Overall and cause-specific hospitalisation and death after COVID-19 hospitalisation in England: A cohort study using linked primary care, secondary care, and death registration data in the OpenSAFELY platform

BACKGROUND

There is concern about medium to long-term adverse outcomes following acute Coronavirus Disease 2019 (COVID-19), but little relevant evidence exists. We aimed to investigate whether risks of hospital admission and death, overall and by specific cause, are raised following discharge from a COVID-19 hospitalisation.

METHODS AND FINDINGS

With the approval of NHS-England, we conducted a cohort study, using linked primary care and hospital data in OpenSAFELY to compare risks of hospital admission and death, overall and by specific cause, between people discharged from COVID-19 hospitalisation (February to December 2020) and surviving at least 1 week, and (i) demographically matched controls from the 2019 general population; and (ii) people discharged from influenza hospitalisation in 2017 to 2019. We used Cox regression adjusted for age, sex, ethnicity, obesity, smoking status, deprivation, and comorbidities considered potential risk factors for severe COVID-19 outcomes. We included 24,673 postdischarge COVID-19 patients, 123,362 general population controls, and 16,058 influenza controls, followed for ≤315 days. COVID-19 patients had median age of 66 years, 13,733 (56%) were male, and 19,061 (77%) were of white ethnicity. Overall risk of hospitalisation or death (30,968 events) was higher in the COVID-19 group than general population controls (fully adjusted hazard ratio [aHR] 2.22, 2.14 to 2.30, p < 0.001) but slightly lower than the influenza group (aHR 0.95, 0.91 to 0.98, p = 0.004). All-cause mortality (7,439 events) was highest in the COVID-19 group (aHR 4.82, 4.48 to 5.19 versus general population controls [p < 0.001] and 1.74, 1.61 to 1.88 versus influenza controls [p < 0.001]). Risks for cause-specific outcomes were higher in COVID-19 survivors than in general population controls and largely similar or lower in COVID-19 compared with influenza patients. However, COVID-19 patients were more likely than influenza patients to be readmitted or die due to their initial infection or other lower respiratory tract infection (aHR 1.37, 1.22 to 1.54, p < 0.001) and to experience mental health or cognitive-related admission or death (aHR 1.37, 1.02 to 1.84, p = 0.039); in particular, COVID-19 survivors with preexisting dementia had higher risk of dementia hospitalisation or death (age- and sex-adjusted HR 2.47, 1.37 to 4.44, p = 0.002). Limitations of our study were that reasons for hospitalisation or death may have been misclassified in some cases due to inconsistent use of codes, and we did not have data to distinguish COVID-19 variants.

CONCLUSIONS

In this study, we observed that people discharged from a COVID-19 hospital admission had markedly higher risks for rehospitalisation and death than the general population, suggesting a substantial extra burden on healthcare. Most risks were similar to those observed after influenza hospitalisations, but COVID-19 patients had higher risks of all-cause mortality, readmission or death due to the initial infection, and dementia death, highlighting the importance of postdischarge monitoring.

Factors associated with deaths due to COVID-19 versus other causes: population-based cohort analysis of UK primary care data and linked national death registrations within the OpenSAFELY platform

BACKGROUND

Mortality from COVID-19 shows a strong relationship with age and pre-existing medical conditions, as does mortality from other causes. We aimed to investigate how specific factors are differentially associated with COVID-19 mortality as compared to mortality from causes other than COVID-19.

METHODS

Working on behalf of NHS England, we carried out a cohort study within the OpenSAFELY platform. Primary care data from England were linked to national death registrations. We included all adults (aged ≥18 years) in the database on 1st February 2020 and with >1 year of continuous prior registration; the cut-off date for deaths was 9th November 2020. Associations between individual-level characteristics and COVID-19 and non-COVID deaths, classified according to the presence of a COVID-19 code as the underlying cause of death on the death certificate, were estimated by fitting age- and sex-adjusted logistic models for these two outcomes.

