Hypoglycaemia: a high-fibre diet helps reduces episodes

Clinical bottom line (level 1b)

  1. Patients with type 1 diabetes who take a high-fibre diet compared with a low-fibre one have lower mean daily blood glucose levels (on average 2.7 mmol/l lower) and fewer hypoglycaemia episodes per month (on average 0.8 fewer).
Giacco et al: Diabetes Care 2000; 23 : 1461-1466
Expires October 2003

The study

Unblinded ?concealed randomised trial without intention-to-treat
Setting: university hospital, Italy

63 patients (aged mean 28, 61% male) with type 1 diabetes

Excluded if
  • symptomatic cardiovascular disease
  • renal failure
  • liver disease

Control Group: (n = 31, 25 analysed): low-fibre diet (15 g/day) - patients were advised to limit legumes to less than once a week, to consume preferentially bananas, fruit juice, tomatoes, lettuce, red cabbage and peppers.
Experimental Group: (n = 32, 29 analysed): high-fibre diet (50 g/day) - patients were advised to eat one serving of legumes, three servings of fruit (such as apples, oranges, pears) and two servings of vegtables (such as artichokes, eggplants, mushrooms and broccoli)
The diets were otherwise similar in terms of protein, fat and carbohydrate content.
86% followed for 6 months

The evidence

Outcome Control Group
(SD)		 Experimental Group
(SD)		 Mean Difference
(95% CI)
hypoglycaemic events per patient per month 1.5
(1.2) 		0.73
(0.7) 		0.8
(0.2 to 1.3)
mean daily blood glucose (mmol/l) 14.5
(4.5) 		11.8
(3.3) 		2.7
(0.6 to 4.8)

Comments

  1. 83% of the patients in the high-fibre group were compliant with the diet compared with 88% in the low-fibre group.
  2. Patients were enrolled in a study on acarbose at the time - similar numbers of patients were treated with acarbose in both groups.

Citation

  1. Giacco R, Parillo M, Rivellese AA, et al: long-term dietary treatment with increased amounts of fiber-rich low-glycemic index natural foods improves blood gluocse control and reduces the number of hypoglycaemic events in type 1 diabetic patients. Diabetes Care 2000; 23 : 1461-1466
Search Terms: from ACP Journal Club Other articles noted
Contributor: Chris Ball, October 2001
Reviewer: Clare Wotton

Clinical Question.
Patient type 1 diabetes
Intervention or Exposure high-fibre diet
Outcome hypoglycaemia