LONGTERM DEFICIENT CALCIUM INTAKE ASSOCIATION WITH BONE TURNOVER MARKERS, HIP AND SPINE BONE MINERAL DENSITY IN POSTMENOPAUSAL WOMEN

Abstract

Introduction: Calcium (Ca) deficit is very important risk factor for osteoporosis development and bone turnover markers disturbance. Objective: The influence of long-term Ca deficit on bone turnover, bone loss and osteoporotic risk was determined. Material and methods: Postmenopausal women (n=120) were divided into 3 groups according to their mean Ca intake: 1st gr. with Ca intake <500mg/day, 2nd gr. 500-1000mg/day and 3rd gr. >1000mg/day. Bone resorption marker C-terminal telopeptide of type I collagen (CTX) was determined as well as spine and hip bone mineral density (BMD) and T-score with dual-energy Xray absorptiometry (DXA). Results: CTX levels were 0.58±0.23ng/ml in the 1st gr, 0.48±0.22ng/ml in the 2nd gr. and 0.38±0.22ng/ml in the 3rd gr., and they were significantly different among the groups (p<0.007). Mean hip neck BMD was 0.76±0.08gr/cm2 in the 1st gr, 0.82±0.09gr/cm2 in the 2nd gr, 0.86±0.12 gr/cm2 in the 3rd gr (p<0.022). Mean neck T-score was -1.67±0.81 in the 1st gr, -1.39±0.84 in the 2nd gr and -0.98±1.12 in the 3rd gr (p<0.023). Mean % of hip BMD reduction in the 1st gr was 27.5±11.33%, in the 2nd gr 19.56±10.62% and in the 3rd gr it was 16.5±11.2% (p<0.005). Mean spine BMD in the 1st gr was 0.89±0.14gr/cm2 , in the 2nd gr 0.93±0.15gr/cm2 and in the 3rd gr 1.02±0.1gr/cm2 (p<0.05). Conclusion: Long-term lower Ca intake induces increased bone turnover, increased bone resorption with significantly higher CTX levels, significant hip and spine BMD and T-score lower values, indicating increased bone loss and increased osteoporotic risk. Bone turnover markers are important in determining of the osteoporotic risk in postmenopausal women with deficient Ca intake.