Cardiovascular risk in adult hypopituitaric patients with growth hormone deficiency: is there a role for vitamin D?

Abstract

Hypovitaminosis D represent an environmental risk factors for cardiovascular (CV) disease. To investigate the prevalence of hypovitaminosis D and the correlation between GH/IGF-I deficiency and hypovitaminosis D with CV risk in GH deficiency (GHD) patients. A link between these hormones has been shown. Forty-one hypopituitaric patients with GHD (22 males, age 18-84 years) and 41 controls were enrolled in the study. Anthropometric parameters, blood pressure, glucose and lipid profile, parathyroid hormone (PTH), 25(OH) vitamin D (vitamin D), metabolic syndrome (MS), GH peak after GHRH + ARG, IGF-I, and standard deviation score (SDS) of IGF-I (zIGF-I) were assessed. Vitamin D levels were lower in patients than in controls (21.3 ± 12.3 vs. 28.2 ± 9.4, p = 0.006). Deficiency was found in 51 % of patients versus 14.6 % of controls (p < 0.01), insufficiency in 26.8 versus 41.4 % (p = 0.269) and normal vitamin D levels in 21.9 versus 43.9 % (p = 0.060). The prevalence of dyslipidemia was 51.2 % in patients versus 12.1 % in controls (p < 0.001), type 2 diabetes mellitus (DM) was 7.3 versus 17 % (p = 0.292), hypertension was 44 versus 22 % (p = 0.060), and MS was 17 versus 14.6 % (p = 0.957). In patients, an association was found between the presence of hypovitaminosis D and the prevalence of dyslipidemia, hypertension and MS and between zIGF-I and the prevalence of hypertension. Hypovitaminosis D was the most powerful predictor of the prevalence of dyslipidemia and hypertension. GHD patients have an increased prevalence of hypovitaminosis D compared with controls. The presence of hypovitaminosis D was the most powerful predictor of the prevalence of dyslipidemia and hypertension in GHD patients, suggesting the involvement of both factors in the CV risk in these patients.