High-Sensitive C-reactive Protein and Atherogenic Lipid Levels in a Group of University Students with Habitual Smoking

High-Sensitive C-reactive Protein (hs-CRP)is a well-known inflammatory and cardiovascular disease (CVD) marker. Non-HDL cholesterol concentration in blood are strongly associated with long-term risk of atherosclerotic CVD. Hs-CRP and atherogenic lipids are suggested to be a central feature of cardiovascular disease (CVD), particularly among smokers. Smoking for long duration seems to be correlated with high level of hs-CRP, plasma cholesterol and LDL-C. This study was done to evaluate the plasma levels of hs-CRP, lipid profile, and magnesium in a group of university students with habitual smoking. Eighty current smoker males participated in this cross sectional study. Estimation of plasma hs-CRP was carried out using latex immune turbidimetric method, plasma lipid profile and magnesium by chemical methods using a spectrophotometer (Biosystem 310)and results were computed by using SPSS. Regarding hs-CRP level, 20% (16/80) participants were at high (>3mg/L) risk to CVD; total cholesterol 6.3% (5/80) participants were at an average greater than 240mg/dL; LDL-C 6.3% (5/80) were at an extremely high risk of greater than 190 mg/dL. A test group of students who smokes for ten years or more had a significant increase in means of plasma hs-CRP, total cholesterol, LDL-CP value < 0.05, while there was a significant decrease in means of plasma HDL-C P value <0.05. Study results revealed that cigarette smoke was associated with considerable changes of hs-CRP, and atherogenic lipids that were considered as risk factors for cardiovascular disease among young male smokers.

The use of tobacco is increasing and broadly spreading throughout the world. It is a bad human behavior and is practiced by people when addicted to nicotine,which causes many harmful diseases 1 .smoking is the highest risk factor in the progress of specific health problems,such as cardiovascular disease and chronic obstructive pulmonary disease 2 . Cigarette smoke consists of over 4000 components,including toxicants, carcinogens, oxidants, and free radicals components 3 .
Hs-CRP is one of an acute-phase reactant proteins, an indicator of systemic inflammation 4 . Hs-CRP is usually related to CVD risk factors, predominantly, with lifestyle features like smoking as well as physical activity behaviors 5,6 .
Dyslipidaemia in smokers shows a superior risk of atherogenic disorder, which comparably correlates to the number of cigarettes, and smoking duration 7 .
Magnesium misbalances are associated with many pathological states such ashypertension, CVD and ischemic brain injury,a rising of extracellular and intracellular magnesium levels can control the addiction to nicotine and tobacco smoking 8 . Several studies reported the associations between hs-CRP and CVD among adolescents and youth 2,7 . In this current study, we targeted the investigation of some CVD risk factors, specifically, hs-CRP, total cholesterol, and LDL-C among Sudanese young adult males aged between 18 and 25years.

Materials and Methods
In this cross-sectional comparative study, approved by research committee of Sudan University of Science and Technology,80 healthy current daily cigarettes smoker male were randomly selected from Sudan university of Science and Technology. The smoker males, age between 18 and25 years, smokes 10 or less cigarettes per day and at least on smoking for 30 days before participation in this study. Participant with diabetes, diagnosed CVD, cerebrovascular disease, stable hypertension treated by drugs, dyslipidemia, renal problems, and chronic hepatic disease, were excluded from this study. After getting their informed consent, 3ml venous blood samples were taken from participants in the morning in lithium heparin containers after a minimum of 8 hours of overnight fasting. Then specimens were centrifuged at 3000 rpm for 5 minutes, plasma was separated and used for high sensitive hs-CRP which was measured by turbidimetric 9 , and plasma magnesium by chemical method 10 , total cholesterol, triglyceride, and HDL-C by enzymatic methods [11][12][13] . Simultaneously, LDL-C was calculated according to Friede wald formula: LDL cholesterol (mg/dL) = total cholesterol -HDL cholesterol -(triglycerides/5) 12 The precision and accuracy of the techniques used in this study were checked each time a batch was analyzed by including commercially prepared control sera.

