Serum IGF 1 as Possible Marker for Risk and Early Diagnosis of Parkinson Disease
With a prevalence of about 2% in the population older than 60 years, Parkinson disease (PD) is one of the most common neurodegenerative disorders. Parkinson disease affects the whole brain; however, the typical symptoms (bradykinesia, rigidity, and resting tremor) are caused by a progressive loss of dopaminergic neurons in the substantia nigra (SN). In view of a steadily increasing life expectancy, new strategies are warranted to protect neurons from early degeneration. Therefore, much effort is put into determining markers to identify individuals at risk to develop PD before the first clear motor symptoms allow clinical diagnosis.
Insulinlike growth factor 1 (IGF-1) is deeply involved in many processes concerning growth and vitality. It is mainly secreted from the liver after stimulation of the somatotropic axis. Serum IGF-1 levels are reduced with increasing age. Several studies have shown that, in patients with PD, serum IGF-1 levels are higher than those in a healthy control population. In earlier studies, increased serum IGF-1 levels in PD were attributed to dopaminergic medication, which is known to induce IGF-1. However, a recent conceptional study demonstrated that serum IGF-1 levels are also elevated in patients who have never received dopaminergic medication. It may therefore be hypothesized that increased serum IGF-1 in early PD might be related to the disease process.
Based on the results of this previous study, researchers set out to (1) determine whether increased serum IGF-1 level is a potential marker for early PD in an independent cohort, (2) assess the association between serum IGF-1 level and motor function in healthy people, and (3) investigate whether serum IGF-1 level may help in the identification of individuals putatively at increased risk for PD. In addition, IGF-1 binding protein 3 (IGFBP-3) was evaluated.
Godau J, Knauel K, Weber K, et al. Serum Insulinlike Growth Factor 1 as Possible Marker for Risk and Early Diagnosis of Parkinson Disease. Arch Neurol 2011;68(7):925-31. Arch Neurol -- Abstract: Serum Insulinlike Growth Factor 1 as Possible Marker for Risk and Early Diagnosis of Parkinson Disease, July 2011, Godau et al. 68 (7): 925
Background: The level of serum insulinlike growth factor 1 (IGF-1) is increased in idiopathic Parkinson disease (PD).
Objectives: To assess whether the (1) IGF-1 level is increased in patients with PD at the time of diagnosis, (2) increased IGF-1 level is related to impaired motor function in healthy individuals, and (3) detection of increased IGF-1 level will help to identify persons at risk for PD.
Design: Cross-sectional cohort study.
Main Outcome Measures: Serum IGF-1 was measured in 15 patients with newly diagnosed untreated PD and 139 healthy elderly individuals. Participants at risk for PD (n = 11) were defined as having altered motor function according to the Unified Parkinson's Disease Rating Scale, Part III (UPDRS-III), and dopaminergic dysfunction as indicated by sonographically determined substantia nigra hyperechogenicity. Results The IGF-1 level was higher in patients with PD compared with healthy participants (P = .004) and inversely correlated with the UPDRS-III score ({rho} = -0.77). The IGF-1 level was not related to motor function in the healthy group. However, there was no significant difference between the IGF-1 level in the at-risk subgroup vs the PD patients (corrected P = .15), and the IGF-1 level was positively correlated with the UPDRS-III score ({rho} = 0.80).
Conclusion: Serum IGF-1 monitoring may be valuable in the diagnosis of PD and for the identification of individuals with a putatively increased risk for PD.
With a prevalence of about 2% in the population older than 60 years, Parkinson disease (PD) is one of the most common neurodegenerative disorders. Parkinson disease affects the whole brain; however, the typical symptoms (bradykinesia, rigidity, and resting tremor) are caused by a progressive loss of dopaminergic neurons in the substantia nigra (SN). In view of a steadily increasing life expectancy, new strategies are warranted to protect neurons from early degeneration. Therefore, much effort is put into determining markers to identify individuals at risk to develop PD before the first clear motor symptoms allow clinical diagnosis.
Insulinlike growth factor 1 (IGF-1) is deeply involved in many processes concerning growth and vitality. It is mainly secreted from the liver after stimulation of the somatotropic axis. Serum IGF-1 levels are reduced with increasing age. Several studies have shown that, in patients with PD, serum IGF-1 levels are higher than those in a healthy control population. In earlier studies, increased serum IGF-1 levels in PD were attributed to dopaminergic medication, which is known to induce IGF-1. However, a recent conceptional study demonstrated that serum IGF-1 levels are also elevated in patients who have never received dopaminergic medication. It may therefore be hypothesized that increased serum IGF-1 in early PD might be related to the disease process.
Based on the results of this previous study, researchers set out to (1) determine whether increased serum IGF-1 level is a potential marker for early PD in an independent cohort, (2) assess the association between serum IGF-1 level and motor function in healthy people, and (3) investigate whether serum IGF-1 level may help in the identification of individuals putatively at increased risk for PD. In addition, IGF-1 binding protein 3 (IGFBP-3) was evaluated.
Godau J, Knauel K, Weber K, et al. Serum Insulinlike Growth Factor 1 as Possible Marker for Risk and Early Diagnosis of Parkinson Disease. Arch Neurol 2011;68(7):925-31. Arch Neurol -- Abstract: Serum Insulinlike Growth Factor 1 as Possible Marker for Risk and Early Diagnosis of Parkinson Disease, July 2011, Godau et al. 68 (7): 925
Background: The level of serum insulinlike growth factor 1 (IGF-1) is increased in idiopathic Parkinson disease (PD).
Objectives: To assess whether the (1) IGF-1 level is increased in patients with PD at the time of diagnosis, (2) increased IGF-1 level is related to impaired motor function in healthy individuals, and (3) detection of increased IGF-1 level will help to identify persons at risk for PD.
Design: Cross-sectional cohort study.
Main Outcome Measures: Serum IGF-1 was measured in 15 patients with newly diagnosed untreated PD and 139 healthy elderly individuals. Participants at risk for PD (n = 11) were defined as having altered motor function according to the Unified Parkinson's Disease Rating Scale, Part III (UPDRS-III), and dopaminergic dysfunction as indicated by sonographically determined substantia nigra hyperechogenicity. Results The IGF-1 level was higher in patients with PD compared with healthy participants (P = .004) and inversely correlated with the UPDRS-III score ({rho} = -0.77). The IGF-1 level was not related to motor function in the healthy group. However, there was no significant difference between the IGF-1 level in the at-risk subgroup vs the PD patients (corrected P = .15), and the IGF-1 level was positively correlated with the UPDRS-III score ({rho} = 0.80).
Conclusion: Serum IGF-1 monitoring may be valuable in the diagnosis of PD and for the identification of individuals with a putatively increased risk for PD.