Glucose metabolism among Norplant® users in northern Nigeria

Twenty-one women who were consecutive accepters of Norplant were recruited for this study in our centre in August 1997. The patients had baseline (pre-insertion) investigations including a standard oral glucose tolerance test (OGTT). At their regular 3, 6, and 12 months follow-up visits, the OGTT was repeated and results were analyzed. The mean age of the clients was 31.3 +/- 4.51 years (range 24-40 years). The mean weights were 61.60 +/- 11.35, 57.63 +/- 7.51, 62.60 +/- 11.98, and 62.17 +/- 11.56 kg at pre-insertion, 3, 6, and 12 months follow-up visits respectively. The differences were statistically insignificant. All OGTT values at pre-insertion and at the follow-up visits were within the normal range. However, in comparison to pre-insertion levels (4.00 +/- 0.10 mmol/L), the fasting blood glucose concentration at 12 months (3.39 +/- 0.12 mmol/L) showed a statistically significant decline (p <0.001). The area under the glucose curve (AUC) rose by 5.8% (p = 0.018) at 3 months but declined by 5.8% (p = 0.110) and 7.3% (p = 0.103) at 6 and 12 months, respectively. The peak pre-insertion plasma glucose level following OGTT occurred at 30 min. At 3 months, the peak OGTT glucose level occurred at 30 minutes and plateaued until 60 min while at 6 and 12 months this occurred at 60 and 90 minutes, respectively. The overall trend of OGTT results within the study period showed that 12 months of Norplant use in Northern Nigerian women has no detrimental effect on glucose metabolism. (C) 2000 Elsevier Science Inc. All rights reserved.