Correlation of serum malondialdehyde level with components of metabolic syndrome

 

P Josephine Latha¹, T Rajalakshmi^2*, R S Monish Anand³

 

¹Associate Professor, Department of Biochemistry, Thanjavur Medical College, Thanjavur-613004, Tamil Nadu, INDIA.

²Assistant Professor, Department of Biochemistry, Government Dharmapuri Medical College, Dharmapuri-636701, Tamil Nadu, INDIA.

³Student, Meenakshi Medical College Hospital & Research Institute, Enathur, Kanchipuram-631552, Tamil Nadu, INDIA.

Email: lathapasel@gmail.com

 

Abstract               Background: Metabolic syndrome is one of the major public health concerns and is emerging as a pandemic. oxidative stress is a hallmark of metabolic syndrome and plays a central role in the progression of the disease. Malondialdehyde is one of the most popular and reliable biomarker of oxidative stress. Aim: to evaluate the level of serum Malondialdehyde (MDA) and correlate that with the components of metabolic syndrome. Methods: A cross-sectional study was carried out. 100 individuals of 21-60 years were included of which the control group comprised 50 healthy individuals and the study groupcomprised50 metabolic syndrome patients. Evaluation of anthropometric variables, blood pressure, blood glucose levels, lipid profiles, and malondialdehyde was done. Results: The metabolic syndrome patients had significantly higher malondialdehyde as compared to control (7.81±2.10vs. 2.81±1.40μmoles/L). There was a positive correlation between WC,FBS,PPBS,TC,TGL,LDL,VLDL and MDA;WC (r =0.915[p<0.001]),Blood sugar(r =0.704[p<0.001] for FBS and r =0.562 [p<0.001] for PPBS),total cholesterol (r =. 971[p<0.001]),Triglycerides(r =0.976[p<0.001]), LDL(r =0.959[p<0.001]),VLDL(r =0.976 [p<0.001]). HDL showed significant negative correlation (r = -0.776[p<0.001]). Both systolic and diastolic blood pressure showed positive correlation with MDA((r =0.770 for SBP and r =0.688 for DBP[p<0.001]) Conclusion: Our study clearly indicates that metabolic syndrome is associated with oxidative stress. Lifestyle modifications through diet and exercise may help in reducing the incidence of metabolic syndrome by reducing the oxidative stress. Future research by interventional studies are needed to know about the benefitial effects of supplementation with antioxidants.

Key Words: Metabolic syndrome, oxidative stress, malondialdehyde, reactive oxygen species, dyslipidemia.

 

 

INTRODUCTION

Metabolic syndrome is one of the major public health concerns and is emerging as a pandemic.Urbanisation and sedentary life style apart from some genetic causes are the major contributing factors for this global health burden. Metabolic syndrome is characterized by a cluster of risk factors that includes atherogenic dyslipidemia, visceral obesity, hyperglycemia and hypertension¹. This increases the susceptibility of metabolic syndrome patients to cardiovascular diseases which is one of the leading causes of morbity and mortality worldwide². Presently we have extensive studies that substantiate the relationship of metabolic syndrome with oxidative stress^3,4,5. It has been postulated thatoxidative stress is a hallmark of metabolic syndrome and plays a central role in the progression of the disease. Oxidative stress is a condition where the free radicals generation surpasses the endogenous antioxidant defensive system. This imbalance between the oxidant and anti-oxidant system may be due to either overproduction of free radicals or decreased efficiency of the anti-oxidant system or both. Factors like hyperglycemia and elevated inflammatory markers in metabolic syndrome increase the production of free radicals and also decrease the antioxidant HDL. When the antioxidant defensive system fails to neutralize these free radicals, oxidative stress ensues resulting in the impairment of structural and functional cellular integrity^6,7. Oxidative stress leads to pathological vascular alterations that results in the accentuation of the biochemical processes involved in the metabolic syndrome⁸. Extensive experimental and clinical observations relate the oxidative stress to the obesity-associated metabolic syndrome, the development of diabetes and its complications and the conditions such as nonalcoholic steatohepatitis (NASH)^9-12. Malondialdehyde is one of the most popular and reliable biomarker of oxidative stress^13,14 since it is a by-product formed during lipid peroxidation which is triggered by free radicals. In the present study we want to evaluate the level of serum Malondialdehyde (biomarker of oxidative stress) and correlate that with the components of metabolic syndrome. This may help in assessing the risk for atherosclerosis and thereby predicting future cardiovascular complications.

