A study of relationships between bone-related vitamins and minerals, related risk markers, and subsequent mortality in older British people: the National Diet and Nutrition Survey of People Aged 65 Years and Over.

SUMMARY: Follow-up of a British national survey of older people found that in men, all-cause mortality was predicted by baseline plasma concentrations of phosphorus, albumin, creatinine and α1-antichymotrypsin, and food energy intake and in women by plasma alkaline phosphatase, creatinine, α1-antichymotrypsin, 25-hydroxy-vitamin D (marginally), and phosphorus intake. INTRODUCTION: Predictive power, for all-cause mortality, of bone-related vitamin and mineral indices and intakes, measured at baseline (primary objective), was studied in the British National Diet and Nutrition Survey (community-living subset) of People Aged 65 Years and Over. A secondary objective was to identify cross-sectional relationships between indices at baseline to help explain mortality predictions. METHODS: Mortality status was recorded for 1,054 (mean age 76.6 ± 7.4 years, 49.0% female) participants from baseline survey in 1994/1995 until September 2008. Seventy-four per cent of male and 62% of female participants died. Cox proportional hazards models were used to relate baseline nutrient and risk marker estimates to subsequent survival. Results below 1.0 signified lower risk at greater nutrient (status or intake) values and vice versa. RESULTS: In both sexes, all-cause mortality was significantly predicted by body weight and mid-upper arm circumference. In men, it was predicted by baseline plasma concentrations (per SD) of: phosphorus (hazard ratio 1.18, 95% confidence interval (CI) = 1.06-1.30), albumin (hazard ratio 0.84, 95% CI = 0.74-0.94), creatinine (hazard ratio 1.20, 95% CI = 1.08-1.33) and α(1)-antichymotrypsin (hazard ratio 1.21, 95% CI = 1.11-1.33). In women, it was predicted by plasma albumin (hazard ratio 0.83, 95% CI = 0.72-0.96), alkaline phosphatase (hazard ratio 1.08, 95% CI = 1.01-1.16), creatinine (hazard ratio 1.37, 95% CI = 1.13-1.66), α(1)-antichymotrypsin (hazard ratio 1.27, 95% CI = 1.11-1.45) and marginally by 25-hydroxy-vitamin D (hazard ratio 0.87, 95% CI = 0.75-1.00). In men, it was predicted by dietary intake (per SD) of food energy; in women, by intake of phosphorus. Adjustment for plasma α(1)-antichymotrypsin or plasma creatinine reduced the significance of plasma phosphorus in men. CONCLUSION: Mortality prediction by higher plasma phosphorus in older British men may imply impaired renal function and/or acute phase status. Further studies are needed on which associations are causal and modifiable.

Dietary patterns, assessed from a weighed food record, and survival among elderly participants from the United Kingdom.

BACKGROUND/OBJECTIVES: There is variability in the association between dietary intake and health outcomes across different countries, especially among the elderly. We used the gold standard dietary assessment method, a weighed food record, to examine the association between dietary pattern and mortality in a representative sample of community dwelling participants from Great Britain aged 65 years and older. SUBJECTS/METHODS: Dietary intake was recorded at baseline in 1017 elderly participants (520 men, 497 women, mean age 76.3+/-7.4 years). Exploratory factor analysis was performed to examine dietary patterns and participants were followed up over an average of 9.2 years for mortality. RESULTS: The factor analysis revealed four interpretable principal components accounting for approximately 9.8% of the total variance, with similar patterns across sex. A 'Mediterranean-style' dietary pattern explained the greatest proportion of the variance (3.7%), followed by 'health-aware' (2.2%), 'traditional' (2.0%) and 'sweet and fat' (1.9%) factors. There were a total of 683 deaths through follow-up. After adjustment for potential confounders, only the Mediterranean-style dietary pattern remained associated with mortality (highest vs lowest tertile; hazard ratio=0.82, 95% CI, 0.68-1.00). The benefits of the Mediterranean-style diet were only observed among women (hazard ratio=0.71, 95% CI 0.52-0.96) although in men the traditional diet was a risk factor for mortality (hazard ratio=1.30, 95% CI 1.00-1.71). CONCLUSIONS: Using a gold standard approach, our results confirm previous evidence that dietary patterns are important in longevity among the elderly.

