Níveis séricos de vitamina D e metabolismo do cálcio em indivíduos com deficiência isolada, congênita e vitalícia do hormônio do crescimento

Abstract

Introduction: Cutaneous vitamin D production and phosphocalcium homeostasis are important for bone health. GH/IGF-I axis plays important effects on phosphocalcium homeostasis. Reduced bone mineral density (BMD) and thin skin are described in panhypopituitarism and may not be attributed only to GH deficiency (GHD). We described a cohort of isolated GHD (IGHD) in Itabaianinha/SE due to a homozygous mutation (c.57 + 1G> A) in the GH releasing hormone receptor gene. Such individuals exhibit a discrepancy between bones (normal volumetric BMD and absence of fragility fractures) and skin (wrinkled, thin, and poorly pigmented). We decided to evaluate the metabolism of calcium and vitamin D in this population. Materials and methods: Cross-sectional study with 20 IGHD subjects (11 men, 49.5±13.4 years) and 20 controls (11 men, 48.9±13.6 years). Results: Individuals with DIGH had lower height [1.3±0.1 vs. 1.6± 0.1 m p<0.0001], weight [40.6±6.4 vs. 77.8±15.0 kg p<0.0001], IGF-I [29.1±6.6 vs. 162±30.5 ng/mL p<0.0001] and urinary volume [686.0±312.1 vs. 1082.0±506.6 mL p=0.006], with no discrepancy in 25(OH)D [30.2±8.6 vs. 31.26±7.5 ng/mL], PTH [56.8±22.0 vs. 57.5±20.8 pg/mL], calcium [10.0±0.3 vs. 11.0±0.5 mg/dL], alkaline phosphatase [189.8±70.8 vs. 169.2±47.6 U/L], phosphorus [3.8±0.5 vs. 3.6±0.4 mg/dL], serum albumin [3.8±0.5 vs. 4.4±0.5 g/dL] and calcium urinary levels corrected by weight [1.2±1.2 vs. 1.6±1.0 mg/kg]. Conclusions: Individuals with congenital IGHD did not show abnormalities in levels of vitamin D, PTH and phosphocalcium homeostasis. In addition, there was no difference in the proportion of vitamin D sufficiency and in the proportion neither of insufficiency nor of deficiency in both group