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Robert Fagard

Publications and source records attributed to Robert Fagard.

45 records · Page 3Linked to original sources
PubMed2002

Birth weight and body composition in young women: a prospective twin study.

BACKGROUND: The intrauterine environment may be critical for the development of obesity. Alternatively, the same genetic factors may influence both birth weight and adult body composition. OBJECTIVE: We evaluated the association between birth weight and adult body composition in female twins, which allowed us to control for maternal and genetic influences. DESIGN: Of 447 twin pairs randomly selected from the East Flanders Prospective Twin Survey, 238 pairs, aged 18-34 y, participated. Adult body mass, height, and lean body mass were measured, and the body mass index (BMI), waist-to-hip ratio, and sum of skinfold thicknesses were calculated. The twins were considered as individuals and pairs. RESULTS: When the twins were considered as individuals, twins who were heavier at birth were taller (3.3 cm/kg greater birth weight) and slightly heavier (1.13 kg/kg greater birth weight) as adults than were lighter twins. They also had more lean body mass and less subcutaneous and abdominal fat at birth. Pairwise comparison showed that for every level of intrapair birth weight difference (> or = 5%, > or = 10%, and > or = 15%), the twin who was heavier at birth was taller in adult life (0.8, 1.2, and 2.0 cm, respectively). When the intrapair birth weight difference exceeded 15%, the heavier twin was also heavier (3.1 +/- 6.08 kg) as an adult than her much lighter sister. CONCLUSION: Birth weight accounts for some of the differences in adult body composition between twins.

Adult↗
PubMed2002

Carotid and femoral intima-media thickness in relation to three candidate genes in a Caucasian population.

BACKGROUND: In a Caucasian population, the prevalence and incidence of hypertension, renal function and large artery stiffness were significantly correlated with polymorphisms in the genes encoding the angiotensin-converting enzyme (ACE I/D), aldosterone synthase (-C344T) and the cytoskeleton protein alpha-adducin (Gly460Trp). OBJECTIVE: This study investigated intima-media thickening, a precursor of atherosclerosis, in relation to these genetic polymorphisms. METHODS: Carotid and femoral intima-media thickness were assessed with a wall-track system in 380 subjects enrolled in a population study. Subjects were genotyped for the presence of the ACE D, aldosterone synthase -344T and alpha-adducin 460Trp alleles. The statistical analysis allowed for confounders, interactions among genes, and the non-independence of the phenotypes within families. RESULTS: The sample included 188 men (49.5%). Mean age was 39.8 years. Intima-media thickness of the carotid and femoral arteries averaged 575 and 719 microm, respectively. Intima-media thickness of the femoral-but not carotid-artery increased with the number of ACE D alleles. The effect of ACE genotype on femoral intima-media thickness was confined to carriers of the 460Trp allele and the -344T allele. Expressed as a percentage of the population mean, the mean differences between II and DD homozygotes averaged 13.4% (95% CI 5.6-21.2%) in all subjects, 21.2% (8.0-34.5%) in carriers of the 460Trp allele, 15.4% (4.1-26.8%) in carriers of the -344T allele, and 25.2% (10.7-39.7%) if the 460Trp and -344T alleles were both present. CONCLUSION: This study shows that a relationship exists between the intima-media thickness of the large muscular femoral artery and the ACE gene. This relationship is only apparent in the presence of either the alpha-adducin 460Trp or the aldosterone synthase -344T allele. These findings may have clinical implications for the assessment of genetic cardiovascular risk.

Adolescent↗
PubMed2002

Terminal digit preference and single-number preference in the Syst-Eur trial: influence of quality control.