Blood indices of selenium and mercury, and their correlations with fish intake, in young people living in Britain.

Relationships between Se and Hg in erythrocytes, and between these indices and intakes of fish and other foods, were studied as an adjunct to the British National Diet and Nutrition Survey (NDNS) of young people aged 4-18 years. Hg was measured in 965 packed erythrocyte samples by inductively coupled plasma mass spectrometry. Fe measurements permitted the calculation of whole-blood Hg. Erythrocyte and plasma Se, and 7 d weighed dietary intake estimates, were available. Erythrocyte Hg was positively skewed, normalised by log-transformation. It was 20 % higher in girls than boys (3.17 v. 2.65 nmol/l, P=0.004), and increased with age in boys but not girls. It was directly and strongly correlated with erythrocyte or plasma Se. Hg and Se concentrations were directly correlated with fish intake. Certain other food groups were also directly correlated with Se and Hg concentrations, but less strongly than for fish. The strength and consistency of the relationship between erythrocyte Hg and Se suggests an important chemical link. Previous studies suggest that Se protects against the toxicity of Hg, and that fish is an important source of both. No toxic levels of Hg were found, which is reassuring because of the known health benefits of fish consumption, especially oily fish. Hg intakes need to be monitored, especially in women of child-bearing age, to ensure that Food Standards Agency guidelines are met.

Relationships between biochemical bone turnover markers, season, and inflammatory status indices in prepubertal Gambian boys.

Seasonal and interindividual differences in food availability and illnesses cause variations in growth, including bone growth, in children in developing countries. We investigated seasonal differences in biochemical (serum) markers of bone metabolism and relationships between these markers (procollagen type I N propeptide [P1NP], serum C-terminal telopeptide of type 1 collagen [S-CTX]) and serum markers of inflammation (alpha(1)- antichymotrypsin [ACT], C-reactive protein [CRP], sialic acid) in prepubertal Gambian boys. Three seasonal time points were chosen: August, mid-rainy season; October, late rainy season (both are associated with decreased food supply, increased prevalence of infection, reduced weight gain, and stunting); and April, late dry season, when environmental conditions are better and rates of weight gain are higher. The prevalence of raised inflammatory markers was high: 29% of ACT values >0.40 g/L in August, 42% >0.40 g/L in October, and 18% >0.40 g/L in April. Of CRP values, 92-96% were >0.47 mg/L and 30%, 46%, and 18% were >3.95 mg/L in August, October, and April, respectively. Also, 42-52% of sialic acid values were >648 mg/L. Of the bone markers, S-CTX exhibited the highest values in August; P1NP did not vary with season. Inverse relationships between each bone marker and the acute phase markers occurred, with the strongest relationships between P1NP and ACT or sialic acid. We conclude that bone collagen synthesis and turnover are reduced during inflammation in rural Gambian boys. Biochemical indices can provide powerful, single-time point evidence of infection and growth-faltering episodes.

Patients' and sleeping partners' experience of treatment for sleep-related breathing disorders with a mandibular repositioning splint.

AIM: To determine in detail the complications associated with the use of mandibular repositioning splints (MRS) to treat sleep-related breathing disorders. METHOD: This prospective cross-sectional cohort study audits the management with mandibular repositioning splints of 121 patients suffering from sleep-related breathing disorders. Investigation of patients' and sleeping partners' perspectives on treatment was undertaken with the use of a questionnaire based study. RESULTS: Sixty-eight per cent of respondents reported that they were compliant with treatment; various side effects were reported of which excess salivation was the most common. Investigation of sleeping partners' perspectives revealed that 70% felt that their partners' snoring was improved and 47% felt that their partner's breathing pauses during sleep were reduced. Sixty-four per cent of the sleeping partners also reported that their own sleep pattern had improved since their partner's treatment. CONCLUSION: Mandibular repositioning splints used in the manner described by this paper are demonstrated to have a good compliance rate, provide successful treatment and exhibit only minor, reversible side effects.

