TABLE 1.
Studies that investigated the relationship between respiratory tract infections (RTI) and islet autoimmunity (IA)/type 1 diabetes (T1D).
| Study (year/region) | Cases (controls) | Outcome | Exposure | OR (95% CI) | p‐value |
|---|---|---|---|---|---|
| Insurance/Medical claims | |||||
| Beyerlein (2016/Germany) 26 | 720 (294424) | T1D | ≥1 RTI in the first 6 months of life | 1.17 (1.00‐1.37) | <0.05 |
| Cardwell (2008/United Kingdom) 45 | 367 (4579) | T1D | Medical consultations in first year of life for | ||
| Upper RTI | 0.84 (0.67‐1.04) | 0.11 | |||
| Lower RTI | 0.81 (0.55‐1.20) | 0.28 | |||
| Lee (2015/Taiwan) 43 | 632 (6320) | T1D | ≥1 acute RTI | 1.74 (1.30‐2.33) | <0.05 |
| ≥1 episode of pneumonia or influenza | 1.80 (1.35‐2.41) | <0.05 | |||
| Ruiz (2018/Norway) 44 | 2376 (2284274) | T1D | Pandemic influenza infection | 1.19 (0.97‐1.46) | >0.05 |
| Laboratory confirmed pandemic influenza infection | 2.26 (1.51‐3.38) | <0.05 | |||
| Self‐reported (postnatal) | |||||
| BABYDIET (2013/Germany) 40 | 26 (122) | IA | RTI in the first 6 months of life | 2.27 (1.32‐3.91) | <0.05 |
| RTI in 6–12 months of life | 1.32 (1.08‐1.61) | <0.05 | |||
| Upper RTI in 6 months prior to seroconversion | 1.57 (1.26‐1.95) | <0.05 | |||
| Lower RTI in 6 months prior to seroconversion | 1.28 (0.51‐3.17) | >0.05 | |||
| DAISY (2012/USA) 50 | 109 (1620) | IA | Upper respiratory symptoms (cough, cold, runny nose, stuffy nose, sinus infection, ear infection) in first 9 months of life | 1.00 (0.98‐1.01) | 0.65 |
| Respiratory disease (croup, pneumonia, bronchitis) in first 9 months of life | 0.99 (0.67‐1.74) | 0.98 | |||
| Diabimmune (2018/Estonia, Finland, Russia) 41 | 46 (744) | IA & T1D | Number of respiratory infections per child in the first year of life (IA cases vs. controls) | 0.003 | |
| Number of respiratory infections per child in the first year of life (T1D cases vs. controls) | 0.002 | ||||
| MIDIA (2011/Norway) 46 | 42 (843) | IA | ≥1 lower RTI by 4 years of life | 3.4 (1.6‐7.1) | 0.001 |
| Norwegian Mother and child (2018/Norway) 49 | 286 (70154) | IA | Upper RTI in first 18 months of life | ||
| 0‐3 | 1.00 (reference) | ||||
| 4‐5 | 0.97 (0.69‐1.38) | 0.88 | |||
| 6‐7 | 0.99 (0.69‐1.42) | 0.97 | |||
| ≥8 | 1.96 (0.77‐1.45) | 0.50 | |||
| ≥1 lower RTI in first 18 months of life | 0.85 (0.59‐1.21) | 0.36 | |||
| Ponsonby (2011/Australia) 42 | 26 (10602) | T1D | ≥1 upper RTI by 5 weeks of life | 2.74 (1.19‐6.32) | 0.02 |
| ≥1 upper RTI by 12 weeks of life | 1.55 (0.65‐3.69) | 0.32 | |||
| Sipetic (2003/Serbia) 59 | 105 (210) | T1D | Frequent (≥3 infections per year) RTI | 2.65 (1.37‐5.11) | <0.01 |
| TEDDY (2003/USA) 52 | 52 (1210) | IA | ≥1 episode of RTI symptoms during pregnancy | 0.66 (0.38‐1.15) | >0.05 |
| TEDDY (2017/Finland, Germany, Sweden, USA) 47 | 454 (7415) | IA | Respiratory infectious episodes during winter | 1.43 (1.17‐1.75) | 0.0005 |
| Common cold | 1.38 (1.11‐1.71) | 0.004 | |||
| Influenza‐like illness | 2.37 (1.35‐4.15) | 0.003 | |||
| Sinusitis | 2.63 (1.22‐5.67) | 0.01 | |||
| Laryngitis/tracheitis | 1.76 (1.04‐2.98) | 0.04 | |||
| TRIGR (2022/Europe, USA, Canada, Australia) 48 | 842 (1175) | IA & T1D | Upper RTI in first 12 months of life (IA as outcome) | 1.20 (1.00‐1.44) | 0.044 |
| Upper RTI in first 12 months of life (T1D as outcome) | 1.05 (0.73‐1.50) | 0.797 | |||
| Self‐reported (pregnancy) | |||||
| ABIS (2022/Sweden) 53 | 137 (16155) | T1D | ≥1 RTI during pregnancy | 1.49 (1.01‐2.22) | 0.04 |
| ≥1 RTI during first trimester | 2.31 (1.32‐4.04) | 0.002 | |||
| ≥1 RTI during second trimester | 1.10 (0.59‐2.04) | 0.77 | |||
| ≥1 RTI during third trimester | 1.15 (0.56‐2.35) | 0.71 | |||
| MIDIA (2011/Norway) 46 | 42 (843) | IA | RTI during pregnancy | ||
| 1 | 1.23 (0.96‐1.58) | 0.09 | |||
| ≥2 | 0.98 (0.74‐1.30) | 0.87 | |||
| TEDDY (2018/Finland, Germany, Sweden, USA) 51 | 438 (7034) | IA | Gestational RTI (IAA as outcome) | 0.88 (0.67‐1.15) | 0.35 |
| Gestational RTI (GADA as outcome) | 0.95 (0.73‐1.25) | 0.73 | |||
| Molecular | |||||
| Ruiz (2018/Norway) 44 | 2376 (2284274) | T1D | Laboratory confirmed pandemic influenza infection | 2.26 (1.51‐3.38) | <0.05 |
Abbreviations: ABIS, All Babies in Southeast Sweden study; CI, confidence interval; GADA, glutamic acid decarboxylase 6 antibodies; IA, islet autoimmunity; IAA, insulin autoantibodies; MIDIA, Norwegian Environmental Triggers of Type 1 Diabetes study; OR, odds ratio; RTI, respiratory tract infection; T1D, type 1 diabetes; TEDDY, the Environmental Determinants of Diabetes in the Young study; TRIGR, Trial to Reduce Insulin‐Dependent Diabetes Mellitus.