Validation of a food frequency questionnaire in Spanish patients with familial hypercholesterolaemia

Factors Contributing to the Link between Physical Well-Being and Chronic Pain in Young People from Galicia, Northwest Spain

Introduction: The relation between physical well-being and chronic pain is complex and involves several subjective and objective covariates. We aimed to assess the role of mediator, confounder, or interactor played by covariates, including sleep quality, physical activity, perceived stress, smoking, and alcohol drinking in the relation between physical well-being and chronic pain. Method: We used Poisson regression to obtain incidence rate ratios (IRR) of the association between physical well-being and chronic pain in a cohort study carried out among university students. We applied General Structural Equation Modeling (GSEM) to assess mediation and stratum-specific analyses to distinguish confounding from interaction. We computed Relative Excess Risks due to Interaction (RERI), Attributable Proportion (AP), and the Synergy index (S) to measure additive interaction. Results: High physical well-being is related to a large decrease in the risk of chronic pain (IRR^{Total Effect} = 0.58; 95% CI: 0.50-0.81). Perceived stress mediates 12.5% of the total effect of physical well-being on chronic pain. The stratum-specific IRRs of current smokers and non-current smokers were different from each other and were larger than the crude IRR (IRR = 1.49; 95% CI: 1.24-1.80), which indicates that smoking could be both confounder and interactor. Interaction analyses showed that physical activity could act as a potential interactor (RERI = 0.25; 95% CI: 0.13, 0.60). Conclusions: Perceived stress is an important mediator of the relation between physical well-being and chronic pain, while smoking is both a confounder and an interactor. Our findings may prove useful in distinguishing high-risk groups from low-risk groups, in the interventions aimed at reducing chronic pain.

Association between Nordic and Mediterranean diets with lipoprotein phenotype assessed by 1HNMR in children with familial hypercholesterolemia

BACKGROUND AND AIMS

Both Nordic and Mediterranean diets are considered healthy despite notable regional differences. Although these dietary patterns may lower cardiovascular risk, it is unclear if they improve the lipoprotein phenotype in children with familial hypercholesterolemia (FH). The aim is to determine the impact of Nordic and Mediterranean diets on the advanced lipoprotein profile in children with heterozygous FH (HeFH).

METHODS

This was a cross-sectional study performed in children with FH recruited from the Lipid Clinics at Sant Joan University Hospital in Reus (Spain) and Oslo University Hospital (Norway). Two-hundred fifty-six children (mean age 10 y/o; 48% girls): 85 Spanish and 29 Norwegian FH children, and 142 non-FH healthy controls (119 from Spain and 23 from Norway) were included in the study. A pathogenic FH-associated genetic variant was present in 81% of Spanish children with FH and all Norwegian children with FH. An ¹H NMR based advanced lipoprotein test (Nightingale®) providing information on the particle number, size and lipid composition of 14 lipoprotein subclasses was performed and correlated to the dietary components.

RESULTS

Levels of LDL-C, HDL-C and triglycerides were not significantly different between the Nordic and Mediterranean FH groups. Spanish children with FH had more LDL particles, mainly of the large and medium LDL subclasses, than Norwegian FH children. Spanish FH children also had more HDL particles, mainly medium and small, than Norwegian FH children. The mean LDL size of Spanish FH children was larger, while the HDL size was smaller than that of the Norwegian FH children. The HDL particle number and size were the main determinants of differences between the two groups. In Norwegian children with FH, dietary total fat and MUFAs showed a significant correlation with all apolipoprotein B-containing lipoproteins and LDL size, whereas there was no correlation to SFA. A weaker association pattern was observed in the Spanish children.

CONCLUSIONS

The lipoprotein profiles of Spanish and Norwegian children showed differences when studied by ¹H NMR. These differences were in part associated with differences in dietary patterns.

Adherence to a Mediterranean diet, dyslipidemia and inflammation in familial hypercholesterolemia

BACKGROUND AND AIMS

Familial Hypercholesterolemia (FH) is characterized by elevated LDL-cholesterol (LDL-C) and high atherosclerosis risk. The impact of different dietary patterns on atherosclerosis biomarkers has been poorly studied in FH. This study verified the association of adherence to a Mediterranean diet with biomarkers of dyslipidemia and low-grade inflammation in molecularly proven FH adults from Brazil (BR) and Spain (SP).

