Effects of dietary fiber and insulin treatment on serum levels of lipids and lipoprotein (a) in patients with type II diabetes mellitus]

OBJECTIVE. As lipoprotein(a) is an independent risk factor for the development of coronary heart disease we determined the effect on serum lipid and lipoprotein(a) levels of dietary fibre and of treatment with insulin in patients with diabetes mellitus type II. METHODS. Twelve type II diabetic patients (mean age 62 (SD 10) yrs, body mass index 25.8 (SD 3.5) kg/m2), all treated with oral antidiabetic agents, were studied in a randomised cross-over trial, in which they used breads meals prepared with guar gum (a mean of 11.2 g guar per day) for 3 months in comparison with normal high-fibre bread. Fifteen other patients (age 70 (8), BMI 27.4 (5.6) kg/m2) poorly controlled on oral hypoglycaemic agents, were treated with insulin. RESULTS. The guar treatment of the 12 patients resulted in lower total cholesterol (5.24 vs 5.7 mmol/l, p less than 0.1) and LDL cholesterol (3.77 vs 4.33 mmol/l, p less than 0.001) in comparison with normal high-fibre bread. Lipoprotein(a) levels were not different (76 vs 82 mg/l). Insulin therapy in the 15 other patients decreased HbA1c levels after 6 months from 11.0 to 7.7% (p less than 0.001), total cholesterol from 6.8 to 6.1 mmol/l (p less than 0.05), and LDL cholesterol from 4.4 to 4.1 mmol/l (p less than 0.05). Lp(a) decreased only slightly in 11/15 patients, from 491 to 441 mg/l (p = 0.07). CONCLUSION. Neither the use of the dietary fibre guar nor improved metabolic control with insulin therapy lowered elevated lipoprotein(a) levels in type II diabetic patients.