Abstract 423: A Combination of Metformin, Quercetin, and Curcumin Restores HDL Function and Improves Atherosclerosis Burden in LDLr-/-/ob.ob leptin-/- and LDLr-/- Mice by attenuating Insulin Resistance, Hyperglycemia, and Low-grade Inflammation

Life-style-induced metabolic derangement and epigenetic changes promote diabetes and oxidative stress leading to NASH and atherosclerosis severity

Energy imbalance resulting from high calorie food intake and insufficient metabolic activity leads to increased body mass index (BMI) and sets the stage for metabolic derangement influencing lipid and carbohydrate metabolism and ultimately leading to insulin resistance, dyslipidemia, and type 2 diabetes. 70% of cardiovascular disease (CVD) deaths occur in patients with diabetes. Environment-induced physiological perturbations trigger epigenetic changes through chromatin modification and leads to type 2 diabetes and progression of nonalcoholic fatty liver disease (NAFLD) and CVD. Thus, in terms of disease progression and pathogenesis, energy homeostasis, metabolic dysregulation, diabetes, fatty liver, and CVD are interlinked. Since advanced glycation end products (AGEs) and low-grade inflammation in type 2 diabetes play definitive roles in the pathogenesis of liver and vascular diseases, a natural checkpoint to prevent diabetes and associated complications appears to be the identification and management of prediabetes together with weight management, since 70% of prediabetic individuals develop diabetes during their life time, and every kg of weight increase is associated with up to 9% increase in diabetes risk. A good proportion of diabetes and obesity population have fatty liver that progresses to non-alcoholic steatohepatitis (NASH) and cirrhosis, and increased risk of hepatocellular carcinoma. Diabetes and NASH both have elevated oxidative stress, impaired cholesterol elimination, and increased inflammation that leads to CVD risk. This review addresses life-style-induced metabolic pathway derangement and how it contributes to epigenetic changes, type 2 diabetes and NASH progression, which collectively lead to increased risk of CVD.

Dysfunctional HDL in diabetes mellitus and its role in the pathogenesis of cardiovascular disease

Coronary artery disease, the leading cause of death in the developed and developing countries, is prevalent in diabetes mellitus with 68% cardiovascular disease (CVD)-related mortality. Epidemiological studies suggested inverse correlation between HDL and CVD occurrence. Therefore, low HDL concentration observed in diabetic patients compared to non-diabetic individuals was thought to be one of the primary causes of increased risks of CVD. Efforts to raise HDL level via CETP inhibitors, Torcetrapib and Dalcetrapib, turned out to be disappointing in outcome studies despite substantial increases in HDL-C, suggesting that factors beyond HDL concentration may be responsible for the increased risks of CVD. Therefore, recent studies have focused more on HDL function than on HDL levels. The metabolic environment in diabetes mellitus condition such as hyperglycemia-induced advanced glycation end products, oxidative stress, and inflammation promote HDL dysfunction leading to greater risks of CVD. This review discusses dysfunctional HDL as one of the mechanisms of increased CVD risks in diabetes mellitus through adversely affecting components that support HDL function in cholesterol efflux and LDL oxidation. The dampening of reverse cholesterol transport, a key process that removes cholesterol from lipid-laden macrophages in the arterial wall, leads to increased risks of CVD in diabetic patients. Therapeutic approaches to keep diabetes under control may benefit patients from developing CVD.