The relationship between severity of obstructive sleep apnoea/hypopnoea syndrome (OSAHS) and lateral cephalometric radiograph values: a clinical diagnostic tool.

BACKGROUND: This prospective cross-sectional cohort study examined the relationship between radiographic anatomy and the severity of OSAHS. The severity of OSAHS can be measured subjectively in terms of the Epworth scale and objectively in terms of the apnoea/hypopnoea Index (AHI). METHODS: 121 lateral cephalometric radiographs were traced under uniform conditions and a series of 56 landmarks identified, from which 48 angular and linear measurements were made. Significant changes occurred when comparison of these measurements with the severity of OSAHS were made. RESULTS: Body mass index (BMI), the maxillary-mandibular planes angle (MMPA) and the linear measurement between points 7 and 12, (the pharyngeal dimension measured from the tip of the soft palate to the corresponding horizontal point on the posterior pharynx), increased significantly with increasing severity of OSAHS as measured by the Epworth score. Overjet, lower lip length, and the distance from the hyoid bone to a point B on the mandible all increased significantly with increasing severity of OSAHS, as measured by the AHI. The hyoid bone was found to rotate counter clockwise as the severity of OSAHS increased, as a result the distance between the most anterior superior point on the hyoid bone and the maxillary plane was seen to decrease as severity of OSAHS increased in terms of AHI. CONCLUSIONS: Some radiographic anatomical features show significant change as the severity of OSAHS increases and these features could be used in the identification of patients who have severe OSAHS. The Logit equation derived from the findings of this study may also be a useful clinical tool in predicting the likelihood of a subject suffering from severe OSAHS.

Vitamin C status and collagen cross-link ratios in Gambian children.

Vitamin C (ascorbate) is essential for hydroxylation of prolyl and lysyl residues in nascent collagen, the failure of which leads to connective tissue lesions of scurvy. Of the pyridinium-type cross-links in mature collagen, pyridinoline requires more hydroxylysyl residues than does deoxypyridinoline. Our study tested the hypothesis that pyridinoline:deoxypyridinoline ratios in urinary degradation products may vary with ascorbate status in man. These ratios were compared between British and Gambian prepubertal boys, mean age 8.3 years, and in Gambian boys between two seasons with contrasting ascorbate availability. The mean cross-links ratio in 216 British boys was 4.36 (SD 0.71), significantly greater (P<0.0001) than in sixty-two Gambian boys: 3.83 (SD 0.52). In the Gambians the cross-links ratio was significantly higher in the dry season (with high ascorbate intake and status) than in the rains (with low intake and status). A 7-week controlled intervention was carried out in Gambian boys during the rainy season (the 'hungry' season, when vitamin C-containing foods are virtually unavailable): 100 mg ascorbate/d was given to one group of thirty-two Gambian boys and placebo to another group. The intervention did not, however, significantly alter the cross-link ratio, possibly because the response time and/or intervention-response delay is >7 weeks. If confirmed, the putative association between ascorbate and collagen cross-link ratios in man could become the basis for a functional test for adequacy of ascorbate status.

Prevalences of hyperhomocysteinemia, unfavorable cholesterol profile and hypertension in European populations.

BACKGROUND: Hyperhomocysteinemia (HHCY) is a risk factor for cardiovascular diseases (CVD). HHCY may interact with hypertension (HTEN) and an unfavorable cholesterol profile (UNFAVCHOL) to alter the risk of CVD. OBJECTIVES: To estimate the prevalences of HHCY (1) isolated and (2) in combination with UNFAVCHOL and/or HTEN in different age categories. To provide information that may improve the screening and treatment of subjects at risk of CVD. DESIGN: Cross-sectional data on 12,541 men and 12,948 women aged 20 + y were used from nine European studies. RESULTS: The prevalence of isolated HHCY was 8.5% in subjects aged 20-40 y, 4.7% in subjects aged 40-60 y and 5.9% in subjects aged over 60 y. When combining all age groups, 5.3% had isolated HHCY and an additional 5.6% had HHCY in combination with HTEN and/or UNFAVCHOL. The combinations of risk factors increased with age and, except for HHCY&UNFAVCHOL, were more prevalent than predicted by chance. Of the young subjects (20-40 y), 24% suffered from one or more of the investigated CVD risk factors. This figure was 75.1% in the old subjects (60+ years). CONCLUSIONS: A substantial number of subjects in selected European populations have HHCY (10.9%). In half of these cases, subjects suffer also from other CVD risk factors like UNFAVCHOL and HTEN. Older people in particular tend to have more than one risk factor. Healthcare professionals should be aware of this when screening and treating older people not only for the conventional CVD risk factors like UNFAVCHOL and HTEN but also HHCY, as this can easily be reduced through increased intake of folic acid via supplement or foods fortified with folic acid.

