Effect of Long-Term Oral Contraceptive Use on Renal Biomarkers and Plasma Proteins among Women Attending Kosti Obstetrics and Gynecology Hospital, Sudan

Abstract

Background: Oral contraceptive pills (OCPs) are widely used for family planning. However, long-term use may affect renal function and plasma protein metabolism. Limited local data exist on these effects in Sudanese women. Therefore, this study aimed to evaluate the effect of long-term OCP use on renal biomarkers and plasma proteins.  Methods: A case-control study was conducted from July to October 2025 at Kosti Obstetrics and Gynecology Hospital. A total of 100 women aged 18-45 years were enrolled: 50 long-term OCP users (≥1 year) and 50 non-users. Plasma urea, creatinine, uric acid, total protein, and albumin were measured using standard spectrophotometric methods. Globulin and eGFR were calculated. Data were analysed using SPSS version 24.  Results: Cases had significantly higher urea, creatinine, and globulin levels and lower albumin and eGFR values than controls (p < 0.05), whereas no significant differences were found in total protein or uric acid (p > 0.05). Strong positive correlations were observed between plasma urea and creatinine and the duration of OC use (r = 0.554 and r = 0.491, respectively), while plasma albumin and eGFR showed strong negative correlations with the duration of OC use (r = -0.087 and r = -0.444, respectively; p ≤ 0.05). Furthermore, weak, non-significant correlations were observed between plasma urea, creatinine, uric acid, albumin, total protein, globulin, and eGFR and both BMI and age (p > 0.05). Conclusion: Long-term OCP use is associated with alterations in renal function and protein metabolism. Routine monitoring of renal biomarkers is recommended for long-term users.