Antioxidant Intake and Risk of Osteoporotic Hip Fracture in Utah: An Effect Modified by Smoking Status

Abstract

The role of antioxidant intake in osteoporotic hip fracture risk is uncertain and may be modified by smoking. In the Utah Study of Nutrition and Bone Health, a statewide, population-based case-control study, the authors investigated whether antioxidant intake was associated with risk of osteoporotic hip fracture and whether this association was modified by smoking status. The analyses included data on 1,215 male and female cases aged > or = 50 years who incurred a hip fracture during 1997-2001 and 1,349 age- and sex-matched controls. Diet was assessed by food frequency questionnaire. Among ever smokers, participants in the highest quintile of vitamin E intake (vs. the lowest) had a lower risk of hip fracture after adjustment for confounders (odds ratio = 0.29, 95% confidence interval (CI): 0.16, 0.52; p-trend < 0.0001). The corresponding odds ratio for beta-carotene intake was 0.39 (95% CI: 0.23, 0.68; p-trend = 0.0004), and for selenium intake it was 0.27 (95% CI: 0.12, 0.58; p-trend = 0.0003). Vitamin C intake did not have a significant graded association with hip fracture risk among ever smokers. Similar findings were obtained when an overall antioxidant intake score was used (odds ratio = 0.19, 95% CI: 0.10, 0.37; p-trend < 0.0001). No similar associations were found in never smokers. Antioxidant intake was associated with reduced risk of osteoporotic hip fracture in these elderly subjects, and the effect was strongly modified by smoking status.

Nuclear Factor-E2-related Factor-1 Mediates Ascorbic Acid Induction of Osterix Expression via Interaction with Antioxidant-Responsive Element in Bone Cells

“…Similarly, epidemiological studies have provided evidence for the increased risk of bone fractures in patients with vitamin C deficiency as well as in smokers with insufficient intake of other antioxidants, such as vitamin E and selenium (6,8). The severity of antioxidant depletion and its relevance to the pathogenesis of multiple cell types and the ability of AA to induce differentiation of multipotent progenitor cells to osteoblasts, chondrocytes, cardiac myocytes, and dopaminergic neurons suggested that AA must be acting via other novel mechanisms to regulate cell differentiation at early stages and subsequent bone formation besides its well studied action to promote collagen synthesis/maturation and matrix protein interaction (14,15,31).…”

Microelements for bone boost: the last but not the least

“…Similarly, studies in humans founded that selenium status was inversely related to bone remodeling and positively correlated with BMD in post-menopausal women (88). A case-control study found selenium intake to be inversely associated with reduced risk of osteoporotic hip fracture (89). These effects can be explained by inhibiting oxidative stress, in fact, adequate selenium intake appears to play an essential role in osteoclast/osteoblast cell proliferation and differentiation enhancing osteoblastic differentiation by the reduction of free radicals (90).…”

Cardiovascular calcification and bone: a comparison of the effects of dietary and serum antioxidants

“…some studies found that low vitamin C status in smokers significantly increased the risk of hip fracture, particularly where vitamin e intake was low 66,71 , although others have found no association 72 . Intervention studies show mixed results, which may be due to trial length.…”

“…among the human studies, Maggio et al found that in women with osteoporosis, plasma levels of vitamin E were significantly lower 29 and a more recent investigation showed that in early postmenopausal women, a lower α-tocopherol/lipid ratio was associated with greater risk of osteoporosis and lower BMd 83 . despite this, Macdonald et al showed that increased dietary intake of vitamin e was inversely associated with BMd although the addition of intake from supplements removed this association 67 and a number of smaller studies have shown a detrimental association between vitamin e intake or serum levels and BMd or fracture risk, particularly among those with high oxidative stress, such as smokers 31,71,72 . In the only two human studies to consider other vitamin e isomers, hamidi et al showed that high serum γ-tocopherol and a low ratio of serum α-tocopherol to γ-tocopherol were associated with increased bone specific alkaline phosphatase, a marker for bone formation, although there was no association with urinary N-telopeptides, a marker for bone resorption 84 , while wolf et al found no association with BMD for serum α-or γ-tocopherol 42 .…”