Vitamin D status and parathyroid hormone relationship in adolescents and its association with bone health parameters: analysis of the Northern Ireland Young Heart's Project

In girls, a plateau in parathyroid hormone (PTH) was observed at a 25-hydroxyvitamin D (25(OH)D) concentration of approximately 60 nmol/l. In boys, there was no plateau in PTH concentrations as 25(OH)D concentration increased. A 25(OH)D threshold of 60 nmol/l appears to have implications for bone health outcomes in both girls and boys.

INTRODUCTION

Our objective was to investigate if there is a threshold 25(OH)D concentration where a plateau in PTH concentration is evident and to examine the impact of this relationship on bone mineral density (BMD) and bone turnover in a representative sample of adolescents.

METHODS

We conducted a cross-sectional analysis among 1,015 Northern Irish adolescents aged 12 and 15 years. Serum 25(OH)D, PTH, osteocalcin, type 1 collagen cross-linked C-telopeptide (CTx), and BMD of the nondominant forearm and heel were measured. Nonlinear regression analysis was used to model the association between 25(OH)D and PTH.

RESULTS

In girls, a plateau in PTH was observed at a 25(OH)D concentration of approximately 60 nmol/l (PTH = 47.146 + 370.314 x exp((-0.092 x 25(OH)D))) while no plateau in PTH was observed in boys (PTH = 42.144 + 56.366 x exp((-0.022 x 25(OH)D))). Subjects with 25(OH)D levels <60 nmol/l had significantly higher osteocalcin concentrations (P < 0.05) compared with those who had >or=60 nmol/l, while no significant (P > 0.05) differences were noted for CTx concentrations. In girls only, nondominant forearm BMD but not heel BMD was significantly higher (P = 0.046) in those with 25(OH)D concentrations >or= 60 nmol/l.

CONCLUSIONS

Serum 25(OH)D levels above 60 nmol/l in Northern Irish adolescent girls prevent an increase in serum PTH levels and maintaining 25(OH)D >60 nmol/l in both girls and boys may lead to improved bone health outcomes.

Pattern of intake of food additives associated with hyperactivity in Irish children and teenagers

A double-blind randomized intervention study has previously shown that a significant relationship exists between the consumption of various mixes of seven target additives by children and the onset of hyperactive behaviour. The present study set out to ascertain the pattern of intake of two mixes (A and B) of these seven target additives in Irish children and teenagers using the Irish national food consumption databases for children (n = 594) and teenagers (n = 441) and the National Food Ingredient Database. The majority of additive-containing foods consumed by both the children and teenagers contained one of the target additives. No food consumed by either the children or teenagers contained all seven of the target food additives. For each additive intake, estimates for every individual were made assuming that the additive was present at the maximum legal permitted level in those foods identified as containing it. For both groups, mean intakes of the food additives among consumers only were far below the doses used in the previous study on hyperactivity. Intakes at the 97.5th percentile of all food colours fell below the doses used in Mix B, while intakes for four of the six food colours were also below the doses used in Mix A. However, in the case of the preservative sodium benzoate, it exceeded the previously used dose in both children and teenagers. No child or teenager achieved the overall intakes used in the study linking food additives with hyperactivity.

UC blood-derived mesenchymal stromal cells: an overview

The UC is a readily available source of blood that may be used for analysis and treatment. Some authors suggest that within the UC blood (UCB) are cells with potential for differentiation down mesenchymal lineages. Isolation and characterization of these cells has been accomplished in some centers. Differentiation of these cells down multiple lineages has been documented. Surface marker expression and gene expression profiling has been performed, and mesenchymal stromal cells (MSC) from BM and adipose tissue have been compared with those derived from UCB. The use of UCB-derived stem cells has been investigated in pre-clinical studies. As this field is rapidly advancing, this review summarizes the current state of our knowledge of MSC derived from UCB.

An examination of the influence of eating location on the diets of Irish children

OBJECTIVES

To examine the influence of eating location on the quality of the diets of Irish children and to compare intakes at home with intakes at other people's homes and intakes outside the home, and to compare intakes at various locations outside the home.

DESIGN

Food intake was measured using a 7-day weighed diary in 594 children from the Republic of Ireland (aged 5-12 years). Details of where the food was prepared or obtained were also recorded.

