Association Analysis Of Blood Heavy Metal Exposure With Oxidative Stress And Triglycerides In The Elderly

Objective:The prevalence of hypertriglyceridemia in the elderly population has been increasing year by year in China,which not only brings harm to the health,but also causes great burden in social and economic.Therefore,it is significance to identify the influencing factors of triglyceride for preventing the development of hypertriglyceridemia and realizing healthy aging.There are many influencing factors of hypertriglyceridemia.The exposure of heavy metal and oxidative stress have attracted increasing attention.Aged 65 years and older were recruited in 9 longevity areas from Heathy Aging and Biomarkers Cohort Study.There were used to investigating the association of heavy metal,blood oxidative stress level and hypertriglyceridemia in the elderly aged65 years and older in China by the biomarkers of oxidative stress levels,including superoxide dismutase and malondialdehyde,and blood levels of heavy metals including lead,cadmium,mercury,arsenic,chromium,manganese,and selenium.Methods:The linear or non-linear association between heavy metals,oxidative stress and hypertriglyceridemia were described by restrictive cubic splines（RCS）fitting multiple linear regression model.The logistic regression model was conducted to assess the association between heavy metals,oxidative stress and hypertriglyceridemia.Mediating effects were used to analyze the association between MDA levels or SOD levels in heavy metals and triglycerides.Epidata 3.0 was used for double entry of the survey data,and SAS 9.3 was used for statistical analysis after verification.Results:1.A total of 2361 subjects were included in this study.The concentration triglyceride level was 1.19（0.89,1.61）mmol/L,and the detection rate of hypertriglyceridemia in males was 17.9%and females was 25.7%;The concentration level of SOD was 52.29（44.67,59.14）U/m L.The concentration level of MDA was3.88（3.16,4.84）nmol/m L.2.The prevalence of hypertriglyceridemia was higher in women,spouses,patients with hypertension（P<0.05）,and diabetics the prevalence of hypertriglyceridemia was higher with the group of low sugar intake,low milk intake or low egg intake（P<0.05）.3.In serum of the elderly in 9 long-lived areas of China,Lead(P_correlation<0.05,Pnonlinear=0.76),Cadmium（Pcorrelation<0.05,Pnonlinear=0.08）,Mercury（Pcorrelation<0.05,Pnonline ar<0.05）Arsenic（Pcorrelation<0.05,Pnonlinear=0.70）,Chromic（Pcorrelation<0.05,Pnonlinear=0.90）,Manganese(P_correlation<0.05,Pnonlinearity=0.44)was correlated with SOD level.Co mpared with the first quartile,after adjusting for potential confounders,the odds ratios of high MDA levels for the second,third,and fourth quartiles of blood cadmium were 1.64（1.06-2.53）,1.90（1.22-2.97）and 2.93（1.90-4.50）,blood merc ury were 0.45（0.29-0.69）,0.52（0.34-0.80）and 0.62（0.41-0.95）,blood arsenic in the O R（95%CI）values were 0.88（0.59-1.30）,0.85（0.57-1.27）,0.60（0.38-0.94）;blood c hromium were 1.18（0.76-1.84）,1.45（0.95-2.21）and 2.57（1.72-3.82）,blood manganese were 1.10（0.73-1.68）1.34（0.89-2.03）and 1.97（1.32-2.94）,respectively.4.In serum of the elderly in 9 long-lived areas of China,Cadmium(P_correlation<0.05,Pnonlinear=0.05),Mercury（Pcorrelation<0.05,Pnonlinear=0.78）,Selenium（Pcorrelatio n<0.05,Pnonlinear=0.18）,Arsenic（Pcorrelation<0.05,Pnonlinear<0.05）,Chromium(Pcorre _lation<0.05,P_nonlinear<0.05)were correlated with MDA level;Compared with the f irst quartile,after adjusting for potential confounders,the odds ratios of high MDA levels for the second,third,and fourth quartiles of bloodcadmium were0.96（0.67-1.38）,0.73（0.49-1.10）and 0.48（0.30-0.75）,blood mercury were 1.05（0.66-1.66）,1.64（1.06-2.55）and 2.32（1.48-3.62）,blood arsenic were 1.31（0.84-2.06）,1.85（1.20-2.87）and 2.36（1.51-3.69）,blood chrome were 0.90（0.63-1.28）,0.79（0.55-1.14）and 0.49（0.32-0.74）,blood selenium were 1.14（0.74-1.74）,1.48（0.97-2.24）and 1.60（1.05-2.45）,respectively.5.MDA level was linear association with triglyceride level(P_correlation<0.05,P_nonlinear=0.61);SOD level was nonlinear association with triglyceride level(P _correlation<0.05,P_nonlinear<0.05).MDA level had significantly association with hyp ertriglyceridemia,and the corresponding OR value was 1.10（95%CI:1.05,1.16）with 1 nmol/ml increment of blood MDA;SOD level had significantly associ ation with hypertriglyceridemia,and the corresponding OR value was 0.97（95%CI:0.96,0.98）with 1 U/ml increment of blood SOD.6.Lead,cadmium,mercury,arsenic,and manganese levels were associated with increased triglyceride levels(P_correlation<0.05).Compared with the first quartile,after adjusting for potential confounders,the odds ratios of hypertriglyceridemia for the second,third,and fourth quartiles of blood lead were 0.99（0.75-1.30）,0.87（0.65-1.17）and 0.74（0.54-1.01）;blood cadmium were1.45（1.08-1.95）,1.44（1.06-1.97）and1.45（1.05-2.00）;blood mercury were 1.37（0.99-1.91）,1.64（1.18-2.27）and1.45（1.03-2.04）;blood arsenic were 1.48（1.09-2.01）,1.27（0.93-1.74）and 1.03（0.74-1.44）.7.The analysis model of the mediating effect of SOD level on triglyceride level showed that the total effect was 1.125（1.008-1.241）,the direct effect was1.082（0.971-1.192）,and the indirect effect was 1.040（1.016-1.063）.The mediating effect analysis model of serum manganese level on triglyceride level mediated by SOD level showed that the total effect was 0.893（0.803-0.984）,the direct effect was0.873（0.784-0.962）,and the indirect effect was 1.023（1.006-1.040）.Conclusion:1.Lead,cadmium,mercury arsenic chromium manganese,selenium levels in serum and oxidative stress state relationship exists The blood lead level Blood manganese levels may reduce the body’s ability to resist oxidative damage of blood cadmium levels of blood chromium levels may also reduce the body’s ability to resist oxidative damage and oxidative stress level,blood mercury levels Blood arsenic levels may also increase the body’s ability to resist oxidative damage and oxidative stress level Slightly elevated blood selenium levels may increase the body’s ability to resist oxidative damage.Higher blood selenium levels may increase oxidative stress in the body.2.There are association between serum oxidative stress level and triglyceride level in the elderly aged 65 years or above in 9 long-lived areas in China,and the increase of oxidative stress level may increase the triglyceride level.3.The levels of cadmium,mercury,arsenic in serum of the elderly aged 65 years or above in 9 long-lived areas of China were correlated with the increase of triglyceride levels,and the increase of serum arsenic,cadmium and mercury might lead to the increase of triglyceride levels.Cadmium in serum can affect triglyceride level by decreasing SOD level.Manganese can directly reduce triglyceride level,but manganese exposure can increase triglyceride level by decreasing SOD level.