Nutritional characteristics of people with impaired mental capacity from a nationally representative survey of British people aged 65 years and over.

BACKGROUND: Mentally impaired older people are frequently excluded from population surveys for practical reasons; thus their nutritional characteristics are poorly delineated. OBJECTIVE: To describe the nutritional characteristics of those who, through mental impairment, were considered to require proxy consent and/or proxy information-givers, within a National Diet and Nutrition Survey (NDNS) of people aged 65 years and over, in the UK. DESIGN AND METHODS: 2043 participants in the NDNS in mainland Britain during 1994-95 were studied. Proxy consent and/or proxy information was provided by the next-of-kin or a carer for 3% of people living in the community and for 35% of people in institutions. A four-day weighed diet estimate and a single blood sample for nutritional status and clinical chemistry indices were obtained. RESULTS: Inclusion of people requiring proxy consent and/or information was acceptable to NHS local research ethics committees. These participants differed in certain food choices, nutrient intakes and biochemical status indices, from those not requiring a proxy. They ate more sugary and milky foods. They had lower blood concentrations of haemoglobin, retinol, cholesterol; and higher plasma levels of urea and creatinine. CONCLUSIONS: Older people who require proxy consent or information-givers can be studied in population surveys. They are nutritionally vulnerable and may need special assistance to ensure acceptable nutritional intake and status.

Gamma-tocopherol as a possible marker for nutrition-related risk: results from four National Diet and Nutrition Surveys in Britain.

Relationships between vitamin E status (alpha and gamma-tocopherol and their ratio in plasma), anthropometric and biochemical indices, and food and nutrient intakes, were studied in four British National Diet and Nutrition Surveys: children aged 1.5-4.5 years, young people aged 4.0-18.0 years, adults 19.0-64.0 years and adults aged > or = 65.0 years. gamma-Tocopherol:alpha-tocopherol ratio declined with age. In older women gamma-tocopherol and gamma-tocopherol:alpha-tocopherol ratios were directly related to indices of obesity. In young men alpha- and gamma-tocopherols were directly correlated with obesity, but gamma-tocopherol:alpha-tocopherol ratio was not. For young people and toddlers, fewer obesity indices were available and relationships were weaker. Other fat- and water-soluble vitamin indices correlated directly with alpha-tocopherol and inversely with gamma-tocopherol and gamma-tocopherol:alpha-tocopherol ratio. Whereas alpha-tocopherol correlated directly with 'healthy' nutrient choices (such as intrinsic sugars, dietary fibre, vitamins and potassium) and inversely with 'unhealthy' choices (extrinsic sugars and monounsaturated fats, i.e. avoidance of polyunsaturated fat), gamma-tocopherol and the gamma-tocopherol:alpha-tocopherol ratio related inversely with 'healthy' choices. Food groups had analogous relationships; thus, alpha-tocopherol related directly to use of polyunsaturated fats, fresh fruits and fruit juices, and inversely to non-polyunsaturated fats and extrinsic sugar. The reverse was true for gamma-tocopherol and gamma-tocopherol:alpha-tocopherol ratio. Although the mechanisms underlying these relationships are obscure, the gamma-tocopherol:alpha-tocopherol ratio may reveal poor dietary choices, status predictors and a propensity for obesity in later life, especially in women.

Nutrient intakes; biochemical and risk indices associated with Type 2 diabetes and glycosylated haemoglobin, in the British National Diet and Nutrition Survey of people aged 65 years and over.

