About the Authors

Nilufer Rahmioglu

Affiliation Department of Twin Research and Genetic Epidemiology, King's College London, London, United Kingdom

Toby Andrew

Affiliation Department of Twin Research and Genetic Epidemiology, King's College London, London, United Kingdom

Lynn Cherkas

Affiliation Department of Twin Research and Genetic Epidemiology, King's College London, London, United Kingdom

Gabriela Surdulescu

Affiliation Department of Twin Research and Genetic Epidemiology, King's College London, London, United Kingdom

Ramasamyiyer Swaminathan

Affiliation Chemical Pathology, Guy's and St Thomas' Hospitals Trust, London, United Kingdom

Tim Spector

Affiliation Department of Twin Research and Genetic Epidemiology, King's College London, London, United Kingdom

Kourosh R. Ahmadi

kourosh.ahmadi@kcl.ac.uk

Affiliation Department of Twin Research and Genetic Epidemiology, King's College London, London, United Kingdom

Competing Interests

The authors have declared that no competing interests exist.

Author Contributions

Conceived and designed the experiments: NR TA TDS KRA. Performed the experiments: NR KRA. Analyzed the data: NR TA KRA. Contributed reagents/materials/analysis tools: LC TDS KRA. Wrote the paper: NR KRA. Helped gathering the questionnaire data from the twins: LC. Preliminary blood sample handling: GS. Performed all the biochemical assays: RS.