FINDINGS

17,456,515 individuals were included. 17,063 died from COVID-19 and 134,316 from other causes. Most factors associated with COVID-19 death were similarly associated with non-COVID death, but the magnitudes of association differed. Older age was more strongly associated with COVID-19 death than non-COVID death (e.g. ORs 40.7 [95% CI 37.7-43.8] and 29.6 [28.9-30.3] respectively for ≥80 vs 50-59 years), as was male sex, deprivation, obesity, and some comorbidities. Smoking, history of cancer and chronic liver disease had stronger associations with non-COVID than COVID-19 death. All non-white ethnic groups had higher odds than white of COVID-19 death (OR for Black: 2.20 [1.96-2.47], South Asian: 2.33 [2.16-2.52]), but lower odds than white of non-COVID death (Black: 0.88 [0.83-0.94], South Asian: 0.78 [0.75-0.81]).

INTERPRETATION

Similar associations of most individual-level factors with COVID-19 and non-COVID death suggest that COVID-19 largely multiplies existing risks faced by patients, with some notable exceptions. Identifying the unique factors contributing to the excess COVID-19 mortality risk among non-white groups is a priority to inform efforts to reduce deaths from COVID-19.

FUNDING

Wellcome, Royal Society, National Institute for Health Research, National Institute for Health Research Oxford Biomedical Research Centre, UK Medical Research Council, Health Data Research UK.

HIV infection and COVID-19 death: a population-based cohort analysis of UK primary care data and linked national death registrations within the OpenSAFELY platform

BACKGROUND

Whether HIV infection is associated with risk of death due to COVID-19 is unclear. We aimed to investigate this association in a large-scale population-based study in England.

METHODS

We did a retrospective cohort study. Working on behalf of NHS England, we used the OpenSAFELY platform to analyse routinely collected electronic primary care data linked to national death registrations. We included all adults (aged ≥18 years) alive and in follow-up on Feb 1, 2020, and with at least 1 year of continuous registration with a general practitioner before this date. People with a primary care record for HIV infection were compared with people without HIV. The outcome was COVID-19 death, defined as the presence of International Classification of Diseases 10 codes U07.1 or U07.2 anywhere on the death certificate. Cox regression models were used to estimate the association between HIV infection and COVID-19 death; they were initially adjusted for age and sex, then we added adjustment for index of multiple deprivation and ethnicity, and then for a broad range of comorbidities. Interaction terms were added to assess effect modification by age, sex, ethnicity, comorbidities, and calendar time.

RESULTS

17 282 905 adults were included, of whom 27 480 (0·16%) had HIV recorded. People living with HIV were more likely to be male, of Black ethnicity, and from a more deprived geographical area than the general population. 14 882 COVID-19 deaths occurred during the study period, with 25 among people with HIV. People living with HIV had higher risk of COVID-19 death than those without HIV after adjusting for age and sex: hazard ratio (HR) 2·90 (95% CI 1·96-4·30; p<0·0001). The association was attenuated, but risk remained high, after adjustment for deprivation, ethnicity, smoking and obesity: adjusted HR 2·59 (95% CI 1·74-3·84; p<0·0001). There was some evidence that the association was larger among people of Black ethnicity: HR 4·31 (95% CI 2·42-7·65) versus 1·84 (1·03-3·26) in non-Black individuals (p-interaction=0·044).

INTERPRETATION

People with HIV in the UK seem to be at increased risk of COVID-19 mortality. Targeted policies should be considered to address this raised risk as the pandemic response evolves.

FUNDING

Wellcome, Royal Society, National Institute for Health Research, National Institute for Health Research Oxford Biomedical Research Centre, UK Medical Research Council, Health Data Research UK.

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.

Diet quality is associated with all-cause mortality in adults aged 65 years and older

Diet quality indices assess compliance with dietary guidelines and represent a measure of healthy dietary patterns. Few studies have compared different approaches to assessing diet quality in the same cohort. Our analysis was based on 972 participants of the British Diet and Nutrition Survey of people aged 65 y and older in 1994/1995 and who were followed-up for mortality status until 2008. Dietary intake was measured via a 4-d weighed food record. Three measures of diet quality were used: the Healthy Diet Score (HDS), the Recommended Food Score (RFS), and the Mediterranean Diet Score (MDS). HR for all-cause mortality were obtained using Cox regression adjusted for age, sex, energy intake, social class, region, smoking, physical activity, and BMI. After adjustment for confounders, the MDS was significantly associated with mortality [highest vs. lowest quartile; HR = 0.78 (95% CI = 0.62-0.98)]. Similarly, the RFS was also associated with mortality [HR = 0.67 (95 % CI = 0.52-0.86)]; however, there were no significant associations for the HDS [HR = 0.99 (95% CI = 0.79-1.24)]. The HDS was not a predictor of mortality is this population, whereas the RFS and the MDS were both associated with all-cause mortality. Simple measures of diet quality using food-based indicators can be useful predictors of longevity.

