@2024 Afarand., IRAN

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ISSN: 2252-0805    The Horizon of Medical Sciences 2017;23(4):307-310

Background
Tuberculosis is the most common cause of death from single-factor infectious diseases in the world caused by Mycobacterium tuberculosis [1].
Previous Studies
… [2-4]. Leptin, a hormone, plays a key role in absorbing and consuming energy through its effect on appetite and metabolism [5]. … [6-8]. Leptin has been shown to play a role in early and primary immune responses to pulmonary tuberculosis. Therefore, in children with low levels of leptin, cellular immunity is impaired and the incidence of infectious diseases increases [9]. … [10-12].
Aim(s)
The relationship between leptin serum levels and pulmonary tuberculosis is not well known. Many studies have done about the level of plasma leptin before and after the treatment of pulmonary tuberculosis, and the results are anti-controversial [5, 10, 11, 13]. Therefore, the necessity of a more detailed review of the plasma level of leptin and its association with active pulmonary tuberculosis seems reasonable. The aim of this study was to evaluate serum leptin levels in patients with active pulmonary tuberculosis, patients with non-tuberculosis pulmonary infections (acute pneumonia) and normal subjects.
Research type
This cross-sectional study was done on a case-observation basis.
Research society, place and time
This study was done in 2010 among patients with active pulmonary tuberculosis and patients with non-tuberculosis pulmonary infections, hospitalized in Bu-Ali Hospital of Zaheden and healthy people.
Sampling method and number
40 patients with active pulmonary tuberculosis (case group), 40 patients with non-tuberculosis pulmonary infections (control group) and 40 healthy subjects (negative control group) were studied. The case group included patients with active pulmonary tuberculosis and hospitalized in Zahedan Bu-Ali hospital whose diseases had been confirmed with positive smear or fluid resulting from Broncho alveolar or positive culture of these samples. The control group included patients with non-tuberculosis pulmonary infections in the Zahedan Bu-Ali Hospital and the other control group included normal people who had no history of any chronic pulmonary and extra pulmonary disease, and were completely healthy physicians. People with active pulmonary tuberculosis and non-tuberculosis pulmonary infections were excluded from the study if they had any other chronic disease, such as diabetes, cancer, Rheumatic diseases and metabolic disorders (in given history). Normal people who had been selected by convenience sampling method were excluded from the study if they had any chronic disease (mentioned above) or any evidence of pulmonary involvement.
Used devices&materials
For measuring serum leptin, 5ml of blood sample were taken from the subjects. After serum isolation, the serum sample were kept at 20 ° C for further experiments. The variables included BMI, age, sex, and plasma level of leptin. It should be noted that subjects with BMI less than 18, and more than 30 were excluded from the study in all three groups. Serum leptin was measured by a radiation device with 450 nm wavelength using a special kit (Diagnostic Biochem, Canada) with serial number CAN-L-4260 and Version 6.5. Data analysis was done by SPSS 18 software. Normal distribution of data was investigated using the Kolmogorov-Smirnov test and few data were analyzed in one of the three groups using the ANOVA.
Findings by Text
In the normal group, 21 and 19 were female and male; in the group of patients with tuberculosis infection, 18 and 22 were female and male respectively, and in the group of patients with non-tuberculosis infection, the number of each of females and males was 20. The age range in the pulmonary-TB patients, non-TB pulmonary infection patients and normal people were 17-83, 18-99, and 24-51 years respectively. Although the mean BMI in the group of patients with tuberculosis pulmonary and patients with non-tuberculosis pulmonary infection was in the normal range (20-25) and the BMI of normal people was slightly higher than normal range, there was a significant difference between the BMI of the patients with tuberculosis and the normal subjects (p<0.001). There was a significant difference between the mean BMI of the tuberculosis patients and the non-tuberculosis patients, as well as between the mean BMI in the normal group and non-tuberculosis patients (p<0.001). The mean serum leptin levels in normal individuals and those with non-tuberculosis pulmonary infections were statistically significant (p=0.030). Significant difference was observed between serum leptin levels in normal individuals and patients with active pulmonary tuberculosis (p=0.004). Although the mean serum leptin level in the pulmonary tuberculosis group was lower than the group of patients with non-tuberculosis pulmonary infections, this difference was not statistically significant (p=0.556; Table 1).
Main comparison to the similar studies
Yurt et al. in a study on patients with pulmonary TB and patients with pulmonary sarcoidosis and controls found that leptin levels in pulmonary tuberculosis patients were significantly lower than those in other groups [10]. While Zhang et al. in a study on three groups of patients with tuberculosis, diabetes and the control group showed that the level of leptin in patients with TB was significantly higher than the other two groups [5]. Herlina et al. in a study on 13 children with tuberculosis and their comparison with the control group showed that leptin levels decreased significantly in patients. They, also, showed that there was a direct correlation between BMI and leptin levels and concluded that tuberculosis reduces leptin levels and causes emaciation in patients [11]. … [14-18].
Suggestions
In the future, it is suggested that accurate studies take into account all the essential factors affecting serum leptin levels. It is also necessary to further investigate the relationship between serum leptin levels and acute and chronic infections.
Limitations
From the limitations of this study, the relatively small number of cases and control can be mentioned.
Conclusions
Serum leptin levels are lower in patients with active pulmonary tuberculosis and in patients with non-tuberculosis pulmonary patients than in normal people. However, there is no difference between patients with active pulmonary tuberculosis and patients with non-tuberculosis pulmonary infections. Therefore, serum leptin levels are not appropriate marker for the differentiation of active pulmonary tuberculosis from non-tuberculosis pulmonary infection (acute pneumonia).
Acknowledgments
The financial and spiritual support of Zahedan University of Medical Sciences is appreciated. We also appreciate all patients and healthy people who participated in this study.
Conflict of interest
Non-declared
Ethical Permissions
This study was approved by the Ethics Committee of Zahedan University of Medical Sciences and explained to all people how to use the results and voluntarily the right to participate or not to participate in this study. A written consent form was received from patients and control group.
Funding Sources
This article is based on Ph.D. program of infection and tropical diseases with code 360/t approved by Zahedan University of Medical Sciences.

TABLES and CHARTS

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