記住我
ORIGINAL ARTICLE
Year : 2023 | Volume
: 12
| Issue : 1 | Page : 38-42
Tuberculosis in elderly population: A cross-sectional comparative study
Varatharajan Sakthivadivel1, Archana Gaur2, Jeganathan Geetha3
1 Department of General Medicine, All India Institute of Medical Sciences, Hyderabad, Telangana, India
2 Department of Physiology, All India Institute of Medical Sciences, Hyderabad, Telangana, India
3 Department of General Medicine, Karpaga Vinayaga Institute of Medical Sciences and Research Center, Maduranthagam, Tamil Nadu, India
Correspondence Address:
Jeganathan Geetha
Department of General Medicine, Karpaga Vinayaga Institute of Medical Sciences and Research Center, Maduranthagam - 603 306, Tamil Nadu
India
Source of Support: None, Conflict of Interest: None
CheckDOI: 10.4103/ijmy.ijmy_235_22
Background: Tuberculosis (TB) is a common but neglected infectious disease of global significance. It has a varied presentation in the elderly compared to adults. The present study was conceived to study the resemblances and differences shared in terms of clinical profile, comorbidities, and laboratory investigations by TB in adults and the elderly population. Methods: In this cross-sectional study, 68 adults and 72 elderly patients of both genders were enrolled. We collected information on demographics, comorbidities, clinical presentations, and laboratory investigations. The comparison of data between groups was done using the unpaired t-test for continuous variables and the Chi-square test for frequency distribution analysis. Results: The mean age of the adults and elderly population was 42.13 ± 10.7 years and 68.78 ± 7.62 years, respectively. The elderly TB group demonstrated loss of weight, appetite, the prevalence of comorbid conditions (coronary artery disease, hypertension, and malnutrition), bilateral, predominantly lower lobe, and diffuse involvement of lungs. Conclusion: As the elderly population increases, nonspecific clinical manifestations or laboratory results in this population mandate awareness of these atypical features for effective management of TB in this group.
Keywords: Clinical profile, comorbidities, elderly, tuberculosis
Tuberculosis (TB) is a major health issue worldwide.[1] It was assessed that around one-third of the population is affected with Mycobacterium tuberculosis globally.[2] The Government of India defines the geriatric population as over the age of 60 years.[3] The geriatric population in India is growing due to the increasing longevity and decreasing fertility rates.[4] In the old-age population, the presence of multiple comorbidities makes TB a specific concern.
The geriatric population is susceptible to infection due to high risk for reactivation of latent TB and more susceptibility to new infection, increase in mortality rates, and adverse reactions such as hepatotoxicity, cutaneous reactions, and hematological problems.[5],[6],[7],[8] This is due to existing comorbidities, inadequate diet, polypharmacy, immunosenescence, impaired renal and hepatic drugs clearance, living conditions, and inability to access to health-care facilities.[9] This has been confirmed worldwide in 2016 by increase in the notification of TB in geriatric population.[10]
Many countries are now reporting a disproportionate increase in elderly TB compared to the rise in the elderly population.[11],[12],[13] Age- and nutrition-related factors have also been shown to negatively impact treatment outcomes among elderly TB. These could further aggravate the situation by establishing the elderly TB case as a potential source of infection in the community.[14],[15],[16]
In this study, we assessed the demographic profiles, radiological profiles, blood investigations, incidence of comorbidities, and presence of extrapulmonary TB between elderly and adult patients with TB.
MethodsStudy population and design
The present study was a cross-sectional comparative study between elderly and adult patients with TB. The study was carried out in the general medicine department from September 2019 to May 2020. We used nonprobability sampling technique (convenient sampling) to achieve the sample size. We enrolled elderly (n = 72) and adults (n = 68), newly diagnosed with pulmonary TB and/or extrapulmonary TB by appropriate measures as per the Revised National Tuberculosis Control Program criteria. Patients with pregnancy, <18 years of age, and unwilling to participate were excluded from the study.
Patient assessment
All the patients recruited presented with the symptoms of TB. The patient's demographic data, comorbidities, and previous history of antituberculous therapy (ATT) were noted. They were directed to the Mantoux test, sputum smear for acid-fast bacilli (AFB) examination, chest X-ray, and laboratory investigations (hematological and pleural fluid). Fine-needle aspiration cytology/biopsy of the lymph node was done for patients with lymphadenopathy. Bronchoalveolar lavage and sputum immunofluorescence were done in patients with negative sputum AFB results.
