Investigation of Mean Platelet Volume and Platelet Count in the Blood of Patients with Lumbago and Sciatica.

BACKGROUND: Mean platelet volume (MPV) is a measurement defining the mean size of platelets in the blood. There has been no previous study of MPV and the level of platelets in lumbago/sciatica patients. AIM: The aim of this study was to investigate whether or not an increase is seen in platelet count and MPV which are indicators of platelet activation in lumbago/sciatica patients compared to a healthy control group. PATIENTS AND METHODS: The study included 151 patients (79 females, 72 males, mean age 43.1 ± 12.9 years) who presented at the Pain Clinic of our hospital and were diagnosed with lumbago/sciatica between July 2017 and September 2017. A control group was formed of 80 healthy individuals (40 females, 40 males, mean age 42.4 ± 12.5 years).
RESULTS: No statistically significant difference was determined in the MPV of the lumbago/sciatica patients (9.76 ± 1.09 fL) compared with the control group (9.56 ± 0.92 fL) (P = 0.34). The platelet level of lumbago/sciatica patients (263.3 ± 68.7 103/mL) was determined to be statistically significantly lower than that of the control group (277.27 ± 70.7 103/mL) (P = 0.02).
CONCLUSION: The results revealed that the platelet count of the lumbago/sciatica patients was lower than that of the control group while no statistically significant increase was determined in MPV. These findings may show platelet activation that is not statistically significant in lumbago/sciatica patients.

INTRODUCTION

Lumbago/sciatica is a painful disease that generally develops in the region between the ribs and the hip bones.[1] Modern-day conditions of a more sedentary lifestyle have increased the possibility of this disease being seen. The muscles of a person without sufficient movement show weakness and the person may lose strength. Thus, the spine is weakened and causes the development of lumbago/sciatica, which has negative effects on total well-being in physical, mental and social aspects, leading to deterioration in the general health status. It is a significant health problem that may be seen in all societies and affects all age groups.[23]

Sciatica is a pain within the sciatic nerve distribution that radiates downward toward the posterior surface of the hip and leg. Sciatica generally forms associated with pressure on L4, 5, S1, 2, 3 from the lumbar nerve roots or from the sciatic nerve itself remaining under pressure. Males are affected more than females and usually between the ages of 40 and 50 years. There is evidence that the complex interaction related to inflammatory and immunological processes with pressure could be effective in the development of sciatica. It must be kept in mind that herniated nucleus pulposus is not the only cause of sciatica. Nevertheless, the vast majority of sciatica cases is self-limiting and tends to recover within a few months. In some cases, it may become chronic, and treatment may be difficult.[45] The pathophysiology of lumbago/sciatica is multifactorial and an increase in intradiscal pressure plays a key role in development. Although the factors increasing intradiscal pressure are not fully known, clinical experience suggests that anatomic compression and/or inflammation are the possible mechanisms of increased pressure. By directly damaging the sciatic nerve, lumbago/sciatica can cause axonal damage and can lead to sciatic nerve ischemia by forming pressure on the vessels in the perineum.

Many studies in the literature have accepted the mean platelet volume (MPV)[67] and neutrophil to lymphocyte ratio[8] as indicators of inflammation. MPV is a parameter of the routine blood count overlooked by many clinicians.[9] MPV is a marker of platelet function and activation.[101112] In the active disease phases of rheumatoid arthritis and ankylosing spondylitis patients, the MPV value is low and has been shown to increase with anti-inflammatory treatment.[13] The MPV value has been shown to be high in psoriasis patients compared to a control group, and a positive correlation has been determined between MPV and the Psoriasis Area Severity Index (PASI) score.[14] In osteoarthritis patients with active synovitis, the MPV value has been revealed to be significantly low compared to a control group.[15] Although MPV levels have been shown to be predictive in several chronic inflammatory diseases, it has not been previously examined in patients with lumbago/sciatica, which is accepted as a chronic inflammatory disease. Therefore, there could be a relationship between increased intradiscal pressure and inflammation in lumbago/sciatica and MPV as a marker of inflammation. To the best of our knowledge, there has been no previous study in the literature showing this relationship.

Therefore, the aim of this study was to investigate the presence of a relationship between MPV and lumbago/sciatica.

PATIENTS AND METHODS

Procedure

A retrospective evaluation was made of the records of patients diagnosed with lumbago/sciatica in the Pain Clinic of Diyarbakir State Hospital. The ethical approval was taken Local Ethical Committee from Diyarbakir State Hospital. Patients with any chronic disease other than lumbago/sciatica were excluded from the study, and 151 patients were included for evaluation. A control group was formed of 80 age- and gender-matched healthy volunteers with no lower back pain. Patients with a chronic disease, ischemic risk factor, hematological disease, or history of the liver or kidney disease were excluded from the study. Blood samples were taken from all the participants in both groups. For the automatic full blood count of the samples in the study, tubes-containing ethylenediamine tetraacetic acid was used. Full blood count measurements were made using an automatic blood analyzer.

Statistical analysis

The whole data was analyzed by the Statistical Package for the Social Sciences (SPSS) version 16 (SPSS Inc., Chicago, IL, USA). The results were calculated as the mean ± standard deviation. The MPV and platelet count values were compared between the patient and control groups using the Student's t-test. A value of P < 0.05 was considered as statistically significant.