RESULTS

Eighty-nine per cent of all eating occasions occurred at home; < 6% occurred at both other people's homes and outside the home (takeaway, restaurant, shop, other). The percentage of food energy from fat was above the recommended 35% at other people's homes and outside the home, specifically at takeaways and restaurants. Fibre and micronutrient intakes (per 10 MJ) were significantly higher at home than at the other locations (P < 0.05). Within the 'out' locations, fibre and micronutrient intakes were generally higher at restaurants and lower at shops. High consumers of foods outside the home had a statistically significant, but relatively small decline in nutrient intakes compared with non- or low consumers. Chips and processed potatoes, meat products, savouries, sugars and confectionery, and savoury snacks made the greatest contribution to foods consumed outside the home.

CONCLUSIONS

The main focus of nutrition policies to improve the diets of Irish children should be the home environment rather than the food service sector. However, guidelines could call for better food choices outside the home to improve nutrient intakes.

Associations between daily food intake and excess adiposity in Irish adults: towards the development of food-based dietary guidelines for reducing the prevalence of overweight and obesity

BACKGROUND

The prevalence of obesity has nearly doubled in Ireland since 1990 and over half of the population has a large waist circumference (WC). No food-based, dietary guidelines exist in Ireland for a reduction in the prevalence of body fat or obesity.

OBJECTIVE

To examine the association between daily food intake and categories of body mass index and WC for the development of dietary guidelines to combat obesity.

DESIGN

Cross-sectional study of a random representative sample of 1379 adults aged 18-64 years from Northern Ireland and the Republic of Ireland.

MEASUREMENTS

Weight, height and WC were measured according to standard procedures. Diet was assessed using a 7-day food diary from which 28 food groups were generated and entered into logistic regression analysis.

RESULTS

Higher mean daily consumption of most of the 28 food groups was associated with an increased likelihood of being classified as obese or at waist action level 2, compared to normal weight and normal WC. The strongest associations were found for savoury snacks, butter and full fat spreads. Contrary to popular opinion, not one individual food group but rather a combination of many foods was associated with excess adiposity.

CONCLUSIONS

Body mass index and WC in adults are strongly influenced by the amount of food consumed. Public health policies for a reduction in body fat and obesity may be more effective if the emphasis is placed on a reduction of food and beverages consumed as opposed to the traditional dietary recommendations for macronutrients.

Dietary patterns in middle-aged Irish men and women defined by cluster analysis

Objectives:

To identify and characterise dietary patterns in a middle-aged Irish population sample and study associations between these patterns, sociodemographic and anthropometric variables and major risk factors for cardiovascular disease.

Design:

A cross-sectional study.

Subjects and methods:

A group of 1473 men and women were sampled from 17 general practice lists in the South of Ireland. A total of 1018 attended for screening, with a response rate of 69%. Participants completed a detailed health and lifestyle questionnaire and provided a fasting blood sample for glucose, lipids and homocysteine. Dietary intake was assessed using a standard food-frequency questionnaire adapted for use in the Irish population. The food-frequency questionnaire was a modification of that used in the UK arm of the European Prospective Investigation into Cancer study, which was based on that used in the US Nurses' Health Study. Dietary patterns were assessed primarily by K-means cluster analysis, following initial principal components analysis to identify the seeds.

Results:

Three dietary patterns were identified. These clusters corresponded to a traditional Irish diet, a prudent diet and a diet characterised by high consumption of alcoholic drinks and convenience foods. Cluster 1 (Traditional Diet) had the highest intakes of saturated fat (SFA), monounsaturated fat (MUFA) and percentage of total energy from fat, and the lowest polyunsaturated fat (PUFA) intake and ratio of polyunsaturated to saturated fat (P:S). Cluster 2 (Prudent Diet) was characterised by significantly higher intakes of fibre, PUFA, P:S ratio and antioxidant vitamins (vitamins C and E), and lower intakes of total fat, MUFA, SFA and cholesterol. Cluster 3 (Alcohol & Convenience Foods) had the highest intakes of alcohol, protein, cholesterol, vitamin B12, vitamin B6, folate, iron, phosphorus, selenium and zinc, and the lowest intakes of PUFA, vitamin A and antioxidant vitamins (vitamins C and E). There were significant differences between clusters in gender distribution, smoking status, physical activity, body mass index, waist circumference and serum homocysteine concentrations.

