The effects of Norplant-2 rods on clinical chemistry in Singaporean acceptors after 1 year of use: metabolic changes.
In this longitudinal study involving 100 Singaporean acceptors, the effects of Norplant-2 rods on metabolic function was evaluated. With respect to liver function, the results indicate possible hepatocellular dysfunction. There was a significant rise in mean serum bilirubin from 0.54 mg/dl to 0.85 mg/dl after 12 months of use (p less than 0.001). Furthermore, there was also a significant fall in total proteins from 7.37 gm/dl to 7.12 gm/dl (p less than 0.001) and serum globulin from 3.18 gm/dl to 2.84 gm/dl (p less than 0.001). As regards lipid metabolism, we have demonstrated significant decreases in mean serum triglycerides (1.04 mmol/l to 0.83 mmol/l), p less than 0.001; total cholesterol (5.04 mmol/l to 4.64 mmol/l), p less than 0.001; and LDL-cholesterol (3.36 mmol/l to 3.10 mmol/l), p less than 0.001 after one year of use. There was a small fall in the HDL-cholesterol (1.21 mmol/l to 1.16 mmol/l) after 12 months of use; this fall was not significant. Despite this, there was a rise in the HDL-cholesterol/Total cholesterol - HDL-cholesterol ratio (0.258 cf 0.244; p less than 0.05) after 1 year of use. 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, though speculative, indicate Norplant-2 use to be non-contributory to cardiovascular risk and indeed it may be a protective factor against such risks in this population. The use of Norplant-2 rods was not associated with any significant effect on glucose tolerance after 12 months of use.