 

MATERIALS AND METHODS

The study was conducted, at Thanjavur Medical College, Thanjavur, after getting approval from the institutional ethical committee. This is a cross-sectional study.100 individuals were chosen for the study. Both males and females in the age group of 21-60 years were included and informed consent was obtained from all of them. Of the 100 subjects, 50 were healthy individuals forming the control group and 50 were patients with metabolic syndrome forming the study group. According to the Adult Treatment Panel III (ATP III) definition¹, metabolic syndrome was diagnosed by the presence of at least three of the following risk factors: fasting plasma glucose ≥110 mg/dl, abdominal obesity (waistcircumference, WC >102 cm in men and >88 cm in women), TG ≥150 mg/dl, low HDL-C (<40 mg/dl in men and<50 mg/dl in women), and blood pressure ≥130/85 mmHg. For waist circumference modified Asian criteria (reducing the waist circumference (WC) was used to define central obesity to 90 cm in men and 80 cm in women¹⁵. Individuals with acute and chronic infections, Chronic inflammatory disorders, Thyroid disorders, Liver diseases and Renal failure were excluded from the study. Smokers and alcoholics were also excluded from the study. Under aseptic precautions, fasting venous blood sample of 6ml was collected from each participant. The vacutainers containing the blood samples were kept at room temperature for 30 minutes and centrifuged at 2000 rpm for 15 minutes for clear separation of serum. The following parameters were estimated, immediately after the serum was separated: Serum Glucose, Serum Total cholesterol, Serum HDL cholesterol, Serum Triacyl glycerol, and Serum Malondialdehyde. Samples for postprandial blood sugar were collected 2 hrs after breakfast from each participant. Serum Malondialdehyde was measured by thiobarbituric acid (TBA) reactivity assay method of Draper and Hadley¹⁶. In the TBA test reaction, MDA and TBA react to form a pink pigment with an absorption maximumat 532 nm. Serum Glucose, Total cholesterol, HDL cholesterol, Triacyl glycerol were estimated by enzymatic methods using standard kits in the Beckman-Coulter fully Auto analyzer (AU480). LDL and VLDL cholesterol levels were calculated from the estimated parameters if TGL < 400 mg/dL. LDL was calculated using Friedwald’s equation (LDL = Total cholesterol – (HDL + VLDL) and VLDL cholesterol was calculated as TGL/5. The results were analyzed using the software SPSS version21. The means of all the biochemical parameters were compared between the groups using student’s T test and the correlation of MDA level with the components of metabolic syndrome in the study group was done by Pearson’s correlation.

RESULTS

In the present study there was no significant difference in the mean ages of the control and study participants. But the waist circumference, BMI and both the systolic and diastolic blood pressures were higher in the metabolic syndrome patients when compared to the healthy controls and the increase was statistically significant (p<0.001). The means of the biochemical parameters; fasting and postprandial blood sugar, the total cholesterol, triglycerides, LDL, and VLDL were also elevated in the metabolic syndrome patients except HDL which was markedly decreased and both elevation and reduction were statistically significant(p<0.001). Analysis of Serum Malondialdehyde showed that the mean Malondialdehyde value of metabolic syndrome patients was significantly increased when compared with that of control group with a p value of <0.001.The descriptive statistics of the parameters were given in Table-1.

 

Table 2: Correlation of MDA with Age, BP, WC, BMI,

** - significant at p value <.001level

 

Table 2: Correlation of MDA with FBS, PPBS, TC, TGL, LDL and VLDL

** - significant at p value <.001level

 