Conclusion:

In this general population sample, cluster analysis methods yielded two major dietary patterns: prudent and traditional. The prudent dietary pattern is associated with other health-seeking behaviours. Study of dietary patterns will help elucidate links between diet and disease and contribute to the development of healthy eating guidelines for health promotion.

The importance of composite foods for estimates of vegetable and fruit intakes

Objective:

To evaluate the contribution of composite foods to vegetable and fruit intakes in Irish adults and to compliance with dietary guidelines for vegetable and fruit intake.

Design:

Data were analysed from the North/South Ireland Food Consumption Survey of 18–64-year-old adults (n= 1379; 662 men, 717 women), which used a 7-day food diary to estimate food intake.

Results:

The mean intake of vegetables (excluding potatoes) was 140g day−1(men 149g day−1; women 132g day−1), of fruit was 136 g day−1(men 133g day−1; women 140 g day−1) and of potatoes was 227 g day−1(men 296g day−1; women 163 g day−1). The mean daily intakes of vegetables, fruit and potatoes from composite foods were 37 g (26%), 6 g (5%) and 17 g (7%), respectively. The mean intake of vegetables from composite foods was unrelated to age or gender, but increased with increasing social class and level of education attained. The proportions of men and women meeting the recommendation for ≥400g day−1(5 servings of 80 g per day) of vegetables and fruit were 21% (15% excluding composite foods) and 19% (12% excluding composite foods), respectively. Compliance with the dietary recommendation decreased with decreasing levels of educational attainment and social class.

Conclusion:

Intakes of vegetables and fruit are low compared with current dietary recommendations, particularly in those of lower levels of educational attainment and social class. Composite foods are an important source of vegetables (less importantly of fruit) and should be included when estimating vegetable intakes. Failure to do so may result in bias in estimates of intake and of compliance with dietary guidelines for population groups, as well as misclassification of individuals by level of intake.

Prevalence of overweight and obesity in Irish school children, using four different definitions

OBJECTIVE

To determine the prevalence of overweight and obesity in Irish children using four different weight-for-height methods and to examine secular trends from previous national data.

DESIGN

A cross-sectional survey. Weight and height were measured according to standard procedures and used to determine the prevalence of overweight and obesity using four weight-for-height methods of assessment, actual relative weight, the Centers for Disease Control and Prevention body mass index (BMI) for age charts for boys and girls, the BMI reference curves for the UK 1990 and the International Obesity Task Force age- and sex-specific BMI cutoffs.

SETTING

The survey was carried out between 2003 and 2004 in the Republic of Ireland.

SUBJECTS

Random representative sample of 596 children aged 5-12 years.

RESULTS

The prevalence of overweight and obesity in Irish children is high, but varies considerably with each method. The prevalence of obesity in boys ranged from 4.1 to 11.2 % and in girls from 9.3 to 16.3%. Between 1990 and 2005, depending on the method used, there was a two-to-fourfold increase in obesity in children aged 8-12 years.

CONCLUSION

It is evident given the variation displayed in the prevalence of obesity when using the different methods, that there is a discernible need for a single definition to identify the obese child in Ireland. The findings show a high prevalence of overweight and obesity in Irish school children and the increase in the prevalence of obesity over the last 15 years highlights this growing public health issue.

Estimation of exposure to food-packaging materials. 2: Patterns of intakes of packaged foods in Irish Children aged 5–12 years