AIMS: To characterize nutritional differences between survey participants diagnosed with Type 2 diabetes; those without diabetes, and those with "undiagnosed diabetes" based on glycosylated haemoglobin (HbA(1c)). SUBJECTS AND METHODS: The 1994/5 British National Diet and Nutrition Survey, of people aged 65 years and over (mean age 78 years), included 73 respondents with diagnosed Type 2 diabetes [mean (sd) HbA(1c) = 7.06 (2.05)%], and 30 with "undiagnosed diabetes" (defined as HbA(1c) > 6.3%; mean (sd) HbA(1c) = 7.40 (1.66)%], among a representative sample of 1038 with anthropometry; 4-day weighed diet; blood and urine status measurements. RESULTS: The prevalence of Type 2 diabetes (diagnosed + undiagnosed) was 10%. In subjects without diagnosis of diabetes, those with HbA(1c) > 6.3% had on average a significantly higher body weight (73.6 vs. 67.9 kg), higher waist circumference (99.8 vs. 91.8 cm), higher body mass index (28.6 vs. 25.9 kg/m(2)) and higher white cell counts (7.64 vs. 7.09 x 10(9)/l), than those with mean HbA(1c) < or = 6.3%. Diagnosed diabetic subjects had significantly higher energy-adjusted intakes of protein, fibre, vitamins and minerals than those not in this category (P < 0.01). In contrast, those with undiagnosed diabetes (HbA(1c) > 6.3%) were nutritionally "at risk", having low plasma concentrations of lycopene (0.13 vs. 0.24 micromol/l) and high density lipoprotein cholesterol (0.99 vs. 1.27 micromol/l) and a trend towards low vitamin C (24 vs. 36 micromol/l) which was significant (P < 0.01) for men. HbA(1c) was positively correlated with white cell count, plasma fasting triglycerides, plasma alkaline phosphatase and homocysteine (all P < 0.01 overall), being particularly striking amongst men. CONCLUSIONS: Among older British citizens, those with diagnosed diabetes had healthier nutritional profiles than those undiagnosed with high HbA(1c). Important health-promoting benefits are therefore predicted following early diagnosis and nutritional advice for people with Type 2 diabetes.

Endothelial cell adhesion molecules in healthy adults during acute hyperhomocysteinemia and mild hypertriglyceridemia.

OBJECTIVE: Hyperhomocysteinemia and hypertriglyceridemia are independently associated with atherosclerotic disease. The process of atherogenesis involves inflammation and endothelial dysfunction. We tested whether concurrent acute hyperhomocysteinemia and mild hypertriglyceridemia increase the concentrations of circulatory cellular adhesion molecules in healthy subjects. STUDY DESIGN AND METHODS: Twelve healthy volunteers aged 37.5 years (range, 25-51) participated in the present study. The concentrations of plasma total homocysteine (p-tHcy), serum triglycerides, circulatory cellular adhesion molecules (CAMs), and concentrations of nitrate were measured at 0 (fasting), 2, 4, and 6 h after loading with (1) methionine, (2) fat, (3) methionine + fat, and (4) water (control). Wash out period between each loading was >or=1 week. RESULTS: Percent relative changes from baseline in the concentrations of p-tHcy, 2, 4, and 6 h after methionine and methionine + fat were significantly different from after water and fat loading. Changes in the concentrations of serum triglycerides 2 h after fat loading were significantly different from water loading, whereas methionine + fat loading caused a significant difference after 2, 4, and 6 h. We detected a synergistic increase in the triglyceride area response to methionine + fat loading. We detected also a significant difference in percent relative changes in the concentrations of P-selectin (PSEL) (P = 0.02), E-selectin (ESEL) (P = 0.003), and vascular cell adhesion molecule-1 (VCAM-1) (P = 0.005) 6 h after methionine + fat loading as compared to water loading. There was an additive increase in the PSEL area response to methionine + fat loading. Furthermore, area response to VCAM was greater to methionine loading than water loading (P = 0.01). A decrease in the concentration of NO(3) was more pronounced after methionine + fat loading and a significantly decreased area response of nitrate to methionine + fat loading was detected than to area response to water loading (P = 0.002). CONCLUSION: Inflammatory activation of the endothelium takes place during concurrent transient hyperhomocysteinemia and mild hypertriglyceridemia.

