Impact of a Nutritional Intervention on Type1 Diabetes Adult With Metabolic Syndrome (MEDIT)

Recent studies have found that up to 45 % of patients with type 1 diabetes have metabolic syndrome, a cluster of conditions (abdominal obesity, hypertension, dyslipidemia, insulin resistance) that increase the cardiovascular risk. The investigators have observed in previous studies a strong association between the adherence to a Mediterranean diet and the prevalence of metabolic syndrome on patients with metabolic syndrome. However, no intervention has been realized on this population and the current recommendations (low fat diet) differ from the Mediterranean diet. A nutritional intervention on the principles of the Mediterranean diet could therefore play a role in the treatment of the metabolic syndrome in Type 1 diabetes patients. The main objective of this study is to examine the impact of a nutritional intervention on the waist circumference after 6 months of an intervention group (Mediterranean diet) versus a control group (low fat diet).

Participants will receive nutritional lessons on the principles of the Mediterranean diet. This type of diet is defined with a carbohydrate intake of 45-55% of total energy intake, 15-20% of proteins, 30-35% of lipids and less than 7% for saturated fat. Nine sessions with a nutritionist are planned to cover various topics of the diet.

Participants will receive nutritional lessons on the principles of the low fat diet. This type of diet is defined with a carbohydrate intake greater than 45% of total energy intake, 15-20% of proteins, less than 30% of lipids and less than 7% for saturated fat. Nine sessions with a nutritionist are planned to cover various topics of the diet.

Carbohydrate counting will be reviewed, as well as hypoglycemia management. The 9 following visits will focus on different aspects of each diets: types of fats, meat and alternatives, grain products, milk and alternatives, fruits and vegetables, salt intake, energy density and restaurants.

The outcome will be measured every month, at admission and visits 4 (1 month) - 6 (2 months) -7 (3 months) -8 (4 months) -9 (5 months) -10 (6 months) -11 (9 months).

The questionnaire allows the calculation of a score reflecting the adherence to the mediterranean diet.

The outcome will be measured based on an internet food frequency questionnaire filled by patients at admission, visit 7 (3 months) and visit 10 (6 months).

Weight wil be measured every month: at admission and visit 4 (1 month), 6 (2 months), 7 (3 months), 8 (4 months), 9 (5 months) and 10 (6 months). The height will be measured only at admission.

The outcome will be estimated based on a formula validated for type 1 diabetes subjects. The formula takes into account waist/hip ratio, glycated hemoglobin and hypertension.

Glycated hemoglobin will be measured with a blood sample. Hypoglycemia frequency will be measured with a 4-day glycemia journal.

Inclusion Criteria: Type 1 Diabetes for at least 12 months On intensive insulin therapy with multiple daily injections or on insulin pump Be overweight or obese (BMI≥25 kg/m2) Stable weight for at least 3 months If on medication for thyroid, hypertension or dislipidemia: stable doses in the last 3 months Presenting at least 3 of the 5 following criteria for metabolic syndrome: Waist circumference >102cm ♂ or >88cm ♀ Triglycerides >1.7mmol/L or medication Cholesterol-HDL <1.0mmol/L ♂ or <1.3mmol/L ♀ or medication Blood pressure ≥130/85 mmHg or medication Estimated insulin resistance (eGDR <6.29) Exclusion Criteria: Mental incapacity, refusal or linguistic barrier that could affect comprehension or cooperation with the study Ongoing pregnancy Diet corresponding to the criteria of a mediterranean diet (score≥27) Vegetarianism Major diabetes complications

Fortin A, Rabasa-Lhoret R, Lemieux S, Labonte ME, Gingras V. Comparison of a Mediterranean to a low-fat diet intervention in adults with type 1 diabetes and metabolic syndrome: A 6-month randomized trial. Nutr Metab Cardiovasc Dis. 2018 Dec;28(12):1275-1284. doi: 10.1016/j.numecd.2018.08.005. Epub 2018 Aug 30.