statistical analysis
A convenient descriptive and analytical, statistical approach was followed using a statistical package SPSS version 20.descriptive statistic, Pearson's correlation was used to compare and correlate hs-CRP magnesium, and lipid profile levels with variables in the study group and the level of significance were expressed as P value < 0.05

results
The study population included 80 nondiabetic, non-hypertensive university student smokers (light smokers: 1 -10 cigarettes/day),age 18-25 years,59 out of 80 participants practice sport two times per week, the mean of BMI (22.9 ± 3.9) kg/m 2 . Table 1 shows 16 participants (20%) had >3.0mg/Lof hs-CRP,5 (6.3%) high level of total cholesterol, 5 (6.3%) had very high level of LDL-C, while 45 (58.2%) had low level of HDL-C. Table 2 shows the statistics of measured hs-CRP, serum magnesium and lipid profile parameters compared according to duration of smoking per year. results were found to  be significantly increased for hs-CRP, total cholesterol, triglycerides, LDL-C and significantly decreased for HDL-C, and magnesium in male smokes more than 10 years when compared with smokes less than 10 years(P<0.05). Table 3 shows a comparison between biochemical parameters according to sport practice (two times per week, for at least 30 minutes) among smokers. The results reflect that there was a significant increase in means of HDL-C level, and decrease in body mass index,while total cholesterol, triglycerides, LDL-C and magnesium, there were no statistical difference in the means according to sport practices. Table 4 shows Pearson's correlation between hs-CRP, lipid profile, magnesium levels and duration of smoking per year. The results reflect statistically significant, positive correlation between the hs-CRP, total cholesterol, triglycerides, LDL-C with duration of smoking per year.

discussion
Cigarette smoking is a classical and a major risk factor in the development of several diseases with an inflammatory component, including the development of cardiovascular disease (CVD) and atherosclerosis 13 . CVD referred to as an inflammatory disease 2 Cigarette smoking alters plasma lipid and lipoprotein levels, nicotine stimulates sympathetic adrenal system leading to increased secretion of catecholamines resulting in increased lipolysis and increased concentration of plasma free fatty acids (FFA) which further result in increased secretion of hepatic FFAs and hepatic triglycerides along with VLDL in the blood stream 14 .
In the present study, although the factors that affect the hs-CRP, lipid profile and magnesium were excluded, we found that20.0% (16/80) of the studied group had high level of hs-CRP (hs-CRP >3mg/L),These results are comparable with the findings of several studies 15,16 .
Our study reveals that there were significant increase in means of hs-CRP, total cholesterol, triglycerides and LDL-C and significant decrease in HDL-C, and magnesium in participants smokes for e" 10 years, also there was significant positive correlation between duration of smoking and hs-CRP, total cholesterol and LDL-C. Our findings are in accordance with the findings of many research workers 6,[17][18][19] . A direct association between elevated levels of hs-CRP, as well as other markers of inflammation, and cigarette smoking has been reported in several investigations 18,19 and most studies showing a dose-response relationship between CRP levels and smoking intensity and/or duration 20,21 .The change in the serum cholesterol and lipoprotein levels became more marked with the number of cigarettes smoked per day and duration of smoking 6 .
Nicotine and other toxic substances from tobacco smoke increases the amount of bad fats (total cholesterol (TC), LDL-C, and triglycerides (TG) circulating in the blood vessels and decreases the amount of good cholesterol HDL-C availability 22 .Nicotine induces oxidative stress, generates free radicals that attack on the membrane lipids resulting in the formation of malondialdehyde (MDA), which causes peroxidative tissue damage 23 .
In this study, there was an insignificant difference between means of hs-CRP among the smoker who practice sport when compared with the smoker not practice sports. Only 21 out of the 80 participants practiced sport twice in a week. Our results were similar to Mazurek et al., who reported that no relationship between hs -CRP concentration and the physical activity 24 , and disagree with another study; hs-CRP concentration levels were conversely identified with cardiorespiratory fitness 25 . Stewart et al. reported exercise training decrease the risk of CVD as defined by a reduction in the concentration of CRP in healthy individuals 26 .
The study revealed that serum magnesium significantly negatively correlated with duration of smoking .This result is in agreement with a previous study 27 ; as cigarette smoking causes decreased supply of magnesium due to lesser appetite and reduced absorption due to digestive system disturbances 28 . Experimental evidence indicates that magnesium insufficiency promotes atherosclerosis and that magnesium fortification attenuates atherogenesis 28,29 . Evidence from observational studies indicates that high circulating magnesium levels and magnesium intake are associated with a modest reduction in risk of cardiovascular disease, including coronary heart disease 30,31 .
conclusion Study results revealed that smoker status was associated with substantial changes in hs-CRP, atherogenic lipid profile, and magnesium that considered risk factors for cardiovascular disease among young adults smoker. Consistent advice for young men considers a healthy lifestyle rich in physical activity and free of smoking.

acknowledgMents
Our appreciation and gratefulness to all who were contributed to the success of this study.