These results indicate that apple cider vinegar improved the serum lipid profile in normal and diabetic rats ... and may be of great value in managing the diabetic complications.
ACV consumption significantly decreased serum total cholesterol, fasting plasma glucose, and HbA1C concentrations. The stratified analysis revealed a significant reduction of serum TC and TG in a subgroup of patients with type 2 diabetes. "...a significant favorable effect of ACV consumption on FPG and blood lipid levels."
There is considerable support for vinegar having a positive acute effect on blood glucose levels when combined with carbohydrate-rich meals. "...daily vinegar intake in amounts of ∼10-30 mL (∼2-6 tablespoons) appear to improve the glycemic response to carbohydrate-rich meals."
Supplementation of a meal based on white wheat bread with vinegar reduced postprandial responses of blood glucose and insulin, and increased the subjective rating of satiety.