Serum folate is significantly correlated with plasma cysteine concentrations in healthy industry workers

BACKGROUND

A low concentration of serum folate is associated with an increased risk of cardiovascular disease. Extracellular cysteine is involved in aging, cancer and cardiovascular disease. The relationship between serum folate and plasma cysteine is poorly understood. Therefore, we investigated this relationship in industry workers, whose health has economic implications.

METHODS

The concentration of serum folate was determined by the Access ImmunoAssay System Sanofi Pasteur. Plasma cysteine and homocysteine were measured by an ion-pair HPLC method. The concentrations of serum triglycerides were determined by an enzymatic colorimetric method.

RESULTS

We detected a positive correlation between the concentration of serum folate and plasma cysteine, whereas the concentration of serum folate was negatively correlated with plasma homocysteine and serum triglycerides. In a multiple regression analysis with adjustment for age, BMI and smoking, serum folate as the dependent variable exhibited a strong relationship with plasma cysteine, and a negative relationship with plasma homocysteine and serum triglycerides.

CONCLUSION

We observed significant correlations between serum folate, plasma cysteine and serum triglyceride concentrations in industry workers, implying that folate may modulate key aspects of the body's cysteine and lipid metabolism.

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.

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

Relationships between vitamin E status (α and γ-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 ≥65·0 years. γ-Tocopherol:α-tocopherol ratio declined with age. In older women γ-tocopherol and γ-tocopherol:α-tocopherol ratios were directly related to indices of obesity. In young men α- and γ-tocopherols were directly correlated with obesity, but γ-tocopherol:α-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 α-tocopherol and inversely with γ-tocopherol and γ-tocopherol:α-tocopherol ratio. Whereas α-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), γ-tocopherol and the γ-tocopherol:α-tocopherol ratio related inversely with ‘healthy’ choices. Food groups had analogous relationships; thus, α-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 γ-tocopherol and γ-tocopherol:α-tocopherol ratio. Although the mechanisms underlying these relationships are obscure, the γ-tocopherol:α-tocopherol ratio may reveal poor dietary choices, status predictors and a propensity for obesity in later life, especially in women.

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.

What influences diet in early old age? Prospective and cross-sectional analyses of the Boyd Orr cohort

BACKGROUND

The aim of this study is to identify the socio-economic and health-related factors in childhood and later life associated with healthy eating in early old age.

METHODS

The study is based on surviving members of the Boyd Orr cohort aged 61-80 years. Data are available on household diet and socio-economic position in childhood and on health and social circumstances in later life. A 12-item Healthy Diet Score (HDS) for each subject was constructed from food frequency questionnaire responses. Complete data on all exposures examined were available for 1234 cohort members.

RESULTS

Over 50% of study members had inadequacies in at least half of the 12 markers of diet quality. In multivariable models having a childhood diet which was rich in vegetables was associated with a healthy diet in early old age. The HDS for those in the upper quartile of childhood vegetable intake was 0.30 (95% confidence interval -0.01 to 0.61) higher than those with the lowest intake levels (P-trend across quartiles = 0.04). The adult factors that were most strongly associated with a healthy diet were not smoking, being an owner-occupier, and taking anti-hypertensive medication.

CONCLUSION

Our analysis indicates that diet in early old age is influenced by childhood vegetable consumption, current socio-economic position, and smoking. Interventions for improving the diet of older people could usefully focus on both encouragement of healthy diet choices from an early age and higher levels of income or nutritional support for older people.

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.

Determination of phylloquinone (vitamin K1) in plasma and serum by HPLC with fluorescence detection

