A three-year evaluation of metabolic changes in Singaporean Norplant acceptors

In a longitudinal study involving 100 Singaporean women, the effect of NorplantR on metabolic function was evaluated. With respect to liver function, the results indicate possible hepatocellular dysfunction as evidenced by a significant rise in serum bilirubin and a significant fall in total proteins and globulin during the period under review. As regards lipid metabolism, total triglycerides and total cholesterol still remained significantly decreased at the end of the three years. The LDL, which was significantly decreased in the first year, increased during the subsequent two years to its preinsertion value at the end of three years. The HDL-cholesterol levels continued to decrease in the second and third year after a significant increase in the first year. Despite this, the HDL cholesterol/total cholesterol-HDL cholesterol remained above 0.200. As we have not incorporated a simultaneous non-pill treated control group, the observed changes in lipoprotein lipids could be attributed to extraneous factors such as diet, exercise, or other environmental changes. Nevertheless, the findings at the end of three years, though speculative, still appear to indicate Norplant use to be not directly contributory to cardiovascular risk. The use of Norplant was not associated with any significant effects on carbohydrate metabolism after three years of use.