European Journal of Nutrition (v.41, #4)

Dual isotope test for assessing β-carotene cleavage to vitamin A in humans by Sabrina J. Hickenbottom; Shawna L. Lemke; Stephen R. Dueker; Yumei Lin; Jennifer R. Follett; Colleen Carkeet; Bruce A. Buchholz; John S. Vogel; Andrew J. Clifford (141-147).
Background: The ability of β-carotene to deliver bioactive retinoids to tissues is highly variable. A clearer understanding of the environmental and genetic factors that modulate the vitamin A potential of β-carotene is needed. Aim of study: Assess the vitamin A value of orally administered β-carotene relative to a co-administered reference dose of preformed vitamin A. Methods: Equimolar doses (30 μmol) of hexadeuterated D6β-carotene and D6 retinyl acetate were orally co-administered in an emulsified formulation to a male subject. The plasma concentration time courses of D6 retinol (derived from D6 retinyl acetate) and bioderived D3 retinol (from D6β-carotene) were determined for 554 h postdosing using gas chromatography/mass spectrometry. Intact D6β-carotene plasma concentrations were determined by high-pressure liquid chromatography. The ratio of the two forms of vitamin A, D6 retinol/D3 retinol, at any single time point is postulated to reflect the quantity of vitamin A derived from β-carotene relative to preformed vitamin A. Additionally, a minute amount of 14C β-carotene (50 nCi; 0.27 μg) was included in the oral dose and cumulative 24-h stool and urine samples were collected for two weeks to follow absorption and excretion of the b-carotene. The 14C nuclide was detected using accelerator mass spectrometry (AMS). Results During the absorption/distribution phase (3–11 h) the D6/D3 ratio of the two retinols was not stable and ranged between a value of 3 and 16. Between 11 and 98 h postdosing the ratio was relatively stable with a mean value of 8.5 (95 % CI: 7.5, 8.7). These data suggest that in this subject and under these conditions, 8.5 moles of β-carotene would provide a vitamin A quantity equivalent to 1 mole of preformed vitamin A. On a mass basis, 15.9 μg of β-carotene was equivalent to 1 μg of retinol. The total administered β-carotene was found to be 55 % absorbed by AMS analysis of cumulative stool. Conclusion: The co-administration of D6β-carotene and D6 retinyl acetate provides a technique for assessing individual ability to process β-carotene to vitamin A. The results indicate that a single time point taken between 11–98 h after dose administration may provide a reliable value for the relative ratio of the two forms of vitamin A. However, results from more subjects are needed to assess the general utility of this method.
Keywords: Key words vitamin A –β-carotene – AMS – stable isotope – carbon-14 – human

Background: Exocrine pancreatic insufficiency is a major clinical manifestation of cystic fibrosis (CF). Almost nine of ten patients develop signs and symptoms of maldigestion and malabsorption, which often deteriorates nutritional status and therefore worsens the prognosis. Human faecal elastase-1 (FE-1) has shown promising results to assess exocrine pancreatic insufficiency, and this test has been used at Haukeland University Hospital since 1996. Aim of the study: To evaluate FE-1 values and fat-soluble vitamin profiles in patients with CF and to correlate exocrine pancreatic function as measured as FE-1 to fat-soluble vitamin profiles. Moreover, we wanted to assess if there are differences between fat-soluble vitamin profiles in patients with impaired versus patent exocrine pancreatic function, and thirdly, if fat-soluble vitamin deficiency at diagnosis is effectively treated by supplementation. Methods: Consecutive analyses (N = 212) of fat-soluble vitamin profiles and 35 analyses of FE-1 were investigated in 35 patients with CF. In 17 out of 35 patients fat-soluble vitamin profiles were also assessed at diagnosis. Results Mean value of FE-1 for all CF patients was 256.9 μg/g faeces (median 24.1 μg/g faeces). CF patients considered to have maldigestion (N=24) showed a mean value of 19.9 μg/g faeces (median 18.7 μg/g faeces), those without pancreas affection had a mean value of 773.9 μg/g faeces (median 728.9 μg/g faeces, p < 0.01). There was no difference in fat-soluble vitamin profiles among patients with or without exocrine pancreatic insufficiency while on appropriate supplementation. Median value for vitamin E in patients with exocrine pancreatic insufficiency at diagnosis was low (3.6 mg/L). Supplementation of pancreatic enzymes and vitamins normalised profiles in this group at follow-up. There was no significant correlation between exocrine pancreatic function as measured as FE-1 and fat-soluble vitamin profiles, neither in patients with impaired nor in those with patent pancreatic function. Conclusions: Severe degree of exocrine pancreatic insufficiency is common in patients with cystic fibrosis. There was no correlation of faecal elastase-1 levels to fat-soluble vitamin status. Fat-soluble vitamins (A, D, E) given in appropriate dosages combined with pancreatic enzymes ensured normal profiles in our patients with CF and malabsorption. Officially recommended supplementation of vitamin A and D in Norway during infancy and childhood may explain why so few patients had vitamin deficiencies at diagnosis.
Keywords: Key words cystic fibrosis – faecal elastase-1 – exocrine pancreatic insufficiency – maldigestion – fat-soluble vitamins