Zinc and vitamin A intake and status in a national sample of British young people aged 4-18 y.

OBJECTIVE: To examine zinc and vitamin A intake and status and associated dietary, socio-demographic, lifestyle and physiological factors in British young people. DESIGN: National Diet and Nutrition Survey of young people aged 4-18 y. SETTING: Great Britain, 1997. SUBJECTS: Complete 7-day weighed dietary records were provided by 1520 participants, while 1193 provided blood samples. RESULTS: A total of 13 and 11% of participants respectively reported low dietary intakes of zinc and vitamin A (retinol equivalents), relative to the UK lower reference nutrient intake. These percentages were not altered significantly by including contributions to intake from supplements, mainly containing vitamin A (as retinol). Likelihood of low zinc and/or vitamin A intake was more often associated with age, sex and likely under-reporting of food consumption than with other socio-demographic and lifestyle factors. Low zinc and vitamin A intakes were generally less likely in those with higher consumption of dairy foods (mainly milk). Zinc and vitamin A status (assessed by plasma zinc and retinol concentrations) were adequate in almost all participants. Plasma zinc concentration was not significantly associated with zinc intake. Plasma retinol concentration was correlated with vitamin A intake (overall r=0.17, P<0.001; adjusted for age and plasma alpha(1)-antichymotrypsin concentration) and increased significantly with age (P<0.001) in both sexes. A significant association was found between plasma zinc and retinol concentrations in boys only (r=0.17, P=0.001). CONCLUSION: Zinc and vitamin A intakes and status were generally adequate in this national sample of British young people.

Tomato consumption and plasma lycopene concentration in people aged 65 y and over in a British national survey.

OBJECTIVE: Assessment of consumption of raw and processed tomatoes, plasma lycopene concentration and their interrelationship in a nationally representative sample of elderly British people. SETTING: : A 1994-1995 National Diet and Nutrition Survey: a nationwide cross-sectional sample of people aged 65 y and over living in mainland Britain, either in the community ("free-living", n=1275) or in institutions such as nursing homes (n=412). METHODS: Consumption of raw and processed tomatoes (including those in tomato-containing composite foods) was recorded by a 4-day dietary record for each participant. Plasma lycopene concentration was assayed by HPLC. Sociodemographic and lifestyle information was recorded by trained interviewers. RESULTS: In all, 29% of free-living people and 24% of those living in institutions did not consume any raw or processed tomatoes during the 4-day recording period. Free-living participants were more likely to consume raw tomatoes (26 vs 16%). Plasma lycopene concentration was positively associated with the weight of raw and processed tomatoes consumed, especially with processed tomatoes and their products, alcohol consumption and with plasma total (as well as HDL and non-HDL) cholesterol concentrations. Among free-living participants, increased age, cigarette smoking habit and manual occupational social class were all associated with lower plasma lycopene concentration. CONCLUSIONS: In the current population, consumption of raw and processed tomatoes varied by sociodemographic and lifestyle characteristics, and made a significant contribution to plasma lycopene concentration. Determinants of plasma lycopene concentration were age, plasma cholesterol concentration and smoking habit.

Risk factors for low iron intake and poor iron status in a national sample of British young people aged 4-18 years.

