Table 1.

Summary of Cross-Sectional Studies on DR and OSA

				Main Findings
Study	Patients	Setting	Analysis	DR	DME
Positive association between DR and OSA and/or PSG measures
Unver et al2 (United States)	44 DM	Outpatient retina clinic	Univariate	Significant association between DR and OSA (OR: 143.18, 95% CI: 7.41–2767.79)†	Significant association between OSA and DME (OR: 14.44, 95% CI: 2.34–147.60)†
Laaban et al3 (France)	303 T2DM	Hospital inpatient (DM)	Univariate	Significant association between DR and OSA (OR: 0.56, 95% CI: 0.35–0.92)†
Borel et al4 (France)	37 T1DM	DM outpatient	Univariate	Difference in presence of DR between borderline (11.1%) and pathological (73.3%) overnight oximetry recording**
West et al5 (United Kingdom)	118 T2DM	1 DM outpatient and 5 primary care centers	Multivariate	Association between retinopathy scores and OSA (R2 = 0.19)*	Association between DME and OSA (R2 = 0.30)*
Shiba et al6 (Japan)	219 T2DM	Hospital inpatient (eye disease)	Multivariate	NPDR versus PDR: association between PDR and OSA (OR: 1.09, 95% CI: 1.01–1.06)** Association between PDR and minimum SpO2 (OR: 0.93; 95% CI: 0.88–0.99)**
Kosseifi et al,7 (United States)	98 T2DM	Outpatient sleep clinic	Univariate	Higher AHI in DR (44.2) versus no DR**
Rudrappa et al8 (United Kingdom)	31 T2DM	DM outpatient	Multivariate	Association between retinopathy scores and OSA* No association between PDR and OSA (OR: 12.6, 95% CI: 0.62255.76)	No association between DME and OSA (effect size not reported)
Nishimura et al,9 (Japan)	136 T2DM	N/A	Univariate	No difference in AHI between patients with no DR (15.1 ± 13.6) and with DR (17.8 ± 15.1)
			Multivariate	Difference in minimum SpO2 between patients with no DR (81.8 ± 7.4) and with DR (78.2 ± 9.6)**
Manin et al,10 (France)	67 T1DM	2 DM outpatient	Univariate	Difference in presence of DR between patients with OSA (84%) and non-OSA (42%)* No difference in presence of NPDR between patients with OSA (10%) and non-OSA (6%)	No difference in presence of DME between patients with OSA (23%) and non-OSA (8%)
Babaetal11 (France)	60 T2DM	DM outpatient	Univariate	Difference in presence of DR between patients with OSA (55%) and non-OSA (15%)** Difference in presence of NPDR** and PDR** between patients with OSA (35% and 20%) and non-OSA (7.5% and 7.5%)	Difference in presence of DME in patients with OSA (20%) and non-OSA (5%)**
No association between DR and OSA
Schober et al12 (Germany)	498 T2DM and 58 T1DM	14 primary care centers	Univariate	No difference in presence of DR between no OSA (AHI < 15; 13.9%) and moderate-to-severe OSA (AHI ≥ 15; 11.5%)
Mason et al13 (United Kingdom)	80 T2DM with DME	DME outpatient	Univariate	No association between DR and OSA
Mehta et al14 (India)	80 T2DM	Outpatient retina clinic	Multivariate	No association between DR and OSA or AHI (effect size not reported)
Banerjee et al15 (United Kingdom)	93 T2DM	Specialist weight management clinic	Multivariate	No association between DR and AHI (OR: 1.00, 95% CI: 0.98–1.02) or PSG measures	No association between DME and AHI (OR: 1.01, 95% CI: 0.98–1.04) Association between DME and minimum SpO2 (OR: 0.79, 95% CI: 0.65–0.95)**
Storgaard et al16 (Denmark)	180 T2DM	DM outpatient	Univariate	No difference in DR between patients with OSA (26.4%) and non-OSA (19.4%) No difference in AHI between patients with no DR (17 ± 25) and with DR (17 ± 20)
Zhang et al17 (China)	233 T2DM	12 hospital inpatient (DM)	Multivariate	No association between DR and AHI or PSG measures PDR versus NPDR: no association between PDR and minimum SpO2 (OR: 0.970, 95% CI: 0.932–1.010) or other OSA parameters

^*P < 0.01;

^**P < 0.05;

^***P < 0.10.

^†P value significant but not reported.

PSG, polysomnography; SpO2, oxygen saturation; T1DM, Type 1 diabetes mellitus; T2DM, Type 2 diabetes mellitus.