Table 4.
Overview of diagnostic methods and operational definitions for OSA and T2DM of the review studies.
| Author/year | OSA assessment method/duration | OSA criteria | T2DM assessment | T2DM criteria | Follow-up in months |
|---|---|---|---|---|---|
| 1 Korshøj 2020 (49) | BQ, Pulse oximetry and nasal airflow for ≥4 h | BQ= high OSA risk (2 positive categories or 2 points in category 1 or 2 + BMI≥ 30kg/m2 or HTN). OSA= No OSA (AHI < 5/h), mild OSA (5/h ≤AHI < 15/h), moderate OSA (15/h ≤ AHI ≤ 30/h), severe OSA (AHI > 30/h) |
Blood sample | HbA1C ≥ 48 mmol/L, random BG > 7 mmol/L | NA |
| 2 Harada 2012 (17) | ESS, home portable machine recodes ≥ 2h | Mild OSA (RDI 5–14.9/hr), moderate OSA (RDI 15–29.9/hr), severe OSA (RDI ≥ 30/hr) | Blood sample and Self-report | FBG ≥ 126 mg/dL, IFG ≥ 110 mg dL and <126 mg dL, hypoglycaemic medication | NA |
| 3 Lindberg 2012 (18) | ESS, home portable machine record for 1 night | ODI >5/hr, AHI>5/hr | Blood sample | FBG 77.0 mmol/L, BPG 6.1 to 7.0 mmol/L | 136 |
| 4 Leong 2014 (50) | Home portable machine record for ≥4 h | Mild OSA (5/h ≤AHI < 15/h), moderate OSA (15/h ≤ AHI ≤ 30/h), severe OSA (AHI > 30/h) | Blood sample and Self-report | HbA1c ≥6.5%, physician referral or self-report, or hypoglycaemic medication | NA |
| 5 Vacelet 2021 (12) | ESS, home portable machine record for ≥5 h | AHI ≥15/h | Blood sample | FBG ≥ 126 mg/d, HOMA-IR ≥ 2 | 84 |
| 6 Appleton 2015 (11) | Home portable machine record for ≥5.5 h | Mil OSA (10–19 AHI/h), moderate OSA (20–29 AHI/h), and severe OSA (≥ 30AHI/h) | Blood sample and Self-report | FBG ≥ 7.0 mmol/L, HbA1c of ≥ 6.5%, self-report of T2DM, or hypoglycaemic medication | 56 |
| 7 Ding 2021 (8) | ESS, clinic PSG | No OSA (AHI < 5/h), mild OSA (5/h ≤AHI < 15/h), moderate OSA (15/h ≤ AHI ≤ 30/h), severe OSA (AHI > 30/h) | Blood sample and Self-report | FBG ≥ 126 mg/dL and new T2DM diagnosis | 61 |
| 8 Deol 2018 (46) | BQ | High OSA risk 2 positive categories or 2 points in category 1 or 2 + BMI≥ 27.5 kg/m2 or HTN | Blood sample and Self-report | FBG ≥ 126 mg/dL, 2-h OGTT ≥ 200 mg/dL, or hypoglycaemic medication | NA |
| 9 Sanchez 2022 (51) | ESS, home portable machine record for ≥3 h | No OSA (AHI < 5/h), mild OSA (5/h ≤AHI < 14.9/h), moderate OSA (15/h ≤ AHI ≤ 29.9/h), severe OSA (AHI ≥ 30/h) | Blood sample | HbA1c 5.7 to 6.4% | NA |
| 10 Xu 2019 (10) | Clinic PSG | No OSA (AHI < 5/h), mild OSA (5/h ≤AHI < 14.9/h), moderate OSA (15/h ≤ AHI ≤ 29.9/h), severe OSA (AHI ≥ 30/h) | Blood sample and Self-report | FBG ≥ 7.0 mmol/L, OGTT ≥ 11.1 mmol/L, random BG ≥ 11.1 mmol/L, HbA1c of ≥ 6.5%, T2DM diagnosis, or hypoglycaemic medication | 87 |
