Luc Van Bortel

Publications (5)24.48 Total impact

• Article: Effects of hunter-gatherer subsistence mode on arterial distensibility in Cameroonian pygmies.

  Daniel Lemogoum, William Ngatchou, Christophe Janssen, Marc Leeman, Luc Van Bortel, Pierre Boutouyrie, Jean Paul Degaute, Philippe Van de Borne
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  ABSTRACT: We aimed to assess whether arterial distensibility estimated by pulse wave velocity (PWV) and augmentation index (AI) differs between Cameroon traditional pygmies (TPs) on hunter-gather subsistence mode, contemporary pygmies who migrated to semiurban area, and the Bantou farmers (BFs) sharing the same environment. For that purpose, we recorded carotid-femoral PWV (ComplioR) in age and sex carefully matched 20 TPs, 20 contemporary pygmies, and 22 BFs. Aortic AI corrected for heart rate and blood pressures were generated from pressure wave analysis (SphygmoCor). Lipid profile was determined in TP and BF participants. TPs were shorter (P=0.02) with lower body weight (P<0.01) in comparison with contemporary pygmies and BFs. TPs had lower low-density lipoprotein cholesterol but higher high-density lipoprotein cholesterol than BFs (P<0.01). Their PWV (5.81±0.21 m/s) was slower (P=0.006) than that of contemporary pygmies (6.82±0.36 m/s) or BFs (6.93±0.29 m/s); however, after its adjustment for age, mean arterial pressure, and heart rate, the difference was slightly attenuated (P=0.051). PWV adjusted for weight did not differ between groups (P=0.10). In the whole study population but not in TPs taken separately, multivariate regression analysis revealed that PWV was independently associated with mean arterial pressure, age, and TP status (P<0.001), whereas age, mean arterial pressure, and height emerged as independent determinants of aortic AI corrected for heart rate (P<0.001). Aortic AI corrected for heart rate did not differ in the 3 groups. In conclusion, hunter-gather lifestyle is associated with low atherosclerosis risk translated by lower aortic stiffness attributed at least partly to low weight and blunted effects of aging and blood pressures on TP arterial structure and function.
  Hypertension 05/2012; 60(1):123-8. · 6.21 Impact Factor
• Article: Ethnic differences in arterial stiffness and wave reflections after cigarette smoking.

  Daniel Lemogoum, Luc Van Bortel, Marc Leeman, Jean-Paul Degaute, Philippe van de Borne
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  ABSTRACT: Smoking increases plasma nicotine. Nicotine releases catecholamines and alters arterial distensibility. The nicotine intake per cigarette is greater and serum cotinine levels, the proximate metabolite of nicotine, are higher in Blacks than in Whites. We tested the hypothesis that cigarette smoking increases the pulse wave velocity (PWV), a marker of arterial stiffness, and the augmentation index (AI), a measure of wave reflection, more in Blacks than in Whites. We matched Black (n = 30) and White (n = 30) smokers for age, gender, body mass index and height. We determined carotid-femoral PWV (PWVCF) and carotid-radial PWV (PWVCR) (Complior), the AI derived from the aortic pressure waveform (applanation tonometry, Sphygmocor), blood pressure, heart rate (HR) and cotinine levels before and after cigarette smoking. We also performed measurements in 16 participants after sham smoking. Smoking increased the AI, PWVCF and PWVCR in the whole population (all P < 0.05, n = 60). Increases in the AI and PWV were positively related to serum cotinine levels (all P < 0.05). Smoking increased serum cotinine (P = 0.01) and mean blood pressure (P = 0.03) more, but raised the HR to a lesser extent, in Blacks [+8 +/- 4 versus +13 +/- 6 beats/min in Whites (mean +/- SD), P = 0.01]. Blacks disclosed larger increases in AI adjusted for HR (Blacks, +7.2 +/- 8 versus Whites, +4.4 +/- 8%; P = 0.03), PWVCF (Blacks, +1.1 +/- 0.2 versus Whites, +0.6 +/- 0.3 m/s; P < 0.01) and PWVCR (Blacks, +1.4 +/- 0.1 versus Whites, +0.7 +/- 0.4 m/s; P < 0.01) normalized for the mean blood pressure. No changes were observed with sham smoking. Smoking acutely increases the PWV and AI in Blacks more than in Whites. Differences in nicotine metabolism and beta-adrenergic sensitivity could explain these findings.
  Journal of Hypertension 05/2006; 24(4):683-9. · 4.02 Impact Factor
• Article: Effect of beta-adrenergic stimulation on pulse wave velocity in black and white subjects.

