TABLE 4.
Poor blood sugar control is associated with an increased risk of TB.
| Ref. country, year | Research design | Simple size (n) | Blood sugar: n (incidence rate or %) | Results | Conclusion |
|---|---|---|---|---|---|
| [137] China, 2008 | Prospective cohort study |
42,116 (DM: 6444 NDM: 35,672) |
DM‐TB: (1) HbA1c ≥ 7%, n = 64 (422/100,000) (2) HbA1c < 7%, n = 11 (136/100,000) |
Subjects with HbA1c ≥ 7% had a 3.11 times risk of developing active TB (adjusted OR = 3.11, 95% CI: 1.63–5.92). | Blood sugar control was shown to be a major factor in the increased risk of TB. |
| [138] India, 2013 | Descriptive study |
7080 (DM‐TB: 47 DM‐NTB: 6113) |
DM‐TB: (1) HbA1c ≥ 7%, n = 37 (78.7%) (2) HbA1c < 7%, n = 7 (14.9%) |
DM‐TB patients have poor blood sugar control. | Screening of DM patients for TB was feasible in a tertiary care hospital. |
| [139] Mexico, 2015 | Cross‐sectional study |
DM: 600 [TST (+): 308 TST (‐): 292] |
DM‐LTBI: (1) HbA1c > 7%, n = 199 (64.8%) (2) HbA1c < 7%, n = 109 (35.2%) |
Subjects with HbA1c > 7% had a 2.52 times risk of developing LTBI (adjusted OR = 2.52, 95% CI: 1.10–8.25). | Poor glycemic control is a risk factor for LTBI in DM patients. |
| [140] China, 2016 | Observational cohort study |
122,402 (DM: 11,260 NDM: 110,782) |
DM‐TB: (1) FPG > 130 mg dL−1, n = 54 (85.7%) (2) FPG ≤ 130 mg dL−1, n = 9 (14.2%) |
Subjects with poorly controlled DM patients had a 2.21 times risk of developing TB (adjusted OR = 2.21, 95% CI: 1.63–2.99). | Good blood sugar control may alter the risk of TB in people with diabetes. |
| [141] Barcelona, 2022 | Retrospective cohort study |
8004 (DM: 7956 DM‐TB: 48) |
DM‐TB: (1) HbA1c ≥ 7.5%, n = 24 (120.5/100,000) (2) HbA1c < 7.5%, n = 22 (70.3/100,000) (3) HbA1c ≥ 8%, n = 21 (143.0/100,000) (4) HbA1c < 7%, n = 25 (68.6/100,000) (5) HbA1c ≥ 9%, n = 16 (183.8/100,000) (6) HbA1c < 7%, n = 30 (70.6/100,000) |
The risk of TB is positively associated with the degree of glycemic control. The risk of TB in patients with moderate glycemic control is 1.80 times higher (adjusted HR = 1.80, 95% CI: 0.60–5.42). The risk of TB in patients with poor glycemic control is 2.06 times higher (adjusted HR = 2.06, 95% CI: 0.67–6.32). The risk of TB in patients with very poor glycemic control is 2.82 times higher (adjusted HR = 2.82, 95% CI: 0.88–9.06). | DM subjects with worse glycemic control show a trend toward a higher risk of developing TB. |
| [142] Indonesia, 2022 | Cross‐sectional study |
T2DM: 242 [QFT (+): 82 QFT (−): 160] |
DM‐LTBI: (1) HbA1c < 7%, n = 22 (26.8%) (2) HbA1c = 7% −9.9%, n = 43 (52.5%) (3) HbA1c ≥ 10%, n = 17 (20.5%) |
Subjects with HbA1c > 7% had a 2.1 times risk of developing LTBI (adjusted OR = 2.13; 95% CI: 1.074–4.225). | A higher HbA1c level may be a predictor of LTBI in T2DM patients. |
| [143] South Africa, 2009 | Cross‐sectional study | T1DM: 263 |
(1) T1DM‐NTB: HbA1c, mean = 10.6%, n = 233 (2) T1DM‐Prevalent TB: HbA1c mean = 12.4%, n = 9 (3) T1DM‐Ever TB: HbA1c mean = 13.3%, n = 25 |
Poor glycaemic control (HR = 1.39, 95% CI: 1.18–1.63 per unit increase in glycated HbA1c) was associated with prevalent TB disease. | There is a high prevalence of TB disease in diabetic children and adolescents. |
| [144] Kiribati, 2019 | Case–control study |
773 (TB: 275 NTB: 498) |
(1) TB HbA1c Median = 6.0%, n = 275 (2) NTB HbA1 Median = 5.6%, n = 498 |
