ORIGINAL RESEARCH


https://doi.org/10.5005/jp-journals-10015-2420
World Journal of Dentistry
Volume 15 | Issue 4 | Year 2024

Analysis of Serum Lactate Dehydrogenase Levels among Tobacco Users with No Oral Lesions: A Cross-sectional Study


Venkatesh V Kulkarni1, Shravani P Parandekar2, Riya S Ranade3, Praveena V Kulkarni4

1–4Department of Oral Pathology and Microbiology, Bharati Vidyapeeth (Deemed to be University) Dental College and Hospital, Pune, Maharashtra, India

Corresponding Author: Praveena V Kulkarni, Department of Oral Pathology and Microbiology, Bharati Vidyapeeth (Deemed to be University) Dental College and Hospital, Pune, Maharashtra, India, Phone: +91 9822343232, e-mail: praveena.kulkarni@bharatividyapeeth.edu

Received: 05 April 2024; Accepted: 06 May 2024; Published on: 17 May 2024

ABSTRACT

Aim: The aim of the study was to evaluate serum lactate dehydrogenase (LDH) levels in tobacco users without oral lesions.

Materials and methods: The study involved a total of 20 subjects, ranging in age from 18 to 60 years, divided into four groups based on tobacco use habits, group I—tobacco chewers, group II—tobacco smokers, group III—individuals who both smoked and chewed tobacco, and group IV (control)—healthy individuals with no history of tobacco use (control group). Participants were selected based on a minimum of 6 months of tobacco use without oral mucosal lesions. Medically compromised patients and those with a history of cancer treatment were excluded from the study. Serum LDH levels were evaluated using a blood sample collected via venipuncture from the antecubital vein. The sample was processed by centrifugation to separate the serum, which was then analyzed for LDH levels within 2 hours of collection. Serum LDH levels across different groups of tobacco users and healthy controls were evaluated and compared using statistical analysis.

Results: The mean serum LDH levels were compared among four groups. The mean LDH levels for each group were group I (tobacco chewers): 198.17 U/L; group II (tobacco smokers): 225.11 U/L; group III (tobacco chewers and smokers): 217.22 U/L, and group IV (control group): 165.69 U/L. Analysis of variance (ANOVA) analysis revealed a significant statistical difference (p < 0.05) among the four groups. The serum LDH levels were higher in tobacco users than in healthy controls. The serum LDH levels were higher in tobacco smokers than in tobacco chewers. The mean LDH levels were significantly greater in group III (tobacco chewers and smokers) compared to the control group (group IV).

Conclusion: The study findings indicated that tobacco use is associated with elevated serum LDH levels with the highest levels observed in individuals who both smoke and chew tobacco.

Clinical significance: This research on LDH levels sought to address the importance of early detection of cancer-related changes at the cellular level in tobacco users to combat the menace of oral cancer. Serum LDH levels can also be used to motivate tobacco users to quit their tobacco habit.

How to cite this article: Kulkarni VV, Parandekar SP, Ranade RS, et al. Analysis of Serum Lactate Dehydrogenase Levels among Tobacco Users with No Oral Lesions: A Cross-sectional Study. World J Dent 2024;15(4):298–302.

Source of support: Nil

Conflict of interest: None

Keywords: Lactate dehydrogenase, Oral cancer, Serum lactate dehydrogenase, Smoking, Tobacco

INTRODUCTION

Tobacco use remains a significant global health concern, contributing to a substantial burden of disease and mortality worldwide. According to recent statistics from the World Health Organization (WHO), tobacco kills >8 million people each year.1 The number of annual deaths can be expected to keep growing, because tobacco kills its users.2 Tobacco use increases the risk of cancers of the head and neck including oral cavity.3

Evidence indicates that an unacceptable percentage of oral carcinomas are diagnosed late, which necessarily leads to high mortality. A primary objective to be achieved in the management of oral cancer, with clear repercussions on its prognosis, is its early diagnosis.4 Despite the progress in research and therapy, survival rate of oral cancer has not improved significantly in the last few decades. The search for prognostic markers represents a continuing challenge for biomedical science.5 Identification of molecular markers may be effective for early detection of cancer, but they can be expensive and require specialized equipment and expertise. In rural areas where resources may be limited, it becomes crucial to consider alternative techniques that are more feasible and cost-effective.6

A better understanding of the cellular and molecular changes during the earliest stages of preneoplastic development would help to elucidate the mechanisms mediating the transition from normal healthy somatic cell to abnormal tumor development, which is still an outstanding question in cancer biology.7 Molecular reprogramming in the tumor microenvironment helps cancer cells to fulfill elevated metabolic demands. One of the ways through which cancer cell achieve this is by regulating the expression of metabolic enzymes. Lactate dehydrogenase (LDH) is the primary metabolic enzyme that plays a significant role in regulating nutrient exchange between tumor and stroma.8 Understanding the tissue damage induced by tobacco use is crucial for tackling the menace of oral cancer. However, limited research has explored the relationship between serum LDH levels and tobacco use in individuals without oral lesions, representing a notable gap in the existing literature.

