Effects of moderate sugar intake on glycaemic control of patients with type 2 diabeted mellitus

[摘要] English: The prevalence of diabetes mellitus in South African communities isincreasing aggressively, due to population and lifestyle changes associatedwith rapid urbanization. It is estimated that the prevalence of diabetes is dueto triple within the next 25 years. Currently 10% of the total energy intake assucrose is allowed as part of a balanced diabetic diet, according to theDiabetes Education Society in Southern Africa. Health professionals areignorant and/or sceptical about this guideline and are reluctant to advise thepatients they consult with.The aim of this study was to evaluate the effects of 15% of the total dailyenergy intake as sucrose on the glycaemic control of patients with type 2diabetes mellitus. To accomplish this aim, the effects of the inclusion of 15%of the total daily energy intake as sucrose were compared to the exclusion ofsucrose in the diets of free-living patients with type 2 diabetes mellitus onglycaemic control (fasting plasma glucose concentrations, serumfructosamine, HbA1cpercentages) and lipid profiles (serum cholesterol, serumHDL cholesterol, serum LDL cholesterol and serum triglycerides).The study was a randomized, controlled, single-centre clinical trail. Only 22of the possible 401 subjects screened, who had type 2 diabetes mellitus(determined by GAD 65 and C-peptide values), and who volunteered tocomply with a prescribed diet for the 16 week study period, participated in thestudy. At baseline, a food record and validated quantitative food frequencyquestionnaire was filled in by the researcher. Anthropometricalmeasurements (weight, height, BMI and body-fat percentage) were measured,and blood samples were analysed. Prior to baseline, subjects were advised toincrease their activity level as part of a healthy lifestyle. Lifestyle patterns(smoking, alcohol consumption, exercise and medication) had to bemaintained throughout the study period. Individual diets were calculated for allsubjects. After a 12 week period during which all subjects were stabilized on adiabetic diet, subjects were randomized into two groups. Group 1, received asucrose inclusive diet (SlD) and Group 2, a sucrose free diet (SFD), for a fourweek trial period. The type of control, namely, oral medication and diet alone,stratified these groups. There was, thus, a separate computer-generatedrandomization list for each of these two strata; randomizing the subjects into astudy and control group. During the entire 16 week study period theresearcher and' nurse had contact sessions with the subjects (fortnightly andweekly, respectively). A short informative talk to motivate and encouragesubjects to adhere to, and gain insight into dietary aspects of type 2 diabetesmellitus, was given by the researcher. A registered nurse measured weightand venous plasma glucose concentrations of all subjects on a weekly basis.The registered nurse measured serum fructosamine concentrations on afortnightly basis. At the end of the study each subject's body-fat percentagewas measured and fasting blood samples (blood lipid concentrations andHbA1c percentages) were analyzed statistically to test for significantdifferences between the two dietary groups.The habitual dietary intake after recruitment showed that all subjects followeda low carbohydrate, high fat diet. The habitual sucrose intake in Group 1(SlD) showed a sugar intake of 4.5%, and Group 2 (SFD) of 4.2%,respectively. The mean BMI of subjects in both groups was within the class I,obese range (BMI= 30-34.9kg/m2). Although all subjects in the study showedweight maintenance, both dietary groups experienced reduction in their body-fatpercentage. However, Group 2 (SFD) showed statistically significantimprovement (95% Cl: -8.5;-0.6) in body-fat percentage (4.5%). The reductionin body-fat percentage of Group 1 (SlD) could be considered as clinicallysignificant (1.1%). No differences occurred in body-fat percentage betweenthe groups. The fact that there was a change in body composition withoutweight loss may be attributed to the strict compliance and adherence of .subjects to their dietary guidelines and exercise. The mean plasma glucoseconcentrations for both groups were within the acceptable glycaemic controlreference range of 6-8 mmol/I throughout the study period. The mean serumfructosamine concentrations of Group 1 (SlD) remained unchanged during thetrial period. The mean serum fructosamine concentrations of Group 2 (SFD)showed statistically significant improvement (95% Cl: -25.3;-3.2) during thetrial period. No significant differences were observed between the twogroups. Both groups maintained a mean HbA1c percentage within the optimalfasting reference range of < 7% throughout the study period. Group 1 (SlD)showed an improvement (from 6.8% at baseline to 6.3% at the end of thestudy period) in HbA1c percentage that were close to statistical significanceand were clinically significant, while Group 2 (SFO) showed a statisticallysignificant improvement (95% Cl: -2.6;-0.2).It can be concluded that subjects with type 2 diabetes mellitus can safelyinclude a moderate amount (15% of the total energy) of sucrose in a balanceddiet, without deleterious effects on their glycaemic control. The long termglycaemic control (as measured by the HbA1c percentages) improved withgood dietary compliance in both diets that included/excluded sucrose. Resultsof this study suggest that moderate intake of sucrose (15% of the total energy)had no aggravating effects on blood lipid concentrations of these subjects fora trial period of four weeks. However, the long term effects of sucrose onblood lipid concentrations could not be assessed. This sucrose modification inthe diabetic diet may lead to improved adherence by subjects, as it minimizesthe sense of deprivation. The inclusion of moderate sucrose in a balanceddiet will enhance overall palatability and might improve long term compliance.Compliance to a balanced diet will improve diabetic control. Furthermore,fewer restrictions in the diet of subjects with type 2 diabetes mellitus may alsolead to a reduction in short and long term complications. More research isneeded to determine the long term effects of sucrose on blood lipidconcentrations in subjects with type 2 diabetes mellitus.If health care workers continue to be reluctant to advise the inclusion ofsucrose in the type 2 diabetic diet, because of personal prejudice or ignoranceregarding the benefits of research such as this, it may create confusion anddisbelief among diabetic patients concerning the efficacy of the diet. Thecolloquial concept of diabetes mellitus being merely a sugar disease, andthe misconception that sucrose causes diabetes mellitus, should be dispelledforthwith.

[发布机构] University of the Free State