| Methods |
74 insulin‐dependent diabetic participants with background retinopathy were randomized to continue with usual diabetic care (group U) or to a more intensive program (group A) using ultralente insulin as basal cover and soluble insulin at mealtimes |
| Participants |
Participants attending routine diabetic clinics were screened for retinopathy by ophthalmoscopy through dilated pupils. Reasons for exclusion were age over 60 years; proliferative retinopathy; renal impairment (plasma creatinine > 175 mol/L), more than one significant cardiovascular event (or one within the previous year); and other major disease processes. Opacities of the ocular media sufficient to impair detailed retinal observation precluded study. |
| Interventions |
The U group continued their usual therapy and attended the routine diabetic clinic. Participants in group A (alternative therapy) were treated more intensively; they were seen at least 6‐weekly in a special clinic set aside for the purpose. Individual dietary advice, given by a single dietitian, aimed to maintain ideal body weight and to adjust the timing and size of meals to help optimize control. Approximately 50% of total daily energy intake was derived from carbohydrate (predominantly fiber‐rich complex carbohydrate) and 30% to 35% of energy from fat. The use of polyunsaturated fat was encouraged. With the aid of a research nurse, all participants were intensively educated in the care of their diabetes. They were taught home blood glucose monitoring with an 'Autolet,16' and either 'BM Glycaemie 20‐800' sticks (Boehringer) or 'Dextrostix' (Ames) with a 'Hypocount' meter (Hypoguard). Participants were encouraged to test 4 times a day (before breakfast, lunch, dinner, and bed) at least twice a week. They were asked to aim for preprandial blood glucose values between 4 mmol/L and 7 mmol/L by adjusting insulin doses on the basis of results obtained. Advice was available over the telephone at any time. Each participant kept a logbook of glucose levels, hypoglycemic episodes, insulin doses, and other events which might relate to their diabetes. |
| Outcomes |
The vibration sensory threshold was assessed with a 'Biothesiometer' 17 (Biomedical Instrument Co., Newbury, Ohio); in each case the mean of 3 readings over both lateral malleoli and the medial border of the distal phalanx of both great toes was recorded. All readings were made by the same research nurse who was aware of the participant’s group but had no record of previous measurements. |
| Notes |
|
| Risk of bias |
| Bias |
Authors' judgement |
Support for judgement |
| Random sequence generation (selection bias) |
Low risk |
Stratified by weight and blood pressure. |
| Allocation concealment (selection bias) |
Low risk |
Sealed envelopes |
| Blinding (performance bias and detection bias)
All outcomes |
High risk |
Research nurse was not blinded |
| Incomplete outcome data (attrition bias)
All outcomes |
Low risk |
2 died (1 each), 3 conventional participants withdrew versus 0 intense participants |
| Selective reporting (reporting bias) |
High risk |
They report vibration perception threshold of the medial malleolus but not at the great toe |
| Other bias |
Low risk |
None |