| 11 Ali 2023 (14) | Home portable machine with no record time | No OSA (AHI 0-4.5 5/h), mild OSA (5/h ≤AHI < 14.9/h), moderate to severe OSA (AHI ≥ 15/h) | Blood sample | FBG ≥ 126 mg/dL, 2-h OGTT ≥ 200 mg/dL | 96 |
| 12 Kim 2013 (48) | Home portable machine with no record time | AHI ≥5 | Blood sample | FBG ≥ 7.0 mmol/L, OGTT ≥ 11.1 mmol/L, HbA1c of ≥ 6.5%, T2DM diagnosis | NA |
| 13 Nagayoshi 2016 (41) | Home portable machine with no record time | No OSA (AHI<5/h), mild OSA (AHI 5/h - 14.9/h), moderate OSA (AHI 15/h - 29.9/h), severe OSA (AHI ≥ 30/h) | Self-report | 2DM diagnosis, or hypoglycaemic medication | 156 |
| 14 Whitaker 2018 (52) | Home portable machine with no record time | Mild OSA (AHI 5/h - 14.9/h), moderate OSA (AHI 15/h - 29.9/h), severe OSA (AHI ≥ 30/h) | Blood sample | HbA1C | NA |
| 15 Beate Strand 2015 (39) | Self-report OSA symptoms | Symptoms of observed apnea, bothersome snoring, and daytime sleepiness | Blood sample and Self-report | FBG ≥ 7.0 mmol/L, random BG ≥ 11.1 mmol/L, hypoglycaemic medication | 61 |
| 16 Sabanayagam 2012 (5) | Self-report OSA symptoms | Symptoms of snoring, snorting, daytime sleepiness | Blood sample and Self-report | FBG ≥ 7.0 mmol/L, random BG ≥ 11.1 mmol/L, HbA1c of ≥ 6.5%, hypoglycaemic medication, T2DM diagnosis | NA |
| 17 Kent 2014 (47) | ESS, polygraphy or clinic PSG | Mild OSA (ODI 5–14.9/hr), moderate OSA (ODI 15–29.9/hr), severe OSA (ODI ≥ 30/hr) | Blood sample | HbA1c of ≥ 6.5% | NA |
| 18 D’Aurea 2017 (45) | BQ | High OSA risk 2 positive categories or 2 points in category 1 or 2 + BMI≥ 30kg/m2 or HTN | Blood sample and Self-report | IFG ≥ 110 mg/dL and <126 mg dL, HbA1c of ≥ 6.5%, hypoglycaemic medication. Prediabetes =HbA1c of 5.7%-6.4% |
NA |
| 19 Kendzerska 2014 (13) | ESS, clinic PSG | No OSA (AHI<5/h), mild OSA (AHI 5/h - 14.9/h), moderate OSA (AHI 15/h - 29.9/h), severe OSA (AHI ≥ 30/h) | Medical record | NR | 67 |
| 20 Strausz 2018 (42) | Medical record | NR | Medical record | NR | 264, 173, 300 |
| 21 Liu 2017 (40) | PSG (not indicated if clinic or home device) | NR | Medical record | NR | 144 |
| 22 Tianyi 2018 (44) | Self-report OSA symptoms | NR | Self-report | Self-report of medication or self-report of IFG | 168 |
| 23 Subramanian 2019 (43) | Medical record | NR | Medical record | NR | 49 |
OSA, obstructive sleep apnea; T2DM, type 2 diabetes mellitus; BQ, Berlin Questionnaire; h, hour; BMI, body mass index; HTN, hypertension; AHI, apnea-hypopnea index; HbA1C, haemoglobin A1C; BG, blood glucose; ESS, Epworth Sleepiness Scale; RDI, respiratory desaturation index; FBG, fasting blood glucose; IFG, impaired fasting glucose; ODI, oxyhemoglobin desaturation index; PSG, polysomnography; OGTT, oral glucose tolerance test; NR, not recorded.