Therefore, to address the issue of early detection and prevention of tobacco-related oral cancers, the present study aimed to evaluate serum LDH levels in tobacco users who do not exhibit oral lesions.

MATERIALS AND METHODS

This cross-sectional study was approved by the Institutional Ethics Committee and conducted at Bharati Vidyapeeth (Deemed to be University) Dental College and Hospital, Pune, India, between February and July 2023. The study involved 20 subjects with an age range of 18–60 years. Healthy individuals with no history of tobacco use were included in the control group. Subjects who had been using tobacco for a minimum of 6 months without oral mucosal lesion were included in the study. Patients with history of cancer treatment and medically compromised patients were excluded from the study. The written informed consent was obtained from each participant. Demographic data, medical history, tobacco habit history, and clinical details were recorded. They were grouped according to habit of tobacco as follows:

About 5 mL blood was collected from antecubital vein under all aseptic precautions in a plain bulb. Then the sample was centrifuged at 2000 rpm for 10 minutes and serum was separated.9 The serum sample was then sent to Dhande Pathlab Diagnostics Pvt., Ltd., Pune, within 2 hours. Beckman Coulter Kit Sr. No. 2012021185 Machine-AU480 was used for serum LDH estimation (Fig. 1). The data were then entered into the Microsoft Excel spreadsheet and compared with the human serum level of LDH in healthy individuals which is below 200 U/L.

Fig. 1: Beckman Coulter Kit Sr. No. 2012021185 Machine-AU480 (Courtesy: Dhande Pathlab Diagnostics Pvt., Ltd., Pune)

Statistical Analysis

Statistical analysis was performed using the Statistical Package for the Social Sciences (SPSS) version 16 for Windows (SPSS Inc., Chicago, Illinois, United States). Descriptive quantitative data were expressed in mean and standard deviation, respectively. Overall comparison among four groups in respect to the mean serum LDH level was done using the analysis of variance (ANOVA) test. An intergroup pairwise comparison between groups was done using the Tukey’s post hoc test. The confidence interval was set at 95% and the probability of α error was set at 5%. The power of the study was set at 80%.

RESULTS

According to habit of tobacco, participants were grouped as follows:

The mean serum LDH levels in tobacco chewers (group I), tobacco smokers (group II), individuals smoking as well as chewing tobacco (group III), and control group (group IV) were found to be 198.17 U/L (29.0), 225.11 U/L (21.29), 217.22 U/L (32.02), and 165.69 U/L (4.58), respectively (Table 1).

Table 1: Descriptive statistics of serum LDH levels in tobacco chewers (group I), tobacco smokers (group II), tobacco chewers and smokers (group III), and control group (group IV), respectively
Groups Mean SD SE Minimum Maximum
Group I (tobacco chewers) 198.17 U/L 29.00 12.97 165.23 U/L 236.21 U/L
Group II (tobacco smokers) 225.11 U/L 31.29 13.99 197.46 U/L 273.74 U/L
Group III (tobacco chewers and smokers) 217.22 U/L 32.02 14.32 180.67 U/L 249.90 U/L
Group IV (control group) 165.69 U/L 4.58 2.04 160.38 U/L 171.30 U/L

SD, standard deviation; SE, standard error

On comparison of mean serum LDH levels among four groups using ANOVA F-test, it was found that there exists a significant statistical difference (p < 0.05) among the four groups (Table 2 and Fig. 2).

Table 2: Comparison of serum LDH levels in tobacco chewers (group I), tobacco smokers (group II), tobacco chewers and smokers (group III), and control group (group IV), respectively using ANOVA F-test
Groups Mean SD ANOVA F-test Significance (p)
Group I (tobacco chewers) 198.17 U/L 29.00 F = 4.877 *p = 0.014, statistically significant difference
Group II (tobacco smokers) 225.11 U/L 31.29
Group III (tobacco chewers and smokers) 217.22 U/L 32.02
Group IV (control group) 165.69 U/L 4.58

p > 0.05, not significant; *p < 0.05, significant difference

Fig. 2: Serum LDH levels

The mean serum LDH levels were statistically significantly greater (p < 0.05) in group III (tobacco chewers and smokers) compared to group IV (control group), whereas in other pairwise comparison, there was no statistically significant difference found (p > 0.05) (Table 3 and Fig. 3).