A modified high-performance liquid chromatography (HPLC) method, based on Davidson and Sadowski [Meth. Enzymol. 282 (1997) 408], with fluorescence detection after zinc postcolumn reduction was developed and validated for the analysis of phylloquinone (vitamin K1) in plasma or serum samples. Compensation for procedural losses of vitamin K1 was made by the method of internal standardization using a proprietary vitamin K derivative. Increased sensitivity of detection by the use of a high-sensitivity Waters 440 fluorescence detector and optimized chromatography conditions increased the sensitivity to 4 fmol vitamin K1. The response was linear and free from interfering peaks and from baseline drift. It is therefore adequately sensitive for 0.25 ml or less of plasma sample. Long-term reproducibility of quality assurance (QA) samples was verified over a period of 4 months. The intraassay precision estimates of the QA samples within-run with mean vitamin K1 concentrations of 0.4, 1.4 and 3.4 nmol/l were 5.2% (n=6), 8.2% (n=6) and 3.0% (n=12), respectively, while interassay precision estimates between runs were 16% (n=22), 12% (n=21) and 8.1% (n=15), respectively. The assay accuracy was validated by comparing the results we obtained for 14 samples from the Vitamin K External Quality Assessment Scheme (KEQAS) with the consensus of the results from the other participating laboratories. Good agreement was obtained, with y=1.06x-0.09, R2=0.99. Validation also included linearity of response, absence of interference and confirmation of vitamin K1 peak purity.

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.

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.

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.

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.

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.

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.

Nutrition and aging: a consensus statement

OBJECTIVE

To consider the relationship between nutrition and aging. To summarize existing knowledge and identify areas of ignorance.

DESIGN

Experts from a range of relevant disciplines received and considered a series of questions related to aspects of the topic.

SETTING

University of Hohenheim, Stuttgart, Germany.

INTERVENTION

The experts met and discussed the questions and arrived at a consensus.

CONCLUSION

Many specific conclusions were drawn that support the general view that as we age an inadequate nutrition contributes to the loss of function and the development and progression of disease. Nutritional status is influenced by a range of medical, physiological, psychological, social and situational variables. Adequate nutrition and physical activity are aspects of a health-promoting lifestyle. The encouraging of better nutrition and the taking of exercise is a cost-effective way of decreasing the incidence and progression of age-related disease. The earlier such interventions are introduced the better.

Selenium status and associated factors in a British National Diet and Nutrition Survey: young people aged 4-18 y

OBJECTIVE

Assessment of selenium status to provide normative reference values, and investigation of associated socio-demographic factors, in a national sample of British young people aged 4-18 y.

SETTING

National Diet and Nutrition Survey-a nationwide cross-sectional sample of young people aged 4-18 y living in mainland Britain in 1997.

METHODS

Selenium status was measured, mainly in fasting blood samples, by plasma selenium concentration in 1127 participants, by red blood cell (RBC) selenium concentration in 1112, and by whole-blood glutathione peroxidase (GPx) activity in 658.

RESULTS

No evidence of severe selenium deficiency or toxicity was observed. Plasma selenium concentration was directly correlated with RBC selenium concentration, and both were associated directly, although less strongly, with GPx activity. Plasma and RBC selenium concentrations increased significantly with age, with RBC concentrations significantly higher in older girls than boys. Region of domicile exhibited a significant relationship. Associations also occurred with parental occupational social class, selenium concentrations being higher in more socially advantaged children. Black and Indian children had considerably higher concentrations than Caucasian children. Concentrations, especially of plasma selenium, were significantly lower in children either (or both) of whose parents were smokers, although, unexpectedly, there was no evidence that children who themselves smoked had lower levels.

CONCLUSIONS

The observed associations between selenium status indices and age, gender, social class, parental smoking and ethnic group indicate a complex network of biological factors which determine selenium concentrations in blood components, and which thus need to be controlled for when using these indices to assess selenium status in young people.

SPONSORSHIP

The survey was commissioned jointly by the Department of Health and the Ministry of Agriculture, Fisheries and Food, whose responsibility has since been transferred to the Food Standards Agency. Support for the further analysis presented in this paper was provided by the Department of Health.

Geographical variations in nutrition-related vascular risk factors in the UK: National Diet and Nutrition Survey of People Aged 65 Years and Over

BACKGROUND

There is a strong north-south gradient of vascular disease in Britain, whose aetiology is not fully understood.

OBJECTIVE

To test the hypothesis, in a cross-sectional survey of older people, that intakes and status indices for protective micronutrients, particularly those for which fruit and vegetables are rich sources, also vary on a north-south axis.

DESIGN

The 1994-5 National Diet and Nutrition Survey of People Aged 65 Years and Over has provided a uniquely appropriate data-set for this purpose. The analysis, confined to free-living participants, compared nutrient intakes and status between people living in the north of Britain, from Scotland to Humberside, with those living south of the Wash, excluding the Midlands and Wales.

