Derosa 2016.
| Methods | RCT, parallel, (n‐3 PUFA capsules vs placebo), 18 months Summary risk of bias: low |
|
| Participants | White overweight/obese patients with impaired fasting glucose (IFG) or impaired glucose tolerance (IGT) N: 138 intervention, 143 control (analysed 128 intervention, 130 control) Level of risk for CVD: low Men: 50.72% intervention, 48.95% control Mean age in years (SD): 53.4 (11.2) intervention, 54.8 (12.1) control Age range: unclear Smokers: not reported Hypertension: not reported Medications taken by at least 50% of those in the control group: not reported 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: Italy Ethnicity: white |
|
| Interventions | Type: capsule (n‐3 PUFA) Comparison: EPA + DHA vs CHO + SFA Intervention: 3 ×1 g capsule/ day n‐3 PUFAs (ethylic esters, each 1‐g capsule of n‐3 PUFAs contains highly concentrated ethyl esters of omega‐3 fatty acids, primarily EPA, and DHA in the proportion of 0.9–1.5). Dose: unclear (approx 2‐3 g/d) Control: placebo (a capsule containing sucrose, mannitol and mineral salts, magnesium stearate (a saturated fat) and silicon dioxide, used as anti‐caking agents) Both groups were given diet advice to follow a controlled‐energy diet based on AHA recommendations (50% of calories from carbohydrates, 30% from fat (6% saturated), and 20% from proteins, with a maximum cholesterol content of 300 mg/day and 35 g/day of fibre). Individuals were also encouraged to increase their physical activity by walking briskly for 20 to 30 min, 3 to 5 times per week, or by cycling Compliance: measured by counting the number of pills returned at the time of specified clinic visits Length of intervention: 18 months |
|
| Outcomes | Main study outcome: insulin resistance Dropouts: 23 across arms (no details on groups but stated that there were no difference between groups) Available outcomes: mortality, CV mortality, CHD event, stroke, combined CVD events, MI, AF, weight, BMI, lipids, diabetes mellitus Response to contact: yes (data provided) |
|
| Notes | Study funding: "The authors have no relevant affiliations or financial involvement with any organization or entity with a financial interest in or financial conflict with the subject matter or materials discussed in the manuscript. This includes employment, consultancies, honoraria, stock ownership or options, expert testimony, grants or patents received or pending, or royalties" | |
| Risk of bias | ||
| Bias | Authors' judgement | Support for judgement |
| Random sequence generation (selection bias) | Low risk | Randomisation was done using a drawing of envelopes containing randomisation codes prepared by a statistician. |
| Allocation concealment (selection bias) | Low risk | Author stated that allocation was concealed from clinicians and researchers, but no methodology provided |
| Blinding of participants and personnel (performance bias) All outcomes | Low risk | Both n‐3 PUFAs and placebo were supplied as identical, opaque, white capsules in coded bottles to ensure the blind status of the study. However no information provided on capsules taste or smell |
| Blinding of outcome assessment (detection bias) All outcomes | Low risk | A copy of the code was provided only to the person performing the statistical analysis |
| Incomplete outcome data (attrition bias) All outcomes | Low risk | An intention‐to‐treat analysis was conducted for patients who received 1 dose of study medication |
| Selective reporting (reporting bias) | Unclear risk | No trial registry or protocol found |
| Attention | Low risk | No difference reported |
| Compliance | Unclear risk | Measured by counting the number of pills returned at the time of specified clinic visits |
| Other bias | Low risk | None noted |