Effects of diabetes mellitus on the clinical presentation and treatment response in tuberculosis.

BACKGROUND AND OBJECTIVE: With the colliding global epidemics of diabetes mellitus (DM) and tuberculosis (TB), we studied the effects of DM on the presentation of TB and its response to treatment. METHODS: Consecutive TB patients from 2006 to 2010 in a territory-wide treatment programme offering 9-month extended treatment for TB patients with DM were examined and followed up prospectively to assess their treatment response. Successful treatment completers were tracked through the TB registry and death registry for relapse, death or till 31 December 2014, whichever was the earliest. RESULTS: DM was independently associated with more chest symptoms (adjusted OR (AOR): 1.13) and systemic symptoms (AOR: 1.30) but less with other site-specific symptoms (AOR: 0.58) at TB presentation. There was more frequent pulmonary involvement (AOR: 1.69), with more extensive lung lesion (AOR: 1.25), lung cavity (AOR: 2.00) and positive sputum smear (AOR: 1.83) and culture (AOR: 1.38), but no difference in the proportion of retreatment cases or isoniazid and/or rifampicin resistance. After treatment initiation, there was higher overall incidence (AOR: 1.38) of adverse effects (mainly gastrointestinal symptoms, renal impairment and peripheral neuropathy but less fever and skin hypersensitivity reactions), more smear non-conversion (AOR: 1.59) and culture non-conversion (AOR: 1.40) at 2 months, and lower combined cure/treatment completion rate at 12 months (AOR: 0.79), but no difference in the relapse rate after having successfully completed treatment. CONCLUSION: DM adversely affected the clinical presentation and treatment response of TB, but there was no difference in the drug resistance and relapse rates.

Smoking adversely affects treatment response, outcome and relapse in tuberculosis.

The impact of smoking on tuberculosis outcome was evaluated in a territory-wide treatment programme. 16,345 consecutive patients undergoing chemotherapy for active tuberculosis in government chest clinics in Hong Kong from 2001 to 2003 were followed up prospectively for 2 years for treatment outcome and subsequently tracked through the territory-wide tuberculosis notification registry for relapse until the end of 2012. Smoking was associated with more extensive lung disease, lung cavitation and positive sputum smear and culture at the baseline. In both current smokers and ex-smokers, sputum smears and cultures were significantly more likely to remain positive after 2 months of treatment. Both categories of smokers were significantly less likely to achieve cure or treatment completion within 2 years. Overall, 16.7% of unsuccessful treatment outcomes were attributable to smoking, with the key contributor being default in current smokers and death in ex-smokers. Among successful treatment completers, there was a clear gradient (hazard ratios of 1.00, 1.33 and 1.63) of relapse risk from never-smokers to ex-smokers and current smokers, with an overall population attributable risk of 19.4% (current smokers: 12.2%; ex-smokers: 7.2%). Smoking adversely affects baseline disease severity, bacteriological response, treatment outcome and relapse in tuberculosis. Smoking cessation likely reduces relapse and secondary transmission.

Passive smoking and tuberculosis.

BACKGROUND: Increasing evidence has incriminated active smoking as a causal factor for tuberculosis (TB). However, the effect of secondhand tobacco smoke exposure on TB has not been similarly elucidated. METHODS: A cohort of 15 486 female never-smokers aged 65 to 74 years and living with their surviving husband were enrolled at 18 Elderly Health Centers in Hong Kong from 2000 to 2003 and followed up prospectively through linkage with the territory-wide TB notification registry and death registry for TB and death until December 31, 2008, using an identity card number as a unique identifier. The relationship between passive smoking and the development of TB was assessed with adjustment for other baseline characteristics. RESULTS: Passive exposure to secondhand tobacco smoke in the household was independently associated with obstructive lung disease (odds [OR], 1.43; 95% confidence interval [CI], 1.16-1.77) and diabetes mellitus (OR, 1.13; 95% CI, 1.02-1.26) at baseline and with the development of both active TB (hazard ratio [HR], 1.49; 95% CI, 1.01-2.19) and culture-confirmed TB (HR, 1.70; 95% CI, 1.04-2.80) on prospective follow-up after potentially confounding background variables were controlled for. Passive smoking accounted for 13.7% of active TB and for 18.5% of culture-positive TB in this cohort. CONCLUSIONS: Similar to active smoking, passive exposure to secondhand tobacco smoke in the household also predisposes to the development of TB. Increased emphasis should therefore be put on tobacco control in national TB programs.

Diabetic control and risk of tuberculosis: a cohort study.