RESULTS

Highly significant north-south differences, especially for vitamin C, but also to a significant extent for B-vitamins and carotenoids, indicated a more vitamin-rich diet, with more frequent use of vitamin supplements, in the south. Vitamin D status and fibre intakes were also higher in the south; sodium intake was greater in the north. Blood lipid indices did not, however, differ between north and south. North-south differences in the likelihood of receiving income support, of having manual socio-economic status and of smoking habit, appeared to be significant underlying socio-demographic factors.

CONCLUSION

These findings are consistent with the hypothesis that for older British people, differences in nutrient intake and status indices between the north and south of Britain run parallel with, and may contribute to, the north-south axis of vascular disease risk.

Intake and sources of phylloquinone (vitamin K1): variation with socio-demographic and lifestyle factors in a national sample of British elderly people

Intake and sources of phylloquinone (vitamin K1) were examined according to socio-demographic and lifestyle factors in free-living British people aged 65 years and over, from the 1994-5 National Diet and Nutrition Survey. Complete 4-d weighed dietary records were obtained from 1152 participants living in private households. Using newly-available, mainly UK-specific food content data, the weighted geometric mean intake of phylloquinone was estimated at 65 (95 % CI 62, 67) microg/d for all participants, with higher intakes in men than in women (70 v. 61 microg/d respectively, P<0.01). The mean nutrient densities of phylloquinone intake were 9.3 and 10.5 microg/MJ for men and women respectively (P<0.01), after adjusting for age group, region and smoking status. Of all the participants, 59 % had phylloquinone intakes below the current guideline for adequacy of 1 microg/kg body weight per d. Participants aged 85 years and over, formerly in manual occupations, or living in Scotland or in northern England reported lower phylloquinone intakes than their comparative groups. Overall, vegetables contributed 60 % of total phylloquinone intake, with cooked green vegetables providing around 28 % of the total. Dietary supplements contributed less than 0.5 % of phylloquinone intake. Participants living in northern England or in Scotland, in particular, derived less phylloquinone from vegetables than those living in southern England.

Plasma phylloquinone (vitamin K1) concentration and its relationship to intake in a national sample of British elderly people

Plasma phylloquinone (vitamin K1) concentration was examined according to season, socio-demographic and lifestyle factors and phylloquinone intake in a nationally representative sample of British people aged 65 years and over from the 1994-5 National Diet and Nutrition Survey. Values for both plasma phylloquinone concentration and phylloquinone intake were available from 1076 participants (561 men, 515 women). Eight hundred and thirty-four were living in private households, 242 in residential or nursing homes. Weighted geometric mean plasma phylloquinone concentrations were 0.36 (inner 95% range [corrected] 0.06, 2.01) and 0.24 (inner 94% range [corrected] 0.06, 0.96) nmol/l in free-living and institution samples respectively. Plasma phylloquinone concentrations did not generally differ between men and women, although values in free-living people were significantly lower during autumn and winter (October to March). Plasma phylloquinone concentration was not significantly associated with age. Plasma phylloquinone concentrations were positively correlated with phylloquinone intake in free-living men and women (r 0.18 and 0.30 respectively, both P<0.001). Stepwise multiple regression analysis found that 11 % of the variation in plasma phylloquinone concentration was explained by phylloquinone intake, season and plasma triacylglycerol concentration. After adjustment for age and corresponding nutrient intakes, plasma phylloquinone concentration was significantly associated (each P<0.01) with plasma concentrations of triacylglycerol, cholesterol, retinol and 25-hydroxyvitamin D in free-living women but not men, and with plasma concentrations of carotenes, alpha- and gamma-tocopherols and lutein in free-living men and women. The possibility of concurrent low fat-soluble vitamin status in elderly populations may be a cause for concern.

Flow instabilities in a graft anastomosis: a study of the instantaneous velocity fields

The major cause of arterial bypass graft failure is intimal hyperplasia. Fluctuating wall shear stresses in the graft, which are associated with disturbed flow, are believed to be important factors in the development and localization of intimal hyperplasia. This study, based upon water as the working fluid, has investigated the flow structure inside a 30 degree Y-junction with different fillet radii at the intersection between the graft and the host artery at various Reynolds numbers and distal outlet segment (DOS) to proximal outlet segment (POS) flow ratios. The structure of the flow has been investigated experimentally using particle image velocimetry (PIV). The two-dimensional instantaneous velocity fields confirm the existence of a very complex flow, especially in the toe and heel regions for the different fillet radii and clearly identify features such as sinks, sources, vortices and strong time dependency.