Sputum sample collection
As per the revised guidelines of the National Tuberculosis Control Program (India), two sputum samples (morning and spot) were collected from the patients. We used hypertonic saline to induce sputum among patients who reported nil spontaneous sputum production. We used the acid-fast staining of the smear using the Ziehl–Neelsen method of staining. Smears of pink, slightly curved bacilli in clusters or singles, occasionally branching, and a blue background with abundant pus cells and few epithelial cells were considered positive for AFB.[17]
Radiological assessment
Radiological assessment categorized tubercular lesion based on the site of the lesion (unilateral or bilateral) and extent of the lesion. Other presentations such as infiltrates, fibrosis, consolidation, bronchiectasis, and military pattern were noted.
Statistical analysis
Categorical data were expressed as frequency (percentage) and compared using the Chi-square test. Continuous data were expressed as mean ± standard deviation and compared using the unpaired Student's t-test. P < 0.05 was considered statistically significant.
ResultsThe mean age of adults was 42.13 years, and the mean age of the elderly population was 68.78 years. The males and farmers are affected more in both the groups. Previous history of antituberculous therapy (ATT) was there in half of the patients in adult group and in one-fifth of the patients in elderly group [Table 1].
Table 1: Gender, occupation, and history of antituberculous therapy between the groupsIn both the groups, maximum numbers of patients were smokers and alcoholics. Majority of the patients were malnourished (36.1%) in elderly group. The elderly group had multiple comorbidities such as diabetes, hypertension, and coronary artery disease (CAD), whereas only diabetes was found to be the most prevalent in adult group [Table 2].
Table 2: Comparison of comorbidities between adult and elderly tueberculosis groupThe most common presenting feature in elderly group was loss of appetite and loss of weight. The adult group had cough and evening rise in temperature as the most common clinical features. The history of dyspnea and anemia was the most common in elderly compared to adult group [Table 3].
The unilateral lesion was common in adults, whereas elderly had both unilateral and bilateral lesions. In adults, the upper lobe involvement was most commonly seen; whereas in elderly, both upper lobes, lower lobes, and diffuse involvement were common. The infiltrative lesions were common in elderly, but the adult group had infiltrative and cavitating lesions [Table 4]. Pleural effusion was the most common extrapulmonary manifestation in both the groups [Table 5]. Most of the hematological parameters were comparable in both the groups, except for hemoglobin, eosinophil, and pleural fluid cell count, which were significantly lower in elderly population compared to adults [Table 6].
Table 4: Comparison of radiological profile of pulmonary tuberculosis between adult and elderly tueberculosis groups
Table 5: Distribution of extrapulmonary tuberculosis between adult and elderly tuberculosis groups
Table 6: Comparison of hematological and microbiological investigations between adult and elderly tuberculosis groupsEthical approval and consent to participate
Ethical approval was obtained from the Institutional Ethics Committee of Karpaga Vinayaga Institute of Medical Sciences and Research Center (KIMS/F/2019/22 dated September 20, 2019). Informed and written consent was obtained from the patients.
DiscussionOur study is the hospital-based cross-sectional comparative study to compare the adult and elderly TB-affected individuals in Southern India. The study groups were evaluated for common symptoms, presence of comorbid conditions, radiographic profiles, and laboratory investigations (hematological, pleural fluid, and sputum examination).
Comparison of demographic profile
Based on demographic profile, in our study, males were affected more than females in both the groups, which could be due to male being the breadwinner of the family, was exposed more, and gets to socialize more than females eventually leading to the transmission of disease. Similar to our study, Lonnroth et al. also found notable prevalence of TB among males.[18] Based on occupation, farmers were common in elderly age group, while farmers and daily wagers were common in adult group. This could be primarily due to the fact that the elderly finds it difficult to go in search of daily jobs. Almost half of the patients in adult group and one-fifth of the elderly had a previous history of antituberculous treatment. Defaulters were common in both the groups.