Mediterranean diet and reduction in the risk of a first acute myocardial infarction: an operational healthy dietary score by Miguel A. Martínez-González; Elena Fernández-Jarne; Manuel Serrano-Martínez; Amelia Marti; J. Alfredo Martinez; José M. Martín-Moreno (153-160).
Background: Although an important secondary prevention trial reported an impressive protection by a Mediterranean dietary pattern on reinfarction and cardiovascular death, scarce direct epidemiologic evidence is currently available regarding the role of the Mediterranean diet in the aetiology of coronary heart disease. Aims: The aim of the study was to quantify the risk reduction of incident myocardial infarction provided by a Mediterranean dietary pattern. Methods: We included 342 subjects (171 patients who suffered their first acute myocardial infarction and 171 matched controls) in a case-control study. A validated semi-quantitative food frequency questionnaire (136 items) was used. We defined an a priori Mediterranean dietary pattern. We assessed six food items that we considered protective: 1) olive oil, 2) fiber, 3) fruits, 4)vegetables, 5) fish and 6) alcohol. For each of these six dietary factors, we calculated the distribution according to quintiles within the study and assigned each participant a score of 1 to 5 corresponding to the quintile of intake, with 1 representing the lowest and 5 representing the highest quintile. We also estimated the quintiles of two other elements assumed to be associated with a higher risk: 7) meat/meat products and 8) some items with high glycaemic load (white bread, pasta and rice). For these two elements we inversely ranked the score, with 1 representing the highest and 5 representing the lowest quintile. Finally, we summed up the eight quintile values for each participant.A second score (post hoc pattern) was built using only a single cut-off point for these eight elements. The cut-off points for each element in this post hoc pattern were decided according to the dose-response relationships between the consumption of each food item and the risk of myocardial infarction observed in the analyses that used quintiles of each food item. Results: For both patterns, we found that the higher the score, the lower the odds ratio of myocardial infarction. A significant linear trend was apparent after adjustment for the main cardiovascular risk factors. For each additional point in the a priori Mediterranean pattern (observed range: 9–38) the odds ratio (95 % confidence intervals) was 0.92 (0.86–0.98). This estimate was 0.55 (0.42–0.73) when we used the post hoc pattern (range: 0–8). Conclusions: Our data support the hypothesis that a Mediterranean diet (that emphasizes olive oil, fiber, fruits, vegetables, fish and alcohol and reduces meat/meat products) can be an effective measure for reducing the risk of myocardial infarction. However, our results support the exclusion of refined cereals with a high glycaemic load as healthy elements of this pattern.
Keywords: Key words myocardial ischemia – olive oil – glycaemic load – white bread – nutritional epidemiology – case control

Background: Hypertension is strongly associated with cardiovascular and renal disease. However, despite the efforts made to control hypertension via drug treatment, prevalence of controlled hypertension could be considered low. Aim of the study: We performed the present study to investigate dietary habits among groups with different blood pressure status (normotensive, non-medicated hypertensive, medicated hypertensive) and to analyze the association between blood pressure and intakes of selected nutrients in normotensive and non-medicated hypertensive subjects (n = 1357), and furthermore in those undergoing hypertension drug treatment (n = 210; controlled and non-controlled). Methods: The present cross-sectional, population-based survey (Gerona, Spain) included cardiovascular risk measurements and analysis of dietary intake with corresponding questionnaires. Results: Nutrient intake was similar among groups of different blood pressure status after adjusting for sex, age and energy consumption. Multiple linear regression analysis, after adjustment for several confounders, showed that dietary intake of sodium was directly related to blood pressure. The same was seen for the sodium to potassium ratio and both were independent of hypertension drug treatment. In contrast, an inverse association was observed between blood pressure and dietary calcium intake. Moderate sodium (< 2400 mg Na/d) intake reduced the risk of hypertension by 30 % and 52 % (Odds ratio 0.70; 95 % CI 0.52–0.94, respectively) in normotensive and non-medicated hypertensive subjects. Furthermore, moderate sodium in combination with a calcium intake of more than 800 mg/d reduced the risk of inadequate blood pressure control, by 52 % (Odds ratio 0.48; 95 % CI 0.24–0.95) in subjects undergoing hypertension drug treatment. Controlled hypertension subjects have a significantly higher calcium intake than non-controlled. Conclusion: These results emphasize the importance of diet and overall of sodium intake as non-pharmacological approach in the prevention and treatment of hypertension.
Keywords: Key words blood pressure – diet – nutrients – hypertension – mediterranean

