Elisabeth H. M. Temme

Serum bilirubin and 10-year mortality risk in a Belgian population

Abstractobjective: The endogenous antioxidant serum bilirubin may scavenge free radicals and protect against free radical-related diseases. Methods: Using the 10-year follow-up mortality data from the Belgium Inter-university Research on Nutrition and Health (BIRNH) study the association between serum bilirubin and all-cause, cardiovascular, and cancer mortality in 5460 men and 4843 women was investigated. Results: In men, with the highest (≥0.6 mg/dl) compared with the lowest serum bilirubin concentration (≤0.2 mg/dl), the adjusted relative risk (RR) was 0.73 (95% confidence interval (CI) 0.57–0.94) for all-cause and 0.42 (95% CI 0.26–0.68) for cancer mortality. The risk for cancer mortality decreased with increasing concentrations of serum bilirubin (p for trend = 0.004) especially for non-lung cancer mortality (p for trend = 0.02). The associations persisted after adjusting for smoking. In women the associations between serum bilirubin and cancer mortality were in the same direction, but did not reach statistical significance (RR = 0.76, 95% CI 0.39–1.5). No significant associations were found between serum bilirubin and cardiovascular mortality in men and women. Conclusions: In this population high serum bilirubin, however, within normal ranges, was associated with low cancer mortality, especially in men. This may be due to the antioxidant activity of bilirubin. Measurement of serum bilirubin concentrations may contribute to cancer risk estimation.

A Salt Reduction of 50% in Bread Does Not Decrease Bread Consumption or Increase Sodium Intake by the Choice of Sandwich Fillings

Bread is a major contributor to sodium intake in many countries. Reducing the salt (NaCl) content in bread might be an effective way to reduce overall sodium intake. The objectives of this study were to examine the effects of gradually lowering the salt content in brown bread, with and without flavor compensation (KCl and yeast extract), on bread consumption and sodium intake compensation by choice of sandwich fillings. A total of 116 participants (age: 21 ± 3 y; BMI: 22 ± 2 kg/m²) consumed a buffet-style breakfast on weekdays for 4 wk. Participants received either regular bread (control group: n = 39), bread whose salt content was gradually lowered each week by 0, 31, 52, and 67% (reduced group: n = 38), or bread whose salt content was also gradually lowered each week but which was also flavor compensated (compensated group: n = 39). A reduction of up to 52% of salt in bread did not lead to lower consumption of bread compared to the control (P = 0.57), whereas less bread was consumed when salt was reduced by 67% (P = 0.006). When bread was flavor compensated, however, a reduction of 67% did not lead to lower consumption (P = 0.69). Salt reduction in bread (with and without flavor compensation) did not induce sodium intake compensation (P = 0.31). In conclusion, a salt reduction of up to 52% in bread or even up to 67% in flavor-compensated bread neither affected bread consumption nor choice of sandwich fillings.

Lifetime estrogen exposure versus age at menopause as mortality predictor.

OBJECTIVES The aim of this study was to evaluate the relation between lifetime estrogen exposure and mortality and compare this with menopausal age as exposure variable. METHODS We studied a cohort of 1462 naturally postmenopausal women, aged 37-77 at enrollment in the Belgian Interuniversity Research on Nutrition and Health study. After a follow-up time of 10 years, 181 women had died, of whom 76 of cardiovascular causes. Logistic regression analysis was used to investigate the relations between lifetime estrogen exposure (calculated as menopausal age minus menarcheal age) and death as well as the relations between age at menopause and death. RESULTS The risk of mortality was lower in women with a longer lifetime estrogen exposure as well as in women with higher menopausal ages. For women with a lifetime estrogen exposure of >or=40 years the odds ratio of all-cause mortality was 0.58 (95% confidence interval (CI) 0.35-0.93) compared to women who had a lifetime estrogen exposure of <or=33 years. Women who became menopausal after the age of 53 years had a similar reduction in mortality risk (odds ratio 0.62; 95% CI 0.36-1.03) when compared to women with menopausal ages of <or=46 years. These decreases in mortality risk were particularly due to a reduction in mortality of cardiovascular diseases. CONCLUSIONS This study indicates that menopausal age predicts mortality. The prediction is not improved by adding the age at menarche, to obtain an estimate for lifetime estrogen exposure.

