The Effect of Improved Glycemic Control on the Composition and Function of High-Density Lipoproteins (HDL) in Patients With Type 1 Diabetes

Effect of Improved Glycemic Control on the Composition and Function of High-density Lipoproteins (HDL) in Patients With Type 1 Diabetes: a Prospective, Single-center Study. Comparison With Non-diabetic, Non-dyslipidemic Control Subjects. - HAGI-T1D Study

The HAGI-T1D study aims to determine the effect of improved glycemic control on the composition and function of high-density lipoproteins (HDL) in patients with type 1 diabetes (T1D). It requires the establishment of a biological plasma/serum bank.

T1D patients hospitalized in the Endocrinology-Diabetology-Metabolic Diseases Department at the Dijon Bourgogne University Hospital for poorly controlled diabetes (defined by glycated hemoglobin HbA1c >8.0%).

The study includes a T1D group of 80 patients with unsatisfactory glycemic control, who will undergo intensified therapy in accordance with standard clinical practice (modification of insulin therapy, therapeutic education, and lifestyle and dietary guidelines). The study also includes a control group of 63 non-diabetic, non-dyslipidemic subjects enrolled based on the results of laboratory tests from the screening visit to assess whether improved glycemic control in the T1D group restores anti-atherogenic functions and HDL composition to a level comparable to that of the control group.

Inclusion Criteria:

Control group non-diabetic and non-dyslipidemic :

• A person who has giver written consent
• Fasting blood glucose < 1,10 g/L
• Triglycerides < 1,50 g/L (< 1,70 mmol/L).
• HDL cholesterol > 1,03 mmol/L (men) or > 1,30 mmol/L (women).
• LDL cholesterol < 1,60 g/L.

Type 1 diabetes group :

• A person who has giver written consent
• Treated type 1 diabetes (regardless of the route of insulin administration).
• HbA1c > 8.0% (> 64 mmol/mol).

Exclusion Criteria:

All participants :

• A person who is not enrolled in or eligible for a social security program
• A person subject to a legal protective measure (guardianship, tutorship)
• A person subject to a judicial protective measure
• Pregnant women, women in labor, or breastfeeding women
• Adults who are legally incompetent or unable to give informed consent
• Minors
• Systemic inflammatory disease
• Medications that affect lipoprotein metabolism: immunosuppressive therapy, long-term corticosteroid therapy.

Control group non-diabetic and non-dyslipidemic :

• Diabetes or use of an antidiabetic medication.

• Dyslipidemia or use of lipid-lowering medication.

• Cardiovascular disease (history of stroke, myocardial infarction, coronary artery disease).

• Kidney disease (glomerular filtration rate CKD-EPI < 75 mL/min/1.73 m²)

• Presence of metabolic syndrome defined by the presence of at least three of the following criteria (NCEP-ATP III criteria):

  • waist circumference > 102 cm in men, > 88 cm in women;
  • fasting triglycerides > 1.70 mmol/L ( > 1.50 g/L);
  • HDL cholesterol > 1.03 mmol/L in men and 1.29 mmol/L in women;
  • systolic blood pressure ≥ 130 mmHg and/or diastolic blood pressure ≥ 85 mmHg;
  • fasting blood glucose ≥ 6.10 mmol/L (≥ 1.10 g/L).

Type 1 diabetes group:

• Diagnosis of type 1 diabetes within 12 months prior to enrollment.
• Glomerular filtration rate (CKD-EPI) < 60 mL/min/1.73 m².
• Albuminuria ≥ 30 mg/g creatinine.
• Initiation of lipid-lowering therapy within the month prior to the study.

Exclusion criteria:

Type 1 diabetes group:

- Initiation of lipid-lowering therapy during the 3 months of the study