  Daniel Lemogoum, Luc Van Bortel, Wouter Van den Abeele, Agneska Ciarka, Jean-Paul Degaute, Philippe van de Borne, Marc Leeman
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  ABSTRACT: Reduced beta-adrenergic sensitivity has been reported in black subjects. We hypothesized that beta-adrenergic stimulation by isoproterenol would affect pulse wave velocity (PWV), a marker of arterial stiffness, differently in black and white subjects. Healthy normotensive black subjects (n = 21) matched for age, gender, height and body mass index with healthy normotensive white subjects (n = 20), participated in a randomized, double-blind, placebo-controlled cross-over study. The PWV was determined using an automated device at baseline and after 30 min of an equal volume infusion of isoproterenol (8 mug/kg per min) or placebo (dextrose 5%), separated by a washout period of 25 min. At baseline, heart rate (HR), systolic and diastolic blood pressure (SBP, DBP) and PWV were comparable in black and in white subjects. Placebo had no significant effect on haemodynamic variables. Isoproterenol increased HR, SBP and pulse pressure and decreased DBP with a comparable magnitude in both groups. Compared with placebo, isoproterenol decreased carotid-femoral PWV in white (from 5.9 +/- 1.2 to 5.7 +/- 1.1 m/s, means +/- SD, P = 0.05), but not in black subjects (from 6.2 +/- 1.3 to 6.6 +/- 1.7 m/s, P = 0.1). The difference in response between black and white subjects was significant (P = 0.04). Isoproterenol decreased carotid-radial PWV only significantly in white subjects. These results are compatible with the hypothesis of an altered beta-adrenergic sensitivity, which is expressed by a blunted effect of isoproterenol on arterial stiffness in black subjects.
  Journal of Hypertension 01/2005; 22(12):2349-53. · 4.02 Impact Factor
• Article: Arterial stiffness and wave reflections in patients with sickle cell disease.

  Daniel Lemogoum, Luc Van Bortel, Boutaina Najem, Anasthase Dzudie, Charles Teutcha, Ernest Madu, Marc Leeman, Jean-Paul Degaute, Philippe van de Borne
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  ABSTRACT: We tested the hypothesis that lower blood pressure and increased vasodilatation reported in sickle cell disease (SCD) patients with hemoglobin SS genotype (SS) are translated by lower arterial stiffness determined by pulse wave velocity (PWV) and wave reflections assessed by augmentation index (AI). We enrolled 20 SS (8 females; 12 male) patients closely matched for age, gender, height, and body mass index to 20 subjects with hemoglobin AA genotype (AA). Carotid-femoral PWV (PWV(CF)) and carotid-radial PWV (PWV(CR)) were recorded with the Complior device. Aortic AI was derived from pressure wave analysis (SphygmocoR). PWV(CF) and PWV(CR) were lower in SS than in AA (4.5+/-0.7 m/s versus 6.9+/-0.9 m/s, P<0.0001 and 6.6+/-1.2 m/s versus 9.5+/-1.4 m/s, P<0.0001, respectively). AI was lower in SS than in AA (2+/-14% versus 11+/-8%, P=0.02). Multivariate analysis revealed that both PWV(CF) and PWV(CR) were negatively associated with hemoglobin SS type and positively related to mean arterial pressure (MAP), whereas AI was positively associated with MAP and total cholesterol (all P<0.0001). Multivariate analysis restricted to SS indicated a positive association between PWV(CF) and PWV(CR) with age but a negative association with MAP (R2=0.57 and 0.51, respectively, both P<0.001), whereas MAP and heart rate were independently associated with AI (R2=0.65, P<0.001). This study provides the first evidence that SCD is associated with both lower arterial stiffness and wave reflections. SS patients have a paradoxical negative association between PWV and MAP, suggesting that low MAP does not protect them against arterial stiffness impairment.
  Hypertension 12/2004; 44(6):924-9. · 6.21 Impact Factor
• Article: Validity of pulse pressure and augmentation index as surrogate measures of arterial stiffness during beta-adrenergic stimulation.

  Daniel Lemogoum, Gabriella Flores, Wouter Van den Abeele, Agnieszka Ciarka, Marc Leeman, Jean Paul Degaute, Philippe van de Borne, Luc Van Bortel
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  ABSTRACT: Increased arterial stiffness is a determinant of cardiovascular mortality. Pulse wave velocity (PWV) is a direct measure of arterial stiffness. Aortic augmentation index (AI) and pulse pressure (PP) are surrogate measures of arterial stiffness. Both PWV, AI and PP increase with cardiovascular risk factors. The aim of this study was to test the validity of AI and PP as surrogate measures of arterial stiffness compared with PWV, during beta-adrenergic stimulation with Isoprenaline (Iso). A total of 41 healthy volunteers entered a randomized, double-blind, placebo-controlled, cross-over study. In random order, subjects were given intravenous infusion in equal volume of Iso 8 microg/kg per min (dissolved in glucose 5%) and placebo (glucose 5%). A wash-out period of 25 min was observed between the infusions. Measurements included blood pressure (BP), heart rate (HR), PWV, and AI. PWV were determined using complior (Complior, Artech-Medical, Paris, France). AI and aortic PP were obtained from pulse wave analysis of radial applanation tonometry, using transfer function (SphygmoCor Windows software). Baseline AI increased (P < 0.05) with aging, a lower height and a larger diastolic BP (DBP). Iso increased (P < 0.0001) HR, brachial SBP, brachial and aortic PP as compared with placebo. In contrast, Iso decreased (P < 0.05) AI, brachial DBP, peripheral PWV, but not aortic PWV. Decrease of AI induced by Iso was not related to PWV. In stepwise multiple regression changes in HR, brachial SBP and DBP were independent determinants of AI response to Iso (r = 0.78, P < 0.0001). Our findings show that AI and PP fail as surrogate measures of arterial stiffness during beta-adrenergic stimulation.
  Journal of Hypertension 03/2004; 22(3):511-7. · 4.02 Impact Factor