Two-year follow-up of changes in clinical chemistry in Singaporean Norplant®-2 rod acceptors: Metabolic changes

In this longitudinal study involving 100 Singaporean acceptors, the effects of Norplant®-2 rods on metabolic function was evaluated. The mean serum bilirubin during the second year remained significantly raised from its preinsertion value (p < 0.001). Furthermore the total proteins and globulin were still significantly decreased (p < 0.001). Thus with respect to liver function, the results still indicate possible dysfunction at the end of two years. As regards lipid metabolism, the serum triglycerides, total cholesterol and LDL-cholesterol still remained significantly decreased at the end of two years when compared to preinsertion values. The HDL-cholesterol levels which showed no significant change during the first year of use decreased significantly during the second year of use. As a result the HDL-cholesterol/Total cholesterol — HDL-cholesterol decreased significantly and was 12.0% lower than the pre-insertion ratio (p < 0.01). Similarly the LDL-cholesterol/HDL-cholesterol increased during the second year of use and was 2.6% higher than its preinsertion ratio. However, this increase was still not statistically significant. As we have not incorporated a simultaneous non-steroid treated control group, the observed changes in lipid metabolism could be attributed to to extraneous factors such as diet, exercise or other environmental changes. Nevertheless, the findings at the end of two years, though speculative, still indicate Norplant®-2 use to be non-contributory to cardiovascular risk in this population. The use of Norplant®-2 was not associated with any significant effect on glucose tolerance after two years of use.