INTRODUCTION
Diabetes is a chronic health condition characterized by elevated levels of blood glucose. India is the diabetes capital of the world and is expected to hit 69.9 million cases by the year 2025 and 80 million by the year 2030.[1] Diabetes is more prevalent in urban areas, affecting 28% of the urban population compared to 5% of the rural population.[1] The overall prevalence of hypertension in India is found to be 29.8%, with significant variations observed in the rural and urban populations.[2]
Platelet indices (PI) are a useful marker to detect thromboembolic disorders. They comprise platelet distribution width (PDW), mean platelet volume (MPV), platelet crit (PCT), and platelet large cell ratio (P-LCR). Platelets that are larger in size contain more granules and are more active compared to their smaller counterparts.[3] MPV and PDW are the simple platelet indices that increase during platelet activation.[4]
Diabetes is a “prothrombotic state,” causing extensive endothelial injury and alteration in platelet morphology.[5] Hence, an increase in the MPV and PDW might be due to an increase in thrombotic potential, which in turn, is a consequence of diabetes mellitus. Hypertension is also a strong risk factor for microvascular complications, which again is an important cause of mortality and morbidity in diabetic patients.[6]
Hypertension has also been shown to be associated with platelet activation.[5] MPV being an indicator of platelet activation, an increase in its value might be attributed to a rise in blood pressure. An increase in platelet aggregation and activation is an important step in the pathogenesis of hypertension and its risk factors.[7] Several articles mention that platelets play a crucial role in mediating immune responses and are responsible for the maintenance of vascular homeostasis and inflammation.[8]
However, till now, no study comparing the platelet indices of diabetic and hypertensive patients with healthy individuals as control, has been done in this area. Therefore, this research aims to provide some useful insight into this clinical demography.
AIMS AND OBJECTIVES
The study aims to find out if there is any association between PI, namely MPV, PDW, and P-LCR, and diabetes mellitus and/or hypertension, both of which promote a state of hypercoagulability in which platelets play a crucial role.
The objectives of this study are to compare and analyze variation in the selected PIs in
- Patients with uncomplicated and complicated DM with those of healthy controls.
- Pre-hypertensive, hypertensive patients, and healthy controls.
- Patients with both hypertension and DM with those of healthy individuals.
MATERIALS AND METHODS
This investigation employed a case-control hospital-based study design to evaluate the PI variations in three groups of patients; one with diabetes, the second with hypertension, and the third, which included patients who had concurrent diabetes and hypertension. Age and gender matched normotensive nondiabetics formed the control group. The study encompassed all consecutive patients who attended the General and Medicine Out-Patient Department of North Bengal Medical College and Hospital from April 2022 to September 2022. Following the standard norms, a sample size of 1096 individuals was calculated. Ethical clearance from the Institutional Ethics Committee was secured. Written informed consent was procured from all participating patients.
Inclusion criteria
All adults who were pre-hypertensive, hypertensive, and/or diabetic with or without complications and who had given consent were included.
- The classification of prehypertension and hypertension was done according to the American Heart Association 2020 guidelines. A systolic blood pressure between 130 and 139 mm of Hg and a diastolic blood pressure between 85 and 89 mm of Hg were classified as pre-hypertensive, and a systolic blood pressure above 140 mm of Hg and a diastolic blood pressure above 90 mm of Hg were classified as hypertensive.
- Following the American Diabetes Association guidelines, a fasting blood glucose level above or equal to 126 mg/dl was considered diabetic.
- Complications resulting from diabetes were obtained from the medical records.
- The control group consisted of normotensive and non-diabetic individuals.
Exclusion criteria
Patients
- With a history of blood transfusion in the past three weeks of data collection
- On antiplatelet drugs and drugs that lead to suppression of bone marrow
- With a history of blood loss (genitourinary or gastrointestinal bleeding)
- Pregnant women
- Male patients with a hemoglobin level below 13g/dl and female patients with hemoglobin below 12 g/dl.
- Known cases of hematological malignancy or qualitative or quantitative platelet disorders.
Blood collection
After overnight fasting and maintaining asepsis, 2 ml of the blood was collected from the antecubital vein by clean venipuncture in an K2-EDTA vial. A complete blood count was obtained using the Sysmex KX-21 autoanalyzer. Hemoglobin and PI were recorded. The tests were done using proper quality control measures.
BP measurement
Blood pressure was measured using a mercury sphygmomanometer. Two readings in sitting posture were taken at an interval of 5 minutes, and the average of the two readings was recorded.