METHODS AND RESULTS

In this cross-sectional study adherence to the Mediterranean diet was assessed by a validated score and generalized estimating equations were used to evaluate its association with plasma LDL-C, apolipoprotein-B (ApoB) and high sensitivity C-reactive protein (hs-CRP) concentrations. We included 92 (mean age 45 years, 58.7% females) and 98 FH individuals (mean age 46.8 years, 60.2% females) respectively from BR and SP. FH causing variants did not differ between countries. LDL-C, ApoB and hs-CRP concentrations were higher in BR than in SP: 179 (135-250) and 161 (133-193) mg/dL; 141 (109-181) and 103 (88-134) mg/dL; and 1.6 (0.8-4.0) and 0.8 (0.4-1.5) mg/L respectively (all p < 0.001). Most of BR had low adherence (n = 77, 83.7%), while the majority of SP were divided into moderate (n = 35, 35.7%) and strong adherence to the Mediterranean diet (n = 37, 37.8%), p < 0.001. There was a significant inverse association of adherence to the Mediterranean diet score with higher LDL-C, ApoB, and hs-CRP after adjusting for socio economic parameters, caloric and fatty acid intakes as well as pharmacological lipid lowering therapies.

CONCLUSIONS

Higher adherence to a Mediterranean diet was associated with better dyslipidemia and low-grade inflammation profiles in FH.

Adults with familial hypercholesterolaemia have healthier dietary and lifestyle habits compared with their non-affected relatives: the SAFEHEART study

Objective

Healthy lifestyle habits are the cornerstone in the management of familial hypercholesterolaemia (FH). Nevertheless, dietary studies on FH-affected populations are scarce. The present study analyses dietary habits, adherence to a Mediterranean diet pattern and physical activity in an adult population with FH and compares them with their non-affected relatives.

Design

Cross-sectional study.

Setting

Data came from SAFEHEART, a nationwide study in Spain.

Participants

Individuals (n 3714) aged ≥18 years with a genetic diagnosis of FH (n2736) and their non-affected relatives (n 978). Food consumption was evaluated using a validated FFQ.

Results

Total energy intake was lower in FH patients v. non-affected relatives (P<0·005). Percentage of energy from fats was also lower in the FH population (35 % in men, 36 % in women) v. those non-affected (38 % in both sexes, P<0·005), due to the lower consumption of saturated fats (12·1 % in FH patients, 13·2 % in non-affected, P<0·005). Consumption of sugars was lower in FH patients v. non-affected relatives (P<0·05). Consumption of vegetables, fish and skimmed milk was higher in the FH population (P<0·005). Patients with FH showed greater adherence to a Mediterranean diet pattern v. non-affected relatives (P<0·005). Active smoking was lower and moderate physical activity was higher in people with FH, especially women (P<0·005).

Conclusions

Adult patients with FH report healthier lifestyles than their non-affected family members. They eat a healthier diet, perform more physical activity and smoke less. However, this patient group’s consumption of saturated fats and sugars still exceeds guidelines.

Application and interpretation of multiple statistical tests to evaluate validity of dietary intake assessment methods

BACKGROUND

Several statistical tests are currently applied to evaluate validity of dietary intake assessment methods. However, they provide information on different facets of validity. There is also no consensus on types and combinations of tests that should be applied to reflect acceptable validity for intakes. We aimed to 1) conduct a review to identify the tests and interpretation criteria used where dietary assessment methods was validated against a reference method and 2) illustrate the value of and challenges that arise in interpretation of outcomes of multiple statistical tests in assessment of validity using a test data set.

METHODS

An in-depth literature review was undertaken to identify the range of statistical tests used in the validation of quantitative food frequency questionnaires (QFFQs). Four databases were accessed to search for statistical methods and interpretation criteria used in papers focusing on relative validity. The identified tests and interpretation criteria were applied to a data set obtained using a QFFQ and four repeated 24-hour recalls from 47 adults (18-65 years) residing in rural Eastern Cape, South Africa.

