Exp Clin Endocrinol Diabetes 2006; 114(10): 577-583
DOI: 10.1055/s-2006-948308
Article

© J. A. Barth Verlag in Georg Thieme Verlag KG · Stuttgart · New York

Low Serum 25-Hydroxyvitamin D Concentrations are Associated with Insulin Resistance and Obesity in Women with Polycystic Ovary Syndrome

S. Hahn 1 , U. Haselhorst 2 , S. Tan 3 , B. Quadbeck 4 , M. Schmidt 5 , S. Roesler 1 , R. Kimmig 5 , K. Mann 3 , O. E. Janssen 3
  • 1Endokrinologikum Ruhr, Center for metabolic and endocrine diseases, Bochum, Germany
  • 2Laboratory Associates, Recklinghausen, Germany
  • 3Division of Endocrinology, Department of Medicine, University of Duisburg-Essen, Essen, Germany
  • 4Private Practice, Haus der Medizin, Essen, Germany
  • 5Department of Obstetrics and Gynaecology, University of Duisburg-Essen, Essen, Germany
Further Information

Publication History

Received: November 11, 2005 First decision: May 24, 2005

Accepted: June 6, 2006

Publication Date:
19 December 2006 (online)

Abstract

Insulin resistance (IR) and central obesity are common features of the polycystic ovary syndrome (PCOS). Vitamin D is thought to play a role in the pathogenesis of type 2 diabetes by affecting insulin metabolism. The aim of our study was to investigate the effect of 25-hydroxyvitamin D (25-OH-VD) on metabolic parameters and IR in PCOS. In 120 untreated PCOS patients (median age 28 years) levels of 25-OH-VD (radioimmunoassay method provided by DiaSorin), calcium and anorganic phosphate were measured. In addition, endocrine and metabolic variables were evaluated and a glucose tolerance test was performed to assess indices of IR. In the entire PCOS cohort, 25-OH-VD concentrations were negatively correlated with body mass index (r=-0.2765), body fat (r=-0.2490), HOMA-IR (r=-0.1947), hyperinsulinemia (r=-0.1892) and leptin levels (r=-0.2834), and positively correlated with HDL cholesterol (r=0.2630) (all p<0.05). Subgroup analysis of lean, overweight and obese women revealed significant higher 25-OH-VD levels in lean women. Differences remained significant when women were divided according to their 25-OH-VD levels. Women with hypovitaminosis D (<9 ng/ml) had higher mean BMI, indices of IR and leptin levels compared to women with normal serum levels (all p<0.05). Analysis of vitamin D and biochemical endocrine PCOS features revealed a significant correlation only between 25-OH-VD and sex hormone-binding globulin as well as the free androgen index. In conclusion, in PCOS women, low 25-OH-VD levels are associated with obesity and insulin resistance but not with PCOS per se.

References

Correspondence

Susanne Hahn, MD 

Endokrinologikum Ruhr·Center for metabolic and endocrine diseases

Alter Markt 4

44866 Bochum

Phone: +49/2327/96 42 0

Fax: +49/2327/96 42 99

Email: susanne.hahn@endokrinologikum.com