Familial resemblance of bone mineralization, XXXX intake, and physical activity in early-adolescent daughters, their mothers, and maternal grandmothers.

@entity1 @entity79 @entity460
OBJECTIVE: To describe familial relationships among @entity79 ( @entity79 ), @entity460 intake, and physical activity in early-adolescent daughters, their premenopausal mothers, and postmenopausal maternal grandmothers. SUBJECTS: Healthy, early-adolescent daughter and premenopausal mother pairs (n=72) were enrolled in the study. In addition, a cohort of 22 postmenopausal maternal grandmothers were measured for comparison of related triads (n=22). DESIGN: Cross-sectional measurements of hip (three sites) and lumbar spine @entity79 by dual energy x-ray absorptiometry (DXA), body height and weight, menstrual function, current @entity460 intake, and current and past physical activity patterns were assessed using recalls and questionnaires. STATISTICAL ANALYSIS: Correlational analysis was used to establish relationships between bone characteristics and body size, menstrual function, @entity460 intake, and physical activity. Multiple regression analyses with backward elimination were used to examine heritability of bone characteristics in daughter-mother and mother-grandmother pairs and daughter-mother-grandmother triads. Quick cluster analysis and cross-tabulation with Pearson's chi(2) were used to evaluate familial patterns for bone characteristics and lifestyle practices. RESULTS: Height, weight, and lumbar spine @entity79 were significantly correlated within mother-daughter pairs. Current and past @entity460 intakes were not related within pairs or triads or to @entity79 in the daughters or the grandmothers. A weak inverse relationship between @entity460 intake and the hip trochanter and lumbar spine @entity79 was observed in the mothers (R(2)=-0.25; P=.05). Physical activity, independent of @entity460 intake, was strong predictor of @entity79 for daughters and mothers. Among the daughters, the hertiability estimates for trochanter and lumbar spine @entity79 were 0.56 and 0.70, respectively (P<.01). The heritability estimate for premenopausal mothers were significant for lumbar spine @entity79 (h(2)=0.66; P<.01). Daughter-mother-grandmother triads with low physical activity had low femoral neck @entity79 whereas those with high physical activity had high femoral neck @entity79 (P<.001). APPLICATIONS: Making physical activity a part of the daily routine, in addition to an adequate intake of @entity460 and bone-related nutrients, is an important goal for maintaining or improving bone health for @entity1 of all ages.