OBJECTIVE: To examine the prevalence and dietary, sociodemographic and lifestyle risk factors of low iron intake and poor iron status in British young people. DESIGN: National Diet and Nutrition Survey of young people aged 4-18 years. SETTING: Great Britain, 1997. SUBJECTS: In total, 1699 young people provided 7-day weighed dietary records, of which 11% were excluded because the participant reported being unwell with eating habits affected. Blood was obtained from 1193 participants, with iron status indicated by haemoglobin, serum ferritin and transferrin saturation. RESULTS: Iron intakes were generally adequate in most young people aged 4-18 years. However, low iron intakes (below the Lower Reference Nutrient Intake) occurred in 44% of adolescent girls (11-18 years), being less prevalent with high consumption of breakfast cereals. Low haemoglobin concentration (<115 g l-1, 4-12 years; <120 or <130 g l-1, 13+ years for girls and boys, respectively) was observed in 9% of children aged 4-6 years, pubertal boys (11-14 years) and older girls (15-18 years). Adolescent girls who were non-Caucasians or vegetarians had significantly poorer iron status than Caucasians or meat eaters, independent of other risk factors. The three iron status indices were correlated significantly with haem, but not non-haem, iron intake. CONCLUSIONS: Adolescent girls showed the highest prevalence of low iron intake and poor iron status, with the latter independently associated with non-Caucasian ethnicity and vegetarianism. Risk of poor iron status may be reduced by consuming (particularly lean red) meat or enhancers of non-haem iron absorption (e.g. fruit or fruit juice) in vegetarians.

In a population study, can parathyroid hormone aid the definition of adequate vitamin D status? A study of people aged 65 years and over from the British National Diet and Nutrition Survey.

The British National Diet and Nutrition Survey of people aged 65 years and over in 1994-5 provided nationally representative estimates of food and nutrient intakes and biochemical status indices. In a further analysis study, parathyroid hormone (PTH) concentrations were measured in plasma samples from 773 subjects and were analyzed with the existing data on vitamin D intake, plasma 25-hydroxyvitamin D (25OHD), total plasma calcium and albumin. As predicted, a strong inverse relationship was observed between PTH and 25OHD. In the free-living respondents aged 65-84 years (n=507) there was a continuous decline in PTH with increasing 25OHD and no plateau, whereas in free-living people aged 85+ years (n=86) there was a significant deviation from a simple inverse relationship, with unexpectedly high PTH values in some people with satisfactory 25OHD status. There was a relationship between both PTH (inverse) and plasma 25OHD (direct) with calcium intake. A direct relationship between 25OHD and total plasma calcium was not significant when calcium was corrected for albumin. Geographically, 25OHD, and to a lesser extent PTH, exhibited a north-south gradient, and 25OHD was associated with self-reported health status. Both 25OHD and PTH were associated with self-reported physical activity. Low calcium intake and 25OHD was associated with receipt of state benefits. The relationship between plasma 25OHD and vitamin D intake revealed a striking seasonal cycle. 25OHD was strongly influenced by vitamin D intake in the winter in free-living subjects, but this was not observed in the summer. In people living in institutions such as nursing homes, who are less likely to be exposed to sunlight throughout the year, plasma 25OHD levels were lower throughout the year.

Impact of nutritional status on antibody responses to different vaccines in undernourished Gambian children.

AIM: To test the efficacy of T-cell-dependent and T-cell-independent vaccines in rural Gambian children suffering from a range of energy/protein and micronutrient deficiencies. METHODS: Nutritional status (anthropometry, haemoglobin, plasma leptin and micronutrient status) and response to two vaccinations (23 valent pneumococcal capsular polysaccharide vaccine, Pneumovax and the Human Diploid-Cell Rabies Vaccine) were assessed in 472 children aged 6 1/2 h to 9 1/2 y. RESULTS: Anthropometry and micronutrient status (as z-scores against European reference values) indicated a range from moderate to severe levels of undernutrition [mean (interquartile range): weight-for-age z-score -1.58 (-2.18 to -0.95); height-for-age z-score -0.94 (-1.51 to -0.35); body-mass-index-for-age z-score -1.43 (-2.05 to -0.84); mid-upper arm circumference -1.41 (-1.72 to -1.13); leptin -1.06 (-1.10 to -1.03); haemoglobin (Hb) -0.30 (-1.18 to 0.79); zinc -1.29 (-2.42 to -0.55); vitamin C -0.01 (-1.18 to 1.15); retinol -1.33 (-1.97 to -0.77)]. A seasonal effect was observed in haemoglobin levels and in all micronutrients (with the exception of zinc and retinol) and in the response to vaccination. After adjusting for seasonality, age and gender, no consistent associations were found between any of the measures of nutritional status and the effectiveness of seroconversion to either of the vaccines. CONCLUSION: The successful short-term seroconversion to whole inactivated viral and bacterial polysaccharide vaccines indicates that the processes leading to antibody secretion remain intact over a wide range of single and combined nutrient deficiencies.