DISCUSSION

The incidence and impact of the Metabolic Syndrome have risen to alarming proportions and there is a great need for therapeutic and preventive measures against this major health problem. The cluster of the cardiovascular risk factors that constitute the metabolic syndrome (low HDL-C, elevated BP, fasting glucose and TG, and abdominal obesity)⁵ accentuate the process of atherosclerosis and further increase the risk of type 2 diabetes. It is a widely accepted fact that the insulin resistance plays a prime role in the metabolic alterations in this syndrome. But we have ample evidence now for the role of increased oxidative stress and chronic low level inflammation as pathogenic mechanism in the development of the conditions like atherosclerosis, endothelial dysfunction, hypertension and type 2 diabetes associated with metabolic syndrome.^17,18,19. These data imply that oxidative stress may be the earliest indicator of the future development of such chronic diseases. In our study also the serum MDA levels (the marker of oxidative stress) in the metabolic syndrome patients were elevated compared to the healthy controls. This finding of lipid peroxidation in metabolic syndrome is shown in the studies of Demircan et al.²⁰ and Armutcu et al.²¹, as they observed, increased plasma MDA levels in metabolic syndrome individuals in their case-control studies. We have wide number of studies supporting this fact^22,23,24. Our study showed high positive correlation of WC with MDA level(r =. 915[p<0.001]). It is a proven fact that visceral obesity contributes to the lipid peroxidation in metabolic syndrome. Similar to this Fujita et al.⁹, found increased levels of urinary 8-epi-prostaglandin F2, a marker of systemic oxidative stress in metabolic syndrome carriers. Visceral obesity leads to the proinflammatory state which is characterized by macrophage infiltration and this is due to the secretion of cytokines(IL-6, TNF- α) and monocyte chemoattractants (MCP-1) through hypertrophic adipocytes²⁵. Moreover there will be increased production of reactive oxygen species through macrophage activation that leads to NADPH oxidase over expression and activation²⁶. These reactive oxygen species lead to the increase in plasma by products of lipid peroxidation (MDA) by oxidizing the cell membrane lipids. The present study also exhibited high positive correlation between MDA and the glycemic status of metabolic syndrome patients(r =. 704[p<0.001] for FBS and r =. 562[p<0.001] for PPBS). The formation of advanced glycation end products in hyperglycemia induce lipoperoxidation by oxidising the cell membrane lipids²⁷. This attributes to the increased level of MDA. Hyperglycemia also promotes lipid peroxidation of LDL by superoxide dependent pathway resulting in the generation of free radicals. This correlation of MDA and hyperglycemia had been proved by many other studies also^{10,17,22,2,28}. The increase in TC, TGL,LDL,VLDL and decrease in HDL were also highly correlated with the serum level of MDA in our study and is depicted in the table-3.Ample number of studies had come out with the same results of correlation of dyslipidemia with high oxidative stress markers^29,30,31. Dyslipidemia in metabolic syndrome (↓ HDL and↑ TGL) increases the formation of small dense LDL, which gets easily modified to oxidized LDL (oxLDL) and accelerates the process of atherosclerosis²⁹. The small dense LDL formation is proportional to the hypertriglyceridemia. Low HDL contributes significantly to the oxidative stress through decreased antioxidant capacity²⁴. MDA level was also found to be highly positively correlated with both systolic and diastolic blood pressures (r = 770 for SBP and r =. 688 for DBP [p<0.001]). This increased oxidative stress with high blood pressure is in consistent with similar studies^32,33. The production of reactive oxygen species is increased in the arterial wall by high blood pressure either by reducing the antioxidant enzymes activity or increasing the activity of the enzymes (xanthine oxidase, NADPH oxidase etc) that produce ROS. Increased ROS further aggravate hypertension by smooth muscle contraction and proliferation³⁴. Thus generating highly reactive oxygen species all the components of metabolic syndrome initiate the endothelial dysfunction, accelerate the atherogenesis and end up in cardiovascular diseases.

 

CONCLUSION

Our study clearly indicates that metabolic syndrome is associated with oxidative stress which is evident from the correlation of serum level of malondialdehyde, the biomarker of oxidative stress with all its components. Lifestyle modifications through diet and exercise may help in reducing the incidence of metabolic syndrome by reducing the oxidative stress. Some studies have proved improvement in the markers of oxidative stress and other markers of cardiovascular risk associated with metabolic syndrome by weight reduction through dietary restriction and moderate-intensity exercise in obese patients³⁵. Future research by interventional studies are needed to know about the benefitial effects of supplementation with antioxidants.

