Vitamin D deficiency in type 2 diabetic patients with hypogonadism.
BACKGROUND
Both type 2 diabetes and secondary hypogonadism may be associated with low vitamin D levels.


OBJECTIVE
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.


METHODS
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.
Unit of Endocrinology and Metabolic Diseases, Department of Medical, Surgical, Neurological, Metabolic and Geriatric Sciences, Second University of Naples, Naples, Italy.
Giuseppe
G
Bellastella
Maria Ida
MI
Maiorino
Laura
L
Olita
Annalisa
A
Capuano
Concetta
C
Rafaniello
Dario
D
Giugliano
Katherine
K
Esposito
D016022:Case-Control Studies; D003924:Diabetes Mellitus, Type 2 / Q000453:epidemiology*; D007172:Erectile Dysfunction / Q000453:epidemiology; D006442:Glycated Hemoglobin / Q000032:analysis; D006801:Humans; D007006:Hypogonadism / Q000453:epidemiology*; D008297:Male; D008875:Middle Aged; D015995:Prevalence; D013739:Testosterone / Q000097:blood; D014807:Vitamin D / Q000031:analogs & derivatives / Q000097:blood; D014808:Vitamin D Deficiency / Q000453:epidemiology*
D006442:Glycated Hemoglobin; D013739:Testosterone; D014807:Vitamin D; C104450:25-hydroxyvitamin D
25-Hydroxyvitamin D; Hypogonadism; Testosterone; Type 2 Diabetes