Pre‐diabetes (HbA1c 5.7%–6.4%) increased the odds of having TB by 1.5 times (OR = 1.5, 95% CI: 1.1–2.3; p < 0.05). Well‐controlled diabetes increased the chances of developing TB by 2.7 times (OR = 2.7, 95% CI: 1.7–4.5; p < 0.001), while uncontrolled diabetes increased the odds by 4.3 times (OR = 4.3, 95% CI: 2.6–7.2; p < 0.001). | As the HbA1c rose so did the odds of TB. |
| [145] India, 2017 | Case–control study |
451 (DM‐TB: 152 DM: 299) |
DM‐TB: (1) HbA1c < 7%, n = 19.0 (12.2%) (2) HbA1c7%−8%, n = 10.0 (6.60%) (3) HbA1c > 8%, n = 78 (51.7%) (4) FBS < 70 mg dL−1, n = 6.0 (4.0%) (5) FBS = 70–100 mg dL−1, n = 15(9.9%) (6) FBS > 100 mg dL−1, n = 111 (87.4%) (7) Urine sugar (1+), n = 12 (7.9%) (8) Urine sugar (2+), n = 13 (8.6%) (9) Urine sugar (3+), n = 30 (19.9%) |
HbA1c value < 7 is an associated protective factor for TB occurrence (OR = 0.52, 95% CI: 0.29–0.93). | Poor glycemic control among people with diabetes is a risk factor for TB occurrence. |
| [146] Brazil, 2019 | Case–control study |
DM‐TB: 45 DM: 90 |
DM‐TB: (1) HbA1c, mean = 8.81%, n = 45 (2) HbA1c1 before TB = 9.43%, n = 22 (3) FBS = 195.12 mg dL−1, n = 45 DM: (1) HbA1c, mean = 7.86%, n = 85 (2) HbA1c1 before TB = 7.86%, n = 85 (3) FBS = 145.04 mg dL−1, n = 90 |
FBS were associated with TB in DM (Adjusted OR = 1.017, 95% CI: 1.007–1.026). | Blood sugar control increases the chance that people with diabetes will develop tuberculosis. |
| [147] Korea, 2012 | Case–control study |
492 DM‐TB: 142 TB: 368 |
DM‐TB: (1) HbA1c ≥ 7%, n = 74 (52.1%) (2) HbA1c < 7%, n = 25 (17.6%) |
Uncontrolled DM was a significant risk factor for a positive sputum culture at 2 months (OR = 4.316; 95% CI: 1.306–14.267; p = 0.017). | TB patients with uncontrolled DM should be carefully managed and treated. |
| [148] Kenya, 2017 | Cross‐sectional study | TB: 454 |
TB: (1) HbA1c ≥ 6.5, n = 23 (5.1%) (2) HbA1c = 5.7–6.4, n = 170 (37.5%) (3) HbA1c < 5.7, n = 260 (57.45%) |
The odds of having pre‐DM or DM among TB patients were 42.6% (95% CI: 38.0–47.3). | High rates of pre‐diabetes and DM were found in adult TB patients. |
| [149] Thailand, 2022 | Prospective cohort study |
DM‐TB: 92 NDM‐TB: 124 |
DM‐TB: (1) FPG median = 153 mg dL−1, n = 92 (2) HbA1c median = 7.0%, n = 92 NDM‐TB: (1) FPG median = 100 mg dL−1, n = 124 (2) HbA1c median = 5.4 mg dL−1, n = 124 |
Having pre‐existing underlying impaired fasting glucose (OR = 8.03, p < 0.001) was associated with newly diagnosed DM cases among patients with TB. | The prevalence of DM in patients with TB in Thailand was unexpectedly high. |
| [150] Ghana, 2018 | Cross‐sectional study | TB: 146 |
TB: (1) FPG = 6.1–7 mmol L−1, n = 8 (5.48%) (2) FPG > 7.1 mmol L−1, n = 5 (3.42%) (3) 2HPP = 6.1–7 mmol L−1, n = 42 (28.77%) (4) 2HPP > 7.1 mmol L−1, n = 17 (11.64%) |
In TB patients, the prevalence of abnormal fasting blood glucose was 8.9% (95% CI: 5.21‐14.82%), and the prevalence of abnormal postmeal blood glucose was 40.4% (95% CI: 32.68‐48.65%). | The prevalence of dysglycaemia was high among smear‐positive TB patients in Ghana. |
Abbreviations: DM, diabetes mellitus; FBS, fasting blood sugar; FPG, fasting plasma glucose; HbA1c, glycated hemoglobin A1c; 2HPP, 2‐hour postprandial values; IGRA, interferon‐gamma release assay; LTBI, latent tuberculosis infection; QFT, QuantiFERON‐TB test; TB, tuberculosis; TST, tuberculin skin test.