Association of total protein intake with bone mineral density and bone loss in men and women from the Framingham Offspring Study. Issue 11 (29th October 2013)

• Record Type: Journal Article
• Authors: Sahni, Shivani; Broe, Kerry E; Tucker, Katherine L; McLean, Robert R; Kiel, Douglas P; Cupples, L Adrienne; Hannan, Marian T
• Is Part Of: Public health nutrition. Volume 17:Issue 11(2014)
• Page Start: 2570
• Page End: 2576
• Publication Date: 2013-10-29
• Subjects: Protein, -- Bone mineral density, -- Bone loss, -- Diet, -- Calcium; Nutrition -- Periodicals; Nutrition policy -- Periodicals; Public health -- Periodicals; 613.2
• DOI: 10.1017/S1368980013002875
• Languages: English
• ISSNs: 1368-9800

Abstract

Abstract: 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. Setting: The Framingham Offspring Study. 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. 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. 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 (<800 mg/d v . ≥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. 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.