RESULTS

102 studies were screened and 60 were included. Six statistical tests were identified; five with one set of interpretation criteria and one with two sets of criteria, resulting in seven possible validity interpretation outcomes. Twenty-one different combinations of these tests were identified, with the majority including three or less tests. Coefficient of correlation was the most commonly used (as a single test or in combination with one or more tests). Results of our application and interpretation of multiple statistical tests to assess validity of energy, macronutrients and selected micronutrients estimates illustrate that for most of the nutrients considered, some outcomes support validity, while others do not.

CONCLUSIONS

One to three statistical tests may not be sufficient to provide comprehensive insights into various facets of validity. Results of our application and interpretation of multiple statistical tests support the value of such an approach in gaining comprehensive insights in different facets of validity. These insights should be considered in the formulation of conclusions regarding validity to answer a particular dietary intake related research question.

Validation and reproducibility of a semi-quantitative FFQ as a measure of dietary intake in adults from Puerto Rico

OBJECTIVE

We aimed to assess the relative validity and reproducibility of a semi-quantitative FFQ in Puerto Rican adults.

DESIGN

Participants completed an FFQ, followed by a 6 d food record and a second administration of the FFQ, 30 d later. All nutrients were log transformed and adjusted for energy intake. Statistical analyses included correlations, paired t tests, cross-classification and Bland-Altman plots.

SETTING

Medical Sciences Campus, University of Puerto Rico.

SUBJECTS

Convenience sample of students, employees and faculty members (n 100, ≥21 years). Data were collected in 2010.

RESULTS

A total of ninety-two participants completed the study. Most were young overweight females. All nutrients were significantly correlated between the two FFQ, with an average correlation of 0·61 (range 0·43-0·73) and an average difference of 4·8 % between them. Most energy-adjusted nutrients showed significant correlations between the FFQ and food record, which improved with de-attenuation and averaged 0·38 (range 0·11-0·63). The lowest non-significant correlations (≤0·20) were for trans-fat, n 3 fatty acids, thiamin and vitamin E. Intakes assessed by the FFQ were higher than those from the food record by a mean of 19 % (range 4-44 %). Bland-Altman plots showed that there was a systematic trend towards higher estimates with the FFQ, particularly for energy, carbohydrate and Ca. Most participants were correctly classified into the same or adjacent quintile (average 66 %) by both methods with only 3 % gross misclassification.

CONCLUSIONS

This semi-quantitative FFQ is a tool that offers relatively valid and reproducible estimates of energy and certain nutrients in this group of mostly female Puerto Ricans.

Repeatability and relative validity of a quantitative food-frequency questionnaire among French adults

BACKGROUND

A 50-item self-administered food frequency questionnaire (FFQ) was developed for French adults, to assess the intake of energy, 10 macronutrients, 11 vitamins, and 11 minerals, and to be used in the context of a medical consultation.

OBJECTIVE

To assess the repeatability and relative validity of this FFQ compared to a 7-day diet record (7-DR).

DESIGN

A total of 54 and 100 French adults were included in the repeatability and validation studies, respectively. Repeatability was assessed using two FFQs, the second carried out 3 weeks after the first. In the validation study, subjects first completed the FFQ, then the 7-DR the following week. Energy and nutrient intakes were compared using Pearson correlation. The degree of misclassification by the FFQ, compared to the 7-DR, was calculated by a contingency table of quintiles. Bland-Altman plots assessed the correlation between FFQ and 7-DR across the intake range.

RESULTS

Repeatability for intake, explored by Pearson correlation, was 0.62-0.90 (median: 0.81). Relative validity, as determined by Pearson correlation for the nutrient intake derived from the FFQ and 7-DR, was 0.36-0.80 (0.64). The FFQ tended to report higher fiber and micronutrient intake than 7-DR. Misclassification into opposite quintiles ranged 0-6% (1%), whereas classification into same or adjacent quintiles ranged 59-83% (74%). Bland-Altman plots showed good agreement for most nutrients across the range of intake.

CONCLUSION

This new FFQ showed a high repeatability and good relative validity, and thanks to its short length, should be a useful tool for rapidly evaluating the nutrient intake of French adults.