Biomedical subjects

G Vyncke

Publications and source records attributed to G Vyncke.

12 recordsLinked to original sources

PubMed1994

Renal function and historical environmental cadmium pollution from zinc smelters.

We investigated whether there was an association between renal function and cadmium pollution in areas with different exposures. Cadmium was measured in the soil and in vegetables in 10 districts, 6 of which were close to zinc smelters; and renal function and the concentrations of metals in blood and urine were measured in 703 randomly selected residents. 6 polluted areas, compared with 4 others showed higher cadmium concentrations in the soil (4.86 vs 0.81 ppm) and in locally grown vegetables, such as celery (2.43 vs 0.68 ppm) and beans (0.42 vs 0.15 ppm). Residents in polluted areas had higher urinary cadmium (10.5 vs 7.9 nmol/24 hours) and copper (0.16 vs 0.14 mumol/24 hours); higher serum creatinine (100 vs 97 mumol/L) urinary excretions of beta 2-microglobulin (109 vs 95 micrograms/24 hours), retinol-binding-protein (136 vs 118 micrograms/24 hours), and N-acetyl-beta-glucosaminidase (1.78 vs 1.38 U/24 hours). Serum zinc (12.2 vs 12.6 mumol/L) and creatinine clearance (87 vs 92 mL/min) were reduced in the 6 polluted areas. In all 10 districts, cadmium in the soil was positively correlated with cadmium in celery (r = 0.77), in beans (r = 0.67), and in residents' urine (r = 0.76). The creatinine clearance was inversely correlated with cadmium in soil (r = -0.78), in celery (r = -0.90), and in beans (r = -0.70). Past emissions from zinc smelters gave rise to contamination of the environment with cadmium, which gets into the food chain and has the potential to cause renal dysfunction and alterations in zinc and copper homeostasis.

Adult↗

PubMed1994

Ambulatory blood pressure and blood pressure measured at home: progress report on a population study.

To determine reference values for ambulatory blood pressure, a population sample of 718 subjects (20 through 88 years old) was investigated. Ambulatory blood pressure was recorded over 24 h, taking measurements at 20-min intervals from 8 a.m. to 10 p.m. and at 45-min intervals from 10 p.m. to 8 a.m. Trained nurses also measured the conventional pressure at each participant's home. The ambulatory blood pressure in the 718 subjects averaged 119/71 mm Hg over 24 h, 125/76 mm Hg during the day (10 a.m.-8 p.m.), and 108/62 mm Hg at night (0 a.m.-6 a.m.). Compared with the daytime pressure, blood pressure at home was on average the same in all 718 subjects but was 3/1 mm Hg lower in 530 normotensive subjects. The 95th percentiles of the 24-h pressures were 134/85 mm Hg in 182 men below age 50, 145/87 mm Hg in 164 men aged > or = 50 years, 127/80 mm Hg in 198 women below age 50, and 141/81 mm Hg in 174 women aged > or = 50 years. In the normotensive subjects of these four strata, these percentiles were 132/82 mm Hg (n = 149), 128/80 mm Hg (n = 103), 125/79 mm Hg (n = 180), and 131/79 mm Hg (n = 98). In comparison with earlier results in a smaller sample (n = 318) from which treated patients were excluded, this analysis demonstrated consistent results in the determination of a reference frame for ambulatory monitoring. Nevertheless, the prognostic significance of such reference values needs to be established in longitudinal studies and clinical trials.

Adult↗

PubMed1994

A consistent reference frame for ambulatory blood pressure monitoring is found in different populations.

This study investigated the consistency of a reference frame for ambulatory pressure monitoring, which using various approaches was determined in two different populations. The two reference groups were 718 subjects randomly selected from the population and 895 bank employees. The reference values derived in these two groups were subsequently tested in 591 untreated hypertensive patients. The ambulatory pressures equivalent to a conventional pressure of 140 mmHg systolic and 90 mmHg diastolic were calculated by regression analysis in all subjects. In addition, in subjects who were normotensive by conventional sphygmomanometry, the mean +2 and +3 standard deviations and the 90th, 95th and 99th percentiles of the ambulatory measurements were determined. The distributions of the ambulatory measurements were similar in the two reference groups and the aforementioned parameters therefore agreed within 4 mmHg in the two populations. There was considerable overlap in the ambulatory pressures between the two reference groups and the hypertensive patients. Classification of the patients according to the means +3 standard deviations and the regression limits gave the same results because in both reference groups these boundaries approximated to each other within 1 mmHg. For the 24 h pressures in the population sample these boundaries were 140 mmHg systolic and 88 mmHg diastolic. Of the patients with systolic hypertension (> or = 160 mmHg on conventional measurement), 39% had a 24 h systolic pressure of < 140 mmHg and of those with diastolic hypertension (> or = 95 mmHg), 44% had a 24 h diastolic pressure of < 88 mmHg; if the corresponding boundaries derived in the bank employees (143/90 mmHg) were applied, these proportions were 47% and 44%, respectively.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗

PubMed1992

Transfer of cadmium from a sandy acidic soil to man: a population study.