 

REFERENCES

• Expert panel on detection, evaluation and treatment of high blood cholesterolin adults: executive summary of the third report of the National Cholesterol Education Program (NCEP): expert panel on detection, evaluation and treatment of High Blood Cholesterol in Adults (Adult Treatment Panel III) final report. Circulation, 2002; 106: 3143–421
• C. Aoqui, S. Chmielewski, E. Scherer et al., “Microvascular dysfunction in the course of metabolic syndrome induced by high-fat diet,” Cardiovascular Diabetology, 2014.vol. 13(1).
• H. Otani, “Oxidative stress as pathogenesis of cardiovascular risk associated with metabolic syndrome,” Antioxidants and Redox Signaling, vol. 15, no. 7, pp. 1911–1926, 2011.
• I. Grattagliano, V. O. Palmieri, P. Portincasa, A.Moschetta, and G. Palasciano, “Oxidative stress-induced risk factors associated with themetabolic syndrome: a unifying hypothesis,” Journal of Nutritional Biochemistry, vol. 19, no. 8, pp. 491–504, 2008.
• F. Armutcu, M. Ataymen, H. Atmaca, and A. Gurel, “Oxidative stress markers, C-reactive protein and heat shock protein 70 levels in subjects with metabolic syndrome,” Clinical Chemistry and Laboratory Medicine, vol. 46, no. 6, pp. 785–790, 2008.
• Freeman BA, Crapo JD: Biology of disease: free radical and tissue injury.Lab Invest, 1982; 47: 412–26
• Mantle D, Preedy VR: Free radicals as mediators of alcohol toxicity.Adverse Drug Reactions, 1999; 18: 235–52
• Stocker R, Keaney Jr JF(2004).Role of oxidative modifications in atherosclerosis.Physiol Rev,84:1381-478.
• K. Fujita, H. Nishizawa, T. Funahashi, I. Shimomura, and M. Shimabukuro, “Systemic oxidative stress is associated with visceral fat accumulation and the metabolic syndrome,” CirculationJournal, vol. 70, no. 11, pp. 1437–1442, 2006.
• GrattaglianoI,VendemialeG,BosciaF,Micelli-Ferrari T,CardiaL,Altomare E(1998).Oxidative retinal products and ocular damages in diabetic patients.FreeRadicBiol Med,25:369-72.
• GrattaglianoI,Vendemiale G, Caraceni P, DomenicaliM, NardoB, Cavallari A et al(2000).Starvation impairs antioxidant defense in fatty livers of rats fed a choline-deficient diet.JNutr, 130(9):2131-6.
• Portincasa P., GrattaglianoI, PalmieriV.O, Palasciano G (2005).Nonalcoholic steatohepatitis:recent advances from experimental models to clinical management.Clin Biochem,38:203-17.
• Redon, J., M. R. Oliva. Antioxidant Activities and Oxidative Stress Byproducts in Human Hypertension. Hypertension 2003; 41(5):1096-1101.
• Kand’a´ r R, Zˇ a´ kova´ P, Muzˇa´kova´ V. Monitoring of antioxidantproperties of uric acid in humans for a consideration measuringof levels of allantoin in plasma by liquid chromatography. ClinChim Acta 2006; 365: 249-56.
• Derrick Henga, Stefan Maa, Jeannette J.M. Lee b, Bee Choo Tai b, Koon HouMakc, Kenneth Hughes d, Suok Kai Chewa, Kee Seng Chia b, Chee Eng Tan b, E Shyong Tai e, Modification of the NCEP ATP III definitions of the metabolic syndrome for use in Asians identifies individuals at risk of ischemic heart disease Atherosclerosis 186 (2006) 367–373
• Draper H, Hadley M: Malondialdehyde determination as index of lipidperoxidation. Methods Enzymol, 1990; 186: 421–31.
• Ceriello A, Motz E. Is oxidative stress the pathogenic mechanism underlying insulin resistance, diabetes, and cardiovascular disease? The commonsoil hypothesis revisited. Arterioscler ThrombVascBiol 2004; 24:816–823.
• Van Guilder GP, Hoetzer GL, Greiner JJ, Stauffer BL, DesouzaCA.Influence of metabolic syndrome on biomarkers of oxidative stress and inflammation in obese adults. Obesity (Silver Spring) 2006; 14:2127–2131.