Correlates of plasma homocysteine, cysteine and cysteinyl-glycine in respondents in the British National Diet and Nutrition Survey of young people aged 4-18 years, and a comparison with the survey of people aged 65 years and over

Plasma total homocysteine (tHcy), cysteine and cysteinyl-glycine were measured in a representative sample of 922 young people aged 4-18 years, participating in the National Diet and Nutrition Survey in mainland Britain in 1997. Both tHcy and cysteine increased markedly with age; cysteinyl-glycine less so. Neither tHcy nor cysteine differed between genders; cysteinyl-glycine was higher in males. tHcy concentrations were lowest in the winter; cysteine and cysteinyl-glycine varied only slightly with season. In respondents aged >15 years, tHcy was higher in smokers, but in respondents aged 7-11 years, tHcy was higher in those whose mothers smoked. tHcy was inversely correlated with serum folate, serum vitamin B12 and vitamin B6 status, but neither cysteine nor cysteinyl-glycine shared these relationships. The relationships between tHcy and B-vitamin status indices ran parallel with those of the 65 years and over survey, but at much lower tHcy concentrations for any given B-vitamin concentration. Age-adjusted tHcy was not correlated with anthropometric indices, blood pressure, haematology, plasma creatinine, urea or cholesterol, but was directly correlated with fasting triacylglycerol. We conclude that disease-risk indices, like tHcy and perhaps cysteine, if established during early life, may be modulated by diet and lifestyle, thereby providing an opportunity for public health intervention.

The relationship among dental status, nutrient intake, and nutritional status in older people

Dental health status may influence nutrition. The objective of this part of the National Diet and Nutrition Survey was to assess if there is a relationship between dental status in people 65 years and older and intake of certain nutrients and any link between dental status and blood-derived values of key nutrients. Random national samples of independently living subjects and those living in institutions had dental examinations, interviews, four-day food diaries, and blood and urine analyzed. In the sample living independently, intakes of most nutrients were lower in edentate than dentate subjects. Intake of non-starch polysaccharides, protein, calcium, non-heme iron, niacin, and vitamin C was significantly lower in edentate subjects. People with 21 or more teeth consumed more of most nutrients, particularly of non-starch polysaccharide. This relationship in intake was not apparent in the hematological analysis. Plasma ascorbate and plasma retinol were the only analytes significantly associated with dental status.

Risk factors for poor iron status in British toddlers: further analysis of data from the National Diet and Nutrition Survey of children aged 1.5-4.5 years

OBJECTIVE

: To examine risk factors for poor iron status in British toddlers.

DESIGN

: National Diet and Nutrition Survey (NDNS) of children aged 1.5-4.5 years.

SETTING

: Mainland Britain, 1992/93.

SUBJECTS

: Of the 1859 children whose parents or guardians were interviewed, a weighed dietary intake was provided for 1675, and a blood sample obtained from 1003.

RESULTS

: Mean haemoglobin (Hb) and ferritin levels were significantly lower in younger (1.5-2.5 years) than in older (3.5-4.5 years) children, with boys having significantly lower ferritin levels than girls. Poor iron status ferritin <10 microg l-1, or low values for both indices) was associated with lower socioeconomic and employment status. Iron status was directly associated with meat and fruit consumption and inversely with that of milk and milk products, after adjustment for age and gender. The latter association remained significant after further adjustment for sociodemographic variables, energy intake and body weight. Children consuming >400 g day-1 of milk and cream were less likely to consume foods in other groups, with those also consuming little meat, fish, fruit and nuts at greatest risk of poor iron status. Few associations were observed between poor iron status and individual nutrient intakes, and iron status was not associated with either iron intake or with consumption of a vegetarian diet.

CONCLUSIONS

: Overdependence on milk, where it displaces iron-rich or iron-enhancing foods, may put toddlers at increased risk of poor iron status. However, this becomes non-significant when moderate-to-high amounts of foods known to enhance iron status (e.g. meat and/or fruit) are also consumed. Milk consumption in this age group should ideally be part of a mixed and balanced diet including all food groups, and particularly lean meat (or other iron-rich or fortified foods) and fruit. This is particularly relevant for households of lower socioeconomic and employment status.

