Vitamin D Deficiency in Type 2 Diabetic Patients with Hypogonadism
Bellastella G, Maiorino MI, Olita L, Capuano A, Rafaniello C, Giugliano D, Esposito K. J Sex Med. 2013 Nov 18. doi: 10.1111/jsm.12384. [Epub ahead of print]


Unit of Endocrinology and Metabolic Diseases, Department of Medical, Surgical, Neurological, Metabolic and Geriatric Sciences, Second University of Naples, Naples, Italy.


INTRODUCTION: Both type 2 diabetes and secondary hypogonadism may be associated with low vitamin D levels.

AIM: The aim of this study was to evaluate 25-hydroxyvitamin D (25(OH)D) concentrations in type 2 diabetic males with and without hypogonadism.

METHODS: We performed a case-control study among 122 male adults with type 2 diabetes, 51 with associated hypogonadism (Group 1) and 71 with normal gonadal function (Group 2). One hundred age-matched nondiabetic males with normal gonadal function served as a control group.

MAIN OUTCOME MEASURES: Levels of 25(OH)D were assessed by a chemiluminescent immunoassay in all patients. Morning testosterone, pituitary, thyroid, parathyroid hormones, fasting glucose, and hemoglobin A1c were also evaluated.

RESULTS: The overall diabetic population showed a mean 25(OH)D concentration (22.3 ± 6.09 ng/mL) significantly lower than the control group (34.3 ± 7.2, P < 0.001), with 81% of diabetic patients presenting 25(OH)D deficiency (<20 ng/mL) or insufficiency (20-29.9 ng/mL). The lowest 25(OH)D concentration was found in Group 1 (20.1 ± 6.58 ng/mL). Concentration of 25(OH)D was significantly lower in the 42 patients with hypogonadotropic hypogonadism as compared with the 9 patients with hypergonadotropic hypogonadism (19.4 ± 7.06 vs. 23.8 ± 6.11 ng/mL, P < 0.001). No difference in erectile dysfunction (ED) prevalence between Group 1 and Group 2 was found, nor was there a correlation between the severity of ED and vitamin D levels (r = -0.10, P = 0.39).

CONCLUSIONS: These results show that type 2 diabetic patients with hypogonadism present lower 25(OH)D concentration and higher prevalence of vitamin D deficiency, compared with patients without hypogonadism. The finding that 25(OH)D concentrations were similar between type 2 diabetic patients with hypergonadotropic hypogonadism and those with normal gonadal function deserves further study. Bellastella G, Maiorino MI, Olita L, Capuano A, Rafaniello C, Giugliano D, and Esposito K. Vitamin D deficiency in type 2 diabetic patients with hypogonadism.