Insulin and body weight but not hyperandrogenism seem involved in seasonal serum 25-OH-vitamin D3 levels in subjects affected by PCOS

Abstract

PCOS patients were frequently characterized by lower plasma vitamin D levels. The mechanisms involved in this dysfunction remains still debated, therefore we evaluated the role of androgen, insulin and body weight on the serum VitD levels in women with or without PCOS. Eighty one patients 18–42 yrs old were studied into “SUMMER” and “WINTER” seasonal period: thirty seven PCOS, seventeen no-ovarian hyperandrogenic (noPCOS), twelve functional hypothalamic amenorrhea (FHA) and finally fifteen healthy (Con). Patients were further divided into: lean (L), obese (O), normo- (nINS) and hyperinsulinemic (hINS). All hormonal and metabolic parameters were measured at 1-7 days of the menstrual cycle. Our results show that VitD levels were lower in PCOS and in noPCOS than in FHA and Con, in particular in (O) and (hINS) PCOSs. Both in summer and in winter, PCOSs had basal VitD levels significantly lower than FHA and Con, whereas they were similar to noPCOS. Yet, LhINS and OPCOS had VitD levels lower than Con and noPCOS. VitD levels were comparable in LnINS PCOS and Con. In conclusion, PCOSs had levels of VitD lower than controls. Weight and hyperinsulinemia had a significant influence on these values. Finally, over 70% of our healthy patients had VitD deficiency.

Chinese abstract

多囊卵巢综合征（PCOS）患者常有的特征是较低的血浆维生素D3浓度。这种功能异常的作用机制仍有争议，因此在伴或不伴PCOS妇女中，我们将雄激素、胰岛素及体重对血浆维生素D水平的影响进行了评估。我们研究了81例年龄在18-42岁患者“夏季”和“冬季”的季节性周期：其中37例PCOS患者、17例无高雄激素血症的PCOS患者（noPCOS）、12例下丘脑性闭经（FHA）患者和15例健康患者（对照组）。这些患者被进一步分为瘦型（L）、肥胖型（O）、胰岛素正常型（nINS）和高胰岛素型（hINS）。所有激素和代谢参数都是在月经第1-7天测量。结果显示与FHA和对照组相比，PCOS和noPCOS尤其是肥胖型和高胰岛素型维生素D水平较低。在夏冬两季，PCOS患者基础维生素D水平明显低于FHA组和对照组而与noPCOS组相似，而肥胖型PCOS组和瘦型高胰岛素组维生素D水平明显低于对照组和无高雄激素血症的PCOS组。瘦型胰岛素正常组与对照组维生素D水平相似。结论：PCOS患者维生素D水平低于控制组。体重和高胰岛素水平明显影响这些参数。最终，有超过70%的健康患者存在维生素D缺乏。

• Hyperandrogenism
• insulin
• PCOS
• seasonal variation
• vitamin D
• weight

Acknowledgements

We kindly thank Mrs Barbara Martin, Mrs Mariangela Auleta, Mrs Sonia Leandri and Mr Flaviano Favaro for their expert nursing and technical assistance. We also kindly thank Dr. Monica Fontana Faughnan for her useful assistance with scientific English.