In the European Union (EU), many assumptions are employed to calculate the intake of migrating chemicals from food packaging. However, very little is known about the actual intake of packaged food, the type of this food and the type of packaging used for this food. The objective of the current study was to examine intakes of packaged food in children aged 5-12 years to provide information on the types of food that are packaged and the type of packaging used. To do this, a food-consumption database, which also recorded information on packaging, was merged with a packaging database, which provided information on the contact layers of packaging. Foods were classified into EU Food categories according to European Council Directive EC 85/575/EEC (European Council 1985), which determined their food type (i.e. aqueous, acidic, alcoholic and fatty). The mean daily intake of all packaged food was 1195 g day-1 with an upper intake of 1959 g day-1 (97.5th percentile); the intake of food packaged in plastic was 993 g day-1 with an upper percentile of 1692 g day-1 (97.5th percentile). The mean daily intake of fat from all packaged food was 62 g day-1, with an upper intake of 100 g day-1 (97.5th percentile). When this was investigated further, it was found that the mean fat intake from packaged 'fatty' foods only was 32 g day-1, with an upper intake of 61 g day-1 (97.5th percentile). The food that contributed most to fat intake was milk. As many food chemical intake assessments are moving towards probabilistic methods, probabilities of a food being packaged and the probability of the type of packaging used were determined. The probability of food being packaged was 0.88. Some foods not 100% packaged included fruit, vegetables, liquid beverages non-alcoholic (includes water) and bread. Probabilities were also derived for the packaging types used for food. It can be concluded that not all the individual assumptions used in the EU exposure assessment are conservative, but in combination they are conservative.

Vitamin D intake and status in Irish elderly women and adolescent girls

AIM

To assess vitamin D status during summer and winter in Irish girls and elderly women, and to estimate vitamin D intake in these two age-groups.

METHODS

Ambulatory free-living, elderly Irish women (aged 70-76 years; n = 43) and girls (aged 11-13 years; n = 17) were recruited. Fasting serums were collected during August/ September 2002 and February/March 2003 and analysed for 25 (OH) D by HPLC.

RESULTS

Mean daily intakes of vitamin D were 4.6 microg and 2.1 microg in elderly women and girls, respectively. Serum 25 (OH) D was significantly lower (P<0.001) during winter than summer in both age-groups. Eight (20%) and one (during late summer) and sixteen (37.2%) and eight (47%) (during late winter) of the elderly women and girls, respectively, had inadequate vitamin D status (serum 25 (OH) D <40 nmol/l).

CONCLUSION

Inadequate vitamin D status during winter time is quite common in elderly women and adolescent girls in Ireland.

Prevalence of suboptimal vitamin D status in young, adult and elderly Irish subjects

With the exception of the elderly, there is a dearth of information about the vitamin D status of Irish subjects. Therefore, we assessed the prevalence of suboptimal vitamin D status in a number of age-groups within the Irish population (including females aged, 11-13 years, 23-50 years, 51-69 years, and 70-75 years; and males, aged 20-64 years) during late-winter and late-summer. In females, depending on the age-group studied, between 4 and 19% and between 34 and 85% had an inadequate serum 25 (OH) D level (<50 nmol/l) during late-summer and late-winter, respectively. During late-summer, there was a marked absence of severe and moderate vitamin D deficiency in all subjects, while, 7% of men and, depending on the age-group studied, between 4 and 19% of females had mild vitamin D deficiency. During late-winter, none of the subjects had severe vitamin D deficiency. While none of the men had moderate vitamin D deficiency, 33% of men had mild vitamin D deficiency. In females, depending on the age-group studied, between 32 to 55% of females had mild vitamin D deficiency, and between 2 to 30% of females had moderate vitamin D deficiency, during late-winter. These findings show that inadequate vitamin D status is quite common in healthy Irish subjects, especially and notably so in young girls and more elderly women.

Clustering of protective factors for glucose intolerance and insulin resistance: a cross-sectional study

AIMS

A cluster of interrelated factors: a body mass index (BMI) < 25 kg/m(2), moderate exercise and alcohol intake, non-smoking and a favourable dietary pattern has been linked with markedly reduced risk of Type 2 diabetes. The aim of this study was to estimate the prevalence of a similar low-risk group in a sample of middle-aged Irish men and women, and determine whether this cluster is associated with a reduced risk of glucose intolerance (IFG and Type 2 diabetes according to ADA/WHO criteria) and insulin resistance [homeostasis model assessment (HOMA) score in upper quartile of distribution].

METHODS

A cross-sectional study involving a stratified random sample of 1018 general practice patients, aged 50-69 years. We defined a low-risk group based on the following variables: BMI < 25 kg/m(2); waist-hip ratio < 0.85 for women and 0.90 for men; never smoking status; participation in medium to high level of physical activity; light drinking (3.5-7 units of alcohol per week) and a 'prudent' dietary pattern. Valid data were available for glucose tolerance status and HOMA score and all exposure variables from 684 and 671 participants, respectively.

