A study of correlation between Platelet Volume Indices (PVI) in patients of Dyslipidemia in tertiary care hospital

Maru A.M.¹, Kokani M.J.B.²

¹Dr. Alpesh M. Maru, Department of Pathology, ²Dr. Mayur JitubhaiKokani, Department of Pathology, both authors are affiliated with GMERS Medical College, Junagadh, Gujarat, India

Corresponding author: Dr. Mayur Kokani, E-mail- mkokon11@gmail.com

Abstract

Background:The dyslipidemia is a risk factors for cardiovascular disease. Ischemic heart disease istheleadingcauseofdeath worldwide. Platelet volume reflects platelet reactivity and has been suggested as an independent risk factor for ischemic events in cardiovascular disease. We have shown preliminary results on production of larger platelets by Mean Platelets Volume (MPV) and Platelets Distribution Width (PDW) determination in a group of patients with lipid profile abnormalities.Materials &Method:The study was performed in patients coming to GMERS Medical College, Junagadh from June 2016 to December 2017. Bloodsamplewascollectedinplaintubefor lipidprofileanalysis,EDTA vaccutainer for haematological analysis. PVI were obtained by usingHorriba 5 part automatedcellcounter & Lipid profile parameters by fully automated analyzer Roche’s COBAS INTEGRA 400plus. Results:our study comprising of 500 patient’s samples and 50 control samples, In patient’s group high levels of total cholesterol correlates more with high value of PDW than with MPV.Conclusion:PVI like MPV and PDW are strongly associated with dyslipidemia. The estimation of these PVI can be considered as an early, economicalandrapidprocedurefor identificationofcomplicationsinhyperlipidemic patients.

Keywords:PDW-Platelet distribution width, MPV-Mean platelet volume, PVI-platelet volume indices.

Manuscript received: 28th July 2018 Reviewed: 6th August 2018 

Author Corrected: 14th August 2018 Accepted for Publication: 19th August 2018

Introduction

The dyslipidemia is a risk factors for cardiovascular disease (CVD) and diabetes. These factors include elevated triglyceride levels, low high-density lipoprotein levels, elevated cholesterol and obesity [1].

Noncommunicablediseaseswhichinclude Diabetesmellitusandcardiovasculardisease are world’s biggest killer diseases, estimated to cause3.5millionsdeatheachyear.Eighty percent of them are found in the low and middle income countries. The WHO has developed an actionplanforimplementationofglobal strategiesinpreventionandcontrolofnon communicablediseases. Ischemicheartdiseaseistheleadingcauseofdeath worldwide.Platelets havedefiniteroleincausingitspathogenesisandits complications. A variety of data indicate patients with dyslipidemia have a high risk of developing cardiovascular morbidity and mortality [2,3]. Platelets play an important role in the pathogenesis of thrombosis and atherosclerosis. Activated platelets interact with endothelium and other inflammatory cells by the action of different molecules present on the platelet surface and/or stored in platelets granules, as P-selectin [4]. Platelet volume reflects platelet reactivity ^[5] and has been suggested as an independent risk factor for ischemic events in cardiovascular disease[6]. Large platelets are metabolically and enzymatically more active than small platelets and produce more thromboxane A2 [7,8].Individuals with dyslipidemia have more tendencies to form atherosclerosis plaques with a consequent increasing consumption of platelets. We have shown preliminary results on production of larger platelets by MPV and PDW determination in a group of patients with lipid profile abnormalities[9].

The objective of the study was to study platelet parameters in the spectrum of dyslipidemia.

Materials and methods

A Prospective study was performed in patients coming to GMERS Medical College, Junagadh from June 2016 to December 2017. Random Bloodsampleswerecollectedinplaintubefor lipidprofileanalysis,EDTA (Ethylenediaminetetraaceticacid)vaccutainer for haematological analysis under standard aseptic procedure.

Inclusion Criteria’s:All routine patients of all age group

Exclusion Criteria’s

1.Child below 5 years.

2. Patients with thrombocytopenia.

3. Patients on chemotherapy.

4.Patients received recent blood transfusion.

Sample was taken after 10-12 hours fasting so triglyceridelevel doesn’tgetaffected.Allpatients’andcontrols’ sampleswereprocessedwithin2hoursof sample collection. All haematological parameter wereprocessedusingHorriba 5 part automatedcellcounter.Automatedcell counters,havemadetheplateletcount(PC) andtheplateletvolumeindices(PVI)—mean platelet volume (MPV), platelet distribution width (PDW) routinelyavailableinmostclinicallaboratories.

Properqualitymeasureslikeinternal (IQC)andexternalquality(EQAS)weredone throughoutthestudy.AllBiochemistry parametershavebeenanalyzedusingfully automated analyzer Roche’s COBAS INTEGRA 400plus.andHDL-C,TotalCholesterolandTriglycerideswere measuredbyenzymaticmethods.

The obtained parameters were evaluated using descriptive statisticalanalysis.Statistical analyses were performed using the IBM SPSS (statistical Package for the SocialSciencesv 20.0) and Microsoft Office Excel 2007 software. The p value <0.05 was taken as significant.

