The Correlation between 25-Hydroxyvitamin D Levels and Testosterone Levels in Type 2 Diabetic Male Patients.

BACKGROUND: Hypovitaminosis D and low testosterone levels are common in men with T2DM, and vitamin D has been proposed to regulate pituitary-testicular function. OBJECTIVE: We investigated the association between testosterone levels and the circulating vitamin D among type 2 diabetic males. METHODOLOGY: We recruited 95 type 2 diabetic males in this cross-sectional study, and investigated the circulating form of vitamin D which is 25-hydroxyvitamin D (25(OH) D). 25(OH) D level <30 ng/mL was used to define vitamin D insufficiency and 25(OH) D level <20 ng/ml defined deficiency. Testosterone deficiency was defined as a total testosterone level less than300 ng/dl. RESULT: Testosterone deficiency prevalence in type 2 diabetic males was 46.3%. Testosterone deficient diabetics had significantly lower 25(OH) D levels than patients with normal testosterone. We observed a higher prevalence of vitamin D deficiency in testosterone deficient diabetics compared with testosterone sufficient patients. Furthermore, significantly lower total testosterone but not LH levels were observed in diabetic males with vitamin D deficiency in comparison to non-deficient patients. We observed that 25(OH) D significantly predicted total testosterone levels in diabetic males evaluated by linear regression analysis. However this association was no longer statistically significant after exclusion of macro-albuminuric patients. Moreover, Vitamin D deficiency was a significant risk factor for testosterone deficiency in logistic regression analysis. CONCLUSION: Testosterone deficient diabetic males had significantly lower 25(OH)D levels and a higher prevalence of vitamin D deficiency in comparison with normal testosterone diabetic males. Likewise, vitamin D deficient patients had lower testosterone levels. Overall, 25(OH) D significantly predicted total testosterone levels. The vitamin D deficiency was thus a significant risk factor for testosterone deficiency in diabetic males.

Different Cabergoline Effect on Metabolic and Anthropometric Parameters in Female Prolactinoma Patients Versus Idiopathic Hyperprolactinemia Patients.

BACKGROUND: Hyperprolactinemia can lead to weight gain, insulin resistance, abnormal glucose homeostasis and dyslipidemia. Reversibility of these changes after normalization of prolactin with dopamine agonists is still controversial and needs more clarification. OBJECTIVE: We aimed to: 1) evaluate and compare metabolic and anthropometric profile in female with newly diagnosed prolactin-secreting adenoma versus female idiopathic hyperprolactinemic patients; 2) compare the effects of one year cabergoline therapy on the metabolic profile and anthropometric parameters (by using visceral adiposity index as index for evaluation of adipose tissue dysfunction) in females with prolactinoma to female idiopathic hyperprolactinemic patients. PATIENTS AND METHODS: We enrolled 40 female patients with newly diagnosed prolactinoma and 40 female patients with idiopathic hyperprolactinemia, who were matched according to: age; weight; BMI; waist; and prolactin levels. We enrolled the participants in this study at the time of diagnosis before therapy and they were followed up for 12 months. RESULTS: Cabergoline therapy had significant favorable effects on metabolic and anthropometric parameters, visceral adiposity index and in all patients (apart from HDLc in prolactinoma patients). Cabergoline therapy was significantly more effective in patient with idiopathic hyperprolactinemia than prolactinoma patients with regard to BMI, waist circumference, HDLc and visceral adiposity index despite normalization of prolactin levels in both groups. CONCLUSION: 12 months of Cabergoline treatment improved most of the anthropometric and metabolic parameters, and visceral adiposity index as a marker for adipose tissue dysfunction in both idiopathic hyperprolactinemia and prolactinoma patients. However, Cabergoline treatment was more effective in idiopathic hyperprolactinemic than prolactinoma patients.

25-hydroxyvitamin D Correlation with Prolactin Levels and Adenoma Size in Female Patients with Newly Diagnosed Prolactin Secreting Adenoma.

OBJECTIVE: The present research explored the relationship of vitamin D status with prolactin levels and adenoma size in female patients with newly diagnosed prolactinoma and determination of hypovitaminosis D prevalence among female patients with prolactinoma. PATIENTS AND METHODS: We enrolled 67 female patients with newly diagnosed prolactinoma (41 with micro adenoma and 26 with macro adenoma) in this case-control study at the time of presentation. We selected 45 female subjects as a control group who were matched according to age, weight, height, body mass index and waist circumference. We investigated 25-hydroxyvitamin D, the major circulating form of vitamin D. RESULTS: Prolactinoma patients had significantly lower 25-hydroxyvitamin D levels in comparison with control subjects. Also, macroadenoma patients showed significantly lower 25-hydroxyvitamin D levels as compared to microadenomoa patients. By contrast, microadenoma patients had nonsignificant lower 25-hydroxyvitamin D levels in comparison with control subjects. Furthermore, we found prolactinoma patients with 25-hydroxyvitamin D >20.00 ng/ml showing significant differences in the prolactin levels and adenoma size when compared with those who had 25- hydroxyvitamin D <20.00 ng/ml. In regression analysis, 25-hydroxyvitamin D level was a significant predictor of adenoma size in patients diagnosed with prolactinoma. CONCLUSION: Female patients with prolactinoma have lower vitamin D levels and have higher prevalence of vitamin D insufficiency and deficiency among prolactinoma patients when compared with normal subjects. Also vitamin D deficiency in prolactinoma patients associated with larger adenoma size and higher prolactin level. Finally, 25-hydroxyvitamin D level was a statistically significant predictor of prolactinoma size but not prolactin levels.