Reproducibility of Blood Markers of Oxidative Status and Endothelial Function in Healthy Individuals

Oxidative processes and endothelial cell dysfunction play an important role in the etiology of atherosclerosis. Oxidative modification of LDL in the subendothelial space of the vessel wall is thought to be important in the initiation of atherosclerosis. Oxidized LDL (OxLDL) may not only contribute to foam cell generation, but also stimulate the synthesis of adhesion molecules by endothelial cells. Expression of intercellular adhesion molecule-1 (ICAM-1) and vascular cell adhesion molecule-1 (VCAM-1) promotes the adherence and migration of new monocytes through the endothelial barrier to the subendothelial space (1)(2). Finally, some OxLDL will diffuse back from the atherosclerotic arterial wall to the blood, in which it can be measured. Coronary atherosclerosis is associated with increased amounts of circulating OxLDL (3). Circulating ICAM-1, VCAM-1, and von Willebrand factor (vWF) may be regarded as markers of endothelial function, and high concentrations of these markers are predictive of the risk, presence, and severity of vascular disease (4)(5)(6). Interest is growing in the measurement of markers of atherosclerosis to predict disease risk and to investigate effects of different interventions. Data on the within-subject variation of these markers are necessary to adequately estimate the required sample sizes for intervention trials and/or the number of blood samples needed to obtain a stable estimate of typical concentrations. However, data on the reproducibility (i.e., within-subject and analytical variation) of oxidative and endothelial markers are still sparse. We therefore investigated the reproducibility of several diagnostic markers of oxidative processes (OxLDL, the endogenous antioxidants bilirubin and uric acid, and ferritin) and endothelial function (sICAM-1, sVCAM-1, and vWF) in healthy individuals. The markers were measured in samples taken on three different occasions within 1 week, and in men and women of different ages. The study population consisted of 25 volunteers (12 men and 13 women; …

Sex ratio of total energy intake in adults: an analysis of dietary surveys

Objective: The ratio of the total energy intake (TEI) reported by men and women in the same dietary survey varies considerably among dietary surveys. The purpose of our study was to investigate the potential value of the sex ratio of TEI as a measure of misreporting dietary intake by comparing it with the sex ratio of biomarkers such as the 24 h urinary excretion of sodium, potassium and total nitrogen.Methods: The sex ratio (m/f) of TEI in adults was calculated from 81 dietary surveys performed in 28 countries. The surveys were conducted in healthy and free-living populations, using the same methodology in both sexes.Results: A mean sex ratio of 1.35 (s.d., 0.13) and 1.33 (s.d., 0.10) was obtained at the individual survey level and at the country level, respectively. The sex ratio of 1.40 in the younger age class (≤60/64 y) was significantly higher than the sex ratio of 1.27 in the older age class (>60/64 y) (P<0.0001). The dietary assessment methodology also influenced the sex ratio (P=0.03). Compared with the INTERSALT study, the sex ratio of TEI was higher than the sex ratios of the 24 h urinary sodium (1.23), potassium (1.20) and total nitrogen (1.25), biomarkers of dietary sodium, potassium and protein intake. Therefore the dietary survey data indicate a mean TEI of 10 476 kJ/d for men and 7784 kJ/d for women, which gives a mean sex difference of 2692 kJ/d. However if the biomarker sex ratio of 1.23, mean sex ratio of the 24 h urinary sodium, potassium and total nitrogen, is correct and the TEI of men is correctly assessed at 10 476 kJ/d, the TEI of women should be 8517 kJ/d, a difference of only 1959 kJ/d.Conclusions: Calculated from dietary surveys, the mean sex ratio of TEI is 1.35. This sex ratio decreases with age and depends on the dietary assessment methods used. In many dietary surveys, the sex ratio of TEI is likely overestimated.Sponsorship: Unilever Chair on Nutrition and Health, Catholic University of Leuven, Belgium.

Alcohol drinkers overreport their energy intake in the BIRNH study: Evaluation by 24-hour urinary excretion of cations

Objective: Alcohol drinkers are generally considered to underreport their alcohol intake, but little is known about whether they correctly report their energy intake (EI). We assessed the validity of the reported energy intake of alcohol drinkers using the 24-hour urinary (U) excretion of potassium (K) and sodium (Na) as biomarkers. Methods: A total of 2,124 men and 1,998 women 25 to 74 years of age with a 24-hour urine collection, a random sample of the Belgian Interuniversity Research on Nutrition and Health (BIRNH), were studied. Dietary intake (D), including alcohol consumption, was assessed by a one-day food record. Basal metabolic rate (BMR) was predicted from age, gender and weight. As a measure for the degree of reporting error, D-K/U-K, D-Na/U-Na, EI/U-K, Non-alcohol EI/U-Na (NAEI/U-Na), EI/U-Na, EI/U-creatinine and EI/BMR ratios were calculated and compared among non-, moderate and heavy drinkers in both genders. Results: EI, NAEI and all seven ratios examined generally increased with the level of alcohol intake in both genders. After adjustment for age, body mass index, smoking and educational level, most ratios were significantly higher in moderate drinkers (p < 0.02 to p < 0.0001) and in heavy drinkers (all p < 0.0001) than in non-drinkers. These differences were most significant in male heavy drinkers. The exceptions were D-K/U-K, D-Na/U-Na and NAEI/U-Na in moderate and female heavy drinkers and EI/U-K in male moderate drinkers. The estimated amount of the overreporting of EI by heavy drinkers was 27.8% in men and 13.7% in women. Conclusions: This study provides evidence that EI and NAEI obtained from the BIRNH study was overreported among alcohol drinkers, especially among male heavy drinkers. It also indicates that EI from alcohol replaced EI from food.