Dietary supplement use at the population level: recent experience from the 1994-5 British National Diet and Nutrition Survey: people aged 65 years and over

The purpose of this article is to alert readers of this issue to the ongoing National Diet and Nutrition Survey series in mainland Britain, and to draw attention to the existence of information on the use of dietary supplements by different age-groups in the UK, and to some specific issues which need to be addressed, in order to achieve reliable estimates of supplement use from surveys of this type.

Visual acuity measurements in a national sample of British elderly people

BACKGROUND

Despite the fact that visual function has an important role in the quality of life in later years, very few studies have measured visual acuity in population based nationwide samples of British elderly people. Such measurements were carried out in the context of the national diet and nutrition survey of people aged 65 years or over (NDNS).

METHODS

NDNS participants, who were living in 80 different randomly selected postcode areas of mainland Britain, were visited at their home by a nurse who measured visual acuity at 3 metres, using the Glasgow acuity card (GAC) method. In addition, a brief questionnaire related to ocular health was administered.

RESULTS

Visual acuity was measured in 1362 NDNS participants who were not classified as mentally impaired. Visual impairment (using the WHO low vision criteria) was measured in 195 (14.3%) subjects. Prevalence of visual impairment increased significantly with age (65-74 years 3.1%; 75-84 years 11.6%; 85+ years 35.5%, p<0.001 for trend). Impaired vision was more common in subjects living in a nursing home (odds ratio adjusted for age 2.59 (95% CI 2.23 to 2. 96)) and in women (odds ratio adjusted for age 1.55 (95% CI 1.21 to 1.89)). 132 (9.7%) subjects had previously undergone cataract surgery and another 157 (11.5%) had been told that they currently had cataract. Vision improved 0.2 log units or more (at least one Snellen line) with the aid of a pinhole occluder in 289 subjects (21. 2%).

CONCLUSION

Results of this nationwide, community based study confirm that problems with poor distance visual acuity exist in a substantial part of the elderly community, particularly in women and people living in nursing homes.

An appraisal of vitamin B6 status indices and associated confounders, in young people aged 4-18 years and in people aged 65 years and over, in two national British surveys

OBJECTIVE

To compare vitamin B6 status indices with each other and with potential confounding factors, in the datasets from two national British surveys and associated studies.

DESIGN

Vitamin B6 status was measured by plasma pyridoxal phosphate (PLP) and plasma pyridoxic acid (PA) in both surveys, and also by erythrocyte aspartate aminotransferase activation coefficient (EAATAC) in one of the surveys. Plasma alpha1-antichymotrypsin was measured as an index of acute phase status; plasma creatinine was measured as an index of renal function; and plasma total alkaline phosphatase activity was measured as a proxy for PLP hydrolase activity.

SETTING

The survey of people aged 65 years and over was carried out in 80 postcode sectors across mainland Britain during 1994-95 and the survey of young people was carried out in 132 postcode sectors across mainland Britain during 1997.

SUBJECTS

Blood samples from c. 1,000 subjects of both sexes in each survey permitted measurements of plasma PLP and PA. There were also measurements of EAATAC in the young people's survey.

RESULTS

According to published limits of normality, only 5% or less of the young people had unacceptable vitamin B6 status as measured by plasma PLP. About half had apparently unacceptable status by EAATAC, but this observation is difficult to interpret. The young people had considerably higher plasma concentrations of PLP and lower concentrations of PA than the older people. In both surveys, plasma PLP was strongly correlated with plasma PA and in the young persons' survey it was also correlated, although much less strongly, with the basal activity and activation coefficient of aspartate aminotransferase. Both plasma PLP and EAATAC (but not PA nor basal aspartate aminotransferase activity) were influenced by acute phase status in young people, as indicated by significant correlations with alpha1-antichymotrypsin. In people aged 65 years and over, PA (but not PLP) was correlated with renal function, as indicated by its relation with plasma creatinine; however PLP (but not PA) was correlated with plasma alkaline phosphatase activity.

CONCLUSIONS

Several potential confounders - acute phase reaction, kidney malfunction and hydrolase activity - may influence vitamin B6 status indices, although differently for different indices and different age groups. Since older people have relatively poor vitamin B6 status, which may have important health implications for them, more reliable vitamin B6 status indices are needed.

