We hypothesized that diet would have direct effects on glucose metabolism with direct and indirect effects on bone metabolism in a cohort of Canadian adults. We assessed dietary patterns (Prudent [fruit, vegetables, whole grains, fish, and legumes] and Western [soft drinks, potato chips, French fries, meats, and desserts]) from a semiquantitative food frequency questionnaire. We used fasting blood samples to measure glucose, insulin, homeostatic model assessment insulin resistance (HOMA-IR), 25-hydroxyvitamin D (25OHD), parathyroid hormone, bone-specific alkaline phosphatase (a bone formation marker), and serum C-terminal telopeptide (CTX; a bone resorption marker). We used multivariate regression models adjusted for confounders and including/excluding body mass index. In a secondary analysis, we examined relationships through structural equations models. The Prudent diet was associated with favorable effects on glucose metabolism (lower insulin and HOMA-IR) and bone metabolism (lower CTX in women; higher 25OHD and lower parathyroid hormone in men). The Western diet was associated with deleterious effects on glucose metabolism (higher glucose, insulin, and HOMA-IR) and bone metabolism (higher bone-specific alkaline phosphatase and lower 25OHD in women; higher CTX in men). Body mass index adjustment moved point estimates toward the null, indicating partial mediation. The structural equation model confirmed the hypothesized linkage with strong effects of Prudent and Western diet on metabolic risk, and both direct and indirect effects of a Prudent diet on bone turnover. In summary, a Prudent diet was associated with lower metabolic risk with both primary and mediated effects on bone turnover, suggesting that it is a potential target for reducing fracture risk.
Bibliographical noteFunding Information:
CaMos is currently funded by the Canadian Institutes of Health Research, Amgen, Eli Lilly and Company, Merck Frosst Canada Ltd, and Novartis. The funding sources were arms-length and played no role in the data collection, analysis, or interpretation of the results.
S.I.B. was a member of the External Scientific Advisory Council for Dairy Farmers of Canada. R.G.J. was an advisory board member for Novartis, Merck Frosst, Amgen, and Eli Lilly. J.D.A. has received honoraria from and served on the advisory boards of Amgen, Eli Lilly, Warner-Chilcott, Merck Frosst, and Novartis. C.S.K. was an advisory board member, consultant, or received speaker fees from Amgen, Danone, Eli Lilly, Merck Frosst, Boehringer Ingelheim, and Novartis. D.A.H. was an advisory board member, consultant, or received speaker fees from Amgen, Eli Lilly, Merck, Novartis, and NPS Pharmaceuticals. S.N.M. holds an unrestricted research grant from Amgen and is a consultant for Novartis, Amgen, Eli Lilly, and Merck Frosst. D.G. was an advisory board member or consultant for Amgen, Eli Lilly, Merck Frosst, and Novartis.
© 2016 Elsevier Inc.
- Bone formation
- Bone resorption
- Cohort study
- Factor analysis
- Type 2 diabetes
- Western diet