title: Sympathetic nervous system activity is associated with obesity-induced subclinical organ damage in young adults.
abstract: Excess weight is established as a major risk factor for cardiovascular diseases, particularly in young individuals. To get a better understanding of the pathophysiology underlying increased cardiovascular disease risk, we evaluated early signs of organ damage and their possible relationship to sympathetic nervous activity. Eighteen lean (body mass index <25 kg/m(2)) and 25 overweight or obese (body mass index >25 kg/m(2)) healthy university students were included in the study. We comprehensively assessed subclinical target organ damage, including the following: (1) assessment of renal function; (2) left ventricular structure and systolic and diastolic function; and (3) endothelial function. Muscle sympathetic nervous activity was assessed by microneurography. Participants with excess weight had decreased endothelial function (P<0.01), elevated creatinine clearance (P<0.05), increased left ventricular mass index (P<0.05), increased left ventricular wall thickness (P<0.01), lower systolic and diastolic function (P<0.01), and elevated muscle sympathetic nervous activity (P<0.001) compared with lean individuals. In multiple regression analysis, endothelial function was inversely related to muscle sympathetic nervous activity (R(2)=0.244; P<0.05), whereas creatinine clearance and left ventricular mass index were positively related to muscle sympathetic nervous activity, after adjustment for body mass index, sex, and blood pressure (R(2)=0.318, P<0.01 and R(2)=0.312, P<0.05, respectively). Excess weight in young individuals is associated with subclinical alterations in renal and endothelial function, as well as in the structure of the heart, even in the absence of hypertension. Sympathetic activity is closely associated with cardiovascular and renal alterations observed in these subjects.
authors.affiliation: Human Neurotransmitters Laboratory, Baker IDI Heart and Diabetes Institute, PO Box 6492, St Kilda Road Central, Melbourne, Victoria 8008, Australia. Elisabeth.lambert@bakeridi.edu.au
authors.forename: Elisabeth
authors.initials: E
authors.lastname: Lambert
authors.forename: Carolina Ika
authors.initials: CI
authors.lastname: Sari
authors.forename: Tye
authors.initials: T
authors.lastname: Dawood
authors.forename: Julie
authors.initials: J
authors.lastname: Nguyen
authors.forename: Mariee
authors.initials: M
authors.lastname: McGrane
authors.forename: Nina
authors.initials: N
authors.lastname: Eikelis
authors.forename: Reena
authors.initials: R
authors.lastname: Chopra
authors.forename: Chiew
authors.initials: C
authors.lastname: Wong
authors.forename: Kanella
authors.initials: K
authors.lastname: Chatzivlastou
authors.forename: Geoff
authors.initials: G
authors.lastname: Head
authors.forename: Nora
authors.initials: N
authors.lastname: Straznicky
authors.forename: Murray
authors.initials: M
authors.lastname: Esler
authors.forename: Markus
authors.initials: M
authors.lastname: Schlaich
authors.forename: Gavin
authors.initials: G
authors.lastname: Lambert
mesh_terms: D000293:Adolescent; D000328:Adult; D015992:Body Mass Index; D004730:Endothelium, Vascular / Q000503:physiopathology; D005260:Female; D006321:Heart / Q000503:physiopathology*; D006801:Humans; D006973:Hypertension / Q000150:complications / Q000503:physiopathology; D007668:Kidney / Q000503:physiopathology*; D008297:Male; D018482:Muscle, Skeletal / Q000294:innervation / Q000503:physiopathology; D009765:Obesity / Q000150:complications / Q000503:physiopathology*; D050177:Overweight / Q000503:physiopathology*; D012044:Regression Analysis; D018709:Statistics, Nonparametric; D013564:Sympathetic Nervous System / Q000503:physiopathology*