Changes in high-density lipoprotein cholesterol (HDL-C) level and the ratio of triglycerides to HDL-C during the first year of type 1 diabetes.

Introduction: Patients in an insulin‑deficient state show reduced high‑density lipoprotein cholesterol (HDL‑C) levels. Insulin treatment affects lipid metabolism in this population. There have been no prospective studies evaluating changes in lipid profile after the diagnosis of type 1 diabetes (T1D).

Objectives: We investigated the effect of subcutaneous insulin therapy initiation on quantitative changes in HDL‑C levels and other components of lipid profile in patients with newly diagnosed T1D.

Patients And Methods: A total of 127 patients with newly diagnosed T1D aged 28 years (interquartile range, 23-34 years) were enrolled in the InLipoDiab1 study. The lipid profile was assessed before the first injection of insulin (baseline) and after 3 and 12 months of insulin therapy. The daily dose of insulin (DDI) was defined as the requirement for insulin per kilogram body weight per day. The DDI was calculated at hospital discharge and during visits in an outpatient clinic at 3 and 12 months.

Results: We observed a persistent increase in HDL‑C levels at 3 and 12 months versus baseline (P <0.001) in men and women. Moreover, a reduction was observed in triglyceride levels (P <0.001) and the ratio of triglycerides to HDL‑C (P <0.001) in men and women. In contrast, a decrease was observed in low‑density lipoprotein cholesterol and non‑HDL‑C levels (P <0.001), but only in men.

Conclusions: Subcutaneous insulin therapy reverses the impaired phenotype of lipoproteins during the first year of treatment. Changes in lipoprotein levels in newly diagnosed T1D differ depending on sex.