The 'globulines anormalment precipitables' (GAP) which have been reported to be raised in current and former oral contraceptive users was measured in Nigerian subjects (which) including male volunteers. The results showed that GAP were present in males who had never used contraceptives and that the mean values were the lowest in intrauterine contraceptive (IUD) users and highest in females who had never used any contraceptive. However, current contraceptive users had lower mean GAP values than either former users or never users. Therefore it has been concluded that GAP levels alone cannot be used to predict the development of thrombo-embolic complications in pill users, and that ethinyl oestradiol cannot be the main physiological stimulus for GAP synthesis.
PIP: Researchers obtained serum samples from 182 healthy men and women living in Jos, Plateau State in Nigeria after fasting to measure abnormal protein (globulins anormalement precipitables [GAP]) levels. Specifically, they wanted to compare the levels of the 5 groups: 30 women who had never used oral contraceptives (OCs), 38 males, 48 women using progesterone only OCs, 32 women who used OCs for 2 years and stopped 6 months before this study, and 34 women using a copper releasing IUD. Former OC users had the highest mean GAP levels (1336.37 mcg/ml). Further the mean GAP levels for males (932.25 mcg/ml) was significantly higher than women using IUDs (p.05). Indeed significant differences existed between all groups (p.05). A more pronounced difference in pattern and magnitude of GAP values for control and experimental groups occurred among these Nigerians than in previous studies involving Whites. Further results of 1 study revealed European Blacks to have a significantly higher GAP level than Whites. Therefore the higher GAP levels in Blacks may be more dependent on genetic factors than dietary factors. Another important finding of this study was the possible role of progesterone only OCs in reducing GAP levels beyond normal physiological limits. In addition, this study suggested that, contrary to earlier belief, ethinyl estradiol may not be the main stimulus for GAP production since men had relatively high levels of GAP. In conclusion, health practitioners should not use GAP levels alone to predict the development of thrombosis in OC users.