Effects of three months' diet after diagnosis of Type 2 diabetes on plasma lipids and lipoproteins (UKPDS 45). UK Prospective Diabetes Study Group.

AIMS: To assess the effect of diet on fasting plasma lipids and lipoproteins in patients with newly diagnosed Type 2 diabetes. METHODS: A total of 2,906 patients each underwent 3 months' diet therapy before allocation to therapy in a randomized controlled clinical trial. Lipids and lipoproteins were measured at diagnosis and after 3 months' diet. RESULTS: The mean body weight at diagnosis was 83 kg. Weight decreased after diet by a mean of 4.5 kg; body mass index (BMI) decreased by 1.51 kg/m2; plasma glucose fell by 3 mmol/l from 11 mmol/l; and HbA1c by 2% from 9%. Triglyceride concentrations were reduced in men by -0.41 (95% confidence interval (CI) -0.47 to - 0.35) mmol/l from a geometric mean 1.8 (1 SD interval 1.0-3.0) mmol/l, and in women by -0.23 (-0.28 to -0.18) mmol/l from a similar level. Cholesterol decreased in men by -0.28 (-0.33 to -0.24) mmol/l from 5.5 (1.1) mmol/l, and in women by -0.09 (-0.14 to -0.04) mmol/l from 5.8 (1.2) mmol/l with corresponding changes in LDL cholesterol. HDL cholesterol increased in men by 0.02 (0.01 to 0.04) mmol/l and in women by 0.01 (0 to 0.02) mmol/l. Triglyceride concentration in the top tertile was reduced by 37% in men (> 2.1 mmol/l) and by 23% in women (> 2.2 mmol/l) with regression to mean accounting for 13% and 6%, respectively. Similarly cholesterol in the top tertile was reduced by 12% in men (> 5.8 mmol/l) and 7% in women (> 6.2 mmol/l) with 6% of the decrease in both men and women accounted for by regression to the mean. CONCLUSIONS: Initial dietary therapy in patients with newly diagnosed Type 2 diabetes substantially reduced plasma triglyceride, marginally improved total cholesterol and subfractions, and resulted in a potentially less atherogenic profile, although this did not eliminate the excess cardiovascular risk in patients with Type 2 diabetes.

UKPDS 18: estimated dietary intake in type 2 diabetic patients randomly allocated to diet, sulphonylurea or insulin therapy. UK Prospective Diabetes Study Group.

Self-reported dietary intake was estimated from 3-day prospective food diaries completed by Type 2 diabetic patients in the UK Prospective Diabetes Study. All patients had received individual dietary advice and had been randomly allocated to diet, sulphonylurea or insulin therapy 3 months after diagnosis. A total of 132 patients (120 white Caucasian, 12 Asian) stratified for gender, obesity and allocated therapy with mean age 55 years (SD 8), body mass index 28 kg m-2 (SD 4), and with a diabetes duration of 3 to 6 years were selected at random from 5 of 23 clinical centres. Patients reported a similar proportion of their energy intake as carbohydrate (43%) to the general population and had not increased to the recommended 50-55%. Their protein intake (21%) was higher than the advised 10-15%. Estimated energy intake from fat (37%) was close to that recommended for diabetic patients (30-35%) and was lower than that reported for the UK population (40%). The estimated polyunsaturated/saturated fat intake ratio (0.48) was higher than that reported for the UK population (0.35) compared with the recommended 1.0. Mean fibre intake at 22 g day-1 was less than the recommended 30 g day-1. The 8 male Asian patients took a higher proportion of their dietary intake as fat (46% vs 37%) and lower as protein (14% vs 21%) than the male white Caucasian patients. No significant differences were seen in estimated nutrient constituents between patients allocated to diet, sulphonylurea or insulin therapy as part of the UK Prospective Diabetes Study and followed for mean 4.2 years (SD1.6). This suggests that dietary factors will not confound UK Prospective Diabetes Study treatment related analyses.