Diurnal rhythms of vitamin D binding protein and total and free vitamin D metabolites.

Vitamin D binding protein (DBP) concentration is known to influence the availability and bioactivity of vitamin D metabolites but its diurnal rhythm (DR), its inter-relationships with the DRs of vitamin D metabolites and its influence on free vitamin D metabolite concentrations are not well described. The DRs of plasma total 25(OH)D, total 1,25(OH)2D, DBP, albumin and calculated free 25(OH)D and free 1,25(OH)2D were measured in men and women aged 60-75 years and resident in the UK (n 30), Gambia (n 31) and China (n 30) with differences in lifestyle, dietary intake and vitamin D status. Blood samples were collected every 4h for 24h and DRs statistically analysed with Fourier regression. Gambians had significantly higher plasma concentrations of vitamin D metabolites and lower albumin concentration compared to the British and Chinese. Significant DRs were observed for all analytes and calculated free vitamin D metabolites (P<0.01). The pattern of DRs was similar between countries. The magnitude of the DRs of free 1,25(OH)2D was attenuated compared to that of total 1,25(OH)2D whereas it was not different between total and free 25(OH)D. Relationships between the DRs were generally weak. There was no phase shift between 1,25(OH)2D and DBP with the strongest cross correlation at 0h time lag (r=0.15, P=<0.001). In comparison, 25(OH)D correlated less well with DBP (1h time lag, r=0.07, P=0.12). These data demonstrate a relationship between the DRs of 1,25(OH)2D and DBP, possibly to maintain free 1,25(OH)2D concentrations. In contrast, the DRs of total and free 25(OH)D appeared to be less influenced by DBP, suggesting that DBP has comparatively less effect on 25(OH)D concentration and 25(OH)D availability. This work highlights the importance of standardisation in timing of sample collection particularly for the assessment of plasma protein concentrations.

Diurnal Rhythms of Bone Turnover Markers in Three Ethnic Groups.

CONTEXT: Ethnic groups differ in fragility fracture risk and bone metabolism. Differences in diurnal rhythms (DRs) of bone turnover and PTH may play a role. OBJECTIVE: We investigated the DRs of plasma bone turnover markers (BTMs), PTH, and 1,25(OH)2D in three groups with pronounced differences in bone metabolism and plasma PTH. PARTICIPANTS: Healthy Gambian, Chinese, and white British adults (ages 60-75 years; 30 per country). INTERVENTIONS: Observational study with sample collection every 4 hours for 24 hours. MAIN OUTCOMES: Levels of plasma C-terminal telopeptide of type I collagen, procollagen type-1 N-propeptide, N-mid osteocalcin, bone alkaline phosphatase, PTH, and 1,25-dihydroxyvitamin D were measured. DRs were analyzed with random-effects Fourier regression and cross-correlation and regression analyses to assess associations between DRs and fasting and 24-hour means of BTMs and PTH. RESULTS: Concentrations of BTMs, PTH, and 1,25-dihydroxyvitamin D were higher in Gambians compared to other groups (P < .05). The DRs were significant for all variables and groups (P < .03) and were unimodal, with a nocturnal peak and a daytime nadir for BTMs, whereas PTH had two peaks. The DRs of BTMs and PTH were significantly cross-correlated for all groups (P < .05). There was a significant positive association between C-terminal telopeptide of type I collagen and PTH in the British and Gambian groups (P = .03), but not the Chinese group. CONCLUSIONS: Despite ethnic differences in plasma BTMs and PTH, DRs were similar. This indicates that alteration of rhythmicity and loss of coupling of bone resorption and formation associated with an elevated PTH in other studies may not uniformly occur across different populations and needs to be considered in the interpretation of PTH as a risk factor of increased bone loss.

Nutrition education and leadership for improved clinical outcomes: training and supporting junior doctors to run 'Nutrition Awareness Weeks' in three NHS hospitals across England.

BACKGROUND: One in four adults are estimated to be at medium to high risk of malnutrition when screened using the 'Malnutrition Universal Screening Tool' upon admission to hospital in the United Kingdom. The Need for Nutrition Education/Education Programme (NNEdPro) Group was developed to address this issue and the Nutrition Education and Leadership for Improved Clinical Outcomes (NELICO) is a project within this group.The objective of NELICO was to assess whether an intensive training intervention combining clinical and public health nutrition, organisational management and leadership strategies, could equip junior doctors to contribute to improvement in nutrition awareness among healthcare professionals in the National Health Service in England. METHODS: Three junior doctors were self-selected from the NNEdPro Group original training. Each junior doctor recruited three additional team members to attend an intensive training weekend incorporating nutrition, change management and leadership. This equipped them to run nutrition awareness weeks in their respective hospitals. Knowledge, attitudes and practices were evaluated at baseline as well as one and four months post-training as a quality assurance measure. The number and type of educational events held, pre-awareness week Online Hospital Survey results, attendance and qualitative feedback from training sessions, effectiveness of dissemination methods such as awareness stalls, Hospital Nutrition Attitude Survey results and overall feedback were also used to determine impact. RESULTS: When the weighted average score for knowledge, attitudes and practices at baseline was compared with four months post-intervention scores, there was a significant increase in the overall score (p = 0.03). All three hospital teams conducted an effective nutrition awareness week, as determined by qualitative data collected from interviews and feedback from educational sessions. CONCLUSION: The NELICO project and its resulting nutrition awareness weeks were considered innovative in terms of concept and content. It was considered useful, both for the junior doctors who showed improvement in their nutrition knowledge and reported enthusiasm and for the hospital setting, increasing awareness of clinical and public health nutrition among healthcare professionals. The NELICO project is one innovative method to promote nutrition awareness in tomorrow's doctors and shows they have the enthusiasm and drive to be nutrition champions.