Obesity: an independent risk factor for oxidative stress
Keywords:Lipid peroxidation, Obesity, Plasma malondialdehyde, Superoxide dismutase
Background: Obesity is increasing in prevalence and presents a serious risk for the development of various disorders like diabetes mellitus, hypertension, heart disease, gall bladder disease and certain forms of cancer. Animal studies have shown that obesity is associated with increased myocardial oxidative stress and increased lipid peroxidation. The objective of this study was to test the hypothesis that obesity per se causes increased plasma lipid peroxidation and decreased erythrocyte cytoprotection.
Methods: A prospective randomized study including 300 obese subjects, was conducted in the Department of Medicine and Department of Biochemistry, G. R. Medical College, Gwalior. Age and sex matched 100 subjects having BMI between 19 to 25 kg/m2 were also enrolled. Patients were grouped as Case (n=300) and Control (n=100). Detailed physical examination and laboratory investigations including lipid profile were performed. Venous blood was obtained and used for the estimation of Superoxide dismutase (SOD) and plasma malondialdehyde (MDA). Unpaired t test and analysis of variance (ANOVA) with post-hoc Bonferroni and Tukey test along with Pearson correlation was used to analyze the data using IMB SPSS ver. 20 software. Significance is assessed at 5 % level.
Results: Mean age of subjects among Case and Control group was 46.2±2.4 years and 44.5±2.2 years respectively with male predominance in each group. Mean weight, height, BMI, waist, hip, waist to hip ratio, mean blood glucose, total cholesterol, triglyceride, LDL-C, HDL-C and VLDL-C among Cases were91.57±9.8 kg, 161.6±9.3 cm, 36.17± 3.4 kgm2, 114.7±6.2 cm, 114.23±17.12 cm, 0.98±0.22, 87.3±2.6 mg/dl, 196.0±12.6 mg/dl, 253.6±27.3 mg/dl, 135±47.03 mg/dl, 47.1±1.2 mg/dl and 45.8±14.03 mg/dl and among Control group were61±5.2 kg, 163.1±8.7 cm, 21.24±1.88 cm, 21.24±1.88 kg m2, 85.2±1.4 cm, 97.32±9.12 cm, 0.86±0.14, 94.4 ± 3.2 mg/dl, 186.6 ± 6.9 mg/dl, 143.4±15.4 mg/dl, 95.73±27.48 mg/dl, 51.6±1.7 mg/dl and 22.4±10.45mg/dl respectively. Mean MDA level in Case and Control group was 4.68 ± 1.72 and 2.06±0.76 μmol/ml respectively (p< 0.001). Mean SOD level among Case and Control groups was 7.65±1.13 and 12.42±2.18 units/ml respectively (p<0.001). Female obese patients had lower level of SOD. A significant negative correlation of SOD was observed with BMI (n=300, r= -0.045, P<0.001), whereas, MDA was positively correlated with BMI (n=300, r= 0.342, P<0.001).Conclusions: Obesity in humans is an independent risk factor for lipid peroxidation and depletion of cytoprotective enzymes even in the absence of other confounding factors such as diabetes and hyperlipidaemia.
Olusi SO. Obesity is an independent risk factor for plasma lipid peroxidation and depletion of erythrocyte cytoprotective enzymes in humans. International Journal of Obesity 2002; 26: 1159–64.
Freedman DS, Serdula, MK, Perey CA, Ballew C, Whitle L. Obesity, levels of lipids and glucose, and smoking among Navajo adolescents. J Nutr. 1997;127:2120S-7S.
Despres JP, Moorjani S, Lupien PJ, Tremblay A, Nadeau A, Bouchard C. Regional distribution of body fat, plasma lipoproteins, and cardiovascular disease. Arteriosclerosis.1990;10:497-511.
Dobrian AD, Davies MJ, Prewitt RL, Lauterio TJ. Development of hypertension in a rat model of dietinduced obesity. Hypertension. 2000;35:1009-15.
Amirkhizi F, Siassi F, Minaie S, Djalali M, Rahimi A, Chamari M. Is Obesity Associated With Increased Plasma Lipid Peroxidation And Oxidative Stress in Women? ARYA Atherosclerosis J. 2007; 2(4):189-92.
Lima S, Arrais RF, Almeida MG, Souza ZM, Pedrosa LFC. Plasma lipid profile and lipid peroxidation in overweight or obese children and adolescents. J Pediatr (Rio J). 2004;80(1):23-8.
Gopal N, Selvam A, Srinivasan AR, Saha S, Muddegowda PH. Serum Gamma GlutamylTransferase levels in Obese South Indian adults with reference to atherogenic lipid risk factors and lipid peroxides. Int J Med Health Sci. 2012;1(2):35-42.
Bitla AR, Kumari NM, Reddy NS, Nagaraju KV, Sachan A, Kumar VP et al. Antioxidant status in patients with metabolic syndrome as measured by ferric reducing ability of plasma (FRAP) assay. J ClinSci Res. 2012;3:114-20.
Selvakumar C, Maheshwari U. Oxidant-Antioxidant disturbance in men classified as obese according to the preliminary WHO guidelines for Asians. Journal of Stress Physiology & Biochemistry. 2012;8(1-2012):172-81.
Nirmitha D, Suresh DR. Significance of hs-CRP and Oxidative Stress as Early Novel Markers of Subclinical Atherosclerosis in Young Healthy Obese Males. J Biomed Sci and Res. 2010;2 (3):143-50.
Patel MD, Kishore PK, Patel DJ. Evaluation of Oxidative Stress and Serum Magnesium Levels in South Indian Obese Males. International J Scientific Research. 2014;3(3):229-30.
Sankhla M, Sharma TK, Mathur K, Rathor JS, Butolia V, Gadhok AK, et al. Relationship of oxidative stress with obesity and its role in obesity induced metabolic syndrome. Clinical laboratory. 2011;58(5-6):385-92.
Sabitha K, Venugopal B, Rafi MD, Ramana KV. Role of Antioxidant Enzymes in Glucose and Lipid Metabolism in Association with Obesity and Type 2 Diabetes. American J Medical Sciences and Medicine. 2014;2(1):21-4.
Bikkad MD, Ghuge SH, Somwanshi SD, Madole MB. Oxidative Stress in Obesity. J Medical Education and Research. 2013;3(1):1-5.