Comparative Study of Hormonal Contraceptives on Biochemical and Atherogenic Parameters of Women in Rivers State University Community, Port Harcourt, Nigeria

Aim: To compare the effect of oral and injectable hormonal contraceptives on lipid parameters, calcium, phosphate and some atherogenic indices among women in Rivers Sate University community, Port Harcourt, Nigeria.

Study Design: One hundred and fifty (150) women between the ages of 18 - 44 years in Rivers State University attending family planning clinics within Port Harcourt, Rivers State that are not pregnant and non-lactating were recruited. Of the 150 women recruited, 50 women were on injectable depo provera contraceptives, 20 of the women were on injectable noristerat contraceptives while 30 of them were on combined oral combined contraceptives. Fifty (50) women not on contraceptives were used as control. These control women did not use oral or injectable contraceptives whether implants, or any other contraceptive method excluding barrier methods like condoms.

Methodology: A randomized controlled design with samples collected randomly within the University community was used in this study. A well-structured questionnaire was given to all the intending participants to obtain demographic information, medical history and pattern of lifestyle after getting consent. Women included were those attending family planning clinics on contraceptives for at least 3 months, not lactating, not pregnant, without history of hypertension, cardiovascular disorders, osteoporosis, diabetes mellitus or smoking. However, women that were lactating, pregnant, not attending family planning clinic or with history of hypertension, cardiovascular disorders, osteoporosis, diabetes mellitus or that are smoking were excluded. Five millilitres (5mls) of fasting whole blood samples was collected into plain bottles. The collected whole blood samples were allowed to clot and later retracted and spun at 400rpm for 10 minutes to obtain serum. The laboratory analysis of calcium, phosphate, and lipid parameters were performed using Standard procedure BS-800 Mindray chemistry analyzer. LDL-C was calculated using Frieldewald equation. Atherogenic Index of Plasma (AIP) was estimated using the equation: AIP=[Log(TG/HDL-C)] while Non-High Density Lipoprotein-C (NHDL) was calculated using the equation NHDL-C=TC–HDL-C.

Results: The results obtained showed higher and lower values levels of LDL-C and HDL-C respectively in women using oral contraceptives. Lower values of calcium and phosphate were also seen in women using oral contraceptives. In addition, AIP and NHDL-C values were higher in women using oral contraceptives compared to control women and women on injectables contraceptives especially Depo provera. On the other hand, women on injectables contraceptives especially depo provera showed lower and higher values levels of LDL-C and HDL-C respectively. Higher values of calcium and phosphate were also seen. In addition, AIP and NHDL-C values were lower in women using injectables contraceptives compared to control women and women on oral contraceptives. More so, results seen at the different age interval showed that women using contraceptives at age 18-26 years had lesser risk for cardiovascular disease compared to age 27 -35 years. However, age 36 -44 years indicated significantly higher values of atherogenic lipids like LDL-C and atherogenic indices like NHDL-C. Significantly lower values of calcium and phosphate were also seen within this age bracket.

Conclusion: Results obtained demonstrated that injectable contraceptives exerted more beneficial effect on lipid metabolism and cardiovascular disease while oral contraceptives had more bone mineralization effect. Again, when age interval were considered, women at age 18-26 years had low risk of dyslipidaemia and mineralization of bones were not affected compared to age 27-35 years while age 36-44 years were at risk of cardiovascular diseases and enhanced bone mineralization tendencies.