Determination of total aluminum, chromium, copper, iron, manganese, and nickel and their fractions leached to the infusions of black tea, green tea, Hibiscus sabdariffa, and Ilex paraguariensis (mate) by ETA-AAS.

Total aluminum, chromium, copper, iron, manganese, and nickel were determined in black tea, green tea, Hibiscus sabdariffa, and Ilex paraguariensis (mate) by electrothermal atomic absorption spectrometry after nitric/perchloric acid digestion. In each case, one ground sample of commercially available leafy material was prepared and three 0.5-g subsamples were run in parallel. The infusions were also analyzed and the percentage of each element leached into the liquor was evaluated. The obtained results indicated that hibiscus and mate contained lower levels of aluminum (272+/-19 microg/g and 369+/-22 microg/g, respectively) as referred to black tea (759+/-31 microg/g) or green tea (919micro29 microg/g) and suggested that mate drinking could be a good dietary source of essential micronutrient manganese (total content 2223+/-110 microg/g, 48.1% leached to the infusion). It was also found that the infusion of hibiscus could supply greater amounts of iron (111+/-5 microg/g total, 40.5% leached) and copper (5.9+/-0.3 microg/g total, 93.4% leached) as compared to other infusions. Moreover, it was found that the percentage of element leached to the infusion was strongly related to the tannins content in the beverage (correlation coefficients > 0.82 with the exception for nickel); for lower tannins level, better leaching was observed.

Prediction of adult hypertension by K4 and K5 diastolic blood pressure in children: the Bogalusa Heart Study.

OBJECTIVE: The objective of this study was to examine the reproducibility of K4 and K5 diastolic blood pressure measurements and the ability to predict adulthood values. STUDY DESIGN: The Bogalusa Heart Study is a long-term epidemiologic study of cardiovascular disease risk factors from birth to early adulthood conducted in the biracial (one third black, two thirds white) community of Bogalusa, Louisiana. Analyses included blood pressure measurements taken on 12,139 subjects during multiple cross-sectional screenings from 1973 to 1994; 20% (N = 2530) had measurements taken as a child, ages 4 to 18 years, and during adulthood, ages 19 to 32 years. Six resting blood pressure measurements were taken by trained observers with mercury sphygmomanometers at each screening with K1, K4, and K5 recorded. Variance components analysis was used to evaluate the reliability of K4 and K5. RESULTS: The total variance was larger for K5 (253 mm Hg2) than for K4 (109 mm Hg2) at age 5 years. Variance for both K4 and K5 decreased with age. The interobserver variability was larger for K5 (more than 50% vs 40%). Childhood K4 (vs childhood K5) was better correlated with adult K1 and K5 (0.28 vs 0.11 for K1; 0.33 vs 0.25 for K5 at age 11 to 13 years). K4 was also shown to have a higher odds ratio for predicting adult hypertension than K5 (1.57 vs 1.14 at age 11 to 13 years). CONCLUSION: During childhood K4 is a more reliable measure of diastolic blood pressure than K5. K4 diastolic blood pressure measured in childhood is a better predictor of adult hypertension.