Association of total protein intake with bone mineral density and bone loss in men and women from the Framingham Offspring Study

作者：Sahni Shivani; Broe Kerry E; Tucker Katherine L; McLean Robert R; Kiel Douglas P; Cupples L Adrienne; Hannan Marian T^*

来源：Public Health Nutrition, 2014, 17(11): 2570-2576.

DOI：10.1017/S1368980013002875

• Protein
• Bone mineral density
• Bone loss
• Diet
• Calcium

Objective: To examine (i) the association of percentage of total energy intake from protein (protein intake %) with bone mineral density (BMD, g/cm(2)) and bone loss at the femoral neck, trochanter and lumbar spine (L2-L4) and (ii) Ca as an effect modifier. %26lt;br%26gt;Setting: The Framingham Offspring Study. %26lt;br%26gt;Subjects: Men (n 1280) and women (n 1639) completed an FFQ in 1992-1995 or 1995-1998 and underwent baseline BMD measurement by dual-energy X-ray absorptiometry in 1996-2000. Men (n 495) and women (n 680) had follow-up BMD measured in 2002-2005. %26lt;br%26gt;Design: Cohort study using multivariable regression to examine the association of protein intake% with each BMD, adjusting for covariates. Statistical interaction between protein intake% and Ca (total, dietary, supplemental) intake was examined. %26lt;br%26gt;Results: The mean age at baseline was 61 (SD 9) years. In the cross-sectional analyses, protein intake% was positively associated with all BMD sites (P range: 0.02-0.04) in women but not in men. Significant interactions were observed with total Ca intake (%26lt;800 mg/d v. %26gt;= 800 mg/d) in women at all bone sites (P range: 0.002-0.02). Upon stratification, protein intake% was positively associated with all BMD sites (P range: 0.04-0.10) in women with low Ca intakes but not in those with high Ca intakes. In the longitudinal analyses, in men, higher protein intake% was associated with more bone loss at the trochanter (P = 0.01) while no associations were seen in women, regardless of Ca intake. %26lt;br%26gt;Conclusions: This suggests that greater protein intake benefits women especially those with lower Ca intakes. However, protein effects are not significant for short-term changes in bone density. Contrastingly, in men, higher protein intakes lead to greater bone loss at the trochanter. Longer follow-up is required to examine the impact of protein on bone loss.

• 出版日期2014-11