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IGF and IGFBP as an index for discrimination between vitamin D supplementation responders and nonresponders in overweight Saudi subjects.
Al-Daghri, NM, Yakout, SM, Wani, K, Khattak, MNK, Garbis, SD, Chrousos, GP, Al-Attas, OS, Alokail, MS
Medicine. 2018;(19):e0702
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Abstract
Vitamin D deficiency is common in the Kingdom of Saudi Arabia (KSA). Therefore, it is significant to recognize which biochemical markers modulate serum 25 hydroxyvitamin D (25(OH)D) in response to vitamin D supplementation in such a population. Our aim was to study the correlation of insulin-like growth factor (IGF) and insulin growth factor binding protein (IGFBP) with serum 25(OH)D in response to vitamin D supplementation in a Saudi population. A total of 199 (89 males/110 females) vitamin D deficient subjects (25(OH)D level <50 nmol/L), aged 40.4 ± 11.4 years, were given vitamin D supplements (50,000 IU/mL every week) for the first 2 months, then twice a month for 2 months, followed by daily 1000 IU in the last 2 months. Fasting blood samples were taken at baseline and 6 months after the final dose of vitamin D. Serum 25(OH)D, IGF-1 and IGF-2, and IGFBPs 2-5 were measured. Vitamin D response was computed for all subjects as the difference in levels of serum 25(OH)D concentration at the end of 6 months compared to baseline. After intervention, serum 25(OH)D concentration significantly increased from 35.6 nmol/L (26.6-43.5) to 61.8 nmol/L (54.8-73.3) in responder subjects (P < .01) and from 35.1 nmol/L (21.2-58.2) to 38.3 nmol/L (25.5-48.3) in nonresponders (P = .13). Subjects with lower baseline serum IGF-II, IGFBP-2, and IGF-1/IGFBP-3 ratio are more sensitive to acute vitamin D status changes. IGF1 and IGF-1/IGFBP-3 ratio significantly increased in all subjects after 6 months (P = .01). Changes in 25(OH)D was significantly associated with changes in IGFBP-2 and IGF-1/IGFBP-3 ratio in responders only. This study proposes that changes in circulating IGF-I and IGFBP-3 are modulated by vitamin D supplementation and can be taken into consideration in investigations involving vitamin D correction. Moreover, increase in serum 25(OH)D and IGF-I/IGFBP-3 molar ratio are more sensitive markers for the response to vitamin D supplementation in Saudi population.
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Endocrine-related causes and consequences of intrauterine growth retardation.
Kanaka-Gantenbein, C, Mastorakos, G, Chrousos, GP
Annals of the New York Academy of Sciences. 2003;:150-7
Abstract
The term intrauterine growth retardation (IUGR) is assigned to newborns born with a birth weight and/or birth length below the tenth percentile for their gestational age. Intrauterine growth retardation is usually due to maternal, fetal factors, or placental insufficiency, while endocrine factors represent just a small minority in its etiology. Main endocrine-related causes of IUGR are disorders in insulin or insulin-like growth factor-I (IGF-I) secretion or action. Newborns with IUGR are at increased risk to develop a metabolic syndrome later in life, namely obesity, arterial hypertension, hypercholesterolemia, cardiovascular disease, impaired glucose tolerance, or diabetes mellitus type 2. This association is the result of the adaptational changes of the fetal endocrine-metabolic mechanisms to the impaired intrauterine milieu to assure survival in the short term. The persistence of these changes after birth can be detrimental in adult life. Furthermore, premature adrenarche, as well as ovarian hyperandrogenism, seem to be associated with IUGR in girls, demonstrating that IUGR may have long-lasting effects on both somatic health and reproductive function. Finally, the intrauterine exposure of the fetus to stressors may affect the individual's ability to face stress in postnatal life. Therefore, if optimization of somatic and psychosocial well-being of the individual is the golden goal of medicine, special attention should be paid to maintain an optimal intrauterine milieu devoid of any stressors with adequate nutrient supply and to reserve ideal psychosocial support to the pregnant woman.