Association of Neutrophil/Lymphocyte (N/L) Ratio and Spatial and Verbal Memory in Females

 

Sahithi Alaghari¹, Kumar Sai Sailesh^2*

¹Second Year BDS Student, Vishnu Dental College, Vishnupur, Bhimavaram, West Godavari

District, Andhra Pradesh, India.

²Assistant Professor and HOD (I/C), Department of Physiology, Vishnu Dental College, Vishnupur, Bhimavaram, West Godavari District, Andhra Pradesh, India.

 

ABSTRACT:

Increase in the ratio of the neutrophils to lymphocytes (N/L ratio) was considered as a predictor for not only the inflammation but also the cognitive disorders like Alzheimer’s disease. Further, the ratio also reported as outcome measure in the treatment of cancer, heart diseases. It was reported that there was negative correlation between the N/L ratio with cognitive functions. The present study was undertaken to observe the association between the neutrophil/lymphocyte ratio and memory in females. 30 healthy females with in the age group of 18-24, who were willing to participate, were included in the study after obtaining written informed consent. Neutrophil lymphocyte ratio was determined by standard procedures. Memory was assessed by immediate word recall and immediate object recall test. Pearson correlation Data was analyzed by SPSS 20.0. Pearson correlation coefficient was used to observe the correlation between the variables. Weak positive correlation was observed between the N/L ratio and immediate word recall scores (R=0.1685; R² = 0.0284). Weak negative correlation was observed between the N/L ratio and immediate object recall scores (R=-0.0684; R²=0.0047). There was positive correlation between the N/L ratio and immediate word recall whereas negative correlation was observed between N/L ratio and immediate object recall. We recommend further detailed studies with larger sample size to investigate the role of the N/L ratio as predictor of cognitive decline.

 

 

 

INTRODUCTION:

Neutrophils belong to the class of granulocytes of white blood cells whereas lymphocytes are agranulocytes. Neutrophils play a major role in first line defense mechanism where they phagocytize the foreign cell and protect the body. Lymphocytes have two classes called B lymphocytes and T lymphocytes based on their maturation process. Both play a major role in immunity. In the hospital setting the ratio of neutrophil and lymphocytes used for evaluation of the inflammation and it predict the morbidity and mortality.

 

 

Increase in the ratio of the neutrophils to lymphocytes (N/L ratio) was considered as a predictor for not only the inflammation but also the cognitive disorders like Alzheimer’s disease^1-4. Further, the ratio also reported as outcome measure in the treatment of cancer, heart diseases^5-6. It was reported that there was negative correlation between the N/L ratio with cognitive functions that was analyzed using Stroop interference scores^7,8. Higher N/L ratio was observed in patients with Alzheimer’s disease when compared with the healthy individuals^9,10. In contrast another study was reported that there was no correlation between the cognitive functions and N/L ratio in diabetic population¹¹. However, the studies on association of N/L ratio and cognition in healthy population are sparse. Hence, the present study was undertaken to observe the association between the neutrophil/lymphocyte ratio and memory in females.

METHODOLOGY:

Study design:

Cross-sectional study

 

Study setting:

The present study was conducted at Department of Physiology, Vishnu Dental College, Bhimavaram, Andhra Pradesh, India.

 

Participants:

A total of 30 female participants with in the age group of 18-24 were part of the study after obtaining the written informed consent. Apparently healthy, willing participants were included in the study. Those with any diseases or under any treatment or therapy were excluded from the study. All the parameters were collected simultaneously in the physiology research lab in between 10 am to 11 am as per the convenience of the participants.

 

Neutrophil/Lymphocyte ratio:

Neutrophil and lymphocyte count was obtained through the differential leukocyte count. Manual method was used in the study as mentioned in the literature. The dye used is Leishman’s stain⁸.

 

Assessment of memory:

Verbal memory: Immediate word recall test was used to assess verbal memory. 20 four letter words like tape, call, lead etc. were displayed to the participants at a constant rate of one word for two seconds. Then the participants were asked to recall the words and write the same on a white paper within 60 seconds. Correct word was given a score of ‘1’ and wrong word was given a score of ‘0’. Total score was tabulated for applying statistics^9,10.