Comparison of comorbid conditions and risk factors
Alcohol and nicotine have been reported to inhibit the cell-mediated immunity by decreasing the secretion of tumor necrosis factor-alpha production from lung macrophages and thereby increasing the risk to TB.[19],[20],[21] Our study population had a considerable number of smokers and alcoholics in both groups. Malnutrition was more common in elderly age group. This could be due to the direct effect of long-standing TB or due to the adverse effects of drug taken for TB. Further, the prevalence of comorbid conditions such as hypertension and CAD was more in elderly group with TB than adult group with TB. The association between these diseases and TB is yet to be delineated. However, one possible cause could be the aging. As age increases, systolic blood pressure increased due to the thickening of vessel wall that leads to a higher risk for CAD. Increase in the incidence of aspiration and age-associated inflammatory diseases such as chronic obstructive pulmonary disease and pulmonary fibrosis make the elderly more likely to have a pulmonary environment, which favors the susceptibility to infections, including TB infection.[22]
Comparison of symptoms
We observed that loss of weight, loss of appetite, and anemia were more common in elderly age group. This goes hand in hand with our previous observation that malnutrition is more common in elderly age group with TB. Inadvertent weight loss has been documented as a common condition among elderly population, which could be due to “physiological anorexia of aging.”[23] Cough was reported more in adults; however, dyspnea was more common in elderly age group.[7] Dyspnea can be due to the malnourished respiratory muscles in the elderly. Other symptoms such as evening rise of temperature and hemoptysis were comparable between the groups.
Comparison of radiological profile
We observed that unilateral involvement is common in adults than bilateral involvement; while in elderly age group, we can see both unilateral and bilateral involvement almost equally. Upper lobe involvement (71.2%) was more common in adult age group compared to the elderly. In elderly group, TB was involving lower lobe (30.5%) and diffusely (20.3%) as compared to the adult. Aging can alter the protective barriers, interfere with microbial clearance, and cause an impaired immune response to M. tuberculosis. This causes an interruption of the healing mechanism.[24],[25] This could have led to the involvement of all zones (diffuse involvement and bilateral involvement) as evidenced by the radiological profile in elderly group. Infiltrates (47.5%) and cavity (38.9%) were the common pattern of involvement in adult age group compared to elderly (16.9%). Infiltrate type (64.5%) was the predominant form of TB seen in elderly age group compared to the adult group. The presence of cavitating lesion is due to secretion of proteases from monocytes and neutrophils causing cell recruitment and tissue damage an indirect evidence of good immunity compared to the elderly.[26]
The proportion of extrapulmonary TB was similar in both adult and elderly groups in our study group. Pleural effusion was the most common extrapulmonary manifestation in both the groups. Similar results were observed by Meira et al.[27] In contrast to our study, Mengesha D et al. reported a less number of extrapulmonary TB in elderly population.[28]
Comparison of laboratory investigations
Hemoglobin levels were less in elderly age group. This goes in line with the malnutrition, loss of appetite, and loss of weight seen in this group. There was no significant mean difference in leukocyte count between adult TB and elderly group. This finding of our study corroborates with Chand et al. and Lee et al.[29],[30] However, pleural fluid cell count was significantly less in elderly age group. Cell-mediated immunity could have been compromised in elderly age group and the reason for the above observations. The compromised immune system of elderly might be the reason for these atypical presentations in elderly. Pleural fluid sugar values are significantly less in elderly age group.
It has been previously reported that the TB presentation among TB in elderly may vary from young TB patients, and it has to be considered a different entity.[7],[9] Observation from our study has shown that the difference in presentation between adult and elderly population could be due to the age-mediated decrease in cell-mediated immunity and malnutrition.
ConclusionTB in elderly presented with loss of appetite, loss of weight, and dyspnea rather than cough, and elderly were malnourished. They showed a lower lobe and diffuse involvement in contrast to the upper lobe involvement in adults. The jeopardized immune system may be responsible for these atypical presentations. A clinician has to be vigilant to look for these symptoms for timely management.
Limitation
Being a hospital-based cross-sectional study, causal effect could not be assessed. A population-based prospective study needs to be carried out to know the entire disease spectrum and to establish a cause-effect relationship.
Financial support and sponsorship
Nil.
Conflicts of interest
There are no conflicts of interest.
References
留言 (0)