Effect of the ethinylestradiol/norelgestromin contraceptive patch on body composition. Results of bioelectrical impedance analysis in a population of Italian women
1 Department of Medical and Surgical Sciences, University of Padova, Italy
2 II Institute of Obstetrics and Gynaecology, University of Milan, Italy
3 Department of Obstetric – Gynaecological, Urological Sciences and Reproduction Medicine, University of Naples, Italy
4 Department of Maternal and Children's Sciences ASL SA 3, San Luca Hospital, Vallo della Lucania (SA), Italy
5 Department of Gynaecology, Perinatology and Human Reproduction University of Florence, Italy
6 Medical Affairs Department, Janssen-Cilag SpA, Cologno Monzese (MI), Italy
Nutrition Journal 2008, 7:21 doi:10.1186/1475-2891-7-21Published: 26 August 2008
As weight gain is one of the most frequently cited reasons for not using and for discontinuing hormonal contraceptives, in an open-label, single-arm, multicentre clinical study we evaluated the effect of the ethinylestradiol/norelgestromin contraceptive patch (EVRA, Janssen-Cilag International, Belgium) on body composition using bioelectrical impedance analysis (BIA).
Body weight and impedance vector components (resistance (R) and reactance (Xc), at 50 kHz frequency, Akern-RJL Systems analyzer) were recorded before entry, after 1, 3 and 6 months in 182 Italian healthy women aged 29 yr (18 to 45), and with BMI 21.8 kg/m2 (16 to 31). Total body water (TBW) was estimated with a BIA regression equation. Vector BIA was performed with the RXc mean graph method and the Hotelling's T2 test for paired and unpaired data.
After 6 months body weight increased by 0.64 kg (1.1%) and TBW increased by 0.51 L (1.7%). The pattern of impedance vector displacement indicated a small increase in soft tissue hydration (interstitial gel fluid). Body composition changes did not significantly differ among groups of previous contraceptive methods. Arterial blood pressure did not significantly change over time.
After 6 months of treatment with the ethinylestradiol/norelgestromin contraceptive patch we found a minimal, clinically not relevant, increase in body weight less than 1 kg that could be attributed to an adaptive interstitial gel hydration. This fluctuation is physiological as confirmed by the lack of any effect on blood pressure. This could be useful in increasing women's choice, acceptability and compliance of the ethinylestradiol/norelgestromin contraceptive patch.