Effect of long term use of oral contraceptives on glucose tolerance

The effect of long term use of oral contraceptives on glucose tolerance was studied in 133 women. Oral contraceptives were taken for a period between 3 and 12 years. 25 women without any hormone treatment served as a control group. The intravenous glucose tolerance test (IVGTT) has indicated no pathological decrease of glucose tolerance, measured by k. The glucose tolerance test was performed on all subjects (0.33 Gm. of glucose per kg bodyweight). In one subject we diagnosticated a clinical diabetes. Two patients had a subclinical diabetes. After 10 years of treatment a significant decline was noted in k, also in women with family history of diabetes or a past obstetrics history. Several doubtfully pathological k-values were recorded in women more than 40 years of age. No significant relation could be established between parity and the developement of an abnormal glucose metabolism, while taking the drugs. The effect upon glucose tolerance is not related to the type of oral contraceptive. The evidence is not sufficient to warrant the elimination of oral contraceptives. In is suggested that at least in diabetes suspects, repeated controls of glucose tolerance be carried out during long term cyclic use of oral contraceptives.