Serum calcium levels of premenopausal, perimenopausal and postmenopausal rural women of Zuturung District, Kaduna State, Nigeria.

Background: Changes in sex hormones during the menopause transition period have an impact on calcium homeostasis. We studied the age at menopause, anthropometric and mean serum calcium levels in a cohort of premenopausal, perimenopausal and postmenopausal women in Zuturung, Kaduna state, Nigeria. Methods:135 subjects participated in the crossectional study. They comprised of 38 premenopausal, 22 perimenopausal and 75 postmenopausal subjects. After administering a questionnaire, the height (m), weight (g), and waist circumference (cm) of the subjects were determined using standard methods while the body mass index (BMI, kg/m2) was calculated. 5 milliliters of blood were collected via venipuncture and serum calcium level was determined by utilizing standard laboratory methods. Results:The results showed a mean and median age at menopause of 44.23±2.74 years and 44 years, respectively. Postmenopausal and perimenopausal subjects were more likely to be overweight with mean BMI 26.07±5.99 kg/m2and 26.42±7.27kg/m2 respectively, compared with their premenopausal counterparts with BMI of 25.18±3.48kg/m2 (p<0.001). The postmenopausal and perimenopausal subjects also had a longer waist circumference of 89.63±10.66cm and 92.19±11.91cm respectively compared with the premenopausal women 83.73±8.00cm (p<0.001). Only 73.86% of the postmenopausal women had a BMI ≥25kg/m2 whereas the prevalence of central obesity as determined using the waist circumference among the postmenopausal subjects was 79%. Mean serum calcium levels were slightly lower amongst both postmenopausal and perimenopausal subjects, 2.30±0.35mg/dl and 2.36±0.13mg/dl respectively as compared with the premenopausal women 2.37±0.15mg/dl. These differences were not significant (p>0.05). Conclusion: These findings suggest a lower mean age at menopause, a higher BMI, a longer waist circumference for the postmenopausal subjects (which was significant) with lower mean serum calcium levels (that was not significant) as compared with their premenopausal subjects. We recommend calcium supplementation and screening of postmenopausal women for postmenopausal osteoporosis. Keywords: Body mass index, calcium, menopause, osteoporosis, waist circumference, Zuturung distric