Insulin-like growth factor is associated with Alzheimer's disease in men, but not in women, says a new study. Researchers from France found that low levels of Insulin-like Growth Factor 1 (IGF-1) and Insulin-like Growth Factor Binding Protein-3 (IGFBP-3) are linked to Alzheimer's disease in men.

The IGF-1 receptor pathway is linked to the process of aging in many organisms. Previous studies have shown that IGF-1 protects against the factors that cause Alzheimer's disease. The researchers in the present study analyzed the effect of IGF-1 in the blood and IGFBP-3 and cognitive decline in people.

The study involved 694 elderly participants of which 218 were men. Blood levels of IGF-1 and IGFBP-3 were measured in the participants.

In the study, about 490 people were diagnosed with Alzheimer's disease. The researchers found that the levels of IGF-1 and IGFBP-3 in the blood were associated with Alzheimer's disease in men, but not in women.

"At this time, no curative treatment is available for Alzheimer's disease so focus on modifiable associated factors is of major importance. Our research shows a possible usefulness of IGF-1 in Alzheimer's disease treatment, especially in early stages," said lead author Emmanuelle Duron, MD, PhD, of Broca Hospital in Paris, France.

"Our cross-sectional association does not mean a causal relationship. Our results justify a longitudinal study to evaluate whether circulating IGF-1/IGFBP-3 are predictive of cognitive decline according to gender," said Duron.

The study is published in the Journal of Clinical Endocrinology and Metabolism.