Measured collagen fibril response to arterial inflation using SAXS.

Arteries are elastic structures containing both elastin and collagen. While the high content of elastin is understood to be important for the elasticity of arteries with systolic and diastolic pressure pulses, the role of collagen in the elastic properties of arteries is less understood. Here we use small angle X-ray scattering to investigate the changes in arrangement of collagen fibrils and the strain experienced by collagen fibrils as arteries are inflated. Collagen fibrils re-orient to become more aligned in both the annular direction and radially as arteries inflate. With arterial pressures up to 32 kPa there is no observable increase in D-spacing of the collagen fibrils (<0.1%) indicating that there is no extension of straightened fibrils and therefore no change in stress on the collagen fibrils. This is in contrast to tissue such as skin where stress of the tissue may induce strains in collagen fibrils of >6%. In arteries the collagen fibril elasticity (strain at the scale of fibrils) is not the main elastic component of the arterial walls. This indicates that wall elasticity is dominated by other factors such as the structural arrangement of the collagen fibers.

Cost-benefit analysis of fall injuries prevented by a programme of home modifications: a cluster randomised controlled trial.

BACKGROUND: Injuries due to falls in the home impose a huge social and economic cost on society. We have previously found important safety benefits of home modifications such as handrails for steps and stairs, grab rails for bathrooms, outside lighting, edging for outside steps and slip-resistant surfacing for outside areas such as decks. Here we assess the economic benefits of these modifications. METHODS: Using a single-blinded cluster randomised controlled trial, we analysed insurance payments for medically treated home fall injuries as recorded by the national injury insurer. The benefits in terms of the value of disability adjusted life years (DALYs) averted and social costs of injuries saved were extrapolated to a national level and compared with the costs of the intervention. RESULTS: An intention-to-treat analysis was carried out. Injury costs per time exposed to the modified homes compared with the unmodified homes showed a reduction in the costs of home fall injuries of 33% (95% CI 5% to 49%). The social benefits of injuries prevented were estimated to be at least six times the costs of the intervention. The benefit-cost ratio can be at least doubled for older people and increased by 60% for those with a prior history of fall injuries. CONCLUSIONS: This is the first randomised controlled trial to examine the benefits of home modification for reducing fall injury costs in the general population. The results show a convincing economic justification for undertaking relatively low-cost home repairs and installing safety features to prevent falls. TRIAL REGISTRATION NUMBER: ACTRN12609000779279.

The prevalence of colorectal adenomas in Maori and New Zealand Europeans parallels colorectal cancer rates.

BACKGROUND: New Zealand (NZ) has a high incidence of colorectal cancer (CRC). Maori have a documented incidence that is approximately half that found in NZ Europeans, possibly the result of under-reporting. AIM: To determine and compare the prevalence of colorectal adenomas in Maori and NZ European patients. METHODS: Colonoscopy records from the Middlemore Colonoscopy Audit Database between 1 July 2001 and 31 December 2005 were reviewed. Studies performed for indications associated with an increased risk of colorectal polyps were excluded from the analysis. Patient demographics, including self-identified ethnicity, and number and location of colonic polyps were recorded. All polyp histology was reviewed. RESULTS: Data was analysed from 2842 colonoscopies--2523 were NZ Europeans (mean age 67 yrs) and 319 were Maori patients (mean age 60.6 yrs). To adjust for age, a comparison of data between 40 and 59 years was undertaken. In 643 (81.2%) NZ Europeans, polyps were identified in 213 (33.1%). In the 149 (18.8%) Maori patients, polyps were identified in 35 (23.5%) p=0.029. The comparative rates of adenomas in NZ Europeans and Maori were 16.7% and 8.7% respectively (p=0.019; 8% difference, CI=2.3-13.9%). CONCLUSION: The prevalence of colorectal adenomas in Maori is approximately half that found in NZ Europeans. This mirrors the reported difference in CRC incidence between these groups and lends support to this being a real finding and not a bias in the manner in which the data has been collected.

A New Zealand linkage study examining the associations between A1C concentration and mortality.

OBJECTIVE: To examine associations between A1C concentration and mortality in a New Zealand population. RESEARCH DESIGN AND METHODS: During a Hepatitis Foundation screening campaign for hepatitis B (1999-2001), participants were offered A1C testing. The participants were anonymously linked to the national mortality collection to 31 December 2004. Hazard ratios (HRs) and 95% CIs adjusted for age, ethnicity, smoking, and sex were estimated using Cox regression. RESULTS: There were 47,904 participants (71% Mâori, 12% Pacific, 5% Asian, and 12% other). A1C measurements were categorized as <4.0% (n = 142), 4.0 to <5.0% (reference category; n = 12,867), 5.0 to <6.0% (n = 30,222), 6.0 to <7.0% (n = 2,669), and >or=7.0% (n = 1,596); there were also 408 participants with a previous diabetes diagnosis. During the follow-up period, 815 individuals died. In those without a prior diabetes diagnosis, there were steadily increasing HRs from the A1C reference category to the highest category (>or=7.0%; HR 2.36 [95% CI 1.72-3.25]). As well as all-cause mortality, A1C was associated with mortality from diseases of the circulatory system; endocrine, nutritional, metabolic, and immunity disorders; and other and unknown causes. Mortality was also elevated in those with a prior diabetes diagnosis (5.19 [3.67-7.35]), but this was only partially explained by their elevated A1C levels. CONCLUSIONS: This is the largest study to date of A1C levels and subsequent mortality risk. It confirms previous findings that A1C levels are strongly associated with subsequent mortality in both men and women without a prior diabetes diagnosis.