RESULTS

A total of 7.5% of participants had none of the 'protective factors', 24.9% had one, 31.0% two, 23.3% three, 10.0% four, 3.0% five and 0.3% had six protective factors. In multivariate analyses the odds ratios for insulin resistance were 0.59, 0.48, 0.14 and 0.04 in persons with one, two, three and four or more low-risk factors, respectively, relative to those with none. Similar linear inverse trends were observed for glucose intolerance.

CONCLUSIONS

The findings are consistent with an inverse linear relation between a cluster of core protective, lifestyle-related factors and the prevalence of both glucose intolerance and insulin resistance.

Effective health care: management of head and neck cancers

The management of head and neck cancer, published in a recent issue of Effective Health Care, is reviewed.

A systematic review of cancer waiting time audits

A summary of a systematic review of clinical audits of cancer referrals in England and Wales.

Teenage girls and elderly women living in northern Europe have low winter vitamin D status

OBJECTIVE

To determine the vitamin D status (serum 25-hydroxyvitamin D; S-25OHD) in adolescent girls and elderly community-dwelling women living in four countries of northern Europe and to explain differences in S-25OHD concentrations between and within the countries.

DESIGN

A cross-sectional observational study conducted in a standardised way during February-March. S-25OHD was analysed by high-performance liquid chromatography. Vitamin D and calcium intake was calculated using a standardised food composition database.

SETTING

Denmark, Finland, Ireland, and Poland.

SUBJECTS

A total of 199 girls (mean (s.d.) age 12.6 (0.5) y) and 221 women (mean (s.d.) age 71.8 (1.4) y).

RESULTS

The median (inter quartiles) concentration of S-25OHD was 29.4 (20.3, 38.3) nmol/l for the girls and 40.7 (28.0, 54.2) nmol/l for the women. S-25OHD below 25 nmol/l was found in 37% of the girls and 17% of the women, and S-25OHD below 50 nmol/l was found in 92% of the girls and 37% of the women. Positive significant determinants for S-25OHD in girls were use of vitamin D supplements, and in women sun habits, dietary vitamin D intake, use of vitamin D and calcium supplements. Body mass index and smoking were negative determinants in women. For women predictors could explain the differences between countries (P(country) = 0.09, R(2) = 0.39), but for girls the difference remained significant even after including predictors (P(country) = 0.03, R(2) = 0.15).

CONCLUSION

Vitamin D status is low in northern Europe during winter. More than one-third of the adolescent girls have vitamin D status below 25 nmol/l and almost all are below 50 nmol/l. Two-thirds of the elderly community-dwelling women have vitamin D status below 50 nmol/l. Use of vitamin D supplements is a significant positive determinant for S-25OHD for both girls and women (P = 0.001).

SPONSORSHIP

The European Fifth Framework Programme (Contract No. QLK1-CT-2000-00623).

Vitamin D intake and status in Irish postmenopausal women

OBJECTIVE

The objective of this study was to assess vitamin D status during late-summer and late-winter/early-spring in postmenopausal Irish women, and whether it was influenced by vitamin D-containing supplement use.

DESIGN

A longitudinal observational study.

SETTING

Cork City, Ireland (51 degrees north).

SUBJECTS

A total of 59 apparently healthy, free-living, postmenopausal women aged between 51 and 69 y were sampled during February/March 2002. Of these, 48 and 47 returned during August/September 2002 and February/March 2003, respectively. None of the women were suffering from any medical condition likely to affect vitamin D status. Fasting serums were collected and analysed for 25-hydroxyvitamin D (25 (OH) D) and parathyroid hormone (PTH) by enzyme immunoassays.

RESULTS

Mean daily intake of vitamin D was 3.2 microg from food sources alone and 5.8 microg when vitamin D-containing supplements were included (P<0.01). Serum 25 (OH) D was significantly lower (P<0.001) during February/March 2002 than both August/September 2002 and February/March 2003. Serum 25 (OH) D was also significantly higher (P < or = 0.05) in women who were vitamin D-containing supplement users than nonusers during all three sampling points. Between 17 and 36% of women had inadequate vitamin D status (defined as serum 25 (OH) D <40 nmol/l) during late-winter, but only 4% had inadequate vitamin D status during late-summer. Serum 25 (OH) D was inversely related to serum PTH (r = -0.33; P = 0.028).