Diabetes mellitus is associated with tuberculosis. A cohort of 42,116 clients aged 65 years or more, enrolled at 18 Elderly Health Service centers in Hong Kong in 2000, were followed up prospectively through the territory-wide tuberculosis registry for development of tuberculosis from 3 months after enrollment to December 31, 2005, by use of their identity card numbers as unique identifier. The effects of diabetes mellitus and diabetic control on tuberculosis risk were assessed with adjustment for sociodemographic and other background variables. Diabetes mellitus was associated with a modest increase in the risk of active, culture-confirmed, and pulmonary (with or without extrapulmonary involvement) but not extrapulmonary (with or without pulmonary involvement) tuberculosis, with adjusted hazard ratios of 1.77 (95% confidence interval: 1.41, 2.24), 1.91 (95% confidence interval: 1.45, 2.52), 1.89 (95% confidence interval: 1.48, 2.42), and 1.00 (95% confidence interval: 0.54, 1.86), respectively. Diabetic subjects with hemoglobin A1c <7% at enrollment were not at increased risk. Among diabetic subjects, higher risks of active, culture-confirmed, and pulmonary but not extrapulmonary tuberculosis were observed with baseline hemoglobin A1c > or =7% (vs. <7%), with adjusted hazard ratios of 3.11 (95% confidence interval: 1.63, 5.92), 3.08 (95% confidence interval: 1.44, 6.57), 3.63 (95% confidence interval: 1.79, 7.33), and 0.77 (95% confidence interval: 0.18, 3.35), respectively.

Lower risk of tuberculosis in obesity.

BACKGROUND: Obesity is increasingly prevalent in both developed and developing areas. Although undernutrition is well associated with tuberculosis, few studies have systematically examined the association with obesity. Method A cohort of 42 116 individuals 65 years or older enrolled at 18 health centers for elderly patients in Hong Kong, China (which has a tuberculosis incidence of approximately 90 per 100,000 population), in 2000 were followed up prospectively through the territory-wide tuberculosis registry for the development of active tuberculosis from 3 months after enrollment until December 31, 2005, using the identity card number as the unique identifier. The association with body mass index (BMI; calculated as weight in kilograms divided by the square of height in meters), as categorized by the Asian standards, was assessed with the control of other baseline characteristics. RESULTS: Obese (BMI>or=30) and overweight (BMI, 25 to <30) individuals were at significantly lower risks of developing active tuberculosis than normal-weight individuals (BMI, 18.5 to <25), with hazard ratios (95% confidence intervals) of 0.36 (0.20-0.66) and 0.55 (0.44-0.70), respectively, after adjustment for baseline demographic, social, and clinical variables. An inverse linear association was observed predominantly for pulmonary but not extrapulmonary tuberculosis. This association persisted after controlling for potential confounders or excluding individuals with known tuberculosis risk factors. CONCLUSIONS: Obesity is associated with a lower risk of active pulmonary tuberculosis in the older population of Hong Kong. The presence of such a strong but selective association across the whole spectrum of BMI could have major biological, clinical, and/or epidemiological implications. Further studies are indicated to explore the underlying mechanisms, potential clinical utilities, and possible epidemiological consequences.

A fourteen-year review of radical cystectomy for transitional cell carcinoma demonstrating the usefulness of the concept of lymph node density.

OBJECTIVE: We studied the long-term outcome of radical cystectomy for transitional cell carcinoma and evaluated prognostic factors for disease specific survival. MATERIALS AND METHODS: A retrospective review was carried out for all cystectomies performed for transitional cell carcinoma between 1989 and 2002. Disease specific survival was correlated to patient, pathological and operative factors as well as to adjuvant therapy. RESULTS: Of the 133 cystectomies included, 100 were male and 33 were female patients. The median age was 69 years (range 43 to 86). The median follow up was 20 months (range 0 to 158). With univariate analysis, pT stage, N stage, lymph node density, carcinoma in-situ, surgical margin and post-operative radiotherapy to distant metastasis were predictive of disease specific survival. On the other hand, with multivariate analysis, only pT stage, lymph node density and post-operative radiotherapy to distant metastasis were predictive of disease specific survival. Within the group of node positive disease, lymph node density also predicted disease specific survival with both univariate and multivariate analyses. Patients with lymph node density 20% or below showed better disease specific survival. CONCLUSIONS: pT stage and lymph node density were found to be the most important predictive factors for disease specific survival after cystectomy in the Asian population.

A fourteen-year review of radical cystectomy for transitional cell carcinoma demonstrating the usefulness of the concept of lymph node density

OBJECTIVE: We studied the long-term outcome of radical cystectomy for transitional cell carcinoma and evaluated prognostic factors for disease specific survival. MATERIALS AND METHODS: A retrospective review was carried out for all cystectomies performed for transitional cell carcinoma between 1989 and 2002. Disease specific survival was correlated to patient, pathological and operative factors as well as to adjuvant therapy. RESULTS: Of the 133 cystectomies included, 100 were male and 33 were female patients. The median age was 69 years (range 43 to 86). The median follow up was 20 months (range 0 to 158). With univariate analysis, pT stage, N stage, lymph node density, carcinoma in-situ, surgical margin and post-operative radiotherapy to distant metastasis were predictive of disease specific survival. On the other hand, with multivariate analysis, only pT stage, lymph node density and post-operative radiotherapy to distant metastasis were predictive of disease specific survival. Within the group of node positive disease, lymph node density also predicted disease specific survival with both univariate and multivariate analyses. Patients with lymph node density 20 percent or below showed better disease specific survival. CONCLUSIONS: pT stage and lymph node density were found to be the most important predictive factors for disease specific survival after cystectomy in the Asian population.