Table 3: Intergroup comparison of serum LDH levels between tobacco chewers (group I), tobacco smokers (group II), tobacco chewers and smokers (group III), and control group (group IV), respectively, using Tukey’s post hoc test
Group Comparison group Mean difference Significance (p)
Group I (tobacco chewers) Group II (tobacco smokers) 26.93 U/L 0.411
Group III (tobacco chewers and smokers) 19.05 U/L 0.680
Group IV (control group) 32.47 U/L 0.260
Group II (tobacco smokers) Group III (tobacco chewers and smokers) 7.88 U/L 0.965
Group IV (control group) 59.41 U/L 0.014*
Group III (tobacco chewers and smokers) Group IV (control group) 51.52 U/L 0.035*

p > 0.05, not significant, *p < 0.05, significant difference

Fig. 3: Intergroup comparison—LDH level

The study aimed to assess serum LDH levels in tobacco users without oral lesions, highlighting potential associations between LDH levels and tobacco use. Results revealed elevated serum LDH levels in tobacco users compared to healthy controls, with the highest levels observed in individuals who both smoked and chewed tobacco. These findings suggest a link between tobacco use and increased LDH levels, indicative of cancer-related changes at the cellular level even in the absence of clinical oral lesions.

DISCUSSION

Tobacco is the only legal product that kills a considerable proportion of its consumers when used as intended by its manufacturers. The WHO has estimated that the number of tobacco-related deaths is projected to increase if strong tobacco control measures are not taken.10 Cancer due to tobacco can be prevented if cancer-related changes at cellular level are diagnosed early in tobacco users.

One of the key features of cancer cells is the demand for their glucose uptake accompanied by an increase in glycolytic energy metabolism. The dramatic increase of glycolysis in cancer cells lead to a significant production of pyruvate, in contrast to the typical aerobic metabolic process found in healthy cells. This surplus pyruvate is converted into lactate within the cytoplasm by cancer cells that heavily rely on the presence of a substantial amount of LDH. This explains why serum LDH is often elevated in cancer patients.11

The level of LDH in human serum from healthy individuals is below 200 U/L. Serum LDH levels may have a diagnostic importance in oncological diseases because they are associated with the cancer cell and tissue damage induced by tumor burden.12

In addition to cancer, elevated LDH levels in the bloodstream can be attributed to conditions such as liver disease, anemia, and heart attacks.13 Hence, medically compromised patients were not included in the study to maintain its focus.

The LDH studies so far focused on patients with malignancies or premalignant conditions. However, the study is the first of its kind to investigate serum LDH levels in individuals who use tobacco but do not exhibit oral lesions. Serum LDH levels were evaluated and compared in four groups—tobacco chewers, tobacco smokers, those who both smoke and chew tobacco, and a control group of healthy individuals. The results obtained from the study revealed that the serum LDH levels were elevated in tobacco users compared to the healthy individuals (control group) and were also higher in tobacco smokers compared to tobacco chewers. Furthermore, individuals who both smoked and chewed tobacco exhibited significantly higher serum LDH levels than the healthy control group, although their levels were at par with those observed in tobacco smokers. The findings of the study suggest that any form of tobacco consumption results in elevated serum LDH levels, signaling oral cancer-related changes at cellular level, even in the absence of oral lesions clinically.

Chari et al. estimated the serum LDH in patients with oral lesions due to the consumption of smokeless tobacco. They concluded that there is a statistically significant increase in the chances of developing a potentially malignant lesion on the consumption of smokeless tobacco since serum LDH values were increased in patients with the habit of chewing smokeless tobacco. In the present study, serum LDH levels were estimated in tobacco users without oral lesions.14

Javaraiah et al. correlated the level of salivary LDH in healthy individuals with tobacco users (with or without oral potentially malignant disorders) and arrived at the conclusion that LDH can potentially be used as a promising biomarker in the very early stages of progression toward oral cancer caused by tobacco use.15

According to Gholizadeh et al., serum LDH is more reliable than salivary LDH and employing LDH as a molecular marker in a blood test particularly suitable for routine screening and early detection efforts of cancer.16 Measuring LDH levels in saliva also require specialized technique and, hence, expensive. Additionally, the equipment and expertise needed for such analysis add to the overall cost, making it less accessible, particularly in rural areas with scarce resources. In contrast, the evaluation of serum LDH level is a simple, cost-effective, and reliable technique. This is especially useful in rural areas, where access to specialized test may be limited or unavailable.

Mishra et al. correlated serum LDH directly with frequency of the habit and mouth opening in oral submucous fibrosis patients and concluded that serum LDH is a better biological marker than salivary LDH.17

According to Sudha et al., serum LDH can play a dual role as a reliable indicator of the degree of oral squamous cell carcinoma for decision-making in treatment modalities and as a prognostic marker of response to therapy.18

Thus, the findings of the study indicated that serum LDH can serve as a molecular marker for the early detection of cancer-related changes in the tobacco-consuming population who do not exhibit oral lesions. A small sample size was the limitation of this study. Hence, the generalizability of the results is limited. Future research with larger samples and using a longitudinal design would be needed to contribute to the development of effective tobacco control measures.

CONCLUSION

Through a comprehensive analysis of serum LDH levels in different groups of tobacco users, the study results illustrated the intricate interplay between LDH, tobacco use, and oral cancer risk, thereby informing future strategies for cancer screening and intervention. The primary strategies for preventing oral cancer involve encouraging tobacco cessation and implementing early cancer screening programs. Monitoring serum LDH levels in individuals undergoing tobacco cessation can be valuable avenues for future research.

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