January 9, 2013
Volume 8 - Issue 2  

DynaMed Weekly Update

For the week ending January 4, 2013

Last week 482 articles were evaluated via DynaMed's Systematic Literature Surveillance and 182 were added to DynaMed content.   


Based on the editors' criteria of selecting "articles most likely to change clinical practice," one article of significant interest was selected for the DynaMed Weekly Update.

Feature Article

Adults Classified As Overweight May Have Lower Mortality Risk Than Normal Weight Adults 


The question of optimal weight from a health perspective is of great interest to clinicians and patients alike. Results from studies evaluating mortality risks that are based on body mass index (BMI) may be difficult to reconcile with each other due to differing definitions of BMI categories used across studies. A recent systematic review of 97 prospective cohort studies assessed all-cause mortality risk in a population of more than 2.88 million persons using standard of weight classifications as defined by the World Health Organization. Normal weight is defined as BMI 18.5-24.9 kg/m2 and overweight as BMI 25-29.9 kg/m2. Obesity was stratified to 3 classes: class 1 includes BMI 30-34.9 kg/m2, class 2 is BMI 35-39.9 kg/m2, and class 3 is BMI ≥ 40 kg/m2.


During follow-up ranging from 3-42 years, there were more than 270,000 deaths. Compared to normal weight, mortality was significantly reduced in persons who were classified as overweight (hazard ratio 0.94, 95% CI 0.91-0.96) in analysis of 93 studies. There was no significant difference in mortality comparing normal weight to class 1 obesity, but mortality was increased in persons with class 2 or 3 obesity (BMI ≥ 35 kg/m2) (hazard ratio 1.29, 95% CI 1.18-1.41) in analysis of 32 studies. In subgroup analyses of persons ≥ 65 years old, being overweight was again associated with reduced mortality compared to normal weight (hazard ratio 0.9, 95% CI 0.86-0.95), and there were no significant differences in mortality comparing normal weight to any obesity category (JAMA 2013 Jan 2;309(1):71).


Previous research has suggested that mortality is lowest for BMI 22.5-25 kg/m2 and somewhat higher at the lower extreme of "normal" as well as at higher levels (Lancet 2009 Mar 28;373(9669):1083). The reduction in mortality associated with being overweight in the current study may be due, in part, to the wide BMI range considered normal by the WHO classification. Nevertheless, these data suggest that categorizing people as overweight or obese by BMI alone may not provide a valid assessment of health risk.

For more information, see the Obesity in adults and Complications of obesity topics in DynaMed.

Click Here to Earn CME credit Earn Credit for Reading this e-Newsletter

 For more information on this educational activity, see the CME sidebar.
New Topics added to DynaMed this Week 

Ocular histoplasmosis

Call for Peer Reviewers

We are currently seeking reviewers for:   

Acute adrenocortical insufficiency 


Learn more about the DynaMed Contribution Opportunities:

DynaMed Peer Review 

Editorial Policies for Reviewers 

About DynaMed Weekly Update

Prepared by the clinician members of the DynaMed Editorial Team, DynaMed Weekly Update is a compilation of one to five articles selected from DynaMed's Systematic Literature Surveillance as articles most likely to change clinical practice.

DynaMed   EP Point-of-Care Resources

Free Weekly Update Subscription Free Newsletter Subscription

Share with Colleagues

Send CommentsSend Comments




Print Printable View

DynaMed iconDynaMed Free Trial 
CME Information


0.25 AMA PRA Category I Credit(s)™
Family Physicians: 0.25 Prescribed credits
Nurse Practitioners: 0.25 Contact hours
Release Date: January 9, 2013
Expiration Date: January 9, 2014
Estimated Completion Time:
15 minutes
There is no fee for this activity.

To Receive Credit 
In order to receive your certificate of participation, you should read the information about this activity, including the disclosure statements, review the entire activity, take the post-test, and complete the evaluation form. You may then follow the directions to print your certificate of participation. To begin, click the CME icon at the end of the article.

Program Overview

Learning Objectives


Upon successful completion of this educational program, the reader should be able to:


1. Discuss the significance of this article as it relates to your clinical practice.
2. Be able to apply this knowledge to your patient's diagnosis, treatment and management.


Faculty Information
Alan Ehrlich, MD - Assistant Clinical Professor in Family Medicine, University of Massachusetts Medical School, Worcester, Massachusetts, USA; Senior Deputy Editor, DynaMed, Ipswich, Massachusetts, USA

Michael Fleming, MD, FAAFP - Assistant Clinical Professor of Family Medicine and Comprehensive Care, LSU Health Science Center School of Medicine, Shreveport, Louisiana, USA; Assistant Clinical Professor of Family Medicine, Department of Family and Community Medicine, Tulane University Medical School, New Orleans, Louisiana, USA; Chief Medical Officer, Amedisys, Inc. & Antidote Education Company

Dr. Ehrlich, Dr. Fleming, DynaMed Editorial Team members, and the staff of Antidote Education Company have disclosed that they have no relevant financial relationships or conflicts of interest with commercial interests related directly or indirectly to this educational activity.


No commercial support has been received for this activity.

Accreditation Statements

ACCME: This activity has been planned and implemented in accordance with the Essential Areas and policies of the Accreditation Council for Continuing Medical Education through the joint sponsorship of Antidote Education Company and EBSCO Publishing. Antidote is accredited by the ACCME to provide continuing medical education for physicians. Antidote Education Company designates this enduring activity for a maximum of 0.25 AMA PRA Category 1 Credits™. Physicians should only claim credit commensurate with the extent of their participation in the activity.

AAFP: Enduring Material activity, DynaMed Weekly Update, has been reviewed and is acceptable for up to 13 Prescribed credits by the American Academy of Family Physicians. AAFP certification begins March 7, 2012. Term of approval is for one year from this date with the option of yearly renewal. Each Weekly Update is worth .25 Prescribed credits. Physicians should claim only the credit commensurate with the extent of their participation in the activity.


AANP: This program is approved for 0.25 contact hour of continuing education by the American Academy of Nurse Practitioners.


Program ID: 1210392S

Copyright 2010 EBSCO Publishing. All rights reserved.