CONCLUSION

Suboptimal vitamin D status is common in postmenopausal Irish women during winter. Vitamin D supplementation is associated with improved vitamin D status, even during summertime.

Risk-benefit analysis of micronutrients

Traditionally, different approaches have been used to determine the recommended dietary allowances for micronutrients, above which there is a low risk of deficiency, and safe upper levels, below which there is a negligible risk of toxicity. The advice given to risk managers has been in the form of point estimates, such as the recommended dietary allowance (RDA) and the tolerable upper level (UL). In future, the gap between the two intake-response curves may become narrower, as more sensitive indicators of deficiency and toxicity are used, and as health benefits above the recommended daily allowance are taken into account. This paper reviews the traditional approaches and proposes a novel approach to compare beneficial and adverse effects across intake levels. This model can provide advice for risk managers in a form that will allow the risk of deficiency or the risk of not experiencing the benefit to be weighed against the risk of toxicity. The model extends the approach used to estimate recommended dietary allowances to make it applicable to both beneficial and adverse effects and to extend the intake-incidence data to provide a range of estimates that can be considered by the risk manager. The data-requirements of the model are the incidence of a response at one or more levels of intake, and a suitable coefficient of variation to represent the person-to-person variations within the human population. A coefficient of variation of 10% or 15% has been used for established recommended dietary allowances and a value of 15% is proposed as default for considerations of benefit. A coefficient of variation of 45% is proposed as default for considerations of toxicity, based on analyses of human variability in the fate and effects of therapeutic drugs. Using this approach risk managers, working closely with risk assessors, will be able to define ranges of intake based on a balance between the risks of deficiency (or lack of benefit) and toxicity.

Management of colorectal cancers

The management of colorectal cancers, published in a recent issue of Effective Health Care, is reviewed.

Prudent diet and the risk of insulin resistance

BACKGROUND AND AIM

Diet is a potentially modifiable risk factor for diabetes. Dietary patterns may exert greater effects on health than individual foods, nutrients or food groups. Data on associations between dietary patterns and the risk of insulin resistance and type 2 diabetes are sparse. The aim of the study was to examine associations between dietary patterns and the risk of insulin resistance.

METHODS AND RESULTS

We performed a cross sectional study involving a group of 1018 men and women, sampled from 17 general practice lists in the South of Ireland, with a response rate of 69%. Participants completed a detailed health and lifestyle questionnaire and provided fasting blood samples for analysis of glucose, insulin and lipids. Dietary intake was assessed using a food frequency questionnaire. The food frequency questionnaire was a modification of the UK arm of the European Prospective Investigation into cancer, EPIC study, which was based on that used in the US Nurses' Health Study. Dietary patterns were assessed by K cluster analysis. Insulin resistance was estimated on the basis of fasting glucose and insulin, using the glucose homeostasis model (HOMA scores). Insulin resistance was defined as the upper quartile of the HOMA scores. Three dietary patterns were identified by cluster analysis (traditional Irish diet, a prudent diet and an alcohol and convenience foods diet). Participants in clusters 1 (traditional Irish diet) and 3 (high alcohol and convenience foods) had a lower intake of more 'healthy' food groups (such as fruit, vegetables, low fat dairy products, poultry, fish and whole grain products) and higher intake of foods richer in total and SFA content (such as high fat dairy products, butter, meat and meat products). Cluster 2 (prudent dietary pattern) was characterized by a higher intake of food groups that are typically recommended in health promotion programs and a lower intake of meat (read meat), meat products, sweets, high fat dairy and white bread (white bread and unrefined cereal). The prudent diet had the lowest HOMA scores in analysis of covariance. The prevalence of insulin resistance in the prudent diet was lower than that in the traditional diet (OR=0.53; 95%CI, 0.33-0.85 in fully adjusted analysis).

CONCLUSION

A prudent diet may be associated with enhanced insulin sensitivity and a lower risk of type 2 diabetes.