The most important consequence of obesity is increased risk of death. Obesity is one of the leading causes of health problems. Obesity is responsible for higher morbidity and mortality. The risk of death from all causes is approximately 100% higher in compared to a normal weight individual. Obesity and overweight (BMI of 25-30) is leading cause of preventable death throughout the world, including in underdeveloped and poor countries. Obesity is responsible for more than 300,000 deaths annually in United States alone. The life expectancy of moderately obese individual is 2-5 years less than normal individuals and much lesser in highly obese individuals.

The important consequences (complications) of obesity include development of insulin resistance and type-2 diabetes, different cardiovascular diseases, respiratory diseases, increased incidence of gall stones, increased incidence of cancer, reproductive disorders, diseases of bones and joints etc.

The transfusion medicine (blood and blood product transfusion) is basically the study of antigen and antibodies to RBCs (red blood cells). The two most important factors of blood transfusion are ABO antigens and antibodies and Rh system, most important being the ABO blood group antigen system and Rh system is the second most important factor in transfusion medicine. Other factors such as transmission of infectious agents, immunologic and non immunologic reaction of blood and blood product transfusion are secondary to ABO blood group antigen system and Rh system.

What is the importance of ABO antigens and antibodies?

The ABO antigen system is the most important in blood and blood product transfusion (also called transfusion medicine) and was first recognized in the year 1900. The ABO antigens are present in the plasma and other body fluids as glycoprotein, although the ABO antigens are carbohydrates and attached to lipids glycosphingolipids or proteins (glycoprotein). H substance is the precursor on which antigen A and antigen B are attached. Addition of N-acetylgalactosamine forms antigen A and addition of galactose produces antigen B. individuals who can not form H substance due to lack of the gene form Bombay phenotype (Bombay blood group).