Large Population Study for Age- and Gender- Related Variations of Platelet Indices in Southwest China Healthy Adults

Abstract

Aim: The present data on the evaluation of platelet parameters in Chinese Han population are still limited. This study was to identify age- and sex-specific variations of platelet indices in Southwest China, including platelet count (PLT), mean platelet volume (MPV), platelet distribution width (PDW), plateletcrit (PCT) and platelet-large cell ratio (P-LCR), through a large-scale investigation of healthy people. Methods: We performed a retrospective analysis on 46872 local healthy individuals (men: n=26,582 and women n=20,290) aged >18yrs. All the subjects were healthy people through the health screening. PLT indices were measured with Sysmex XE-2100 blood cell automatic analyzer. Associations of platelet indices with dependent variables were investigated by ANOVA analysis. Correlation was assessed by the Pearson’s correlation coefficient(r). Statistical analyses were performed with SPSS 20.0 software (Chicago, IL) and Excel 2007. Results: The distribution of platelet count and PCT by age and gender shows a slow, progressive decline with aging in both males and females. On average, a 10-year increase in age corresponds to an average of 6×109/L decrease in platelet count, adjusting for gender (P<0.001). On the contrary, the distribution of MPV, PDW, P-LCR and MPV/PLT ratio by age and gender shows a slow, progressive increasing trend with aging in both genders. The age was negatively correlated with PLT (r=-0.23, P=0.000), PCT (r=-0.24, P=0.000). While age was positively correlated with either MPV (r=0.1, P=0.72), PDW (r=0.1, P=0.024), P-LCR (r=0.09, P=0.002), and MPV/PLT (r=0.21, P=0.001). A positive correlation between MPV and PDW, MPV and P-LCR, PDW and P-LCR was observed, while negative correlation between MPV and PLT, PDW and PLT, P-LCR and PLT was also presented. It’s very interesting that mean PLT in Southwest China Chengdu region was lower than other countries while the MPV, PDW, P-LCR, MPV/PLT values in our study was found to be higher than all other results reported. All of the platelet indices except for MPV showed significantly different distributions from males to females. Conclusion: These findings suggest that the platelet indices could be greatly influenced in healthy subjects by age and sex. The lower platelet count accompanied with higher MPV, PDW and P-LCR, which were possibly the result of the adaption to the basin environment. Based on these findings, it would be reasonable to conduct formal prospective studies to determine the clinical significance. Further studies should be necessary to make additional verification. Unique reference ranges of some routine inspection items should also be established for people of different ethnic groups or in different regions.