Elevated blood glucose is one of the characteristics of metabolic syndrome and diabetes. These disorders are secondary causes of elevated levels of cholesterol and are associated with higher risk for cardiovascular problems, such as hypertension, heart attack or stroke. Importantly, both glucose and cholesterol levels are modifiable by changes in diet and increased physical activity. If these changes are not sufficient, you need to be treated with lipid and glucose lowering drugs to limit the cardiovascular complications.
Cholesterol
Cholesterol is a lipid molecule that is essential for your life. It is a structural component of cell membranes, as well as a key part of several secreted molecules, such as bile acids, vitamin D or steroid hormones. Cholesterol is formed by almost all cells in your body. The organs with the highest cholesterol synthesis are liver, intestine, adrenal glands and gonads. A smaller portion of your cholesterol is obtained from food.
Cholesterol in Blood
Cholesterol is nearly insoluble in water. Blood transport of lipids is possible due to lipoproteins. These molecules encircle lipids in such an arrangement that the water-soluble part of the proteins is on the outside surface of this structure. Inside of lipoprotein units are triglycerides and cholesterol. Triglycerides are three carbon molecules to which are attached long, multi-carbon chains of fatty acids. The ratio of lipids and proteins in lipoprotein units varies. The highest content of cholesterol and triglycerides is in very-low density lipoproteins, or VLDL, while the lowest content of the lipids is in high-density lipoprotein, or HDL. In between are intermediate-density lipoproteins, IDL, and low- density lipoproteins, or LDL. The LDL is often called the bad cholesterol, while the HDL is referred to as the good cholesterol.
Laboratory Studies of Lipids
The laboratory analysis of your blood usually involves blood levels of triglycerides, LDL and HDL. Healthy levels of triglycerides should fall below 150mg/dL and LDL should be less than 70mg/dL. In contrast, your HDL should be higher than 40mg/dL in men and 50mg/dL in women.
Glucose
Glucose in your blood comes mainly from your food. This molecule is used as a source of energy in all cells of your body. Glucose moves from blood into the cells via glucose transporters in cell membranes. Glucose transporters are regulated by insulin. When this regulation is disrupted, you may have elevated levels of glucose in your blood, and the glucose cannot get into the cells.
Glucose Laboratory Studies
The levels of glucose are mostly measured after eight to 10 hours of fasting. The normal levels of glucose in this situation should be less than 100mg/dL. Levels between 100 and 125mg/dL indicate insulin resistance. When your levels are even higher, you are diagnosed with diabetes.
References
- "Physiological Basis of Medical Practice"; John B. West, M.D., Ph.D., D.Sc.; 1990
- American Heart Association: Good vs. Bad Cholesterol
- Medscape Reference; Metabolic Syndrome; Stanley S. Wang, et al.; September 2010
- "Diabetes Care"; Standards of Medical Care in Diabetes---2011; January 2011
