Mullen 2000.

Methods	Participants were not taking cholesterol‐lowering medication; therefore no wash‐out period was required 6‐Week randomised double‐blind placebo‐controlled 2 × 2 factorial trial
Participants	84 men and women aged 18 to 45 years with type 1 diabetes mellitus; LDL‐C < 4.5 mmol/L Exclusion criteria: none reported Baseline TC: 4.92 mmol/L (190 mg/dL) Baseline LDL‐C: 3.08 mmol/L (119 mg/dL) Baseline HDL‐C: 1.47 mmol/L (57 mg/dL) Baseline TG: 0.83 mmol/L (74 mg/dL)
Interventions	Placebo + placebo Arginine + placebo Arginine + atorvastatin 40 mg/d Placebo + atorvastatin 40 mg/d
Outcomes	Per cent change from baseline at 4 weeks of serum TC, LDL‐C, HDL‐C and TG
Notes	No lipid data provided for the 3 groups titled: Placebo + placebo Arginine + placebo Arginine + atorvastatin 40 mg/d Data were provided for the group titled placebo + atorvastatin 40 mg/d This last group was analysed SDs were imputed
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Unclear risk	Atorvastatin 40 mg/d; intervention was analysed, and as no placebo group was included for comparison, assessment of random sequence generation is not applicable
Allocation concealment (selection bias)	Unclear risk	Atorvastatin 40 mg/d; intervention was analysed, and as no placebo group was included for comparison, assessment of allocation concealment is not applicable
Blinding (performance bias and detection bias) All outcomes	Unclear risk	Atorvastatin 40 mg/d; intervention was analysed, and as no placebo group was included for comparison, blinding status is not applicable
Incomplete outcome data (attrition bias) All outcomes	Low risk	Data on all participants were reported
Selective reporting (reporting bias)	Low risk	All lipid parameters were measured
Other bias	Low risk	The study appears to be free of other sources of bias