Table 1.
Clinical trials on lipid markers and diabetic retinopathy
| Study, year, references | Reference | Participants Size | NOS score | Quality | Major Results | Biomarkers of serum lipid profiles | |||
|---|---|---|---|---|---|---|---|---|---|
| TC (mmol/L) |
TG (mmol/L) |
LDL-C (mmol/L) |
HDL-C (mmol/L) |
||||||
| Cross-sectional studies | |||||||||
| EURODIAB, 2008 | [35] | 2,991 | 8 | High | NPDR | 5.42 ± 1.11 | 1.22 ± 0.82 | 3.25 ± 1.10 | 1.76 ± 0.45 |
| PDR | 5.51 ± 1.51 | 1.36 ± 1.08 | 3.12 ± 0.94 | 1.65 ± 0.51 | |||||
| WESDR, 2008 | [22] | 2,366 | 8 | High | Hard exudates | 5.61 ± 1.20 | 1.37 ± 0.54 | 3.53 ± 1.10 | 1.24 ± 0.71 |
| ETDRS, 1991 | [31] | 2,709 | 8 | High | Hard exudates | 5.44 ± 1.38 | 1.46 ± 0.48 | 3.30 ± 1.25 | 1.28 ± 0.33 |
| SN-DREAMS. 2017 | [24] | 1,414 | 8 | Moderate | CSME | 5.12 ± 0.95 | 1.45 ± 0.78 | 3.45 ± 1.31 | 1.54 ± 0.53 |
| CURES, 2005 | [32] | 1,736 | 9 | High | Any DR | 5.37 ± 1.66 | 1.39 ± 0.86 | 3.20 ± 1.16 | 1.47 ± 0.98 |
| DCCT/EDIC, 2004 | [36] | 1,441 | 8 | Moderate | DR severity | 5.40 ± 1.15 | 1.34 ± 0.67 | 3.35 ± 1.45 | 1.25 ± 0.50 |
| AusDiab, 2003 | [29] | 2,177 | 8 | High | Any DR | 5.50 ± 1.03 | 1.81 ± 0.36 | NA | NA |
| Javadi et al., 2009 | [27] | 7,989 | 8 | High | Any DR | 5.24 ± 0.86 | 1.47 ± 0.74 | 3.32 ± 1.41 | 1.05 ± 0.21 |
| ARIC, 2016 | [33] | 1,600 | 8 | High | Hard exudates | 5.43 ± 1.18 | NA | 3.53 ± 1.47 | NA |
| Hoorn, 2003 | [37] | 626 | 9 | Moderate | Hard exudates | 5.57 ± 1.25 | 1.31 ± 0.51 | 3.55 ± 1.04 | 1.23 ± 0.52 |
| Prospective studies | |||||||||
| WESDR, 2008 | [22] | 2,366 | 8 | High | Hard exudates | 5.61 ± 1.20 | 1.37 ± 0.54 | 3.53 ± 1.10 | 1.24 ± 0.21 |
| DCCT/EDIC, 2004 | [36] | 1,441 | 8 | Moderate | CSME | 5.14 ± 0.75 | NA | 3.66 ± 1.03 | NA |
| Cohen et al., 1999 | [25] | 497 | 8 | Moderate | PDR | 5.01 ± 1.17 | 1.21 ± 3.01 | 3.16 ± 0.96 | 1.34 ± 0.45 |
Summary of diverse clinical trials on lipid markers and diabetic retinopathy. The quality assessment of each studies was accessed and scored by using the Newcastle–Ottawa Quality (NOS) Assessment Scale. This scale varied from 0 to 9 stars, which indicated that studies were graded as good if they met greater than 8 criteria. All the following criteria for enrolling the clinical trials had to be met: (1) the design was a case–control study in humans, reporting on two outcome groups: one with DR and one without DR; (2) published observational studies with data on both patients with DR and healthy age-and sex-matched controls; (3) study provided the detailed data in both cases and controls, including the levels of other serum lipids; (4) the healthy controls were clearly described. If study with data published more than once or using the same subjects, we considered all publications for data abstraction, only the article with adequate study strategy was chosen. In addition, studies were excluded if they were reviews, clinical trials, case report, animals’ experiments and discussion papers
Abbreviations: CSME Clinically significant macular edema, TC total cholesterol, TG triglyceride, LDL-C low-density lipoprotein cholesterol, HDL-C high-density lipoprotein cholesterol, DR Diabetic retinopathy, NPDR Non-proliferative diabetic retinopathy, PDR Proliferative diabetic retinopathy, NA Not applicable