An incident case-referent study on plasma enterolactone and breast cancer risk by Kerstin Hultén; Anna Winkvist; Per Lenner; Robert Johansson; Herman Adlercreutz; Göran Hallmans (168-176).
Objective: Using a nested case-referent design, we evaluated the relationship between plasma levels of the lignan enterolactone and the risk of developing breast cancer. Methods: 248 cases and 492 referents were selected from three population-based cohorts in northern Sweden. Blood samples were donated at enrolment. All blood samples were stored at −80 °C. Cases and referents were matched for age, date of blood sample and sampling centre. Breast cancer cases were identified through the regional and national cancer registries. Results: Plasma enterolactone was lower among smokers in all cohorts and in subjects with BMI < 23 and BMI > 28 in one of the cohorts. Low plasma concentrations of enterolactone, below the 12.5th percentile (mean plasma enterolactone 2.9 nmol/l), were associated with an increased risk of breast cancer. Also, high values of plasma enterolactone, above the 87.5th percentile (mean plasma enterolactone 58.2 nmol/l) were significantly associated with an increased breast cancer risk among women from two cohorts with only incident cases and a higher number of pre-menopausal women. High plasma enterolactone concentrations among older women from a mammary screening project with mostly prevalent cases were associated with a non-significant slightly reduced breast cancer risk. Conclusion: Very low plasma concentrations of enterolactone were associated with an increased breast cancer risk in all three cohorts. In two of the cohorts, with only incident cases, very high plasma concentrations were also associated with an increased breast cancer risk. In the third cohort with mainly screen-detected cases from a mammary screening program, high plasma enterolactone concentrations were associated with a weak decreased breast cancer risk.
Keywords: Key words plasma – enterolactone – phyto-oestrogens – breast cancer

Background: Most preterm infants are still preterm and have a low birth weight when they are discharged from the hospital. An important issue is whether the long-term consequences of early growth restriction can be diminished by nutritional intervention in preterm infants after discharge from the hospital. Aim: To evaluate differences in growth and in weight gain composition of preterm infants fed standard term formula (SF) or enriched formula (PDF) after discharge from hospital during the first 2 months of life. Methods: Thirty-three healthy preterm infants, birth weight < 1750 g at gestational age < 35 weeks, were randomised to SF or PDF at the time of discharge from hospital. Anthropometric variables were studied longitudinally and body composition was measured using dual energy x-ray absorptiometry (DEXA) twice, before hospital discharge and two months later. Weight gain composition was calculated as the difference between the two determinations. Results: Seventeen infants were fed SF and 16 PDF. Anthropometric variables and whole body composition were similar at birth, at the start of the nutritional study (mean age 45 days), and at the end of the study 2 months later. Over the whole study period, weight gain and weight gain composition were similar in the two groups. Sex did not appear to influence weight gain and weight gain composition. In infants with growth restriction at discharge there was a significant reduction of weight gain, fat mass gain, and bone mineral content deposition independently of the formula provided. Conclusions: There is no immediate effect on preterm infants of a nutrient enriched formula compared with a standard formula on growth, weight gain, or weight gain composition.
Keywords: Key words preterm infant – body composition – dual energy x-ray absorptiometry – weight gain – postdischarge formula

Short- and long-term mortality in a prevalent cohort of morbidly obese patients in Italy by Amelia Brunani; Domenico Palli; Simonetta Salvini; Giovanna Masala; Luciana Vallone; Eros Barantani; Antonio Liuzzi (183-185).
Background: Morbid obesity has been associated with increased mortality. Aim of the study: We evaluated the risk of short- (2 years) and long-term (10 years) mortality in two consecutive series of Italian morbidly obese patients hospitalized in a Metabolic Unit. Methods: The vital status of 569 patients (435 females and 134 males, BMI 44.4 kg/m2, age 46.1 years), first admitted for clinical treatment in two separate periods (1988 and 1996), was ascertained in 1999. Results: Twenty-seven deaths were identified and compared with expected deaths according to mortality rates in the Italian population, to estimate the standardized mortality ratio (SMR). In the first two years after admission only 3 deaths were observed and the SMR tended to be reduced (SMR = 0.5, 95 % CI 0.1–1.5). In contrast, the long-term follow-up showed a significantly elevated risk of death (SMR = 1.6, 95 % CI 1.1–2.4). Conclusions: The follow-up of this Italian prevalent cohort confirm that morbid obesity is associated with increased mortality. The observed SMR might have been attenuated by inclusion in our study of subjects with relatively good health conditions, who are possibly more representative of the general obese population than subjects affected by important obesity-related complications, observed in other studies. The excess risk was not evident in the first two years after clinical treatment.
Keywords: Key words obesity – mortality – standardized mortality ratio – follow-up

Vademecum for vitamin formulations by V. Bühler (186-186).