PSA Level And Its Influencing Factors In Healthy Men Aged 40 Years Or Older In Zhengzhou City

Prostate cancer is the most common cancer affecting men and the third leading cause of cancer death in the world.Prostate-specific antigen(PSA)is a serine protease secreted by prostate cells,which is an important tumor marker for prostate cancer screening.But its specificity is controversial.A few factors which are related to serum PSA,such as age,race and family history have been established.However,the association between smoking,drinking,behavioral lifestyles,anthropometric indicators and biochemical indicators such as cholesterol and serum PSA is still controversial.To date,there is no epidemiological data on serum PSA level in Zhengzhou.Therefore,based on the data collected in previous studies,we comprehensively analyzed the correlation between demographic characteristics,anthropometric indicators,behavioral lifestyles and biochemical indicators and serum PSA levels.Objective To analyze the correlation between demographic characteristics,anthropometric indicators,behavioral lifestyles and biochemical indicators and serum PSA levels.Methods Men of 40 years or older collected by multi-stage cluster sampling in previous study in Zhengzhou were studied.Finishing its demographic characteristics(age,nationality,place of residence,marital status,educational level and occupation),the human body measurements(body mass index(BMI),prostate volume(PV),height,weight,waist circumference,systolic blood pressure and diastolic blood pressure,etc.),behavioral lifestyles(smoking,drinking,exercise,sleep,recent month sex,and dietary factors),and biochemical indicators(total cholesterol(TC),high density lipoprotein cholesterol(HDLc),low density lipoprotein cholesterol(LDLc),triglycerides(TG),and fasting blood glucose(GLU),tec.Pearson correlation was used to analyze the correlated factors of PSA(Spearman rank correation was used for the correlation analysis of grade data),and single-factor and multifactor linear regression analysis were used to determine the correlation between serum PSA levels and demographic characteristics,anthropometric indicators,behavioral lifestyle and biochemical indicators.Results 1.The mean PSA level of the men age 40 years old or older in Zhengzhou was 1.06±0.84 ng/m L,with an average of 63.15±11.02 years old.Rural population accounted for 64.54%.The men who took physical exercise accounted for 73.93%.The mean TC was 4.94±1.07 mmol/L.2.Demographic characteristics.The serum PSA level of urban population was higher than that of rural population(t=﹣4.595,P<0.001).Age was positively correlated with serum PSA level(r=0.286,P<0.001).The serum PSA levels of married or cohabiting men were lower than that those of unmarried,widowed,divorced or separated men(t=﹣3.998,P<0.001).The higher the education level,the lower the serum PSA level(F = 8.579,P < 0.001).Among different occupations,career workers had the highest serum PSA level(F=6.962,P<0.001).Multivariate analyses after adjusting for age showed that occupation was related to serum PSA level.Compared with institution staff member,The β and P value for commercial workers,factory workers and farmers were β=﹣0.380,P=0.037;β=﹣0.398,P=0.029;and β=﹣0.391,P=0.028,respectively.The other variables were unrelated to serum PSA level.3.Anthropometric index.Serum PSA level were correlated with BMI(r=﹣0.070,P=0.011),PV(r=0.320,P<0.001),height(r=﹣0.073,P=0.012),weight(r=﹣0.096,P<0.001),waist circumference(r=﹣0.081,P=0.003),International Prostate Symptom Score(IPSS)(r=0.119,P<0.001),and Quality of life(Qo L)(r=0.095,P=0.001).The results of multivariate analysis showed that PV was positively with serum PSA(P<0.001),and waist circumference was negatively correlated with serum PSA(P=0.009).The remaining variables were independent of serum PSA level.The mediated effect of age on PSA via PV was 22.9%(95% CI: 16.4-31%).4.Behavioral lifestyles.The serum PSA levels of smokers,drinkers,tea drinkers and physical exercisers were lower than those of non-smokers,non-drinkers,non-tea drinkers and non-physical exercisers(t=2.070,P=0.039;t=3.150,P=0.002;t=2.129,P=0.033 and t=2.089,P=0.039,respectively).The results of multivariate analysis after adjusting for age showed that physical exercise and sex life in the last month were correlated with serum PSA level.Compared with non-physical exercisers,the β and P values of physical exercise frequency<4 times/month,4-11 times/month and≥12 times/month were β=﹣0.234,P<0.05;β=﹣0.317,P=0.002 and β=﹣0.446,respectively.Compared with the asexual group in the last month,the β and P values of sex frequency in the last month <4 times/momth,4-13 times/month group were β=0.177,P=0.001 and β=0.320,P<0.001,respectively.The other variables were unrelated to PSA.5.Biochemical factors.The serum TC was negatively correlated with serum PSA level(r=﹣0.081,P=0.003).Univariate linear regression analysis after adjusting age showed that the serum PSA level decreased with the increased of TC,and its β value and 95% CI were﹣0.069(﹣0.109,﹣0.028),respectively.Interaction analysis showed an interaction between physical exercise and TC on serum PSA(Pinteraction =0.017).Conclusions 1.The average serum PSA level of Zhengzhou population was 1.06±0.84 ng/m L.The urban population had higher serum PSA level than that of rural population.2.The older the age,the higher the serum PSA level.The serum PSA level was associated with PV,waist circumference,physical activity,sexual life in recent one month and TC level.3.PV mediated the relationship between age and PSA.There was an interaction between physical exercise and the TC on the serum PSA level.