A common cause of recurrent vertigo which was characterized by perception of movement of the surrounding objects with brief attacks is Benign paroxysmal position vertigo (BPPV) [1]. BPPV was the common cause of recurrent vertigo. After sudden head movements and canalolithiasis of the posterior semicircular canal, vertigo attacks occurs. The quality of life with reduced daily living activities is impacted by BPPV and morbidity and medical costs are increased and also impairs psychosocial functioning [2]. In elderly patients, the BPPV incidence is significantly higher, but it occurs in any age. BPPV was experienced by approximately 9-11% of patients over 70 years. It is of high importance that the risk factors of BPPV is to be known because of its high incidence. In general practise, some atypical cases are misdiagnosed. Risk of falls and high morbidity are associated with unrecognised diagnosis [3]. The etiological factors in BPPV are inflammation and traumas in the neck or head. Additionally, stress related inflammation might be caused by vertigo associated anxiety. From the blood samples, inflammatory biomarkers show association with the diagnosis of BPPV [4]. High sensitive C-reactive protein (hsCRP) and erythrocyte sedimentation rate (ESR) are the most widely used inflammatory markers in current clinical practice [5]. In patients with neurological diseases, neutrophil to lymphocyte ratio (NLR) and platelet to lymphocyte ratio (PLR) are novel inflammatory biomarkers which are calculated from white blood cell count. Inflammation is associated with increased monocyte count and decreased levels of HDL cholesterol (HDL-C). A new inflammatory biomarker is monocyte to HDL-C ratio (MHR). In various diseases, high bilirubin levels were related with anti-inflammation and anti-oxidation. In patients with coronary artery disease, kidney failure, pulmonary embolism, chronic obstructive pulmonary disease and migraine, lower bilirubin concentrations were detected. Worse prognosis of inflammatory bowel disease is associated with higher mean platelet volume (MPV). This study evaluates the hsCRP, ESR, NLR, PLR, MHR and bilirubin levels in BPPV patients and compare with levels in healthy subjects.

This study which was conducted for a period of one year from January 2017 to January 2018,

The continuous variables were described as mean ± standard deviation. The categorical variables were presented in terms of their frequencies and proportions. For comparison of means between the groups, independent t-test was used. For comparison of ratios, Mann-Whitney U test was used.

This study was approved by institutional ethics committee. An informed written consent was collected from all the patients.

Table-1: Demographic characteristics of patients.

Table 1 showed that the patients were aged between 15 and 75 years. Females were higher than males in both the groups. 10 (11.1%) patients were smoking in control group and 30 (33.3%) patients were smoking in patient group. Smoking rate was higher in-patient group when compared to the control group. Alcohol consumption was 0% in control group and 2.2% in patient group.

Table-2: Clinical characteristics of patients.

In multivariate model, there was significant difference in patient group for serum creatinine, SGOT, fT4, MPV, total bilirubin, indirect bilirubin. (p=0.001, p=0.021, p=0.000, p=0.011, p=0.015, p=0.004) respectively.

In the present study, the preliminary results showed that pathogenesis of BPPV is connected to inflammation. Compared to healthy volunteers, NLR, PLR, MPV and ESR were significantly higher and bilirubin levels were lower in BPPV patients. In elderly and in women, incidence of BPPV is higher. In the present study, BPPV was higher in women. The most common cause of BPPV is infection, trauma, ear operations, ototoxicity, in majority of patients, it was idiopathic in the present study.

It has been reported that the median duration of an episode of BPPV is around 2 weeks as per the study by Von Brevern M et al [1]. They also found these patients to have significant positive association with hypertension, dyslipidemia and stroke. The present study excluded patients with coexisting metabolic illness such as Diabetes, hypertension and dyslipidemia. This study was the first to investigate NLR exclusively in BPPV patients. Role of NLR as a biomarker in inflammatory conditions such as autoimmune diseases, Diabetes and malignancies has been evaluated before. However, underlying inflammation during an acute attack of BPPV has not been previously evaluated.

In a study conducted by Tekesin A et al it was reported that the laboratory investigations conducted included serum hemogram, full biochemistry profiles, vitamin levels, thyroid hormone profiles, high sensitivity C-reactive protein (hsCRP) and erythrocyte sedimentation rate (ESR) [6]. Neutrophil-to-lymphocyte ratio (NLR), platelet-to-lymphocyte ratio (PLR), and monocyte to HDL-cholesterol ratio (MHR) values were calculated and compared between the patients and healthy subjects. The mean age was 39.1±12.4 years for patients, and 37.0±11.9 for controls.

Vitamin B12, hematocrit (Hct), creatinine, urea, and fT4 values, lymphocyte, total bilirubin, direct bilirubin and indirect bilirubin levels were significantly lower in BPPV patients (p ˂ 0.05), while HDL, SGOT, and ESR values were significantly higher. In the BPPV patients the mean NLR, PLR, and mean platelet volume (MPV) values were significantly higher than in the control subjects.

Albumin and SUA values were independently associated with BPPV in multiple logistic regression models (P < 0.05 and P < 0.001, respectively) [10]. A cutoff value of 4 for SUA level with a sensitivity of 0.72 (0.58-0.84) and a specificity of 0.60 (0.43-0.75) was obtained in the receiver operating characteristic analyses. There was a significant decrement in SUA level 1 month after the vertigo attack compared with the values obtained during the attack (P < 0.001). Among the most involved type of BPPV (PSC BPPV), the right side was affected in 26 patients (57.8%) and the left side in 19 patients (42.2%). SUA levels did not differ statistically in patients with PSC BPPV for either the right or left sides (P > 0.05) [11,12].

According to Sahin C et al the NLR in patients of peripheral vertigo was elevated during admissions and it declined at the time of discharge [13]. The mean NLR baseline in healthy adults in China was 1.5 ± 0.05 and a study from Chennai, India reported NLR of 1.5 ± 0.41 among healthy non-diabetic individuals [14,15]. The median absolute neutrophil and absolute lymphocyte counts were 4742.08 ± 1853.7, 1767.06 ± 821.4 respectively, and the median (Inter Quartile Range) of NLR was 2.3 (1.5,4.2). Thus, this could possibly explain an underlying inflammation in patients with BPPV in the present study population. Intense research is very much needed with comparison to control groups in order to derive evidences for the exact link of BPPV with elevated NLR.

Studies have reported high NLR values, indicating increased mortality rates in colorectal, hepatocellular, gastric, and endocrine malignancies [11,12,13,14]. Liu et al. compared the outcomes in 159 patients with malignant thyroid nodules and 318 patients with benign nodules and reported a correlation between high preoperative NLR values and the tumor size and prognosis [15]. Many hypotheses have been proposed to explain this situation.

Neutrophilia and/or lymphopenia have been accepted as indicators of increased NLR and inflammation. It has been demonstrated that the cytolytic activities of natural killer cells and lymphocytes have been inhibited with the increase in the neutrophil count and, therefore, neutrophil infiltration into tumor tissue has been accepted as an indicator of poor prognosis [16,17].

Inflammatory cytokines and chemokines, as well as neutrophils, are produced by the tumor cells.