Comparison of vitamin C deficiency with food restriction on collagen cross-link ratios in bone, urine and skin of weanling guinea-pigs.

Mild-to-moderate vitamin C depletion in weanling guinea-pigs affects pyridinoline:deoxypyridinoline (collagen cross-link) ratios in femur shaft and urine, attributed to impairment of hydroxylation of collagen lysine. We investigated: (1). whether the picture at two time points is compatible with progressive accumulation of abnormal collagen; (2). whether any changes are seen in skin, where little deoxypyridinoline occurs; (3). whether total food restriction has similar effects. Male weanling Dunkin-Hartley guinea-pigs were fed diets containing either 0.5 (vitamin C-restricted) or 160.0-320.0 (vitamin C-adequate) mg vitamin C/d. Two groups receiving the vitamin C-adequate diet received it ad libitum. Two other groups received the vitamin C-adequate diet in a restricted amount, limited to that which permitted nearly the same growth rate as in the vitamin C-restricted groups. Animals were fed for 4 or 8 weeks; urine was collected, and vitamin C and collagen indices were measured. In the femur shaft, the hydroxyproline content per unit weight was unaffected by vitamin C restriction or by total food restriction. Deoxypyridinoline was increased and the pyridinoline:deoxypyridinoline ratio was decreased in vitamin C-restricted groups, but not in food-restricted groups. Changes in the value of the ratio were greater after 8 than after 4 weeks. Urine indices mirrored bone indices. In skin, the main effect of vitamin C restriction was to reduce hydroxyproline. Here, the cross-link ratios changed less markedly than in bone, and there was less deoxypyridinoline. We conclude that the picture at two time points is compatible with a progressive accumulation of pyridinoline-enriched collagen in vitamin C-deprived animals, that the picture in skin differs from that of bone and urine, and that cross-link changes are not produced by total food restriction.

Relationship between methylmalonic acid, homocysteine, vitamin B12 intake and status and socio-economic indices, in a subset of participants in the British National Diet and Nutrition Survey of people aged 65 y and over.

OBJECTIVE: Assessment of functional vitamin B(12) status in a subset of the respondents in the British National Diet and Nutrition Survey of people aged 65 y and over. SETTING: National Diet and Nutrition Survey: a British nationwide cross-sectional sample of people aged 65 y and over, living either in the community or in institutions such as nursing homes, during one calendar year spanning 1994-1995. METHODS: Methylmalonic acid (MMA) concentrations were measured in plasma samples from 313 subjects (ca 14% of those originally enrolled in the survey). The results were compared with those for serum vitamin B(12), vitamin B(12) intakes and other status and intake estimates and with socio-demographic indices. RESULTS: Of the NDNS participants overall, 20% had serum vitamin B(12) concentrations<150 pmol/l. In the subset studied here, 24% of free-living and 46% of institution-living participants had MMA>0.5 micromol/l. Geometric mean MMA increased with age, from 0.25 micro mol/l in people aged 65-74 y to 0.38 micro mol/l in people aged 85+y. There was little evidence for any gender difference in MMA. It was inversely correlated with serum vitamin B(12) and with red blood cell folate; it was positively correlated directly with total homocysteine, but not significantly with serum folate or with vitamin B(12) intake. Among respondents with high MMA, a subgroup had normal serum vitamin B(12) but higher-than-average plasma urea and creatinine. Socio-demographic co-variates of MMA included receipt of State income benefits, social class of head of household, and educational attainment. These indices were not correlated with serum vitamin B(12). CONCLUSIONS: The progressive increase in MMA with age is metabolic evidence for increasing risk of functional vitamin B(12) deficiency with increasing age in older people. There is evidence that renal function is linked to high MMA in some older people. Age and renal function are thus both important when establishing upper reference limits for MMA. The socio-demographic observations suggest a link between poverty and poor functional vitamin B(12) status in older British people.