BACKGROUND: Terminal digit and single-number preference may produce inaccuracy and biased results when measuring blood pressure. We describe these preferences in the Syst-Eur randomized placebo-controlled trial of the treatment of isolated systolic hypertension and describe how we sought to eliminate these problems. METHODS: The Data Monitoring Committee of the trial conducted yearly quality control meetings in Belgium and visited the participating centres to check their adherence to the protocol. These meetings involved identifying terminal digit preference, improving blood pressure control and boosting recruitment. RESULTS: The prevalence of use of terminal digit zero when measuring sitting systolic blood pressure (first readings) reduced from an average of 42.4% in the year prior to the date when a centre first randomized a patient to 31.5, 25, 22.3, 26.3, 23.2 and 22% in the subsequent 6 years. This trend was independent of the calendar year during which a centre entered the trial and supports the hypothesis that data-quality monitoring, including the feedback of digit preference to centres, led to a reduction in terminal digit zero preference. In addition, a higher than expected prevalence of the systolic blood pressure value of 148 mmHg was found in the active treatment groups in the double-blind phase. Selection for 148 mmHg persisted over time and constituted a single-number preference bias. This arose from the instruction to investigators to reduce systolic blood pressure to below 150 mmHg. CONCLUSION: Monitoring and feedback of data quality should be undertaken to minimize digit and number preference. Automatic devices should ideally be employed to help to avoid these problems as long as the devices are fully validated and regularly serviced, and providing that readings are not rejected and repeated.

Bias↗
PubMed2002

Host and environmental determinants of polychlorinated aromatic hydrocarbons in serum of adolescents.

This study investigated host factors and environmental factors as potential determinants of polychlorinated aromatic hydrocarbons (PCAHs) in serum of adolescents. We recruited 200 participants (80 boys and 120 girls), with a mean age of 17.4 years (SD, 0.8), in Belgium from a rural control area (Peer) and from two polluted suburbs of Antwerp where a nonferrous smelter (Hoboken) and waste incinerators (Wilrijk) are located. We quantified polychlorinated biphenyls (PCBs; congeners 138, 153, and 180) in serum by gas chromatography and obtained the toxic equivalents (TEQs) of PCAHs in serum with the chemically activated luciferase gene expression bioassay (CALUX). Serum PCB concentration was higher in boys than in girls (1.67 vs. 1.02 nmol/L or 377 vs. 210 pmol/g serum lipids; p< 0.001). In the whole adolescent group, multiple regression showed that serum PCB concentration decreased 0.06 nmol/L per 1% increase in body fat content (p< 0.001) and increased 0.39 nmol/L and 0.14 nmol/L per 1 mmol/L increase in serum concentrations of triglycerides (p < 0.001) and cholesterol (p = 0.002), respectively. Host factors explained 44% of the serum PCB variance. In the same model, serum PCB concentration increased 0.14 nmol/L with 10 weeks of breast-feeding (p< 0.001) and 0.06 nmol/L with intake of 10 g animal fat per day (p < 0.001), and was associated with residence in the waste incinerator area (9% higher; p = 0.04); 11% of the variance could be explained by these environmental factors. The geometric mean of the serum TEQ value was similar in boys and girls (0.15 TEQ ng/L or 33.0 pg/g serum lipids). In multiple regression, TEQ in serum decreased 0.03 ng/L per centimeter increase in triceps skinfold (p = 0.006) and was 29% higher in subjects living close to the nonferrous smelter (p < 0.001). This study showed that in 16- to 18-year-old teenagers host factors are important determinants of serum concentrations of PCAHs, whereas environmentally related determinants may to some extent contribute independently to human exposure to these persistent chemicals in the environment.

Adipose Tissue↗
PubMed2002

The influence of maternal BMI and age in twin pregnancies on insulin resistance in the offspring.

OBJECTIVE: There is strong evidence that low birth weight is associated with glucose intolerance and diabetes in adults. We have carried out a twin study to distinguish among maternal influences, which affect both twins; fetoplacental influences, which are unique to each twin; and the genetic factors that may underlie this association. RESEARCH DESIGN AND METHODS: We identified a sample of 423 twin pairs (250 monozygotic and 173 dizygotic) from the East Flanders Prospective Twin Survey who were born between 1964 and 1982. Data collected in this study included the mother's body composition and weight gain during pregnancy, the twins' birth weights, and gestational age. The twins (aged 18-34 years) attended a research center for measurement of height, weight, and waist-to-hip ratio as well as fasting glucose, proinsulin, and insulin concentrations. RESULTS: Among twin pairs discordant for birth weight, we found little evidence that the lighter twin had abnormal glucose-insulin metabolism in adult life. However, both a low prepregnancy maternal BMI and older maternal age at delivery were associated with hyperinsulinemia and evidence of insulin resistance in the offspring. Fasting insulin increased by 1.3% (95% CI 0.1-2.6%) per unit fall in maternal BMI and by 1.1% (0.02-2.0%) per year increase in maternal age. These associations were independent of the twins' BMI and waist-to-hip ratio and their zygosity. CONCLUSIONS: These novel findings suggest that in twin pregnancies, maternal factors are more important than fetoplacental factors in determining glucose-insulin metabolism in the offspring.

