The validity of questionnaire-based micronutrient intake estimates is increased by including dietary supplement use in Swedish men.
ABSTRACT Although many validation studies of FFQ have been reported, only a few addressed the effect of inclusion of dietary supplement use on the validity of micronutrient estimates. The purpose of the present study was to assess reproducibility and validity of a self-administered FFQ, intended to measure total nutrient intake from diet and from dietary supplements, in a random population-based sample of 248 middle-aged and elderly men (40-74 y old) in central Sweden. Fourteen 24-h recall interviews were used as the reference method. Participants were telephoned about once a month for 1 y, covering every day of the week, twice in random order. Spearman correlation coefficients increased 13% (from 0.49 to 0.62), between FFQ-based micronutrient estimates and the fourteen 24-h recall interviews (reference method) when supplement use was included. Correct classification into highest quintiles was also improved by 14% (from 37 to 51%). There were no differences in mean intraclass correlation coefficients for 1-y reproducibility between total micronutrient intake and micronutrients from foods only. The increase in the validity of micronutrient estimates due to inclusion of supplements in nutrient intake assessment has important implications for sample size in epidemiologic studies. Because a dramatic increase in dietary supplement use has occurred in recent decades in many countries, the issue of including supplements in dietary assessment should be of highest priority in nutritional epidemiologic studies of chronic diseases.
Article: Comparison of apolipoprotein (apoB/apoA-I) and lipoprotein (total cholesterol/HDL) ratio determinants. Focus on obesity, diet and alcohol intake.[show abstract] [hide abstract]
ABSTRACT: The ratio between apolipoprotein B and apolipoprotein A-I (apoB/apoA-I) has been suggested to be a powerful and more accurate predictor of future cardiovascular disease risk than total cholesterol and HDL cholesterol. Since diet and lifestyle can directly influence dyslipidemia, it is of interest to identify modifiable factors that are associated with high levels of the apolipoprotein ratio and if they can have a different association with a more traditional indicator of cardiovascular risk such as total cholesterol/HDL. The relationship between obesity and dyslipidemia is established and it is of interest to determine which factors can modify this association. This study investigated the cross-sectional association of obesity, diet and lifestyle factors with apoB/apoA-I and total cholesterol/HDL respectively, in a Swedish population of 2,907 subjects (1,537 women) as part of the INTERGENE study. The apolipoprotein and lipoprotein ratios were highly correlated, particularly in women, and obesity was strongly associated with both. Additionally, age, cigarette smoking and alcohol intake were important determinants of these ratios. Alcohol was the only dietary factor that appreciably attenuated the association between obesity and each of the ratios, with a stronger attenuation in women. Other dietary intake and lifestyle-related factors such as smoking status and physical activity had a lower effect on this association. Because the apolipoprotein and lipoprotein ratios share similar diet and lifestyle determinants as well as being highly correlated, we conclude that either of these ratios may be a sufficient indicator of dyslipidemia.PLoS ONE 01/2012; 7(7):e40878. · 4.09 Impact Factor
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ABSTRACT: To evaluate the reproducibility of a semi-quantitative FFQ used in the Seguimiento Universidad de Navarra (SUN) project. The data that were analysed were collected from an FFQ answered twice by a 326-participant subsample of the SUN project (115 men, 35.3 %; 211 women, 64.7 %), with either less than 1 year or more than 1 year between responses. The questionnaire included 136 items. Pearson correlation coefficients (r) were calculated to evaluate the magnitude of the association between both measures after energy adjustment and correcting for within-person variability. We also evaluated misclassification by quintiles distribution. The highest corrected correlations among participants who answered before 1 year were found for PUFA (r = 0.99). Among participants who answered after 1 year between both questionnaires, olive oil had the highest corrected correlation (r = 0.99). The highest percentage of gross misclassification, lowest quintile in FFQ1 and highest quintile in FFQ2 or highest quintile in FFQ1 and lowest quintile in FFQ2 was for cereals, fish or seafood, and n-3 fatty acids (7.6 %). Alcoholic drinks had the highest percentage of reasonable classification, same or adjacent quintile, in FFQ1 and FFQ2 (86.4 %). Our study suggests that FFQ reproducibility is acceptable for participants who answered the same questionnaire twice less than 1 year apart. Participants who answered FFQ more than 1 year apart showed worse values on reproducibility. We consider this Spanish FFQ as an important, valid and reproducible tool in nutritional epidemiology.Public Health Nutrition 09/2010; 13(9):1364-72. · 2.17 Impact Factor
Article: Psychological factors related to physical, social, and mental dimensions of the SF-36: a population-based study of middle-aged women and men.[show abstract] [hide abstract]
ABSTRACT: Measures of health-related quality of life (HRQoL) are increasingly used as patient-reported outcome measures in routine health care. Research on determinants and correlates of HRQoL has, therefore, grown in importance. Earlier studies have generally been patient-based and few of them have examined differences between women and men. The aim of this study was to explore the relationship between psychological factors and physical, social, and mental dimensions of HRQoL, as measured by the Medical Outcome Study Short Form-36 Health Survey (SF-36), in a normal population and to see if observed relations were the same for women and men. Relations between scale scores for the eight scales of SF-36 and scale scores for Self-esteem, Sense of Coherence, Perceived Control, Depressed Mood (CES-D), and Cynicism were assessed through partial correlation and multiple linear regression analyses on a sample of 505 women and 502 men (aged 45-69 years), stratified for sex and adjusted for effects of age, presence of disease, back pain, lifestyle, and social support. All psychological factors tested, except Cynicism, were significantly correlated to all scales of the SF-36 for women and men (Pearson product-moment partial correlation coefficient, |r| = 0.11-0.63 and |r| = 0.11-0.60, respectively). The addition of psychological factors into regression models resulted in significant total explained variance (R(2)) changes in all scales of the SF-36 for both sexes. Any discrepancies between women and men pertained more to the strength of relationships rather than the significance of different psychological factors. In this population-based study, psychological factors showed significant correlation, for women and men alike, with the physical and social scales of SF-36, as well as the mental scales. These findings suggest that assessments of HRQoL are not merely a measure of absolute function but are also dependent on people's perception of their ability.Patient Related Outcome Measures 07/2010; 1:153-62.