Submitted to: Federation of American Societies for Experimental Biology Conference
Publication Type: Abstract Only
Publication Acceptance Date: November 11, 2010
Publication Date: March 17, 2011
Citation: Nielsen, F.H. 2011. Plasma C-reactive protein (CRP), an indicator of inflammation, is decreased but plasma lipids are increased, especially with magnesium (Mg) deprivation, in rats made obese by high dietary butter oil. Federation of American Societies for Experimental Biology Conference. 25:109.8. Technical Abstract: Chronic low-grade inflammation and low Mg status often are concomitant in obesity. A 2 x 3 factorial experiment was conducted to determine whether Mg deprivation exacerbates inflammatory stress in obesity. Groups of 24 male Sprague-Dawley rats aged 6 wk were fed dietary Mg at 250, 500 or 750 mg/kg and dietary energy at 10% as soybean oil or 10% as soybean oil plus 35% as butter oil. After 3 and 6 mo of treatment, indicators of obesity and inflammation were determined in 12 rats from each group. The high fat diet increased % fat (determined by MRI), epidydimal fat, and body weight at both times, with the increases in % fat and epidydimal fat at 6 mo greatest in rats fed 750 mg dietary Mg. Plasma leptin was increased in obese rats at 3 mo with the increase most marked in rats fed 750 dietary Mg. Plasma cholesterol and triglyceride concentrations were increased at 6 mo in obese rats; the greatest cholesterol increase was in rats fed 250 mg Mg/kg diet. Plasma CRP, an indicator of inflammation, was decreased and plasma inflammatory cytokines, including TNF-a, IL-1, and IL-6, were not affected by the diet-induced obesity at 6 mo. Mg did not affect the butter oil-induced decrease in CRP. A factor in butter oil, most likely a conjugated linoleic acid, apparently prevented inflammatory stress in the obese rats. Obesity induced in rats by butter oil is not a suitable model to determine whether Mg status affects chronic inflammation in obesity.