Abstract
Objective To determine the extent to which intensive dietary intervention can influence glycaemic control and risk factors for cardiovascular disease in patients with type 2 diabetes who are hyperglycaemic despite optimised drug treatment.
Design Randomised controlled trial.
Setting Dunedin, New Zealand.
Participants 93 participants aged less than 70 years with type 2 diabetes and a glycated haemoglobin (HbA(1c)) of more than 7% despite optimised drug treatments plus at least two of overweight or obesity, hypertension, and dyslipidaemia.
Intervention Intensive individualised dietary advice (according to the nutritional recommendations of the European Association for the Study of Diabetes) for six months; both the intervention and control participants continued with their usual medical surveillance.
Main outcome measures HbA(1c) was the primary outcome. Secondary outcomes included measures of adiposity, blood pressure, and lipid profile.
Results After adjustment for age, sex, and baseline measurements, the difference in HbA(1c) between the intervention and control groups at six months (-0.4%, 95% confidence interval -0.7% to -0.1%) was highly statistically significant (P=0.007), as were the decreases in weight (-1.3 kg, -2.4 to -0.1 kg; P=0.032), body mass index (-0.5, -0.9 to -0.1; P=0.026), and waist circumference (-1.6 cm, -2.7 to -0.5 cm; P=0.005). A decrease in saturated fat (-1.9% total energy, -3.3% to -0.6%; P=0.006) and an increase in protein (1.6% total energy, 0.04% to 3.1%; P=0.045) in the intervention group were the most striking differences in nutritional intake between the two groups.
Conclusions Intensive dietary advice has the potential to appreciably improve glycaemic control and anthropometric measures in patients with type 2 diabetes and unsatisfactory HbA(1c) despite optimised hypoglycaemic drug treatment.