Trial characteristics
| Study, year | n | Design | Blinding | Study duration, weeks | Age, years | BMI, kg/m2 | Baseline HbA1c, % | Antihyperglycemic therapy (n participants) | Diabetes duration, years | Background diet | Total fiber intake, g | Intervention dose, g | Description | Setting | Funding | Outcomes |
| Stevens et al, 198532 | 25 (M: 8, F: 17) | P | OL | 6 | I: 53±10.8 | NR | NR | None | I: 7.7±9.7 | I: increased fiber diet | I: 11.0 | 3.5 | I: 50 g oat bran as hot cereal or in muffins | OP, USA | A | HbA1c, FG |
| C: 56±10.4 | C: 3.2±2.8 | C: usual | C: 11.0 | C: no dietary intervention | ||||||||||||
| Kabir et al, 200236 | 13 (M: 13, F: 0) | CO | DB | 4 | 59±7.2 | 28±3.6 | I: 8.3±1.80 | Medication* (12); diet (1) | NR | Usual | NR† | 3 | I: cereal with muesli containing 3 g oat ß-glucan | OP, France | A, IN | HbA1c, FG, FI |
| C: 8.1±1.08 | NR† | C: wheat cereal and bread | ||||||||||||||
| Cugnet-Anceau et al, 201031 | 53 (M: 32, F: 21) | P | DB | 8 | I: 62±9.1 | I: 30.5±4.1 | I: 7.3±0.92 | Insulin or medication (9); diet and/or medication (20) | NR | Usual | I: 19.7±5.3 | 3.5 | I: oat ß-glucan-enriched soup | OP, Sweden and France | A | HbA1c, FG |
| C: 62±7.5 | C: 29.0±4.1 | C: 7.5±1.29 | Insulin or medication (12); diet and/or medication (12) | C: 22.3±12 | C: soup without oat ß-glucan | |||||||||||
| Liatis et al, 200934 | 41 (M: 23, F: 18) | P | DB | 3 | I: 60±9.1 | I: 29.6±4.8 | I: 7.3±1.61 | Medication* (19); diet (4) | I: 7.6±6 | General dietary instruction | NR | 3 | I: oat ß-glucan-enriched bread | OP, Greece | NR | HbA1c, FG, FI, HOMA-IR |
| C: 67±8.9 | C: 27.0±3.7 | C: 6.9±1.50 | Medication* (15); diet (3) | C: 10.1±8.2 | NR | C: bread made with wheat flour | ||||||||||
| McGeoch et al, 201333 | 27 (M: 18, F: 9) | CO | OL | 8 | 61±6.4 | 31.5±5.1 | 6.8±0.14 | NR | 3.1±0.7 | I: oat-enriched diet | I: 23.9 | 5.5 | I: carbohydrate content substituted for oat-based product | OP, Scotland | A | HbA1c, FG, FI, 2h-PG, HOMA-IR |
| C: healthy eating recommendations | C: 25.4 | C: standard dietary advice and avoid oats | ||||||||||||||
| Ballesteros et al, 201535 | 29 (M: 10, F: 19) | CO | SB | 5 | 54±8.3 | I: 30.8±6.5 | 6.8±0.89 | Medication* (26); insulin (6) | NR | Usual | I: 27.5±9.2 | 2.0 | I: 40 g oatmeal | OP, Mexico | IN | HbA1c, FG, FI, HOMA-IR |
| C: 30.8±6.4 | C: 26.0±10.1 | C: 1 egg | ||||||||||||||
| Li et al, 201630 | 140 (M: 80, F: 60) | P | SB | 4 | I: 59±6.1 | I: 26.9±2.7 | I: 8.4±1.44 | Medication* (43); insulin (16); combined (15) | I: 8.3±6.3 | I: low-fat and high-fiber | I: 36.1±4.2 | 2.65 | I: 50 g whole grain oats | IP, China | IN | HbA1c, FG, 2h-PG, HOMA-IR |
| C: 59±3.9 | C: 25.2±0.9 | C: 8.1±1.52 | Medication* (32); insulin (12); combined (11) | C: 6.6±3.0 | C: usual | C: 22.1±4 | C: no dietary intervention | |||||||||
| 139 (M: 72, F: 67) | P | SB | 4 | I: 59±6.8 | I: 27.4±2.4 | I: 8.3±1.35 | Medication* (47); insulin (12); combined (14) | I: 7.9±6.4 | I: low-fat and high-fiber | I: 39.0±4.8 | 5.30 | I: 100 g whole grain oats | IP, China | IN | HbA1c, FG, 2h-PG, HOMA-IR | |
| C: 59±3.9 | C: 25.2±0.9 | C: 8.1±1.52 | Medication* (32); insulin (12); combined (11) | C: 6.6±3.0 | C: usual | C: 22.1±4 | C: no dietary intervention |
*Specified oral agent.
†Treatments matched for fiber.
A, agency; BMI, body mass index; C, control; CO, crossover; DB, double-blind; F, female; FG, fasting glucose; FI, fasting insulin; HbA1c, hemoglobin A1c; HOMA-IR, homeostatic model assessment of insulin resistance; 2h-PG, 2-hour postprandial glucose from a 75 g oral glucose tolerance test; I, intervention; IN, industry; IP, inpatient; M, male; NR, not reported; OL, open-label; OP, outpatient; P, parallel; SB, single-blind.