Determinants of spirometric abnormalities among silicotic patients in Hong Kong.

BACKGROUND: Silicosis is the second commonest notified occupational disease in Hong Kong. AIM: To characterize the determinants of spirometric abnormalities in silicosis. METHOD: The spirometric patterns of consecutive silicotic patients on confirmation by the Pneumoconiosis Medical Board from 1991 to 2002 were correlated with demographic characteristics, occupational history, smoking history, tuberculosis (TB) history and radiographic features by univariate and multiple regression analyses. RESULTS: Of 1576 silicotic patients included, 55.6% showed normal spirometry, 28.5% normal forced vital capacity (FVC>or=80% predicted) but reduced forced expiratory ratio (FER<70%), 7.6% reduced FVC but normal FER, and 8.4% reduced both FVC and FER. Age, ever-smoking, cigarette pack-years, industry, job type, history of TB, size of lung nodules and progressive massive fibrosis (PMF) were all significantly associated with airflow limitation on univariate analysis (all P<0.05), while sex and profusion of nodules were not. Only age, cigarette pack-years, history of TB, size of lung nodules and PMF remained as significant independent predictors of airflow obstruction in multiple logistic regression analysis. After controlling for airflow obstruction, only shorter exposure duration, history of TB and profusion of nodules were significant independent predictors of reduced FVC. As well as age, history of TB, cigarette pack-years, PMF and nodule size contributed comparable effects to airflow obstruction in multiple linear regression analyses, while profusion of nodules was the strongest factor for reduced vital capacity. CONCLUSIONS: In an occupational compensation setting, disease indices and history of tuberculosis are independent predictors of both airflow obstruction and reduced vital capacity for silicotic patients.

Smoking and tuberculosis among the elderly in Hong Kong.

A cohort of 42,655 clients that were first registered with the Elderly Health Service in 2000 were followed prospectively through the tuberculosis (TB) notification registry until the end of 2002. A total of 286 active TB cases (186 culture confirmed) were identified. The annual TB notification rates were 735, 427, and 174 per 100,000 among current smokers, ex-smokers, and never-smokers, respectively (p < 0.001). The trend in TB risk persisted after the control of background characteristics using Cox proportional hazards analysis (adjusted hazard ratios [HRs]: 2.63, 1.41, and 1, p < 0.001). In comparison with never-smokers, current smokers had an excess risk of pulmonary TB (adjusted HR, 2.87; 95% confidence interval [CI], 2.00-4.11; p < 0.001), but not extrapulmonary TB (adjusted HR, 1.04; 95% CI, 0.33-3.30; p = 0.95). Among the current smokers, those who developed TB smoked more cigarettes per day than those who did not (13.43, SD 8.76 vs. 10.96, SD 7.87, p = 0.01). A statistically significant dose-response relationship was observed with respect to active TB and culture-confirmed TB (both p < 0.05). Smoking accounted for 32.8% (95% CI, 14.9-48.0%), 8.6% (95% CI, 3.3-15.1%), and 18.7% (95% CI, 7.7-30.4%) of the TB risk among males, females, and the entire cohort, respectively. Approximately 44.9% (95% CI, 20.7-64.6%) of the sex difference was attributable to smoking.

Tuberculosis in older people: a retrospective and comparative study from Hong Kong.

OBJECTIVES: To compare tuberculosis (TB) in older and younger patients. DESIGN: A retrospective and comparative observational study. SETTING: Four chest clinics and two chest hospitals in Hong Kong. PARTICIPANTS: All notifications from the participating hospitals and clinics in 1996 were extracted from the TB notification registry. The characteristics of patients aged 65 and older were compared with a one-in-three random sampling of those aged 16 to 64. MEASUREMENTS: Demographic, clinical, radiological, and laboratory data of the two groups were compared alongside treatment and outcomes. RESULTS: Older people with TB were more likely to be male, to smoke, to have had TB previously, to have coexisting medical diseases, to be socioeconomically disadvantaged, and to weigh less than younger people with TB. Dyspnea, weight loss, and malaise were more common, whereas extrathoracic lymph node enlargement was less common. Chest radiograph showed more extensive disease and lower zone involvement. Positive tuberculin test was present in only 61.9%. Sputum bacteriology was more likely to be positive. There was a longer delay in presentation and commencement of treatment, and 77.2% required at least one admission. Adverse effects of treatment, notably hepatic dysfunction, occurred more commonly. Fluoroquinolones appeared well tolerated. Only 72.5% of the older people were cured or completed their treatment. Mortality was 16%. Age of 65 and older, comorbidity, socioeconomic disadvantage, moderate-extensive disease, positive sputum smear, and poor adherence were factors independently associated with unfavorable outcomes (P <.001 to P = .01; odds ratios = 1.61-27.02). CONCLUSION: Substantial differences were found between older and younger TB patients. Many of these were associated with unfavorable outcome. Increased awareness in disease recognition and better medical and social support are therefore needed in addressing the growing problem of TB in older people.