Siobhan O'Donnell

Efficacy of food fortification on serum 25-hydroxyvitamin D concentrations: systematic review

BACKGROUND Many residents of the United States and Canada depend on dietary sources of vitamin D to help maintain vitamin D status. Because few natural food sources contain vitamin D, fortified foods may be required. OBJECTIVE We aimed to determine the effects of vitamin D-fortified foods on serum 25-hydroxyvitamin D [25(OH)D] concentrations. DESIGN We searched MEDLINE (1966 to June Week 3 2006), Embase, CINAHL, AMED, Biological Abstracts, and the Cochrane Central Register of Controlled Trials for randomized controlled trials (RCTs) comparing vitamin D-fortified foods with a control and reporting serum 25(OH)D concentrations. Two reviewers independently determined study eligibility, assessed trial quality, and extracted relevant data. Disagreements were resolved by consensus. Meta-analyses of absolute mean change in 25(OH)D were conducted by using a random-effects model, with evaluation of heterogeneity. RESULTS Nine RCTs (n = 889 subjects) were included, of which 8 consistently showed a significant beneficial effect of food fortification on 25(OH)D concentrations. Although 7 RCTs (n = 585 subjects) potentially were meta-analyzable, we were unable to combine the overall results because of significant heterogeneity. The individual treatment effects ranged from 14.5 (95% CIs: 10.6, 18.4) nmol/L to 34.5 (17.64, 51.36) nmol/L (3.4-25 microg vitamin D/d). Subgroup analyses showed a reduction in heterogeneity and significant treatment effect when 4 trials that used milk as the fortified food source were combined. CONCLUSION Most trials were small in size and inadequately reported allocation concealment, but results showed that vitamin D-fortified foods improved vitamin D status in adults.

Systematic review of the benefits and harms of calcitriol and alfacalcidol for fractures and falls

Our objective was to conduct a systematic review on the benefits and harms of calcitriol and alfacalcidol in the reduction of fracture and fall risk. Randomized controlled trials (RCTs) comparing these agents to placebo or calcium and reporting fracture and fall incidence were retrieved from MEDLINE, Embase, and the Cochrane Central Register of Controlled Trials. Two reviewers independently determined study eligibility, assessed trial quality, and extracted data. Twenty-three RCTs were included (2139 participants), and 16 trials had sufficient data for meta-analysis. Vertebral fractures were not significantly reduced based on the combined results of 13 trials; however, subgroup analyses demonstrated a significant reduction with alfacalcidol [odds ratio (OR) = 0.50, 95% confidence interval (CI), 0.25–0.98], but not with calcitriol. There was a significant reduction in nonvertebral fractures (six trials, OR = 0.51, 95% CI, 0.30–0.88), and falls (two trials, OR = 0.66, 95% CI, 0.44–0.98). There was an increased risk of hypercalcemia (OR = 3.63, 95% CI, 1.51–8.73) and a trend toward an increased risk of hypercalciuria. There is evidence to suggest that these agents may reduce the incidence of nonvertebral fractures and falls; however, their benefit on vertebral fracture reduction may depend on the type of active vitamin D. Hypercalcemia and hypercalciuria are potential side effects.

