Saverio Stranges, MD, PhD; James R. Marshall, PhD; Raj Natarajan, MS; Richard P. Donahue, PhD; Maurizio Trevisan, MD; Gerald F. Combs, PhD; Francesco P. Cappuccio, MD; Antonio Ceriello, MD; Mary E. Reid, PhD
Potential Financial Conflicts of Interest: None disclosed.
Requests for Single Reprints: Saverio Stranges, MD, PhD, Clinical Sciences Research Institute, Warwick Medical School, University Hospital Coventry and Warwickshire, Clifford Bridge Road, Coventry CV2 2DX, United Kingdom; e-mail, firstname.lastname@example.org.
Current Author Addresses: Drs. Stranges, Cappuccio, and Ceriello: Clinical Sciences Research Institute, Warwick Medical School, University Hospital Coventry and Warwickshire, Clifford Bridge Road, Coventry CV2 2DX, United Kingdom.
Drs. Marshall and Reid and Mr. Natarajan: Roswell Park Cancer Institute, Carlton House Building, Elm and Carlton Streets, Buffalo, NY 14263.
Drs. Donahue and Trevisan: Department of Social and Preventive Medicine, State University of New York at Buffalo, South Campus, 3435 Main Street, Farber Hall, Buffalo, NY 14214.
Dr. Combs: Human Nutrition Research Center, U.S. Department of Agriculture, 2420 Second Avenue North, Stop 9034, Grand Forks, ND 58202.
Author Contributions: Analysis and interpretation of the data: S. Stranges, R. Natarajan, R.P. Donahue, M. Trevisan, G.F. Combs, F.P. Cappuccio.
Drafting of the article: S. Stranges, R.P. Donahue, M. Trevisan.
Critical revision of the article for important intellectual content: S. Stranges, R.P. Donahue, M. Trevisan, G.F. Combs, F.P. Cappuccio.
Final approval of the article: S. Stranges, M. Trevisan, F.P. Cappuccio.
Statistical expertise: R. Natarajan, M. Trevisan.
Administrative, technical, or logistic support: G.F. Combs, F.P. Cappuccio.
Collection and assembly of data: G.F. Combs.
Findings from animal models suggest that selenium supplementation improves glucose metabolism.
To examine the effect of long-term selenium supplementation on the incidence of type 2 diabetes.
Secondary analysis of a randomized, double-blind, placebo-controlled trial.
Areas of low selenium consumption of the eastern United States.
1202 persons seen in dermatology clinics who did not have type 2 diabetes at baseline.
Oral administration of selenium, 200 μg/d, or placebo.
Incidence of type 2 diabetes.
During an average follow-up of 7.7 years (SD, 2.7), type 2 diabetes developed in 58 selenium recipients and 39 placebo recipients (incidence, 12.6 cases per 1000 person-years vs. 8.4 cases per 1000 person-years, respectively; hazard ratio, 1.55 [95% CI, 1.03 to 2.33]). The lack of benefit of selenium supplementation on the incidence of type 2 diabetes persisted in analyses stratified by age, sex, body mass index, and smoking status. An exposure–response gradient was found across tertiles of baseline plasma selenium level, with a statistically significantly increased risk for type 2 diabetes in the highest tertile of baseline plasma selenium level (hazard ratio, 2.70 [CI, 1.30 to 5.61]).
Diabetes was a secondary outcome in the parent trial. Diagnoses of diabetes were self-reported but were validated in most participants. The sample was mostly older and white.
Selenium supplementation does not seem to prevent type 2 diabetes, and it may increase risk for the disease.
Research suggests that selenium supplements may improve glucose metabolism.
The investigators examined the incidence of type 2 diabetes among participants in a clinical trial designed to assess the effects of selenium supplementation on skin cancer. Participants randomly assigned to receive selenium were more likely to develop type 2 diabetes than were those assigned to placebo.
Diabetes was a secondary outcome of the original trial. The diagnosis was self-reported, and most participants were older and white.
Long-term selenium supplementation appears to increase the risk for type 2 diabetes.
Mean plasma selenium levels.
Flow diagram of the Nutritional Prevention of Cancer Trial, 1983–1996.
Table 1. Baseline Characteristics
Cumulative incidence of type 2 diabetes.P
Table 2. Incidence of Type 2 Diabetes
Table 3. Incidence of Type 2 Diabetes, by Baseline Plasma Selenium Level
The In the Clinic® slide sets are owned and copyrighted by the American College of Physicians (ACP). All text, graphics, trademarks, and other intellectual property incorporated into the slide sets remain the sole and exclusive property of the ACP. The slide sets may be used only by the person who downloads or purchases them and only for the purpose of presenting them during not-for-profit educational activities. Users may incorporate the entire slide set or selected individual slides into their own teaching presentations but may not alter the content of the slides in any way or remove the ACP copyright notice. Users may make print copies for use as hand-outs for the audience the user is personally addressing but may not otherwise reproduce or distribute the slides by any means or media, including but not limited to sending them as e-mail attachments, posting them on Internet or Intranet sites, publishing them in meeting proceedings, or making them available for sale or distribution in any unauthorized form, without the express written permission of the ACP. Unauthorized use of the In the Clinic slide sets will constitute copyright infringement.
A study found that selenium supplements are not effective in reducing the risk of type 2 diabetes, and in fact increase the risk of developing the disease.
Stranges S, Marshall JR, Natarajan R, Donahue RP, Trevisan M, Combs GF, et al. Effects of Long-Term Selenium Supplementation on the Incidence of Type 2 Diabetes: A Randomized Trial. Ann Intern Med. 2007;147:217–223. doi: 10.7326/0003-4819-147-4-200708210-00175
Download citation file:
Published: Ann Intern Med. 2007;147(4):217-223.
Cardiology, Coronary Risk Factors, Diabetes, Endocrine and Metabolism.
Results provided by:
Copyright © 2018 American College of Physicians. All Rights Reserved.
Print ISSN: 0003-4819 | Online ISSN: 1539-3704
Conditions of Use