Coenzyme Q10 concentration in plasma and blood cells of juvenile patients hospitalized for anorexia nervosa

Relationship between functional capacity and body mass index with plasma coenzyme Q10 and oxidative damage in community-dwelling elderly-people

The impact of aging and physical capacity on coenzyme Q10 (Q10) levels in human blood is unknown. Plasma Q10 is an important factor in cardiovascular diseases. To understand how physical activity in the elderly affects endogenous Q10 levels in blood plasma, we studied a cohort of healthy community-dwelling people. Volunteers were subjected to different tests of the Functional Fitness Test Battery including handgrip strength, six-minute walk, 30 s chair to stand, and time up and go tests. Anthropometric characteristics, plasma Q10 and lipid peroxidation (MDA) levels were determined. Population was divided according to gender and fitness. We found that people showing higher levels of functional capacity presented lower levels of cholesterol and lipid peroxidation accompanied by higher levels of Q10 in plasma. The ratio Q10/cholesterol and Q10/LDL increased in these people. No relationship was found when correlated to muscle strength or agility. On the other hand, obesity was related to lower Q10 and higher MDA levels in plasma affecting women more significantly. Our data demonstrate for the first time that physical activity at advanced age can increase the levels of Q10 and lower the levels of lipid peroxidation in plasma, probably reducing the progression of cardiovascular diseases.

Analytical problems with the determination of coenzyme Q10 in biological samples

The article discusses analytical problems related to the determination of coenzyme Q10 in biological samples. The assaying of coenzyme Q10 in complex samples, such as plasma, tissues, or food items requires meticulous sample preparation prior to final quantification. The process typically consists of the following steps: deproteinization, extraction, and ultimately reduction of extract volumes. At times drying under a gentle stream of neutral gas is applied. In the case of solid samples, a careful homogenization is also required. Each step of the sample preparation process can be a source of analytical errors that may lead to inaccurate results. The main aim of this work is to point to sources of analytical errors in the preparation process and their relation to physicochemical properties of coenzyme Q10. The article also discusses ways of avoiding and reducing the errors.