RESULTS

The study included 151 patients (79 females, 72 males, mean age 43.1 ± 12.9 years) diagnosed with lumbago/sciatica and a control group of 80 healthy individuals (40 females, 40 males, mean age 42.4 ± 12.5 years) who presented at the blood bank. No statistically significant difference was determined between the groups in respect of age and gender (P < 0.05) [Table 1].

Table 1

Demographic data of patients

No statistically significant difference was determined in the MPV of the lumbago/sciatica patients (9.76 ± 1.09 fL) compared with the control group (9.56 ± 0.92 fL) (P = 0.34) [Table 2]. The platelet level of lumbago/sciatica patients (263.3 ± 68.7 103/mL) was determined to be statistically significantly lower than that of the control group (277.27 ± 70.7 103/mL) (P = 0.02) [Table 2 and Figures 1, 2].

Table 2

Mean platelet volume and platelet counts of patient and control group

Figure 1

The distribution of mean platelet volume between patient and control groups

Figure 2

The distribution of platelet count between patient and control groups

DISCUSSION

A literature scan using PubMed and Google Scholar search engines with the keywords of lumbago/sciatica and MPV yielded no study which has researched the relationship between the two. In the current study, whereas the platelet count of lumbago/sciatica patients was found to be low compared to the control group, no statistically significant increase was determined in the MPV.

MPV is a blood component measured as a part of blood count. MPV score indicates the size of mean blood platelet in the body. The score of MPV which is normally high can be an indicator of medical diseases such as immune thrombocytopenic purpura and Bernard Soulier. The highness of MPV count can cause the problems of blood coagulation. In different studies having been done, MPV has increased in acute myocardial infarction, acute ischaemic stroke, preeclampsia, renal artery stenosis, type 2 diabetes mellitus, and smokers. The highness of MPV can be a poor indicator following myocardial infarction, restenosis following coronary angioplasty, and the development of preeclampsia.[16] Besides, in the study done by Coban et al., it has been determined that MPV is high in obesity compared with nonobesities.[17]

The possible reasons for MPV highness in lumbago/sciatica patients can be due to the decrease of platelet count or the increase of platelet activity. These findings show that there could be platelet activation but not of significant importance in lumbago/sciatica patients. MPV is an important indicator of platelet activation which has a significant role in the pathophysiology of the atherothrombotic process. Large platelets contain more dense granules than small platelets and have greater thrombotic potential as they are more active enzymatically and metabolically. In large platelets, there are more prothrombotic components such as thromboxane A2.[1819] In conditions where MPV is increased, there is a tendency for a decrease in the platelet count[20] Therefore, because of increased bone marrow aggregation, there could be increased platelet production or increased platelet consumption.[13] The low platelet count of lumbago/sciatica patients in the current study could show that large platelets were more evident in lumbago/sciatica patients with a nonsignificant MPV level.

Recent studies have shown that platelets have a role in inflammation, angiogenesis, thrombosis, and immunity.[132122] Various studies have investigated the association of the MPV value to inflammation. Smyth et al. reported that a low MPV value was related to inflammation, but it increased with anti-inflammatory treatment.[23] Koçer et al. determined that the MPV value was high in Parkinson's disease patients but in those with the advanced disease it was lower, and this was attributed to inflammation in advanced disease.[24] In contrast to those findings, Canpolat et al. determined that the MPV value was higher in patients with psoriasis and arthritis compared to patients with psoriasis and no arthritis and a significant positive correlation was determined between MPV and PASI and the disease duration. On the basis of these findings, it was reported that platelets could have a role in the pathogenesis of psoriasis.[6] Furthermore, in case-control study of the Subacromial Impingement Syndrome (SSS) patients, Çalık et al. have stated that MPV is low at SSS group compared with control group and there has not been statistically logical relationship.[25]

Measurement of MPV is a simple, inexpensive, widely available investigation that does not require a specialist for interpretation. Millions of complete blood counts are ordered annually, and MPV is reported routinely as part of this. However, MPV has received little attention and our results suggest that MPV might be a novel, yet simple marker of coronary artery disease (CAD). As at the review examining the relationship CAD with MPV, we assume that this relationship can also be used in lumbago/sciatica patients.[16] However before such an indicator is used, risk classification should be done for lumbago/sciatica by these risk prediction models with MPV and without MPV according to the area under receiver operator characteristic curve.

There were some limitations to the current study. First, as it was retrospective, no clinical evaluation could be made of the patients in the acute period. Therefore, provocative tests and symptoms could not be evaluated. Furthermore, as the study was retrospective, the hospital information management system was limited in respect of factors such as obesity which could affect the development of lumbago/sciatica. Another limitation of the study was the small number of patients and if a comparison of other inflammatory laboratory tests had been added, it could have increased the power of the results. The platelet count of lumbago/sciatica patients was found to be lower than that of the control group, and no statistically significant increase was determined in MPV. A decrease in platelet count could be associated with an increase in platelet activity and combined platelets.

CONCLUSION

In the studies done recently, MPV, which is thought to be a possibly inflammatory indicator and also can be acquired cheaply, easily and fastly, accurately has been examined whether it has a relationship with various chronic inflammatory or not, but it has not been determined a relationship. Moreover, we have not statistically determined a meaningful relationship with lumbago/sciatica and MPV. There is a need for prospective studies to be provided with multicenter wide attendance.

Financial support and sponsorship

Nil.

Conflicts of interest

There are no conflicts of interest.