Influence of demographic and metabolic variables on forearm blood flow and vascular conductance in individuals without overt heart disease

Thiago E Sartori, Rafael A B Nunes, Gisela T da Silva, Sandra C da Silva, Maria U P B Rondon, Carlos E Negrão, Alfredo J Mansur, Thiago E Sartori, Rafael A B Nunes, Gisela T da Silva, Sandra C da Silva, Maria U P B Rondon, Carlos E Negrão, Alfredo J Mansur

Abstract

Purpose: Vascular reactivity is involved in the regulation of vascular function either in normal conditions or in the pathophysiology of cardiovascular diseases. We tested the hypothesis that vascular reactivity evaluated by forearm blood flow may vary according to demographic and metabolic variables in a cohort of individuals without any evidence of heart disease after clinical examination.

Subjects and methods: We studied 186 individuals (mean age 41.4 years, standard deviation 13.1 years; 95 (51%) men and 91 (49%) women. We investigated forearm blood flow and vascular conductance with venous occlusion plethysmography at baseline, during handgrip isometric exercise and during the recovery phase. Demographic and laboratory data were collected. Statistical analysis was performed with mixed linear models appropriate for repeated measurements.

Results: Mean forearm blood flow values in the different study conditions ranged between 1.7+/-0.47 mL.min(-1).100 mL(-1) of tissue and 2.82+/-1.13 mL.min(-1).100 mL(-1) of tissue. Forearm blood flow was higher in men than in women (P<0.005) and increased as the heart rate increased during handgrip maneuver (P<0.0001). Serum triglyceride levels were inversely related to forearm blood flow at baseline, during isometric exercise and recovery phase (P=0.0209). Body mass index was inversely related to forearm vascular conductance at baseline, during isometric exercise and recovery phase (P=0.0223).

Conclusion: Our findings suggest that forearm blood flow and vascular conductance as a surrogate of the vascular function may be influenced by gender, heart rate, serum triglyceride levels and body mass index in individuals without overt heart disease.

Keywords: body mass index; forearm blood flow; gender; triglycerides.

Figures

Figure 1
Figure 1
Forearm blood flow (mL.min−1·100 mL−1 of tissue) with lognormal adjustment. Notes: Each graph represents the study condition – baseline 5 minutes and 3 minutes before handgrip, 1st, 2nd and 3rd minutes of hand grip, and 1st, 2nd and 3rd minutes of recovery.
Figure 2
Figure 2
Estimates of values of forearm blood flow before handgrip, during handgrip, and during recovery. Notes: Estimates of values of forearm blood flow (mL.min−1·100 mL−1 of tissue) for the men and the women at baseline (heart rate 65 beats per minute), 1st (heart rate 70 beats per minute), 2nd (heart rate 72 beats per minute), and 3rd (heart rate 74 beats per minute), minutes of handgrip, and 1st (heart rate 65 beats per minute), 2nd (heart rate 65 beats per minute), and 3rd (heart rate 65 beats per minute), minutes of recovery. Estimates were done for triglycerides 122 mg/dL. Abbreviation: CI, confidence interval.
Figure 3
Figure 3
Estimates of vascular conductance values relative to body mass index before handgrip, during handgrip, and during recovery. Notes: Estimates of vascular conductance values (mL.min−1·100 mL−1 of tissue/mmHg−1) relative to body mass index at baseline, 1st, 2nd and 3rd minutes of handgrip, and 1st, 2nd and 3rd minutes of recovery. Abbreviation: BMI, body mass index.

References

    1. Middlekauff HR, Nguyen AH, Negrao CE, et al. Impact of acute mental stress on sympathetic nerve activity and regional blood flow in advanced heart failure: implications for ‘triggering’ adverse cardiac events. Circulation. 1997;96:1835–1842.
    1. Wilkinson IB, Webb DJ. Venous occlusion plethysmography in research: methodology and clinical applications. J Clin Pharmacol. 2001;52:631–646.
    1. Thompson BC, Fadin T, Pincivero DM, Scheuermann BW. Forearm blood flow responses to fatiguing isometric contractions in women and men. Am J Physiol Heart Circ Physiol. 2007;293:H805–H812.
    1. Gonzales JU, Thompson BC, Thistlethwaite JR, Harper AJ, Scheuermann BW. Forearm blood flow follows work rate during submaximal dynamic forearm exercise independent of sex. J Appl Physiol. 2007;103:1950–1957.
    1. Kneale BJ, Chowienczyk PJ, Brett SE, Coltart DJ, Ritter JM. Gender differences in sensitivity to adrenergic agonists of forearm resistance vasculature. J Am Coll Cardiol. 2000;36:1233–1238.
    1. Sarabi M, Millgard J, Lind L. Effects of age, gender and metabolic factors on endothelium dependent vasodilatation: a population-based study. J Intern Med. 1999;246:265–274.
    1. Sarabi M, Vessby B, Millgard J, Lind L. Endothelium-dependent vasodilatation is related to the fatty acid composition of serum lipids in healthy subjects. Atherosclerosis. 2001;156:349–355.
    1. Trombetta IC, Batalha LT, Rondon MUPB, et al. Weight loss improves neurovascular and muscle metaboreflex control in obesity. Am J Physiol Heart Circu Physiol. 2003;285:H974–H982.
    1. Lind L, Sarabi M, Millgard J, Kahan T. Endothelium-dependent vasodilatation is impaired in apparently healthy subjects with a family history of myocardial infarction. J Cardiovasc Risk. 2002;9:53–57.
    1. Lerman A, Zeither AM. Endothelial Function – Cardiac Events. Circulation. 2005;111:363–368.
    1. Negrão CE, Hamilton E, Foronow G, Hage A, Moriguchi JD, Middlekauff HR. Impaired endothelium-mediated vasodilation is not the principal cause of blood vasoconstriction in heart failure. Am J Physiol Heart Circ Physiol. 2000;278:H168–H174.
    1. Hunter SK, Schletty JM, Schlachter KM, Griffith EE, Polichnowski AJ, Ng AV. Active hyperemia and vascular conductance differ between men and women for isometric fatiguing contraction. J Appl Physiol. 2006;101:140–150.
    1. Sanders JS, Mark AL, Ferguson DW. Evidence for cholinergically mediated vasodilatation at the beginning of isometric exercise in humans. Circulation. 1989;79(4):815–824.
    1. de Man FH, Weverling-Rijnsburger AW, van der Laarse A, Smelt AH, Jukema JW, Bluw GJ. Not acute but chronic hypertriglyceridemia is associated with impaired endothelium-dependent vasodilatation. Arterioscler Thromb Vasc Biol. 2000;20:744–750.
    1. Capell WH, DeSouza CA, Poirier P, et al. Short-term triglycerides lowering with fenofibrate improves vasodilator function in subjects with hypertriglyceridemia. Arterioscler Thromb Vasc Biol. 2003;23:307–313.
    1. Gandotra P, Miller M. The role of triglycerides in cardiovascular risk. Current Cardiol Rep. 2008;10:505–511.
    1. Di Angelantonio E, Sarwar N, Perry P, et al. Major lipids, apolipoproteins, and risk of vascular disease. JAMA. 2009;302(18):1993–2000.
    1. Ribeiro MM, Silva AG, Santos NS, et al. Diet and exercise training restore blood pressure and vasodilatory responses during physiological maneuvers in obese children. Circulation. 2005;111:1915–1923.

Source: PubMed

Sponsors et collaborateurs

Les conditions médicales

Interventions en matière de drogue

3
S'abonner