Insulin like Growth Factor 1 and risks of sarcopenia and mortality in patients with cognitive impairment : a multicentric prospective cohort study

Introduction:Insulin like Growth Factor 1 (IGF-1) is an important hormone involved in the neurotrophic synaptic network of cogni- tive functions. We evaluated IGF-1 as an independent risk factor for sarcopenia and mortality in patients with cognitive impairment. Methods:This was a multicentric prospective cohort study of 589 participants with cognitive impairment who enrolled between June 2008 and September 2013. Inclusion criteria were: age>65 years and MMSE<24. Exclusion criteria were: pancreatic and GH-related disorders, acromegaly, recent bone fractures or immobility and cancer. Results: At baseline, the mean (SD) estimated Mini Mental State Examination was 21.3 (5.5), and the median IGF-1 level was 79 ng/mL (interquartile range [IQR], 54.6–185.7 ng/mL). During a median follow-up of 3.7 years (IQR, 2.4–4.7 years), 76 participants died and sarcopenia was diagnosed in 140 patients. In adjusted analyses, low IGF-1 was independently associated with a higher risk of death (hazard ratio [HR], per SD of natural log-transformed IGF-1,1.5; 95% confidence interval [CI], 1.3–1.7). Mortality risk increased by lower quartile of IGF-1: the HR was 2.9 (95%CI, 1.2–4.4) for the first quartile, 2.1 (95%CI, 0.9–3.2) for the second quartile, and 1.5 (95%CI, 0.6–2.3) for the third quartile. Besides, decreased IGF1 was independently associated with significantly higher risk of sarcopenia among participants with MMSE between 9 and 22 (HR,1.2; 95%CI, 1.01–1.9).Conclusions: Low level of IGF-1 seems to be an independent risk factor for sarcopenia and mortality in patients with cognitive impairment.