Bone turnover markers and bone mineral density in healthy mother–daughter pairs from South India

Bone turnover markers (BTMs) provide important insights into the dynamics of bone remodelling and are subjected to preanalytical and ethnic variations in addition to influence of genetic and environmental factors. Aim/Objectives: To derive ethnicity specific reference range for BTMs and to study their correlation with Bone Mineral Density (BMD) in a cohort of healthy postmenopausal women and their premenopausal daughters and to look at the impact of maternal bone mineral status on daughters bone health. Material and Methods: This community based cross sectional study included 300 subjects (150 mother-daughter pairs). Demographic details were collected. Fasting blood and a second void morning urine samples were obtained for measurement of BTMs (sCTX, sPTNP1, sOC and urine DPD respectively) and bone mineral parameters. BMD was measured by DXA scan. Results: Osteoporosis was seen in 44·7% of the postmenopausal women. Ethnicity specific reference ranges of BTMs were derived for the study population. Significant inverse correlation was found between all BTMs (except urine DPD) and BMD(P < 0·05). Daughters of mothers with osteoporosis at spine and femoral neck had lower BMD, compared to daughters of mothers without osteoporosis(P = 0·03 & 0·05). Conclusion: Apart from deriving the ethnicity specific reference range for BTMs and finding a significant inverse correlation between BTM and BMD, this study found significantly lower BMD in daughters of mothers with osteoporosis at spine and femoral neck implicating the probable interplay of genetic, epigenetic and similar environmental factors.