Kleefstra 2006.
| Methods | Parallel randomised controlled clinical trial | |
| Participants |
Inclusion criteria: Individuals with type 2 diabetes, glycosylated haemoglobin (A1c) ≥ 8%, daily use of insulin ≥ 50 units, creatinine ≤ 150 μmol/L for men and ≤ 120 μmol/L for women, creatinine clearance ≥ 50 ml/min, alanine aminotransferase ≤ 90 units/L and age < 75 years Exclusion criteria: included pregnancy, or intention to become pregnant during the study, and a history of liver or renal disease Diagnostic criteria: BMI, A1c |
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| Interventions |
Number of study centres: 1 Treatment before study: not stated Titration period: not stated |
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| Outcomes | Outcomes reported in abstract of publication: A1c, BMI, blood pressure, lipid profile and insulin requirement. | |
| Study details |
Run‐in period: 6 months Study terminated before regular end: no |
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| Publication details |
Language of publication: English Commercial / non‐commercial / other funding: not stated Publication status: peer review journal |
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| Stated aim for study | Quote: "To determine the effect of chromium treatment on glycemic control in a western population of insulin‐dependent patients with type 2 diabetes". | |
| Notes | Abbreviations: BMI: body mass index | |
| Risk of bias | ||
| Bias | Authors' judgement | Support for judgement |
| Random sequence generation (selection bias) | Low risk | Comment: computer‐generated randomisation list |
| Allocation concealment (selection bias) | Low risk | Comment: independent pharmacists dispensed either chromium capsules or placebo in numbered containers according to a computer‐generated randomisation list. |
| Blinding of participants and personnel (performance bias) Objective outcomes | Low risk | Quote: "All capsules, including placebo, were furnished by our hospital pharmacy and were indistinguishable from each other. Neither the researchers nor the patients knew into which group they had been randomised" |
| Blinding of participants and personnel (performance bias) Subjective outcomes | Unclear risk | Quote: "All capsules, including placebo, were furnished by our hospital pharmacy and were indistinguishable from each other. Neither the researchers nor the patients knew into which group they had been randomised" |
| Blinding of outcome assessment (detection bias) Objective outcomes | Low risk | Comment: no details provided |
| Blinding of outcome assessment (detection bias) Subjective outcomes | Unclear risk | Comment: no details provided |
| Incomplete outcome data (attrition bias) Objective outcomes | Low risk | Comment: no attrition bias was detected |
| Incomplete outcome data (attrition bias) Subjective outcomes | Low risk | Quote: "Of 53 patients randomised, 1 patient was lost to follow‐up, and all attempts to locate this participant were in vain (telephone contact, letters, and visits). Six other individuals, one in the placebo group, three in the 500 µg group, and two in the 1,000 µg group, discontinued the study for the following reasons: one patient required a blood transfusion and was hospitalised, and three other patients were hospitalised due to percutaneous transluminal coronary angioplasty, chronic obstructive pulmonary disease, and glycemic dysregulation.Two patients discontinued the study due to possible adverse effects. Unfortunately, intention‐to‐treat analyses were not possible because for five of six excluded patients follow‐up data were lacking. However, the main conclusions of the per‐protocol analyses would likely not have been different in an intention‐to‐treat analyses" |
| Selective reporting (reporting bias) | Low risk | Comment: all of the outcomes listed in the methods section were reported as results |
| Other bias | Low risk | Comment: no other details given to assess whether an important risk of bias exists |