The impact of different calibration matrices on the determination of insulin-like growth factor 1 by high-resolution-LC-MS in acromegalic and growth hormone deficient patients.

Objectives: Calibration is an important source of variability in liquid chromatography mass spectrometry (LC-MS) methods for insulin-like growth factor 1 (IGF-1). This study investigated the impact of different calibrator matrices on IGF-1 measurements by LC-MS. Moreover, the comparability of immunoassays and LC-MS was assessed.

The relationship between plasma free fatty acids, cognitive function and structural integrity of the brain in middle-aged healthy humans.

Background: The cerebral composition of ω-3 and ω-6 polyunsaturated fatty acids (PUFAs) is believed to influence cognitive function and structural damage of the aging brain. However, existing data is inconsistent.

Materials And Methods: This retrospective study explored the association between free plasma PUFA concentrations, cognitive function and brain structure atrophy in a well-characterized community-dwelling cohort of elderly individuals without stroke and dementia.

Association of vitamin D metabolites with cognitive function and brain atrophy in elderly individuals - the Austrian stroke prevention study.

Background: Vitamin D is a well-established regulator of calcium and phosphate metabolism that has neurotrophic and neuroprotective properties. Deficiency of vitamin D has been proposed to promote cognitive dysfunction and brain atrophy. However, existing studies provide inconsistent results.

Simultaneous determination of 24,25- and 25,26-dihydroxyvitamin D3 in serum samples with liquid-chromatography mass spectrometry - A useful tool for the assessment of vitamin D metabolism.

Vitamin D status is typically assessed by the measurement of 25-hydroxyvitamin D (25(OH)D). However, in selected patient groups the sole determination of 25(OH)D has been proven insufficient for this purpose. The simultaneous measurement of additional vitamin D metabolites may provide useful information for a better evaluation of the vitamin D status.