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Serum IGF-1 Concentration (serum + igf-1_concentration)

Distribution by Scientific Domains

Medical Sciences	50%

Selected Abstracts

Long-term effects of calorie or protein restriction on serum IGF-1 and IGFBP-3 concentration in humans

AGING CELL, Issue 5 2008
Luigi Fontana
Summary Reduced function mutations in the insulin/IGF-I signaling pathway increase maximal lifespan and health span in many species. Calorie restriction (CR) decreases serum IGF-1 concentration by ~40%, protects against cancer and slows aging in rodents. However, the long-term effects of CR with adequate nutrition on circulating IGF-1 levels in humans are unknown. Here we report data from two long-term CR studies (1 and 6 years) showing that severe CR without malnutrition did not change IGF-1 and IGF-1 : IGFBP-3 ratio levels in humans. In contrast, total and free IGF-1 concentrations were significantly lower in moderately protein-restricted individuals. Reducing protein intake from an average of 1.67 g kg,1 of body weight per day to 0.95 g kg,1 of body weight per day for 3 weeks in six volunteers practicing CR resulted in a reduction in serum IGF-1 from 194 ng mL,1 to 152 ng mL,1. These findings demonstrate that, unlike in rodents, long-term severe CR does not reduce serum IGF-1 concentration and IGF-1 : IGFBP-3 ratio in humans. In addition, our data provide evidence that protein intake is a key determinant of circulating IGF-1 levels in humans, and suggest that reduced protein intake may become an important component of anticancer and anti-aging dietary interventions. [source]

Leptin and ghrelin concentrations and weight loss in Parkinson's disease

ACTA NEUROLOGICA SCANDINAVICA, Issue 4 2010
U. Fiszer
Fiszer U, Micha,owska M, Baranowska B, Woli,ska-Witort E, Jeske W, Jethon M, Pia,cik-Gromada M, Marcinowska-Suchowierska E. Leptin and ghrelin concentrations and weight loss in Parkinson's disease. Acta Neurol Scand: 2010: 121: 230,236. © 2009 The Authors Journal compilation © 2009 Blackwell Munksgaard. Objectives,,, To investigate the role of leptin, ghrelin, GH and IGF-1 in energy balance disturbances in Parkinson's disease (PD). Materials and methods,,, Thirty-nine patients were included: 11 PD patients with unintentional weight loss, 16 PD patients without weight loss and 12 controls. UPDRS, MMSE, MADRS, appetite scale, BMI, adipose tissue content, plasma leptin and active ghrelin concentrations and serum GH, IGF-1, TSH, T3 and T4, concentrations were evaluated. Results,,, A lower plasma leptin concentration and a higher serum IGF-1 concentration were found in PD patients with weight loss. BMI and the content of adipose tissue were positively correlated with leptin concentration in all PD patients. Paradoxically, the lower BMI was, the lower plasma active ghrelin concentration was in PD patients with the weight loss. Conclusion,,, These findings confirm that changes of plasma leptin concentration occur in PD patients with loss of weight. [source]

Unmasking of central hypothyroidism following growth hormone replacement in adult hypopituitary patients

CLINICAL ENDOCRINOLOGY, Issue 1 2007
Amar Agha
Summary Background, The effect of GH replacement on thyroid function in hypopituitary patients has hitherto been studied in small groups of children and adults with conflicting results. Objective, We aimed to define the effect and clinical significance of adult GH replacement on thyroid status in a large cohort of GH-deficient patients. Patients and method, We studied 243 patients with severe GH deficiency due to various hypothalamo-pituitary disorders. Before GH treatment, 159 patients had treated central hypothyroidism (treated group) while 84 patients were considered euthyroid (untreated group). GH dose was titrated over 3 months to achieve serum IGF-1 concentration in the upper half of the age-adjusted normal range. Serial measurements of serum T4, T3, TSH and quality of life were made at baseline and at 3 and 6 months after commencing GH replacement. Results, In the untreated group, we observed a significant reduction in serum T4 concentration without a significant increase in serum T3 or TSH concentration; 30/84 patients (36%) became hypothyroid and needed initiation of T4 therapy. Similar but lesser changes were seen in the treated group, 25 of whom (16%) required an increase in T4 dose. Patients who became hypothyroid after GH replacement had lower baseline serum T4 concentration, were more likely to have multiple pituitary hormone deficiencies and showed less improvement in quality of life compared with patients who remained euthyroid. Conclusion, GH deficiency masks central hypothyroidism in a significant proportion of hypopituitary patients and this is exposed after GH replacement. We recommend that hypopituitary patients with GH deficiency and low normal serum T4 concentration should be considered for T4 replacement prior to commencement of GH in order to provide a robust baseline from which to judge the clinical effects of GH replacement. [source]