Trends in hip fracture rates in Canada: An age‐period‐cohort analysis

Age‐standardized rates of hip fracture in Canada declined during the period 1985 to 2005. We investigated whether this incidence pattern is explained by period effects, cohort effects, or both. All hospitalizations during the study period with primary diagnosis of hip fracture were identified. Age‐ and sex‐specific hip fracture rates were calculated for nineteen 5‐year age groups and four 5‐year calendar periods, resulting in 20 birth cohorts. The effect of age, calendar period, and birth cohort on hip fracture rates was assessed using age‐period‐cohort models as proposed by Clayton and Schiffers. From 1985 to 2005, a total of 570,872 hospitalizations for hip fracture were identified. Age‐standardized rates for hip fracture have progressively declined for females and males. The annual linear decrease in rates per 5‐year period were 12% for females and 7% for males (both p < 0.0001). Significant birth cohort effects were also observed for both sexes (p < 0.0001). Cohorts born before 1950 had a higher risk of hip fracture, whereas those born after 1954 had a lower risk. After adjusting for age and constant annual linear change (drift term common to both period and cohort effects), we observed a significant nonlinear birth cohort effect for males (p = 0.0126) but not for females (p = 0.9960). In contrast, the nonlinear period effect, after adjustment for age and drift term, was significant for females (p = 0.0373) but not for males (p = 0.2515). For males, we observed no additional nonlinear period effect after adjusting for age and birth cohort, whereas for females, we observed no additional nonlinear birth cohort effect after adjusting for age and period. Although hip fracture rates decreased in both sexes, different factors may explain these changes. In addition to the constant annual linear decrease, nonlinear birth cohort effects were identified for males, and calendar period effects were identified for females as possible explanations.

Self-management strategies in overweight and obese Canadians with arthritis.

To estimate the prevalence of overweight and obese Canadians with arthritis and to describe their use of arthritis self‐management strategies, as well as explore the factors associated with not engaging in any self‐management strategies.

Exercise/physical activity and weight management efforts in Canadians with self-reported arthritis.

To describe the exercise/physical activity and weight management efforts of Canadians with self‐reported arthritis, to examine factors associated with their engagement in these strategies to help manage their arthritis, and to explore reasons for lack of engagement.

Childhood maltreatment as a risk factor for arthritis: Findings from a population-based survey of Canadian adults

To establish whether there is a relationship between the frequency and severity of different types of childhood maltreatment and adulthood arthritis.

Trends in Hip Fracture Rates in Canada

Over the next few decades, hip fractures will be a major public health concern as the number of elderly, a population at high risk for osteoporosis, increases substantially. The rising incidence of hip fracture is a concern for both afflicted individuals and the health care system because these fractures are associated with significant morbidity, mortality, and costs. This study investigated trends of hip fractures in Canada from 1985 to 2005 through analysis of national databases on hospitalization and morbidity. The primary study outcome measures were age-specific and age-standardized hip fracture rates. The Cochran-Armitage test for linear trend was used to estimate yearly changes in age-specific hip fracture subgroups. Joinpoint regression analysis identified points at which a statistically significant change over time occurred in the linear slope of the trends in hip fracture rates. Over the 21 years of observation, 570,872 cases of hospitalization for hip fractures were identified. A progressive decrease in age-specific hip fracture rates occurred over time among both males (25.0%) and females (31.8%) (P < 0.001 for both): Age-adjusted hip fracture rates among females decreased from 118.6 per 100,000 person-years (95% confidence interval [CI], 115.9-121.4) in 1985 to 80.9 (95% CI, 79.2-82.6) in 2005. Similarly, the age-adjusted hip fracture rates for males decreased from 68.2 per 100,000 person-years (95% CI, 65.6-70.8) to 51.1 (95% CI, 49.4-52.7). Among males and females, joinpoint regression analysis identified a change in the linear slope around 1996. During the early part of the study (1985-1996), the average percentage decrease per year in hip fracture rates was 1.2% (95% CI, 1.0%-1.3%) whereas during the later part of the study (1996-2005), the decrease was 2.4% (95% CI, 2.1%-2.6%) per year from 1996 to 2005 (P < 0.001 for difference in slopes in both time periods). Large changes occurred among both females and males with greater slope reductions after 1996 (P < 0.001 for difference in slopes for both). These findings demonstrate significant progressive decreases in age-standardized rates of hip fracture between 1985 and 2005 and show a more rapid decline in rates in the second half of the study period. The factors contributing to the earlier reduction in hip fracture at a time when there was no widespread diagnostic testing or modern drug therapy are unknown.