North-south differences in some indices of Vitamin B6 nutritional status in older British people

The National Diet and Nutrition Survey, nationally representative for the British population aged 65 years and over, has revealed a north-south geographical gradient, with a decline from south to north of vitamin B6 status indices. The present study further explores the possible explanatory factors (dietary intake of vitamin B6 and riboflavin, alcohol consumption, smoking habits and some other lifestyle determinants) on the difference of vitamin B6 indices--plasma concentrations of pyridoxal phosphate (pPLP) and pyridoxic acid (pPA), between older people living in the north (Scotland, North of England) and the south (Southern England, Wales and Midlands). The results showed that older people living in the northern half of Britain are at greater risk of poor vitamin B6 status, mainly as a result of low intakes of this vitamin, than the people living in the southern half of the country. Riboflavin intake, alcohol consumption, smoking and socio-economic status also correlated with the north-south gradient of pPLP and pPA. Other potential determinants such as use of vitamin B6 supplements, medicines probably affecting vitamin B6 metabolism, were not independent correlates of the north-south gradient in vitamin B6 status indices. This may have important implications for disease-risk geographical gradients in the UK.

Is VZV reactivation a common cause of unexplained unilateral pain? Results of a prospective study of 57 patients

OBJECTIVE

Pain is a common reason for patients to present to a doctor. Many patients with zoster have seen their doctor with pain during the days before the rash and zoster sine herpete is well described. If early varicella zoster virus (VZV) reactivation could be identified confidently, it could provide an opportunity for early antiviral intervention. This prospective study was performed to assess how often patients presenting to their general practitioner with unilateral pain of no obvious clinical cause proved to have evidence of VZV reactivation.

METHODS

Fifty-seven patients were recruited and followed for 28 days; laboratory testing included VZV polymerase chain reaction (PCR) from peripheral blood mononuclear cells, VZV IgG, IgA and IgM. The control group consisted of 81 blood donors.

RESULTS

Only two study patients developed the rash of zoster. There was no significant difference in PCR or serological responses between the study group and control group. Clinical characteristics did not enable identification of patients presenting to their doctor with unilateral pain who had prodromal zoster.

CONCLUSION

There was no evidence on clinical or laboratory tests used in this study to support the view that reactivation of VZV is a common cause of unexplained unilateral pain.

Gender differences in food and nutrient intakes and status indices from the National Diet and Nutrition Survey of people aged 65 years and over

OBJECTIVES

To determine the patterns and possible explanations for gender differences in food choices, nutrient intakes and status indices, especially for micronutrients, in a representative sample of older people living in Britain, who participated in the National Diet and Nutrition Survey of people aged 65 y and over during 1994-95.

DESIGN

The Survey procedures included a health-and-lifestyle interview, a four-day weighed diet record, anthropometric measurements and a fasting blood sample for biochemical indices.

SETTING

Eighty randomly-selected postcode sectors from mainland Britain.

SUBJECTS

Of 1556 older people not living in institutions who were interviewed, 80% agreed to provide a complete four-day diet record and 63% agreed to give a blood sample for status index measurements.

INTERVENTIONS

None.

MAIN RESULT

The most highly significant gender differences in food choices were that women ate more butter, full-fat milk and certain beverages, cakes, apples, pears and bananas, whereas men ate more eggs, sugar, certain meat products and drank more alcoholic drinks, especially beer and lager. When adjusted for energy intakes, the younger women (65-79 y) had higher intakes than the younger men, of fat, retinol, vitamin C and calcium. The older women (80+ y) had higher intakes than older men, of fat and vitamin E, but lower intakes of protein, zinc and beta-carotene. The younger women had better status indices than the younger men: for alpha- and beta-carotenes, beta-cryptoxanthin and vitamin C. Women had higher plasma concentrations of cholesterol and HDL cholesterol, phosphate and copper, but lower indices of iron and vitamin D status, than men. These gender differences in status were not altered by inclusion of the corresponding nutrient intakes in the model.

CONCLUSIONS

There are gender differences in food choices, in energy and nutrient intakes and in nutritional blood status indices in older British people, especially those aged 65-79 y. Some of the status differences are attenuated in the age group of 80 y and older, whereas others are enhanced. The relationships between the quantity and type of foods or nutrients consumed, and nutrient status, are complex. With respect to suspected risk and protective factors for vascular disease, women aged 65-79 y had significantly better status for plasma alpha- and beta-carotene, ascorbate, HDL-cholesterol and homocysteine; but, in contrast, they had lower blood haemoglobin concentrations and higher concentrations of total and non-HDL-cholesterol.