• Skalicky J, Muzakova V, Kandar R, Meloun M, Rousar T, PalickaV.Evaluation of oxidative stress and inflammation in obese adults withmetabolic syndrome. ClinChem Lab Med 2008; 46: 499–505.
• N. Demircan, A. G¨urel, F. Armutcu, M. ¨ Unalacak, E. Aktunc¸,and H. Atmaca, “The evaluation of serum cystatin C, malondialdehyde,and total antioxidant status in patients with metabolicsyndrome,” Medical Science Monitor, vol. 14, no. 2, pp. CR97–CR101, 2008.
• F. Armutcu, M. Ataymen, H. Atmaca, and A. Gurel, “Oxidative stress markers, C-reactive protein and heat shock protein 70 levels in subjects with metabolic syndrome,” Clinical Chemistryand Laboratory Medicine, vol. 46, no. 6, pp. 785–790, 2008.
• Fernando Moreto,¹ Erick P. de Oliveira,^1,2 Rodrigo M. Manda,¹ and Roberto C. Burini; The Higher Plasma Malondialdehyde Concentrations Are Determined by Metabolic Syndrome-Related Glucolipotoxicity.June 2014(1-7)
• Nejat Demircan1ABCDEFG, Ahmet Gürel2ABCDEF, Ferah Armutcu2BCDEF, Murat Ünalacak, Erol Aktunç, HulusiAtmaca; The evaluation of serum cystatin C, malondialdehyde, and total antioxidant status in patients with metabolicsyndrome: Med Sci Monit, 2008; 14(2): CR97-101
• Muhamed T Osman3, Rahman T1, 2, Ismail TS.2, Azlina A.R.2, H. Nawawi1,2. Investigation of Oxidative Stress Status in Metabolic Syndrome Patients Using Lipid Peroxidation Biomarkers: International Archives of Medicine Section: Laboratory Medicine; 2016; 9(8); 1-9.
• S. Cinti, G. Mitchell, G. Barbatelli et al., “Adipocyte death defines macrophage localization and function in adipose tissue of obese mice and humans,” Journal of Lipid Research, vol. 46,no. 11, pp. 2347–2355, 2005.
• S. P. Weisberg, D. McCann, M. Desai, M. Rosenbaum, R.L. Leibel, and A. W. Ferrante Jr., “Obesity is associated with macrophage accumulation in adipose tissue,” Journal of ClinicalInvestigation, vol. 112, no. 12, pp. 1796–1808, 2003.
• F. N. Ahmed, F. N. Naqvi, and F. Shafiq, “Lipid peroxidation and serum antioxidant enzymes in patients with type 2 diabetes mellitus,” Annals of the New York Academy of Sciences, vol. 1084,pp. 481–489, 2006.
• N.P.Suryawanshi, A.K.Bhutney et al, Study of Lipid Peroxide and lipid Profile in Diabetes Mellitus, Indian Journal Of Clinical Biochemistry, 2006,2(1)126-130.
• Patrick Mathieu,PhilippePibarot et al; Metabolic syndrome: the danger signal in Atherosclerosis; Vascular Health and Risk Management 2006:2(3) 285–302
• Marques de Mattos A, Marino LV, Ovidio PP, JordãoAA, Almeida CC, Chiarello PG (2012). Protein oxidative stress and dyslipidemia in dialysis patients. TherApher Dial, 16:68-74.
• Zelzer S, Fuchs N, Almer G, Raggam RB, PrüllerF,Truschnig-Wilders M et al. (2011). High densitylipoprotein cholesterol level is a robust predictor of lipid peroxidation irrespective of gender, age, obesity, and inflammatory or metabolic biomarkers. ClinChim Acta, 412:1345-9.
• J. Red´ on,M. R. Oliva, C. Tormos et al., “Antioxidant activities and oxidative stress byproducts in human hypertension,”Hypertension, vol. 41, no. 5, pp. 1096–1101, 2003.
• D. Wang, S. Strandgaard, J. Iversen, and C. S. Wilcox, “Asymmetric dimethylarginine, oxidative stress, and vascularnitric oxide synthase in essential hypertension,” American Journal of Physiology, vol. 296, no. 2, pp. R195–R200, 2009.
• Torricillas G et al. The role of hydrogen peroxide in the contractile response to angiotensin II.MolPharmacol 2001; 59(1):104-12.
• Rector RS, Warner SO, Liu Y, Hinton PS, Sun GY, Cox RH, et al. Exercise and diet induced weight loss improves measures of oxidative stress and insulin sensitivity in adults with characteristics of the metabolic syndrome. Am JPhysiol Endocrinol Metab 2007; 293:E500‑6.