Rossing 1996.
| Methods | RCT, parallel, (fish oil vs olive oil), 12 months Summary risk of bias: moderate or high |
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| Participants | Adults with insulin‐dependant diabetes mellitus, diabetic nephropathy and normal BP N: 18 intervention, 18 control (analysed, 17 intervention, 15 control) Level of risk for CVD: moderate Men: 64% intervention, 67% control Mean age (SD) years: 32 (7) intervention, 34 (10) control Age range: 18‐55 years Smokers: 50% intervention, 47% control Hypertension: not reported Medications taken by at least 50% of those in the control group: insulin Medications taken by 20%‐49% of those in the control group: not reported Medications taken by some, but less than 20% of the control group: not reported Location: Denmark Ethnicity: not reported |
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| Interventions | Type: supplement Comparison: EPA + DHA vs MUFA Intervention: cod‐liver oil emulsion (Pharma‐Vinci A/S Denmark). EPA 2 g, DHA 2.6 g, total PUFA 4.6 g/day. Dose: 4.6 g/d EPA + DHA Control: olive oil emulsion (Pharma‐Vinci A/S Denmark) Compliance: assessed through omega 3 incorporation in platelets, and the paper reports significantly higher omega 3 levels in platelets at 12 months Duration of intervention: 12 months |
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| Outcomes | Main study outcome: diabetic nephropathy Dropouts: 1 intervention, 3 control (though 3 further intervention participants are not included in all data) Available outcomes: mortality (nil), breast cancer, total and LDL cholesterol, sBP (TGs reported as medians so not used, albuminurea, fractional albumin clearance, transcapillary escape rate of albumin, prothrombin fragment reported as geometric means or medians, HbA1c, HDL and diastolic BP too different at baseline to include, GFR, PAI1, TPA, fibrinogen, etc. not relevant) Response to contact: yes |
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| Notes | Study funding: the Danish Heart Association. Eskisol Fish oil and placebo oil emulsions were provided by Pharma‐Vinci A/S, Frederiksvaerk, Denmark | |
| Risk of bias | ||
| Bias | Authors' judgement | Support for judgement |
| Random sequence generation (selection bias) | Low risk | Patients were randomised using concealed randomisation to receive either fish oil or olive oil in blocks of 4 according to their glomerular filtration rate." |
| Allocation concealment (selection bias) | Unclear risk | No further details |
| Blinding of participants and personnel (performance bias) All outcomes | Low risk | "Active and placebo (olive oil) were given as emulsions with orange flavour. At the end patients were allowed to guess about treatment and ˜50% were right" |
| Blinding of outcome assessment (detection bias) All outcomes | Unclear risk | No details |
| Incomplete outcome data (attrition bias) All outcomes | Low risk | Dropouts similar between groups although relatively high for small sample size. 3 dropouts from fish oil and 1 from control due to side effects. Intention‐to‐treat analysis appears to have been given for albuminuria only |
| Selective reporting (reporting bias) | Unclear risk | No trials registry entry or protocol found |
| Attention | Low risk | Time and attention appear to be the same. All patients were given dietary advice. |
| Compliance | Low risk | Reports significantly higher omega 3 levels in platelets at 12 months for the intervention group |
| Other bias | Low risk | None noted |