Observations &Results

Table-1: Correlation between various parameters of lipid profile and platelet indices in Case group

Table-2: Correlation between various parameters of lipid profile and platelet indices in Control group

In our study comprising of 500 patient’s samples and 50 control samples, we have observed that in patient’s group high levels of total cholesterol correlates more with high value of PDW (Platelet distribution width) than with MPV (Mean Platelet Volume). Same observation was made in case of high levels of Triglyceride, High Density lipoproteins (HDL) and Low density lipoproteins (LDL). These observations are summarized in table-1.

Out of 500 samples, we have included 180 dyslipidemic patients with uncontrolled diabetes. Here also we observed high MPV and PDW.

In control group, out of 50 samples, only 2 samples showed high values of PDW and only one sample showed high MPV. This observation is summarized in Table-2.

Discussion

Dyslipidemia, often an asymptomatic hidden state of blood might be the root behind a large number of complications including the life-threatening thromboembolic events. Role of platelets in such thromboembolic events is well-known and various platelet volume indices have been largely studied in these conditions.

Total cholesterol, triglycerides, and HDL cholesterol are measured directly. TC and TG values reflect cholesterol and TGs in all circulating lipoproteins, including chylomicrons, VLDL, intermediate-density lipoprotein (IDL), LDL, and HDL.

TC and HDL cholesterol can be measured in the nonfasting state, but most patients should have all lipids measured while fasting (usually for 12 hour) for maximum accuracy and consistency.LDL cholesterol values are most often calculated as the amount of cholesterol not contained in HDL and VLDL.LDL can also be measured directly using plasma ultracentrifugation, which separates chylomicrons and VLDL fractions from HDL and LDL, and by an immunoassay method. Direct measurement may be useful in some patients with elevated TGs.

Lipid measurement should be accompanied by assessment for other cardiovascular risk factors, including diabetes, hypertension, smoking.

 Pre-sent study was a humble attempt to study the changes in platelet volume indices in cases of dyslipidemia.

Studies have shown that platelet count and size might be gender and age dependent[10]. Hence wehave conducted this case control study with both age and sex matched controls to avoid any such bias in our results.

The collection of samples was done in EDTA bulbs and the samples were run between 2–6 hours after venepuncture to avoid bias due to swelling of plateletsinEDTA [11].

We found that all three PVI – MPV, PDW were significantly higher (p-value <0.05) in the study group than the controls, i.e. hyper-lipidemic patients had significantly higher MPV, PDW than the normolipidemic patients.

The association of increased MPV, PDW, P-LCR, and platelet count with diseases related to endothelial dysfunction such as metabolic syndrome, diabetes, coronary artery disease (CAD), and malignancy has been shown in many studies[12,13,14,15].

PDWisameasureofplateletanisocytosiswithhigher value indicating reactive platelet population[16].

Apracticaland reliableindexofplateletactivationhasbeen tested,asmeasurementsofplateletnumber and size, the tendency to form aggregates and the concentration of released substances stored inplateletgranules [17].

AlargerMPVisan indicatorofinvivoplateletactivationanditis increasedinvasculardiseasesasmyocardial andcerebralinfarction[18].

We know that larger platelets are considered to be metabolically, enzymatically and functionally more active than the smaller platelets. They contain more dense granules and hence are more potent and thrombogenic and this might be a cause for hyper-lipidemia being a pre-thrombotic state. This study is correlated well with other study Khemka et al[19]andDesai KN [20].

Patel DS et al[21]have performed study of44 patients of dyslipidemia & metabolic syndrome. Results shows that, MPV and PDW were significantly high in patients having metabolic syndrome and dyslipidemia in case group compared to control group. The correlation between variables were significant in both groups (p<0.0005). these results are correlated well with our study.

Hyperlipidemic patients who have larger platelets are more likely to have an associated disease condition and the platelet volume indices may form a basis for the prediction of these diseases in hyperlipidemic patients.

An attemptwasalsomadetocorrelatethese platelet volume indices with the severity of hyperlipidemia. For this, PDW and MPV values were correlated with the increasing values of total cholesterol and triglyceride levels in This might be possibly due to the more likelihood of occurrence of hyperlipidemia associated complicationslikethromboticdiseaseswithincreaseinits severity. our study and these results are comparable with some other study also like KhandekarM.M.[22], Fuchs J[23].

We have observed that that increased MPV, PDW is associated with poor glycometabolic control with dyslipidemic patients.Insulin resistance plays a pivotal role in the development of diabetic dyslipidemia by influencing several factors. similar findings are observed in study of Desai KN[24].

Conclusion

PVI (Platelet Volume Indices) like MPV and PDW are strongly associated with dyslipidemia. Thepresentstudyhighlightstheplateletvolumeindicesinhyperlipidemicpatients comparedtocontrolsubjects.

The results showed that larger plateletsarepresentinpatientswithmetabolic syndrome & dyslipidemia.Becauselargerplateletsaremore reactive,theycancontributetoanincreased riskforcardiovasculardiseasesasa complicationofmetabolicsyndrome. So, estimation of these PVI can be considered as an early, economicalandrapidprocedurefor identificationofcomplicationsinhyperlipidemic patients.

Also, further studies will elucidate the reactivity of the larger platelets and the utility of the new parameter in assessing qualitativeabnormalitiesinplatelets.

We conclude that high MPV and PDW can be considered as biomarkers for early detection of impendingdiabeteic complications like microvascular complications.So these are very cost effective revolutionary markers for early detections of such complications in developing countries at low cost.

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