Acromegaly(from Greek akros "extreme" or "extremities" and megalos "large" - extremities enlargement) is a syndrome that results when the pituitary gland produces excess growth hormone (hGH) after epiphyseal plate closure. A number of disorders may be affecting the pituitary to create this circumstance, although most commonly it involves a GH producing tumor derived from a distinct type of cells (somatotrophs) and called pituitary adenoma (more than 99% of cases).
Acromegaly is a rare condition with an approximate incidence of 3-4 new cases per million of population per year and a prevalence of 60 per million.
An Association Study Between Gene Polymorphisms of Folic Acid Metabolism Enzymes and Biochemical and Hormonal Parameters in Acromegaly. 2015
Free 25-hydroxyvitamin D [25(OH)D] is suggested to be important in the determination of vitamin D deficiency, since vitamin D-binding protein (VDBP) may affect total 25(OH)D levels. There are no data about free 25(OH)D concentrations in acromegaly. We aimed to investigate serum VDBP and total and free 25(OH)D levels in patients with acromegaly in comparison with control subjects. We recruited 54 patients with acromegaly and 32 control subjects who were similar according to age, gender, and body mass index. Serum VDBP levels were found to be increased in patients with acromegaly compared to control subjects [90.35 (72.45-111.10) vs. 69.52 (63.89-80.13) mg/l, p = 0.001]. There was statistically no significant difference in serum total 25(OH)D levels between the patients with acromegaly and control subjects [18.63 (13.35-27.73) vs. 22.51 (19.20-28.96) ng/ml, p = 0.05]. Free 25(OH)D levels were significantly decreased in patients with acromegaly compared to control subjects [14.55 (10.45-21.45) vs. 17.75 (15.30-23.75) pg/ml, p = 0.03]. Free 25(OH)D levels correlated positively with total 25(OH)D (p = 0.0001) and HDL cholesterol (p = 0.04) and negatively with fasting blood glucose (p = 0.04). Our findings indicate that VDBP is increased and free 25(OH)D is decreased in acromegaly, while there is no significant alteration in total 25(OH)D.
Hormones and immune function: implications of aging. 2004
- However, other hormonal changes that occur with aging and that potentially impact on immune function include the release of the pineal gland hormone melatonin and pituitary growth hormone, adrenal production of dehydroepiandrosterone and tissue-specific availability of active vitamin D.
Localization of a negative vitamin D response sequence in the human growth hormone gene. 2002
- Our results indicate that vitamin D inhibits hGH gene transcription, directly or by interference with other transcription factors.
Vitamin D interferes with transactivation of the growth hormone gene by thyroid hormone and retinoic acid. 1996
Incubation of pituitary GH4C1 cells with nanomolar concentrations of vitamin D markedly reduces the response of the rat growth hormone mRNA to thyroid hormone triiodothyronine (T3) and RA.
A functional common polymorphism in the vitamin D-responsive element of the GH1 promoter contributes to isolated growth hormone deficiency. 2007