiovascular disease Hormone and metabolic research 2007 39(10):743-51. [Google Scholar]
. Garg N, Singh R, Dixit J, Jain A, Tewari V, Levels of lipid peroxides and antioxidants in smokers and nonsmokers J Periodontal Res 2006 41(5):405-10.Epub 2006/09/07 [Google Scholar]
. Moukarzel A, Chromium in parenteral nutrition: too little or too much? Gastroenterology 2009 137(5):S18-S28. [Google Scholar]
. Štupar J, Vrtovec M, Dolinšek F, Longitudinal hair chromium profiles of elderly subjects with normal glucose tolerance and type 2 diabetes mellitus Metabolism-Clinical and Experimental 2007 56(1):94-104. [Google Scholar]
. Anderson RA, Roussel A-M, Zouari N, Mahjoub S, Matheau J-M, Kerkeni A, Potential antioxidant effects of zinc and chromium supplementation in people with type 2 diabetes mellitus Journal of the American College of Nutrition 2001 20(3):212-18. [Google Scholar]
. Mishu FA, Muttalib M, Serum magnesium and copper levels in Bangladeshi women with gestational diabetes mellitus IMC Journal of Medical Science 2017 11(1):25-28. [Google Scholar]
. Keen CL, Uriu-Hare JY, Hawk SN, Jankowski MA, Daston GP, Kwik-Uribe CL, Effect of copper deficiency on prenatal development and pregnancy outcome The American Journal of Clinical Nutrition 1998 67(5):1003S-11S. [Google Scholar]
. Kazi TG, Afridi HI, Kazi N, Jamali MK, Arain MB, Jalbani N, Copper, chromium, manganese, iron, nickel, and zinc levels in biological samples of diabetes mellitus patients Biological Trace Element Research 2008 122(1):1-18. [Google Scholar]
. Fernández-Real JM, López-Bermejo A, Ricart W, Cross-talk between iron metabolism and diabetes Diabetes 2002 51(8):2348-54. [Google Scholar]
. Atari-Hajipirloo S, Valizadeh N, Khadem-Ansari M-H, Rasmi Y, Kheradmand F, Altered concentrations of copper, zinc, and iron are associated with increased levels of glycated hemoglobin in patients with type 2 diabetes mellitus and their first-degree relatives Int J Endocrinol Metab 2016 14(2):e33273 [Google Scholar]
. Choi R, Sun J, Yoo H, Kim S, Cho YY, Kim HJ, A prospective study of serum trace elements in healthy Korean pregnant women Nutrients 2016 8(11):749 [Google Scholar]
. Alfadhli EM, Gestational diabetes mellitus Saudi Medical Journal 2015 36(4):399-406. [Google Scholar]
. Ebdon L, Evans EH, Fisher A, Hill SH, An Introduction to Analytical Atomic Spectrometry 2004 15th ed [Google Scholar]
. Jahromi EZ, Bidari A, Assadi YY, Hosseini MRM, Jamali MR, Dispersive liquid–liquid microextraction combined with graphite furnace atomic absorption spectrometry: Ultra trace determination of cadmium in water samples Anal Chimica Acta 2007 585(2):305-11. [Google Scholar]
. Noureldeen AF, Al-Ghamdi MA, Al-solami YS, Maternal status of trace elements in normal pregnancy and in gestational diabetes mellitus International Journal of Pharmaceutical and Phytopharmacological Research 2018 8(1):1-9. [Google Scholar]
. Chen X, Scholl T, Oxidative stress: change in pregnancy and with gestational diabetes mellitus Curr Diab Rep 2005 5:282-88. [Google Scholar]
. Woods S, Ghodsi V, Engel A, Miller J, James S, Serum chromium and gestational diabetes J Am Board Fam Med 2008 21:153-57. [Google Scholar]
. Shindea U, Sharma G, Xu Y, Dhallac N, Goyal R, Insulin sensitising action of chromium picolinate in various experimental models of diabetes mellitus J Trace Elem Med Biol 2004 18:23-32. [Google Scholar]
. Babalola O, Ojo L, Akinleye A, Status of the levels of lead and selected trace elements in type 2 diabetes mellitus patients in Abeokuta, Nigeria Afr J Biochem Res 2007 1(7):127-31. [Google Scholar]
. Akhlaghi F, Bagheri SM, Rajabi O, A comparative study of relationship between micronutrients and gestational diabetes ISRN obstetrics and gynecology 2012 :2012 [Google Scholar]
. Ugwuja EI, Akubugwo EI, Ejikeme BN, Plasma copper and zinc in pregnancy complicated with diabetes mellitus Pak J of Nut 2010 9(9):861-64. [Google Scholar]
. Balk E, Tatsioni A, Lichtenstein A, Lau J, Pittas A, Effect of chromium supplementation on glucose metabolism and lipids:a systematic review of randomized controlled trials Diabetes Care 2007 30:2154-63. [Google Scholar]
. Rajendran K, Manikandan S, Nair LD, Karuthodiyil R, Vijayarajan N, Gnanasekar R, Serum chromium levels in type 2 diabetic patients and its association with glycaemic control Journal of Clinical and Diagnostic Research: JCDR 2015 9(11):OC05 [Google Scholar]