RESUMO
OBJECTIVES: The aim of this study was to compare the effect of a simple dietary advice with two energy-restricted diets with different carbohydrate and fiber contents on anthropometric, biochemical, and inflammatory markers over an 8-wk intervention period in individuals with diabetes. METHODS: Forty-seven patients with type 2 diabetes (31 women and 16 men; age: 52.9 ± 8.0 years, body mass index: 29.5 ± 4.9 kg.m-2) completed an 8-wk randomized intervention trial that compared a simple dietary advice aimed to modulate carbohydrate intake (n = 13) with the two calorie-restricted (CR) diets (25% caloric restriction from total energy requirements) differing with regard to carbohydrate and fiber content, one with higher fiber (CRHF) containing 55% energy from carbohydrate plus a tablespoon of psyllium powder (n = 18) and the other with lower carbohydrate (CRLC) containing 40% energy from carbohydrate plus placebo powder (n = 16). Weight, plasma concentrations of glucose, insulin, lipids, interleukin-6 (IL-6), and tumor necrosis factor alpha (TNF-α) were determined at baseline and after 8 weeks. RESULTS: The mean change of body weight and plasma lipids were not different between the groups. Fasting plasma insulin and the homeostasis model assessment of insulin resistance (HOMA-IR) were significantly lower in the CRHF group (changes from baseline values in simple advice, CRHF, and CRLC were 1.3 ± 1.9, -1.0 ± 1.2, and 0.3 ± 3.1 µIL/mL for insulin and 0.5 ± 0.7, -0.3 ± 0.6, and 0.2 ± 0.9 for HOMA-IR, respectively). The levels of IL-6 significantly decreased in the CRHF and CRLC groups (changes from baseline values in simple advice, CRHF, and CRLC were 7.5 ± 6.8, -1.2 ± 4.7, and -4.2 ± 5.6 pg/mL, respectively). TNF-α levels were significantly lower only in the CRHF compared to the advice group (P < 0.05). CONCLUSIONS: Our results suggest that in comparison with simple advice to modify carbohydrate intake, a calorie-restricted, moderate carbohydrate diet supplemented with psyllium has better effects on plasma insulin and pro-inflammatory cytokines in patients with type 2 diabetes.
RESUMO
The purpose of this study was to compare effects of a moderate carbohydrate diet supplemented with psyllium with those of a lower carbohydrate diet supplemented with placebo powder on glycemic control in patients with type 2 diabetes (T2D). In an open randomized controlled trial, 37 patients with T2D with body mass index (BMI) 25-35 kg/m2 received either a low-energy, moderate carbohydrate diet plus 7 grams of psyllium powder (MoCyllium group) or a low-energy, lower carbohydrate diet plus placebo powder (LoCarb group) for 2 weeks. Fasting and 2-hour postprandial plasma glucose, insulin, and tumor necrosis factor-α (TNF-α) as well as the homeostasis model assessment of insulin resistance (HOMA-IR) were determined at the beginning and end of the 2-week period. Postprandial samples were obtained after ingestion of a standardized breakfast meal in both groups. Body weight change did not differ between the two groups. There was no significant intervention effect on fasting plasma glucose. Fasting plasma insulin and TNF-α significantly decreased from baseline in the MoCyllium group (p = .01). The differences of absolute change of insulin and TNF-α between the groups were statistically significant (p = .002 and p = .017, respectively). Insulin sensitivity, evaluated by HOMA-IR, increased significantly in the MoCyllium group (p = .016), and comparison of absolute change between the groups showed a trend toward statistical significance. No statistical differences were detected among postprandial glucose, insulin, and TNF-α concentrations. The finding supports the concept that in diabetic patients with cultural preferences to a higher carbohydrate diet, an increase in soluble fiber intake should be encouraged.
