Over the last decade, China has witnessed a dramatic increase in the incidence of cerebral infarction with high morbidity and mortality rates, which might be caused by changes on lifestyle behavior. It is still hard to take effective way to reduce the mortality of acute cerebral infarction. However, many patients diagnosed as primary cerebral infarction have developed into acute type. Therefore, timely diagnosis of cerebral infarction is of vital importance in planning intervention effect of rapid rehabilitation. Traditional risk factors are not always enough to predict or diagnose the incidence of cerebral infarction. In the present study, results (shown in Table 2 and Fig. 3) illustrate that use of three biomarkers in combination by calculating (sdLDLc*HCYc)/HDLc ratio could improve the diagnosis ability for primary cerebral infarction.
Our current results (Table 1) show that middle-old aged male is likely to develop cerebral infarction. This indicates that gender still has an impact on the risk of cerebral infarction. Many reports have pointed out that men are affected by smoking, drinking and obesity, and these factors could illustrate the phenomenon that cerebral infarction increases with male [16, 17].
sdLDL is considered risk factor for cardiovascular disease owing to its ability to aggregate large amounts of cholesterol in the artery intima. Therefore, sdLDLc could serve as a key risk factor in predicting the incidence of cardiovascular disease. Some reports have illustrated that sdLDLc was higher in the cerebral infarction group than that in non-cerebral infarction group (p < 0.05) [9, 18]. Here, our findings that sdLDL levels were significantly higher in the experiment group than in the control group, which is consistent with recent reports. Through analysis, we found that sdLDLs have certain predictive value for diagnosis of primary cerebral infarction.
In contrast, HDL could resist the accumulation, preservation and oxidation of LDL, and serve as a protective factor. The HDLc could affect the development of acute ischemic stroke and a low HDL cholesterol concentration could be found in cerebral infarction population (shown in Table 1) . HDL combined with other biomarkers has a good predictive value for stroke cardiovascular disease. As shown in Table 1, platelets, lymphocytes, neutrophils and monocytes are significantly different between patients in cerebral infarction group and healthy people in control group. It is reported that monocyte/high-density lipoprotein has a good predictive value for cardiovascular disease . Our results show that the monocyte/high-density lipoprotein ratio in cerebral infarction group is significantly higher than that in control group (Data not shown). Previous studies also have suggested that LDLc to HDLc ratio (LDLc/HDLc) is significantly associated with acute coronary syndromes . In current study, higher sdLDLc/HDLc ratio was still significantly associated with increased presence of carotid plaques, indicating that the sdLDLc/HDLc ratio might deserve more attention for these high-stoke-risk population. Our results also indicated that sdLDLc/HDLc ratio could be a better prediction indicator than single biomarker, such sdLDL, HDL (shown in Table 2).
In the 1980s, it was proposed that HCY is an independent risk factor for atherosclerosis and coronary heart disease . HCY was also an independent risk factor of cerebral infarction. Our study shows that compared with participants with health people, serum HCY level in first cerebral infarction continues to increase, which indicates that HCY is the risk factor of cerebral infarction and might be as the biomarker of first cerebral infarction judgement. These conclusions have been confirmed by current studies [22, 23].
Analysis based on ROC curve shows that (sdLDLc*HCYc)/HDLc ratio has better predictive value for first cerebral infarction. (sdLDLc*HCYc)/HDLc ratio might be better indicator in clinical auxiliary diagnosis of primary cerebral infarction than single biomarker, including sdLDLc, HCYc and HDLc, even two biomarkers (sdLDLc/HDLc ratio). This better diagnostic ability may result from taking homocysteine into account. For people with different (sdLDLc*HCYc)/HDLc ratio, we should pay more attention to the changes of thrombus and other indicators, which might help clinician to provide them with thrombolytic, oral anticoagulant and other different treatments based on above findings.
Nevertheless, the present work has some limitations. Firstly, the volume of specimens included was not large. Then, the dynamic monitoring of (sdLDLc*HCYc)/HDLc variation might be more helpful in judging the condition and evaluating the prognosis of cerebral infarction. In addition, the paper shows that there are obvious differences in age and hemogram between the population in control group and the population in first cerebral infarction. These biomarkers, including platelets, lymphocytes, neutrophils and monocytes, were good predictors for cerebrovascular events . In the future, more large-scale research is needed to establish a model based on these indicators to predict cerebral infarction.
In conclusion, three biomarkers in combination by calculating (sdLDLc*HCYc)/HDLc ratio is closely associated with the occurrence of cerebral infarction and could improve the diagnosis ability of single biomarker, including sdLDLc, HCYc and HDLc, for primary cerebral infarction. The new indicator could predict the occurrence of cerebral infarction and provide a scientific basis for risk stratification management and early prevention in people with high risk of stroke due to cerebral infarction.