Blood pressure is also higher in those with android obesity which leads to cardiovascular disease.Women who are infertile and have polycystic ovary syndrome show high amounts of android fat tissue. In contrast, patients with anorexia nervosa have increased gynoid fat percentage  Women normally have small amounts of androgen, however when the amount is too high they develop male psychological characteristics and male physical characteristics of muscle mass, structure and function and an android adipose tissue distribution. Women who have high amounts of androgen and thus an increase tendency for android fat distribution are in the lowest quintiles of levels of sex-hormone-binding globulin and more are at high risks of ill health associated with android fat High levels of android fat have been associated with obesity  and diseases caused by insulin insensitivity, such as diabetes. Insulin responsiveness is dependent on adipose cell size. The larger the adipose cell size the less sensitive the insulin. Diabetes is more likely to occur in obese women with android fat distribution and hypertrophic fat cells. It is not just general obesity that is a consequence of android fat distribution but also other health consequences. There are connections between high android fat distributions and the severity of diseases such as acute pancreatitis - where the higher the levels of android fat are, the more severe the pancreatitis can be. An increase in android fat distribution is positively correlated with foot pain and disability associated with foot pain.
These studies compare monozygotic and dizygotic twins for medical, genetic, or psychological characteristics to try to isolate genetic influence from epigenetic and environmental influence. Twins that have been separated early in life and raised in separate households are especially sought-after for these studies, which have been used widely in the exploration of human nature. Classical twin studies are now being supplemented with molecular genetic studies which identify individual genes. Unusual twinnings
Bi-paternal twins
This phenomenon is known as heteropaternal superfecundation. One 1992 study estimates that the frequency of heteropaternal superfecundation among dizygotic twins, whose parents were involved in paternity suits, was approximately 2.4%; see the references section, below, for more details.Dizygotic twins from biracial couples can sometimes be mixed twins, which exhibit differing ethnic and racial features. One such pairing was born in London in 1993 to a white mother and Caribbean father. Monozygotic twins of different sexes
Among monozygotic twins, in extremely rare cases, twins have been born with different sexes (one male, one female). When monozygotic twins are born with different sexes it is because of chromosomal defects. The probability of this is so small that multiples having different sexes is universally accepted as a sound basis for in utero clinical determination that the multiples are not monozygotic. Another abnormality that can result in monozygotic twins of different sexes is if the egg is fertilized by a male sperm but during cell division only the X chromosome is duplicated. This results in one normal male (XY) and one female with Turner syndrome (45,X).