Dietary guar gum supplementation does not modify insulin resistance in gross obesity

Obesity is considered an insulin resistant state. Dietary guar gum supplementation is able to reduce blood glucose and plasma insulin response to a carbohydrate meal. In order to evaluate whether guar is able to reduce hyperinsulinemia and insulin resistance in gross obesity, we studied 9 obese patients, >50% overweight with impaired glucose tolerance before and after 4+4 g/day guar for 6 weeks. Six patients repeated the treatment with 8+8 g/day guar after a 3-month interval. Guar was added to the usual diet in order to maintain the body weight constant. Pre-treatment and post treatment study included: total specific insulin binding on circulating monocytes; 3H-glucose infusion and euglycemic hyperinsulinemic clamp at ∼100 μU/ml. The differences between post-treatment and pre-treatment values were not significant for any of the parameters studied. Fasting glucose production was: 2.17±0.33 SEM (pretreatment)vs 2.18±0.18 (4+4 g/day)vs 2.28±0.14 (8+8 g/day) mg/kg/min; glucose utilization was: 3.52±0.43 vs 3.22±0.44 vs 3.49±0.63 mg/kg/min; total specific insulin binding was: 2.80±0.20 vs 2.75±0.25 vs 2.78±0.31%; body weight was: 101.4±5.4 vs 100.2±6.2 vs 100.5±7.0 kg. These results indicate that dietary guar gum supplementation per se is unable to reduce insulin resistance in gross obesity if overweight is maintained constant.