Lipid metabolism in Norplant-2 users--a two-year follow-up study. Total cholesterol, triglycerides, lipoproteins and apolipoproteins.

Changes in lipid metabolism in 25 healthy female volunteers during a 24-month application of Norplant-2 were evaluated in an open clinical trial. Total serum cholesterol decreased significantly (p less than 0.05/p less than 0.05) by 10%/9% after 12 months and by 3%/7% (n.s./n.s.) after 24 months of Norplant-2 use (all subjects/subjects completing 24 cycles). Serum triglycerides decreased by 34%/28% (n.s./p less than 0.05) after 12 months and by 29%/25% (p less than 0.05/p less than 0.05) after 24 months of Norplant-2 use (all subjects/subjects completing 24 cycles). HDL-cholesterol decreased significantly by 18%/12% (p less than 0.01/p less than 0.05) after 12 months and by 12%/12% (p less than 0.05/p less than 0.05) after 24 months of Norplant-2 use (all subjects/subjects completing 24 cycles). No statistically significant difference between serum levels of LDL-cholesterol prior to and after 12 and 24 months of Norplant-2 use could be found. VLDL-cholesterol levels decreased significantly by 38%/38% (p less than 0.05) after 12 and by 25%/25% after 24 months of Norplant-2 application (p less than 0.01) (all subjects/subjects completing 24 cycles). Apolipoprotein Al decreased significantly by 23%/23% (p less than 0.001/p less than 0.01) after 12 and by 21%/22% after 24 months of Norplant-2 application (p less than 0.01/p less than 0.01) (all subjects/subjects completing 24 cycles). No statistically significant difference between apolipoprotein All levels prior to and after 12 and 24 months of Norplant-2 implantation could be found. Apolipoprotein B decreased significantly by 27%/17% (p less than 0.05/p less than 0.05) after 12 months of Norplant-2 application (all subjects/subjects completing 24 cycles). The decline after 24 months of Norplant-2 use was not significant. Changes in lipid metabolism caused by oral hormonal contraceptives differ in the various clinical trials; however, most investigators found that serum levels of total cholesterol and triglycerides increase under the application of OCs. Contrary to this, a decrease of total cholesterol and triglycerides under Norplant-2 use was noted. Furthermore, we found a significant decrease of lipoproteins and apolipoproteins--with the exception of LDL-cholesterol and apolipoprotein All, which did not show any significant modifications. Thus, Norplant-2 seems to be non-contributory to cardiovascular risk and might even provide protection against such risks.