Premium
Serum Retinoids and β‐Carotene as Predictors of Hip and Other Fractures in Elderly Women
Author(s) -
Barker Margo E,
McCloskey Eugene,
Saha Shikha,
Gossiel Fatma,
Charlesworth Diane,
Powers Hilary J,
Blumsohn Aubrey
Publication year - 2005
Publication title -
journal of bone and mineral research
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.882
H-Index - 241
eISSN - 1523-4681
pISSN - 0884-0431
DOI - 10.1359/jbmr.050112
Subject(s) - medicine , retinyl palmitate , retinol , hip fracture , vitamin d and neurology , population , prospective cohort study , vitamin , endocrinology , univariate analysis , osteoporosis , physiology , multivariate analysis , environmental health
There is debate about the possible deleterious effect of excessive vitamin A exposure on fracture risk. In this nested case control study in older women (312 cases and 934 controls), serum retinol, retinyl palmitate, and β‐carotene were not associated with fracture risk, and there was no evidence of excess risk with multivitamin or cod liver oil supplementation. Introduction: Recent studies have suggested that higher vitamin A intake may account for a component of fracture risk within the general population and that supplemental vitamin A may be harmful even within recommended limits. No studies have examined the relationship between biochemical retinol status and fracture in older women. Materials and Methods: We examined serum retinol, retinyl palmitate, and β‐carotene as predictors of incident hip and other fractures in a large prospective study of British women over the age of 75 years ( n = 2606, 312 incident osteoporotic fractures, 92 incident hip fractures; mean follow‐up duration, 3.7 years). Fasting blood samples (9:00‐11:00 a.m.) were collected at baseline. Using a case‐control design (three controls per case), serum retinol, retinyl palmitate, and β‐carotene were assessed as univariate predictors of incident osteoporotic fracture or hip fracture. Baseline BMD at the total hip, age, 25(OH)D, serum β Crosslaps, bone‐specific alkaline phosphatase, weight, height, and smoking were considered as covariates in a multivariate model. Results: Serum retinol, retinyl palmitate, and β‐carotene were not significant univariate predictors of either hip fracture or any fracture (all p > 0.05; Cox proportional hazards regression). For all osteoporotic fractures, the hazard ratio (HR) was 0.92 (95% CI, 0.81‐1.05) per 1 SD increase in serum retinol. Risk of any osteoporotic fracture was slightly less in the highest quartile of serum retinol compared with the lowest quartile (HR, 0.85; 95% CI, 0.69‐1.05; p = 0.132) There was a tendency for increased serum retinol to predict benefit rather than harm in terms of BMD ( r = 0.09, p = 0.002). Multivitamin or cod liver oil supplementation was associated with a significantly lower risk of any fracture (HR, 0.76; 95% CI, 0.60‐0.96; p = 0.021). In multivariate analysis, only age, total hip BMD, and weight were associated with fracture risk ( p < 0.05). Conclusions: We found no evidence to support any skeletal harm associated with increased serum indices of retinol exposure or modest retinol supplementation in this population.