This population study included 230 subjects (age range 20-83 years) who consumed vegetables grown in kitchen gardens on a sandy acidic soil (mean pH approximately 6.3). The study investigated the association between the Cd (cadmium) levels in blood and urine and the Cd concentration in the soil (range 0.2-44 ppm). Seventy-six subjects were current smokers and 122 participants lived in a district with known Cd pollution. Urinary Cd in the 230 subjects averaged 8.7 nmole/24 hr, (range 1.3 to 47 nmole/24 hr) after age adjustment positively correlated with the Cd level in the soil; a twofold increase of the Cd concentration in the soil was accompanied by a 7% rise in urinary Cd in men (R2 = 0.05; P = 0.04) and by a 4% rise in women (R2 = 0.02; P = 0.05). Blood Cd averaged 11.5 nmole/liter (range 1.8-41 nmole/liter) and was negatively associated with the Cd level in the soil. After adjustment for significant covariates (smoking and serum gamma-glutamyl transpeptidase in both sexes, and age and serum ferritin in women), a twofold increase in the Cd concentration in the soil was accompanied by a 6% decrease in blood Cd in men (R2 = 0.03; P = 0.09) and by a 10% decrease in women (R2 = 0.06; P less than 0.01). In conclusion, in a rural population, consuming vegetables grown on a sandy acidic soil, 2 to 4% of the variance of urinary Cd was directly related to the Cd level in the soil. The negative correlation with blood Cd, a measure of more recent exposure, was biased by the implementation of preventive measures in the polluted district.

Adult↗

PubMed1992

The diurnal blood pressure profile. A population study.

This population study included 399 subjects, of whom 370 (93%) showed a significant diurnal blood pressure (BP) rhythm. The nocturnal BP fall was normally distributed and averaged 16 +/- 9 mm Hg systolic and 14 +/- 7 mm Hg diastolic (mean +/- SD). The amplitude of the diurnal BP curve followed a positively skewed distribution, with a mean of 16 +/- 5 mm Hg for systolic BP and 14 +/- 4 mm Hg for diastolic BP. The daily BP maximum occurred at 15:54 +/- 4:47 for systolic BP and at 15:11 +/- 4:20 for diastolic BP. Thirty-four subjects were reexamined after a median interval of 350 days. The test for the presence of a significant diurnal rhythm was discordant in only two subjects. Repeatability (twice the standard deviation of the differences between paired recordings expressed as a percentage of the mean) varied from 11 to 25% for the 24 h, daytime, and overnight BP, and from 76 to 138% for the parameters describing the diurnal BP rhythm. In nine subjects with an initial night/day ratio of mean BP less than 0.78, the nighttime BP was significantly increased at the repeat examination, whereas the opposite tendency was observed in nine subjects with an initial ratio greater than 0.87. In conclusion, the distribution of the nocturnal BP fall is unimodal. The reproducibility of the ambulatory BP is satisfactory for the level of BP and for the presence of a diurnal BP rhythm, but not for the parameters of the diurnal BP curve. Thus, one 24 h recording is insufficient to fully characterize an individual's diurnal BP profile.

Adult↗

PubMed1991

Reference values for the ambulatory blood pressure and the blood pressure measured at home: a population study.

In order to determine reference values for the ambulatory blood pressure, a population sample of 328 subjects, aged 20-81 years, who reported themselves to be in good health, was investigated. The ambulatory blood pressure was recorded over 24 h, taking measurements at 20 min intervals from 8 am to 10 pm, and at 45 min intervals from 10 pm to 8 am. Blood pressure was also measured by trained observers on each of two separate home visits (5 readings per visit). The ambulatory blood pressure in the 328 subjects averaged 118/71 mmHg over 24 h, 124/76 mmHg during the day (10 am-8 pm), and 108/62 mmHg at night (0 am-6 am). Blood pressure measured by an observer at the occasion of the second home visit was 4/5 mmHg lower (P less than 0.001) than the daytime ambulatory blood pressure. The 95th centiles for the daytime ambulatory pressures were 144/95 mmHg in 85 men below age 50; 154/90 mmHg in 74 men aged greater than or equal to 50 years; 132/85 mmHg in 96 women below age 50; and 151/91 mmHg in 73 women aged greater than or equal to 50 years. The 95th centiles for the nighttime pressures in these four sex-age groups were 124/79, 140/83, 121/70, and 132/72 mmHg, respectively.

Adult↗

PubMed1991