Adult↗
PubMed2002

Stimulation of collagen gel contraction by angiotensin II and III in cardiac fibroblasts.

OBJECTIVE: The aim of the present study was to investigate whether angiotensin II (Ang II), angiotensin III (Ang III) or Ang II (2-8), angiotensin IV (Ang IV) or Ang II (3-8) and Ang II (1-7), Ang II (4-8), Ang II (5-8) and Ang II (1-4) can stimulate collagen gel contraction in cardiac fibroblasts in serum-free conditions. METHODS: Cardiac fibroblasts (from male adult Wistar rats) from passage 2 were cultured to confluency and added to a hydrated collagen gel in a Dulbecco's Modified Eagle's Medium, with or without foetal bovine serum, for one, two or three days. The area of the collagen gels embedded with cardiac fibroblasts was determined by a densitometric analysis. Collagen gel contraction was characterised by a decrease in the gel area. RESULTS: Ang II dose-dependently stimulated the contraction of collagen mediated by cardiac fibroblasts after one, two or three days of incubation in a serum-free medium. Telmisartan completely blocked the Ang II-induced collagen contraction by cardiac fibroblasts. PD 123319 and des-Asp(1)-Ile(8)-Ang II had no effect on the Ang II-induced collagen contraction by cardiac fibroblasts. Ang III also stimulated the contraction of collagen mediated by cardiac fibroblasts after one, two or three days of incubation in a serum-free medium. des-Asp(1)-Ile(8)-Ang II and telmisartan completely blocked the Ang III-induced collagen gel contraction by cardiac fibroblasts. des-Asp(1)-Ile(8)-Ang II, however, had no effect on the Ang II-induced collagen gel contraction by cardiac fibroblasts. Ang IV and Ang II (4-8), (5-8), (1-7) and (1-4), however, had no effect on collagen gel contraction by cardiac fibroblasts. Addition of telmisartan, PD 123319 or des-Asp(1)-Ile(8)-Ang II alone did not affect collagen gel contraction by cardiac fibroblasts. CONCLUSION: Our data demonstrate that the effects of Ang II on the collagen gel contraction by adult rat cardiac fibroblasts in serum-free conditions are Ang II type 1(AT(1))-receptor- mediated, because they are abolished by the specific AT(1)-receptor antagonist, telmisartan, and not by the AT(2)-receptor antagonist PD 123319 or by the Ang III antagonist des-Asp(1)-Ile(8)-angiotensin. The Ang III- stimulated contraction of collagen by cardiac fibroblasts is completely blocked by the Ang III receptor antagonist, des-Asp(1)-Ile(8)-angiotensin II, and by telmisartan.

Angiotensin II↗
PubMed1993

Age and the Hemodynamic Response to Posture and Exercise.

The effects of age on hemodynamic variables at rest, in response to orthostatic challenges, and during exercise were assessed from overall weighted statistical summaries of reports in the medical literature. In normotensive subjects at supine rest, cardiac output and stroke volume (p is less than 0.001), but not heart rate, declined with aging, whereas systemic vascular resistance increased (p is less than 0.001). The results were similar in hypertensives, but the slope of the change in cardiac output was steeper than in normotensives (p is less than 0.01). This age-related hemodynamic pattern was also observed in longitudinal follow-up studies. The orthostatic fall in stroke volume and rise in heart rate became less pronounced with increasing age (p is less than 0.05), but the postural increase in systemic vascular resistance was, on average, not related to age. Though the hemodynamic studies in healthy individuals observed that blood pressure is relatively well maintained when older subjects assume the upright position, population studies suggest that an increasing number of these subjects show a postural fall in blood pressure. This is overwhelming evidence that the oxygen uptake at peak exercise decreases with age, mainly related to a lesser peak cardiac output and heart rate (p is less than 0.001).

Journal Article↗