Related Experiment Video
Updated: Jan 31, 2026
Author Spotlight: Advancing Cellular and Protein Engineering to Control Biological Functions and Develop Novel Therapies
Published on: September 27, 2024
Low Serum IGF-1 in Boys with Recent Onset of Juvenile Idiopathic Arthritis
Anna-Carin Lundell1, Malin Erlandsson1, Maria Bokarewa1
1Department of Rheumatology and Inflammation Research, Institute of Medicine, Sahlgrenska Academy at University of Gothenburg, Sweden.
Background:
Liver-derived insulin-like growth factor-1 (IGF-1) contributes bone formation. Decreased IGF-1 levels are common in juvenile idiopathic arthritis (JIA), but whether IGF-1 is related to sex and differ during the pathogenic progress of JIA is unknown.
Objective:
The aim of this study was to examine IGF-1 levels in boys and girls with newly diagnosed JIA, with established JIA and in controls.
Methods:
The study group included 131 patients from the Estonian population-based prevalence JIA study. Blood samples were obtained from 27 boys and 38 girls with early JIA (≤1 month from the diagnosis), 29 boys and 36 girls with established JIA (mean disease duration 18 months), and from 47 age- and sex-matched controls.
Results:
IGF-1 levels in boys were significantly decreased in early JIA compared to male controls, while IGF-1 levels in girls were comparable between JIA and controls. In early JIA, IGF-1 levels were 12-fold lower in boys relative to girls. In controls, IGF-1 levels correlated with both age and height, while these correlations were lost in boys with early JIA.
Conclusion:
We report a sex-dependent deficiency in serum IGF-1 in boys with early JIA, which argues for sex-related differences in biological mechanisms involved in the disease pathogenesis.
Related Concept Videos
01:30Serum Laboratory Studies, Stool Test, Breath Test
01:24Serum Studies: Renal Function Tests
02:15SN1 Reaction: Stereochemistry
In the first step of an SN1 reaction, the bond between the electrophilic carbon and the leaving group ionizes to generate the carbocation intermediate. The second step of the mechanism is the nucleophilic attack.
In the formed carbocation, the positively charged carbon is sp2 hybridized with a trigonal planar geometry. As all the three substituents lie on the same plane, a plane of symmetry for the...
02:05SN1 Reaction: Kinetics
However, Sir Christopher Ingold and Edward D. Hughes, who studied the kinetics of various nucleophilic substitution reactions, noticed that a tertiary alkyl halide does undergo a nucleophilic substitution reaction in the presence of a weak nucleophile. While studying the substitution...
02:25SN1 Reaction: Mechanism
Firstly, the haloalkane ionizes to generate a carbocation intermediate and a halide ion. This heterolytic cleavage is highly endothermic with large activation energy. The ionization of the substrate, facilitated by a...
02:42Acidity of 1-Alkynes
The acidic strength of hydrocarbons follows the order: Alkynes > Alkenes > Alkanes. The strength of an acid is commonly expressed in units of pKa — the lower the pKa, the stronger the acid. Among the hydrocarbons, terminal alkynes have lower pKa values and are, therefore, more acidic. For example, the pKa values for ethane, ethene, and acetylene are 51, 44, and 25, respectively, as shown here.