High Dose of A Conjugated Linoleic Acid Mixture Increases Insulin Resistance in Rats Fed Either A Low Fat or A High Fat Diet.

Obesity and related diseases are becoming more prevalent. Conjugated linoleic acid (CLA) might be a useful coadjutant treatment helping to decrease fat mass. However, the precise impact of CLA is unclear because the decreased body fat mass is followed by an increase in insulin resistance. This study aimed to evaluate some of the consequences of a high dose of CLA in rats fed a normal low fat or a high fat diet for 30 days. Male Wistar rats were separated into 4 groups (each n = 10): Control group receiving 7% fat (soybean oil); CLA group receiving 4% soybean oil and 3% CLA mixture; animal fat (AF) group, receiving 45% fat (lard); and animal fat plus CLA (AF+CLA) group, receiving 42% lard and 3% CLA mixture. The CLA mixture contained 39.32 mole% c9,t11-CLA and 40.50 mole% t10,c12-CLA. After 30 days, both CLA groups (CLA and AF+CLA groups) developed insulin resistance, with an increase in glucose in the fasting state and in an insulin tolerance test. The CLA group had increased liver weight and percentage of saturated fatty acids in liver and adipose tissue. Feeding the high fat diet resulted in increased hepatic triacylglycerol accumulation and this was exacerbated by dietary CLA. It is concluded that a high dose of CLA mixture increases insulin resistance and exacerbates hepatic steatosis when combined with a high fat diet.

Estimation of Body Composition and Water Data Depends on the Bioelectrical Impedance Device.

Overweight, obese and chronic kidney disease patients have an altered and negative body composition being its assessment important. Bioelectrical impedance analysis is an easy-to-operate and low-cost method for this purpose. This study aimed to compare and correlate data from single- and multi-frequency bioelectrical impedance spectroscopy applied in subjects with different body sizes, adiposity, and hydration status. It was a cross-sectional study with 386 non-chronic kidney disease volunteers (body mass index from 17 to 40 kg/m2), 30 patients in peritoneal dialysis, and 95 in hemodialysis. Bioelectrical impedance, body composition, and body water data were assessed with single- and multi-frequency bioelectrical impedance spectroscopy. Differences (95% confidence interval) and agreements (Bland-Atman analyze) between devices were evaluated. The intraclass correlation coefficient was used to measure the strength of agreement and Pearson's correlation to measure the association. Regression analyze was performed to test the association between device difference with body mass index and overhydration. The limits of agreement between devices were very large. Fat mass showed the greatest difference and the lowest intraclass and Pearson's correlation coefficients. Pearson's correlation varied from moderate to strong and the intraclass correlation coefficient from weak to substantial. The difference between devices were greater as body mass index increased and was worse in the extremes of water imbalance. In conclusion, data obtained with single- and multi-frequency bioelectrical impedance spectroscopy were highly correlated with poor agreement; the devices cannot be used interchangeably and the agreement between the devices was worse as body mass index and fat mass increased and in the extremes of overhydration.