High density lipoprotein and diabetes mellitus

Area of Science:

• Metabolic disorders
• Cardiovascular health
• Lipid metabolism

Background:

• Non-insulin-dependent diabetes mellitus (NIDD) is associated with altered high-density lipoprotein (HDL) metabolism.
• Understanding HDL subfractions (HDL2-C, HDL3-C) and apolipoproteins (apo AI, apo AII) is crucial for assessing cardiovascular risk in diabetics.

Purpose of the Study:

• To investigate HDL metabolism in NIDD patients.
• To determine the effect of different diabetes treatments (insulin, oral agents, diet) on HDL parameters.
• To assess the relationship between HDL components and ischemic heart disease (IHD) in diabetics.

Main Methods:

• Serum levels of HDL2-C, HDL3-C, apo AI, and apo AII were measured.
• NIDD patients were categorized into insulin-treated, oral agent-treated, and diet-only groups.
• Comparisons were made with age- and risk-factor-matched normal subjects.
• Diabetic patients were further stratified based on the presence or absence of IHD.

Main Results:

• Insulin treatment significantly increased serum HDL2-C levels compared to normal controls, irrespective of total cholesterol, triglycerides, obesity, or age.
• No significant changes in HDL2-C were observed in patients treated with oral agents or diet alone.
• Serum apo AI and apo AII levels were significantly lower in diabetic patients with IHD compared to those without IHD.
• No significant difference in apo AI and apo AII levels was found between the insulin-treated group and normal controls.

Conclusions:

• Insulin therapy appears to elevate HDL2-C levels in NIDD, potentially increasing the cholesterol-to-apoprotein ratio in HDL2.
• Reduced levels of apo AI and apo AII are associated with an increased risk of IHD in diabetic individuals.
• Apo AI and apo AII play a significant role in the prevention of IHD development in diabetic patients.