Quantitation of circulating GDF-11 and ß2-MG in aged patients with age-related impairment in cognitive function.

Growth differentiation factor 11 (GDF-11) has been implicated in reverse effects of ageing on the central nervous system of humans. ß2-microglobulin (ß2-MG) has been reported to negatively regulate cognition. However, there is a lot of controversy about the role of GDF-11 and ß2-MG in ageing and cognitive regulation. To examine the involvement of GDF-11 and ß2-MG in the ageing process and cognitive dysfunction, a total of 51 healthy subjects and 41 elderly patients with different degrees of age-related cognitive impairment participated in the study. We measured plasma GDF-11 and ß2-MG levels using ELISA and immunoturbidimetry, respectively. The results were statistically analyzed to evaluate the associations between levels of GDF-11 and ß2-MG, and ageing and cognitive impairments. Circulating GDF-11 levels did not decline with age or correlate with ageing in healthy Chinese males. We did not detect differences in circulating GDF-11 levels amongst the healthy advanced age and four cognitive impairment groups. ß2-MG levels increased with age, but there was no significant difference between healthy elderly males and advanced age males. Increased levels of ß2-MG were observed in the dementia group compared with the healthy advanced age group. Our results suggest that circulating GDF-11 may not exert a protective effect during the ageing process or on cognitive function, and ß2-MG may play a role in ageing and cognitive impairment. However, it is possible that the relatively small sample size in the present study affected the quality of the statistical analysis, and future studies are needed to further validate our findings.