 

Spatial memory:

Immediate object recall was used to assess spatial memory. 20 familiar objects like watch, mobile etc. were arranged on a table. 15 seconds time was given to the participants to observe those objects. Then the participants were asked to recall the names of the objects and write the same on a white paper within 60 seconds. Correct word was given a score of ‘1’ and wrong word was given a score of ‘0’. The total score was tabulated to apply statistics^9.10.

 

Ethical Consideration:

The present study was approved by institutional research committee of Vishnu Dental College, Bhimavaram.

 

Data analysis:

Data was analyzed using SPSS 20.0. Pearson correlation coefficient was used to observe the correlation between the variables. Data was presented as mean and SEM.

RESULTS:

The value of R for N/L ratio and verbal memory is 0.1685. It indicates a weak a positive correlation. The value of R², the coefficient of determination, is 0.0284 (table no 1). The value of R for N/L ratio and spatial memory is-0.0684. It indicates a weak negative correlation. The value of R², the coefficient of determination, is 0.0047 (table no 2).

 

Table no 1: Association of neutrophil/lymphocyte (N/L) ratio and verbal memory in females. (Data was presented as Mean and SEM).

Parameter	Mean ±SEM	R	R2
N/L ratio	1.92±0.078	0.1685	0.0284
Immediate word recall score	12.16±0.52

 

Table no 2: Association of neutrophil/lymphocyte (N/L) ratio and spatial memory in females. (Data was presented as Mean and SEM).

Parameter	Mean ±SEM	R	R2
N/L ratio	1.92±0.078	-0.0684	0.0047
Immediate object recall score	13.86±0.44

 

DISCUSSION:

Neutrophil and lymphocyte count was a routine hematological test which is relatively cheaper. In recent years, this ratio has been used as a marker for many disease conditions including decline in cognitive functions. The study was undertaken to observe the association of neutrophil/lymphocyte (N/L) ratio and memory in females. Interestingly, we have observed positive correlation between the neutrophil/lymphocyte (N/L) ratio and immediate word recall whereas negative correlation between the neutrophil/lymphocyte (N/L) ratio and immediate object recall. Upon thorough review of literature, it was observed that the studies on relation between neutrophil/lymphocyte (N/L) ratio and cognition in healthy individuals are sparse. Hence, studies are necessary in healthy individuals also to understand the underlying mechanism. Most of the studies address the correlation in diseased conditions. A study conducted by Hadi J. Halazun et al., reported that there was negative correlation between cognitive functions and the neutrophil/lymphocyte (N/L) ratio. They have observed increased neutrophil/lymphocyte (N/L) ratio in the patients with cognitive dysfunction¹². It was reported that the inflammation was related to the impairment of cognitive functions and may leads to disorders like Alzheimer’s disease¹³. This inflammation may be systemic or cerebral¹⁴. In contrast it was reported that there was no correlation between the neutrophil/lymphocyte (N/L) ratio and cognition in diabetic patients¹⁵. However, other studies have reported negative correlation between these parameters in diabetic patients. The difference in results may be due to selection of different age groups of participants^16,17. In the present study we have observed negative correlation with object recall but positive correlation with word recall. This different result observed may be due to two possible reasons. The first possible reason may be due to the inclusion of the healthy participants. Whereas, other studies were conducted in different disease conditions. The second possible reason may be due to the age group of the participants. In the present study the age group of the subjects is 18-24. Whereas, in other studies the participants included are adults and elderly population. The process of inflammation is normally a protective mechanism in the body. However, prolonged inflammation may leads to damage of tissues which includes neurons also and hence contributes to cognitive decline. Earlier studies suggested that increase in the infections leads to decrease in the cognitive functions and through activating immune response¹⁸.

 

LIMITATIONS:

Major limitation in the study was less sample size and included only female participants.

 

CONCLUSION:

There was positive correlation between neutrophil/ lymphocyte (N/L) ratio and verbal memory and negative correlation with spatial memory. We recommend further detailed studies in this area to understand the mechanisms underlying.

 

CONFLICT OF INTEREST:

Nil.

 

SOURCE OF FUNDING:

Self.

 

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Accepted on 02.11.2018        © RJPT All right reserved

Research J. Pharm. and Tech 2018; 11(12): 5337-5339.