Dr. Ron’s Research Review – September 23, 2015

© 2015                                                                                                        

This week’s research review focuses on platelet count and metabolic syndrome.

A study published in Platelets described a cross-sectional (stage 1, 10 579 subjects aged >/=60 years) and prospective (stage 2, 7718 subjects from stage 1 with a mean 3.8 year follow-up) cohort study. (Chen et al., 2014)
There was significant difference in the area under the ROC curve (AUC) only of high platelet count (HPC) women, which exceeded the standard curve (AUC = 0.542, p < 0.001), with a cutoff PC of 223 x 103/mul. HPC women had an OR of 1.287 (95% confidence interval: 1.135-1.461) of developing metabolic syndrome after 3.8 years. The Kaplan-Meier curve demonstrated a higher incidence of metabolic syndrome development in HPC women.
These results suggest that platelet count was associated with metabolic syndrome with sex effects. Most of the metabolic syndrome components were independent factors for increasing PC, and the risk for subsequent development of metabolic syndrome was noted when PC >223 x 103/mul in elderly women.

Another study examined platelet count and volume associations with cardiovascular health indicators in three Framingham Heart Study cohorts (original n = 964, offspring n = 2699, and third generation n = 2419). (Sloan et al., 2015)

Results were concordant with the hypothesis that higher platelet counts are associated with less favorable cardiovascular risk profiles, although mean platelet volume associations were weaker. In our analysis, increased platelet count across FHS cohorts was consistently associated with smoking, triglycerides, low-density lipoprotein, and total cholesterol levels. Some associations with platelet count appeared sex dependent.

Dr. Ron


 

Articles

Platelet count can predict metabolic syndrome in older women
            (Chen et al., 2014) Download
Abstract Platelet count (PC) has been found to be related to the metabolic syndrome (MetS). However, the role of PC on MetS remained unclear. In order to evaluate the relationship between PC and MetS components cross-sectionally and determine the optimal cutoff PCs for predicting the subsequent risk of MetS development with sex specificity, two stages included cross-sectional (stage 1) and prospective (stage 2) cohort study were conducted. Stage 1 involved 10 579 subjects aged >/=60 years, of which 7718 subjects advanced to stage 2 with a mean 3.8 year follow-up were enrolled. The MetS components and PC were determined. The PC cutoffs for higher chances of developing MetS in stage 1 were calculated using receiver operating characteristic (ROC) curve analyses. In stage 2, non-MetS subjects were classified into high-PC (HPC) and low-PC (LPC) groups according to the cutoff values from stage 1. We examined the difference of future MetS incidence and calculated the odds ratio (OR) between these two groups. In stage 1, multiple regression showed that age and triglyceride (both sexes) and waist circumstance and high-density lipoprotein cholesterol (only women) were independently correlated with PC. There was significant difference in the area under the ROC curve (AUC) only of HPC women, which exceeded the standard curve (AUC = 0.542, p < 0.001), with a cutoff PC of 223 x 103/mul. HPC women had an OR of 1.287 (95% confidence interval: 1.135-1.461) of developing MetS after 3.8 years. The Kaplan-Meier curve demonstrated a higher incidence of MetS development in HPC women. In conclusion, our results suggest that PC was associated with MetS with sex effects. Most of the MetS components were independent factors for increasing PC, and the risk for subsequent development of MetS was noted when PC >223 x 103/mul in elderly women.

Cardiovascular correlates of platelet count and volume in the Framingham Heart Study.
            (Sloan et al., 2015) Download
PURPOSE:  Platelet count and volume are inexpensive, routinely assayed biomarkers associated with cardiovascular health, but specific relationships among platelet indices, cardiovascular risk factors, and disease warrant further investigation. The purpose of this study was to understand associations among platelet count, volume, and 20 cardiovascular health-related variables in the Framingham Heart Study (FHS). METHODS:  Cross-sectional analyses were performed on platelet count and volume associations with cardiovascular health indicators in three FHS cohorts (original n = 964, offspring n = 2699, and third generation n = 2419) using multivariate linear regression analysis. Time-to-event analysis was used for cardiovascular disease-related event incidences using Kaplan-Meier plots and Cox proportional hazards regression adjusted for age and sex. RESULTS:  Results were concordant with the hypothesis that higher platelet counts are associated with less favorable cardiovascular risk profiles, although mean platelet volume associations were weaker. In our analysis, increased platelet count across FHS cohorts was consistently associated with smoking, triglycerides, low-density lipoprotein, and total cholesterol levels. Some associations with platelet count appeared sex dependent. CONCLUSIONS:  Significant associations of common blood platelet measurements are observed with sex and cardiovascular risk factors, namely smoking and lipids. Research is warranted to confirm these relationships in other cohorts, evaluate differences by ethnicity, and examine longitudinal effects on disease risk.

 

References

Chen, Y. L., et al. (2014), ‘Platelet count can predict metabolic syndrome in older women’, Platelets, PubMedID: 24512307
Sloan, A, P Gona, and AD Johnson (2015), ‘Cardiovascular correlates of platelet count and volume in the Framingham Heart Study.’, Ann Epidemiol, 25 (7), 492-98. PubMedID: 25771288