Serum Calcium Level is Associated with Lipids in Young Nigerian Women Using Low‑Dose Oral Contraceptive Pills

Background: The formulation of low‑dose oral contraceptive pill (OCP) has not been able to completely eliminate the cardiovascular risks associated with its use. Studies have associated serum calcium with metabolic syndrome, high blood pressure and lipids in the general population. Aim: To examine the association of serum total calcium with lipids levels and blood pressure in young Nigerian women who use OCP. Subjects and Methods: Fasting serum triglyceride, total cholesterol, high‑density lipoprotein cholesterol (HDL‑c), low‑density lipoprotein cholesterol (LDL‑c), very low‑density lipoprotein cholesterol (VLDL‑c), total lipids and total calcium were assayed in 160 young women (110 OCP users and 50 controls) using colorimetric methods. Body mass index (BMI) and blood pressure were also measured. Results: Serum triglyceride (1.19(0.01) vs 0.94(0.02), total cholesterol (4.08(0.06) vs 3.52 (0.05), LDL‑c (1.79(0.04) vs 1.24 (0.02), VLDL‑c (0.25(0.02) vs 0.18(0.03), total lipids (7.55(0.2) vs 6.26(0.2), total calcium (2.25(0.01) vs 2.06(0.03), systolic (108.9(0.9) vs 103.1(0.9) and diastolic (67.7(0.7) vs 65.0(0.5) blood pressures were significantly higher (P < 0.001) in OCP users than non‑users. Conversely, HDL‑c levels in OCP users were lower (1.77(0.08) vs 1.84(0.02); P = 0.30) compared with non‑users. Serum calcium positively correlated with blood pressure and lipid parameters except HDL‑c in women OCP users. Women on OCP who had lower serum total calcium levels had statistically significant lower lipid parameters while those women on OCP who had higher serum calcium levels had significantly higher lipid parameters. The BMI of both study population and control was not significantly different. Conclusion: Low‑dose OCPs induce increased levels of serum lipids, calcium and blood pressures. Serum total calcium level was positively associated with blood pressure, measured lipid parameters except HDL‑c in women on OCP. These data suggest that serum calcium may have some influences on lipids and blood pressure in subjects who use OCP irrespective of their BMI.  Keywords: Blood pressure, oral contraceptive pill, serum total calcium, total lipids and lipoproteins