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.

The prevalence of osteoporosis and the incidence of age-related fragility fracture vary by ethnicity. There is greater than 10-fold variation in fracture probabilities between countries across the world. Mineral and bone metabolism are intimately interlinked, and both are known to exhibit patterns of daily variation, known as the diurnal rhythm (DR). Ethnic differences are described for Ca and P metabolism. The importance of these differences is described in detail between select ethnic groups, within the USA between African-Americans and White-Americans, between the Gambia and the UK and between China and the UK. Dietary Ca intake is higher in White-Americans compared with African-Americans, and is higher in White-British compared with Gambian and Chinese adults. Differences are observed also for plasma 25-hydroxy vitamin D, related to lifestyle differences, skin pigmentation and skin exposure to UVB-containing sunshine. Higher plasma 1,25-dihydroxy vitamin D and parathyroid hormone are observed in African-American compared with White-American adults. Plasma parathyroid hormone is also higher in Gambian adults and, in winter, in Chinese compared with White-British adults. There may be ethnic differences in the bone resorptive effects of parathyroid hormone, with a relative skeletal resistance to parathyroid hormone observed in some, but not all ethnic groups. Renal mineral excretion is also influenced by ethnicity; urinary Ca (uCa) and urinary P (uP) excretions are lower in African-Americans compared with White-Americans, and in Gambians compared with their White-British counterparts. Little is known about ethnic differences in the DR of Ca and P metabolism, but differences may be expected due to known differences in lifestyle factors, such as dietary intake and sleep/wake pattern. The ethnic-specific DR of Ca and P metabolism may influence the net balance of Ca and P conservation and bone remodelling. These ethnic differences in Ca, P and the bone metabolism may be important factors in the variation in skeletal health.

BackgroundOne 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.MethodsThree 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.ResultsWhen 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.ConclusionThe 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.

HighlightsPlasma concentrations of DBP, albumin, 25(OH)D & 1,25(OH)2D exhibited significant diurnal rhythms (DR).DRs were similar in British, Gambian and Chinese men and women aged 60–75 years.The free 1,25(OH)2D DR was attenuated compared to that of total 1,25(OH)2D.The magnitude of the free 25(OH)D DR was not different to that of total 25(OH)D.

SummaryEthnic differences in renal calcium and phosphate excretion exist, which may depend on differences in their dietary intakes and regulatory factors. We report highly significant differences in urinary calcium and phosphate excretion between white British and Gambian adults after statistical adjustment for mineral intakes, indicating an independent effect of ethnicity.IntroductionPopulations vary in their risk of age-related osteoporosis. There are racial or ethnic differences in the metabolism of the bone-forming minerals calcium (Ca) and phosphate (P), with a lower renal Ca and P excretion in African-Americans compared to white counterparts, even at similar intakes and rates of absorption. Also, Africans in The Gambia have a lower Ca excretion compared to white British subjects, groups known to differ in their dietary Ca intake. Here, we report on differences in urinary Ca and P excretion between Gambian and white British adults while allowing for known predictors, including dietary intakes.MethodsParticipants were healthy white British (n = 60) and Gambian (n = 61) men and women aged 60–75 years. Fasting blood and 2-h urine samples were collected. Markers of Ca and P metabolism were analysed. Dietary intake was assessed with country-specific methods.ResultsWhite British older adults had higher creatinine-corrected urinary Ca and P excretion (uCa/uCr, uP/uCr) and lower tubular maximum of Ca and P compared to Gambian counterparts. The predictors of urinary Ca and P differed between groups. Multiple regression analysis showed that dietary Ca and Ca/P were predictors of uCa/uCr and uP/uCr, respectively. Ethnicity remained a significant predictor of uCa/uCr and uP/uCr after adjustment for diet and other factors.ConclusionsGambian older adults have higher renal Ca conservation than British counterparts. Dietary mineral intakes were predictors of the differences in urinary Ca and P excretion, but ethnicity remained a highly significant predictor after statistical adjustment. This suggests that ethnicity has an independent effect on renal Ca and P handling.

Ethnic groups vary in their risk of age-related osteoporosis. There are ethnic differences in the metabolism of the bone forming minerals, calcium (Ca) and phosphate (P), with differences in renal Ca excretion, even at similar intakes and rates of absorption. We have previously reported a lower urinary Ca excretion in Black Gambian (G) compared to Caucasian British (B) subjects (1) . These ethnic groups are known to differ in their dietary Ca intake and vitamin D (VD) status. We have investigated ethnic differences in urinary Ca excretion while allowing for other known predictors of renal Ca handling, including dietary Ca.Subjects were healthy older (60-75 years) G (n = 61) and B (n = 60) men and women. Blood and timed 2 h urine samples were collected after an overnight fast. Dietary intake was assessed with country specific food diaries and food composition tables. Anthropometry was performed. Blood ionised Ca (iCa), plasma (p) total Ca (pCa), P (pP), 25-hydroxy VD (25VD), 1,25-dihydroxy VD (1,25VD), parathyroid hormone (PTH), and urinary (u) Ca (uCa), creatinine (uCr), and uP were analysed (1) . The fractional excretion of Ca (FECa) and the tubular maximum of Ca (TmCa) were calculated (2) . Multiple regression was performed to investigate the effect of predictors of renal Ca handling. Ethnicity was used as an independent binary variable to test for differences between ethnic groups in a regression model. Data were transformed to natural logarithms to allow for the expression of ethnic differences (D) between G and B subjects as a % (3) . G subjects had significantly lower body weight [DG-B: -31( -37, -25) %; P < 0.001], pCa [DG-B: -5( -7, -2) %; P < 0.001], and higher 25VD [DG-B: + 35( + 22, + 48)%; P < 0.001], PTH [DG-B: + 62( + 38, + 85) %; P < 0.001] and 1,25VD [DG-B: + 48( + 38, + 58)%; P < 0.001]. Markers of bone turnover were higher in G compared to B subjects (P < 0.001).There were significant ethnic differences in renal Ca handling as measured by uCa (mmol/minute); uCa/uCr (mmol/mmol); FECa (%); and TmCa (mmol/L) (P < 0.001). The p-value and the effect size of these ethnic differences were similar after including dietary Ca (mg/day), or dietary Ca:P ratio (mg/mg) in the model (see table). In a multiple regression analysis without ethnicity, the significant predictors of uCa/uCr were: dietary Ca, diastolic blood pressure, iCa, pP, P1NP, CTX and uP. However, in a model including ethnicity, dietary Ca was no longer a significant predictor of uCa/uCr; whereas diastolic BP, iCa, pP, P1NP, CTX and uP remained significant predictors of uCa/uCr. Ethnicity was a significant predictor of uCa/uCr in the multivariate model ([DG-B: -133( -175, -107) %; P < 0.001]). These data suggest that G subjects have higher renal Ca conservation than B counterparts. The ethnic differences remained in the presence of other known predictors of renal Ca handling.

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