Statistical analysis
Data was collected and cleaned using MS Excel 2017 and thereafter exported to IBM Statistical Packages for Social Sciences (SPSS) version 22.0. A Student t-test was performed to calculate the significant difference, and an ANOVA test was done between the above-mentioned groups. The data was expressed in mean and standard deviation format. A P- value less than 0.05 has been considered statistically significant.
RESULTS
The study includes a total of 472 diabetic patients out of which 194 patients had complications and 278 patients didn’t have any complications. The hypertensive population comprised 88 prehypertensive and 132 hypertensive patients. The control group of normotensives and non-diabetic individuals was 264 individuals.
In the diabetic group, most of the patients were male (68.2%). The age group with the maximum number of individuals was 42-60 years. The study depicts MPV is increased in diabetes with complications (11.93 ± 1.52) as compared to diabetes without complications (10.91 ± 1.57), the result obtained was statistically significant (p<0.05). A significant difference in PDW and P-LCR was also seen between the groups (p<0.001) and (p<0.05) respectively. These results are summarised in Table 1.
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Table 1: Variation of platelet indices in Diabetics with and without complications and control group
Table 2: Variation of platelet indices among hypertensives and pre-hypertensives with the control group
Table 3: Variation of platelet volume indices in patients with both hypertension and diabetes with respect to the control group
The variation of platelet indices with hypertensive and prehypertensive groups showed similar trends. MPV was significantly higher in the prehypertensive (11.54±1.38 ) and hypertensive group (12.15±1.42) as compared to the control group (9.54±1.57). PDW and P-LCR also showed significant upward trends as compared to the control group(P<0.001 and p=0.053) respectively.
The variation of platelet volume indices in patients with both hypertension and diabetes also showed a similar upward trend in both MPV, PDW, and P-LCR, data obtained were statistically significant.
DISCUSSION
Diabetes and hypertension are two common modern-world problems. Hypertension causes an increase in platelet and endothelial microparticles, promoting coagulation and thrombin generation.[9] In individuals with diabetes, there is a documented elevation in platelet count and activity, indicated by heightened levels of GPs IIb/IIIa, 1b-IX, and 1a/IIa.[10] The combination of hypertension and diabetes creates a prothrombotic environment, increasing the risk of cardiovascular complications.
Increased use of hematology analyzers (HA) in recent times has made routine examination of PIs more accessible and affordable. Platelet indices serve as useful, quick, reliable, and cost-effective markers to detect platelet dysfunction and thromboembolic disorders. MVP and PDW are simple platelet indices that increase during platelet activation.[4] Platelet indices also serve as prognostic markers for cardiovascular conditions.[11]
An increase in MPV implies larger-sized and more reactive platelets. The larger reactive platelets secrete more prothrombotic factors. Recent studies have pointed toward the association of increased MPV with thromboembolic disorders.[12] In this study, MPV, PDW, and P-LCR were significantly higher among hypertensive and pre-hypertensive groups as compared to the control group. An increased MPV among hypertensive patients was also noted in a study conducted by Nadar SK et al.[13] They also found that among hypertensives, those with target organ damage had a significantly higher MPV.[13] Also, Yazici et al.[14] in their study found MPV to be significantly increased among pre-hypertensive subjects.
Our study also shows a significantly higher MPV among the diabetics, both with and without complications, when compared to the control group. A possible explanation suggested for the increased MPV is the osmotic swelling of platelets due to increased blood glucose.[15] A study by Dindar et al.[16] also shows a significant increase in MPV among diabetics with complications as compared to diabetics without complications.
In our study, P-LCR was found to be significantly higher in patients with DM and/or hypertension. The difference in P-LCR between the diabetic patients with and without complications was also seen to be statistically significant. This finding was obtained. This finding is in line with a study done by Taderegew MM et al.[17]
The present study also shows similar findings, with a more significant increase in PVI among diabetic patients with complications and among diabetic and hypertensive patients with both diabetes and hypertension.
Limitations
The present case-control study addresses the rising interest in PI amid advancements in HA, though hindered by the lack of standardized analyzers. Given the metabolic nature of diabetes and hypertension, often coupled with hypertriglyceridemia, analyzing participants’ lipid profiles alongside PI could offer deeper insights. Furthermore, longitudinal tracking of PI variations during disease progression would enhance understanding.
CONCLUSION
PI, which are easily available, by reliable and cost-effective methods and can be studied as part of routine examinations, could serve as potential biomarkers for monitoring the risk of cardiovascular complications in patients with hypertension and diabetes.
Financial support and sponsorship
Nil.
Conflicts of interest
There are no conflicts of interest.
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