Prevalence of diabetes mellitus (DM) in tuberculosis (TB) patients: clinical and radiologic features in the TB-DM association based on a five-year hospital study.

A previously known association of tuberculosis (TB), now a global emergency, with diabetes mellitus (DM), a chronic disease of increasing prevalence worldwide, has resurfaced. DM is a recognised TB risk factor and M. tuberculosis infection usually disturbs glycoregulation. We aimed to estimate DM prevalence among TB patients and to analyse clinical and radiologic manifestations of TB in this group. The cross-sectional study included 1017 patients discharged with a TB diagnosis from a tertiary level facility in a five-year period. After exclusion of 128 patients with TB sequelae, we selected 889 patients with confirmed active TB, and the final selection led to 88 subjects with both active TB and DM. DM was found in 9.89% of active TB patients. Testing hypotheses for single-sample proportions showed that the prevalence was significantly higher than the prevalence in the general population (p<0.01). The average patient age was 60.47±14.88 years (range: 20-88), while the male/female ratio was 2.26. We found pulmonary TB in 96.3% of the 88 subjects, and extrapulmonary in 3.4%, the latter more frequently in women (p=0.08). Cavities were more frequently found in tobacco smokers compared to non-smokers (p=0.002) and in patients living in rural settings (p=0.002); haemoptysis was detected more frequently in men compared to women (p=0.044). Half of the patients had no fever at all, and only 14.8% had tachycardia. Auscultatory findings were positive in 57 (64.8%) patients. Radiographic changes were atypical in 17/88 (19.3%) patients and included pulmonary bases in seven patients, upper lobe anterior segment, and disseminated miliary pattern in two patients. DM prevalence is significantly higher among TB patients compared to the general population. The mean age of TB patients with DM is significantly higher than expected in TB patients alone. Knowledge of TB clinical and radiologic variations in this group of patients may reduce the delay in TB diagnosis with its clinical and epidemiologic consequences.