Lipoprotein-specific transport of circulating lipid peroxides

Figures & data

Table I. Base-line characteristics of the participants.

	Trial 1	Trial 2	Trial 3	Trial 4	Trial 5
n	10	36	11	20	12
Male/female	10/0	26/10	11/0	20/0	12/0
Age (years)	42 (23–58)^a	32 (20–50)	48 (34–59)	24 (19–33)	39 (22–51)
BMI (kg/m^2)	28 (26–30)	24 (21–28)	26 (23–29)	20 (17–25)	24 (20–27)

^aMean (min–max).

Table II. Basic nutritional characteristics of test meals.

	Hamburger meal	Oat meal
Energy (kcal)	965	330
Fat (g)	48	7
Protein (g)	34	15
Carbohydrate (g)	99	52
Lipid peroxides (μmol)	1030 (350 μmol/100 g)	70 (42 μmol/100 g)

Figure 1. Lipophilic lipid peroxides (A) and malondialdehyde (B) concentrations in serum lipoproteins after consumption of a meal rich in lipid peroxides. Lipid peroxidation products were analyzed in blood samples of healthy volunteers (trial 1, n = 10) during the post prandial period after consumption of a standard hamburger meal. LDL = low-density lipoproteins; TRL = triglyceride-rich lipo proteins; HDL = high-density lipoproteins. Mean ± SD are indicated. *Statistically different from 0 h time point, P < 0.05; **P < 0.01; ***P < 0.001.

Table III. Effect of hamburger meal on serum lipids and indicators of oxidative stress in trial 2.^a

Parameter	0 h	2 h	4 h	6 h
OxLDL	34.1 ± 11.9	44.8 ± 14.5	47.0 ± 18.4	40.7 ± 13.2
(μmol/L)		(+31%)^d	(+38%)^d	(+19%)^d
OxLDL/LDL cholesterol	12.0 ± 2.7	16.1 ± 3.8	16.4 ± 4.8	14.3 ± 3.5
(μmol/mmol)		(+34%)^d	(+37%)^d	(+19%)^d
LDL cholesterol	2.83 ± 0.72	2.81 ± 0.73	2.86 ± 0.73	2.87 ±0.75
(mmol/L)		(–1%)	(+1%)	(+1%)
Total cholesterol	4.89 ± 1.11	4.88 ± 1.12	4.92 ± 1.13	4.90 ± 1.08
(mmol/L)		(0%)	(+1%)	(0%)
HDL cholesterol	0.99 ± 0.25	0.98 ± 0.25	0.96 ± 0.26	1.01 ± 0.26
(mmol/L)		(–1%)	(’”3%)	(+2%)
Triglycerides	1.38 ± 0.74	2.17 ± 1.03	2.15 ± 1.06	1.59 ± 0.76
(mmol/L)		(+57%)^d	(+56%)^d	(+15%)^c
8-Isoprostanes	59.2 ± 46.8	73.4 ± 51.9	51.8 ± 33.0	54.0 ± 5.1
(ng/L)		(+24%)	(−12%)	(−9%)
Malondialdehyde	2.49 ± 0.54	2.21 ± 0.49	2.33 ± 0.49	2.62 ± 0.62
(μmol/L)		(−11%)^b	(−6%)	(+5%)
8-oxo-deoxyguanosine	1.00 ± 0.38	0.95 ± 0.35	0.98 ± 0.27	0.84 ± 0.30
(8-oxo-dG/dG)		(−5%)	(−2%)	(−16%)
Antioxidant potential	750 ± 199	765 ± 211	753 ± 198	740 ± 188
(μmol/L)		(+2%)	(0%)	(−1%)
Paraoxonase	158 ± 75	154 ± 79	156 ± 76	154 ± 71
(U/L)		(−3%)	(−1%)	(−3%)
Insulin	9.0 ± 7.3	23.2 ± 15.1	9.7 ± 5.8	6.1 ± 3.2
(mU/L)		(+158%)^d	(+8%)	(−32%)^c
Glucose	4.78 ± 0.57	4.23 ± 0.78	5.99 ± 0.43	5.23 ± 0.47
(mmol/L)		(−12%)^c	(+4%)	(+9%)^c

^aMean values±SD (n=36). Percentage of change from the pre-meal value is given in parentheses.

^bP < 0.05.

^cP < 0.01.

^dP < 0.001.

OxLDL = LDL-oxidized lipids; 8-oxo-dG = 8-oxo-deoxyguanosine; dG = deoxyguanosine.

Figure 2. Correlation of the AUC for LDL-oxidized lipids with that of serum triglyceride concentration (A) and with the body mass index (BMI) (B). The data are based on analyses made in blood samples of healthy volunteers (trial 2, n = 36) during the postprandial period after consumption of a standard hamburger meal.

Figure 3. A: Postprandial LDL-oxidized lipids concentrations after a hamburger meal (trial 1, n = 10) or an oat meal (trial 3, n = 11). Mean ± SD are indicated. B: The amount of lipid peroxides in test meals.

Table IV. Effect of HDL level on meal-induced postprandial responses in LDL-oxidized lipid and triglyceride concentrations.^a

Parameter	Low HDL	High HDL
HDL cholesterol (mmol/L)
range	0.72–0.99	1.00–1.80
mean	0.81 ± 0.06	1.12 ± 0.23
LDL-oxidized lipids (AUC 6 h)	66.3 ± 38.8	33.2 ± 20.2	(P= 0.008)
Triglycerides (AUC 6 h)	3.12 ± 1.56	2.84 ± 1.51	(P= 0.695)
n	13	13

^aMale subjects in trial 2 were divided to two subgroups according to the HDL cholesterol concentration. Mean±SD are indicated.

Figure 4. The effect of acute physical exercise (trial 4, n = 20) on the concentration of LDL-oxidized lipids and paraoxonase activity (A), and on the concentration of HDL-oxidized lipids (B). The effect of physical exercise on lipid peroxide concentrations in various HDL lipid fractions (C). The effect of intensity of the physical exercise (trial 5, n = 12) on the level of HDL-oxidized lipids (D). Mean ± SD are indicated. ***Statistically different from the pre-exercise value, P < 0.001. Different letters indicate significant differences between the time points (P < 0.05).