The Skinny on Obesity
Posted: May 19 2016

Overview of Obesity: 1,2,3
Obesity is defined as a disease involving an excess amount of body fat.  The terms “overweight” and “obese” are further distinguished by measurement of the Body Mass Index (BMI), a metric that is established using a combination of an individual’s height and weight.  Adults with a BMI between 25 and 29.9 kg/m2 are considered overweight, while adults with a BMI greater than 30 kg/m2 are considered obese.  BMI is currently considered the standard measurement for assessing obesity and is commonly utilized as part of clinical trials in order to identify study participants.  The prevalence of obesity in the U.S. is substantial.  Currently, over one-third of the U.S. adult population is considered obese (78.6 million individuals).  Additionally, obesity affects approximately 17% of children between the ages of 2 and 19 (12.7 million individuals).  There are multiple risk factors associated with the development of obesity.  They include, but are not limited to: 

• Environmental factors – physical inactivity, unhealthy dietary habits
• Diseases – polycystic ovary syndrome, depression, thyroid disorders
 Medications – antipsychotics, anti-epileptics, glucocorticoids
• Lack of sleep
• Age
• Socioeconomic status
• Genetics

Table 1 – BMI Categories for Adults (age 20 and older)

BMI (kg/m2)

Weight Status

Below 18.5

Underweight

18.5-24.9

Normal

25-29.9

Overweight

30-34.9

Obese (Class I)

35-39.9

Obese (Class II)

40 and higher

Extreme Obesity (Class III)

Table 2 – BMI Categories for Children and Adolescents (age 2 - 10)

 

WHO Percentile

Weight Status

At or above the 85th percentile

Overweight

At or above the 95th percentile

Obese

Consequences of Obesity: 4,5,6
In 2013, the American Medical Association officially recognized obesity as a disease state with multiple pathophysiological aspects requiring a range of interventions to advance obesity treatment and prevention.  In regards to mortality, obesity has been linked to a significant reduction in life expectancy.  Results of the Framingham Study demonstrated a decrease in lifespan ranging from three to seven years amongst overweight and obese individuals.  Furthermore, obesity increases the risk of developing a host of serious conditions including diabetes, heart disease, hypertension, dyslipidemia, stroke, osteoarthritis, respiratory problems, and certain cancers.  Lastly, the high prevalence of obesity poses a major economic challenge to the U.S. healthcare system.  In 2008, it was estimated that obesity carried a medical cost (both direct and indirect) of $147 billion.  Additionally, the per capita medical spend has been suggested to be $1,429 more amongst obese individuals compared to those with a normal weight. 

 

Pharmacologic Management of Obesity: 7,8,9,10
Treatment of obesity with prescription medications is only recommended in individuals with a BMI greater than 30 kg/m2 or greater than 27 with particular disease states.  The goal of therapy is to prevent, reverse, or reduce complications associated with obesity.  FDA-approved agents on the market today induce weight loss through a variety of mechanisms.  These mechanisms include appetite suppression, promotion of satiety (a feeling of fullness), and prevention of fat absorption in the gastrointestinal tract.  Side effects vary in severity and are medication class-specific.  Examples include gastrointestinal symptoms, increased heart rate and blood pressure, insomnia, and dry mouth.  Side effects are one of several reasons that utilization of older weight-loss agents has declined over time.  In the past two years the FDA has approved four new agents for the treatment of obesity, some of which possess novel mechanisms of action.   These medications represent a new era of treatment options for patients requiring pharmacotherapy to promote weight loss. Data regarding both the traditional and the newer weight-loss agents are summarized in the table below.   
                             
Table 3 – Anti-Obesity Medications*11,12,13,14,15,16,17,18

Medication

Mechanism of Action

% Weight-Loss**

(approximated)

Average Monthly Cost (AWP)***

Traditional Agents

Xenical, Alli

(orlistat)

Prevents dietary fat absorption

5-17%

$669

Adipex-P

(phentermine)

Appetite suppression/satiety

Limited data available

$17

Tenuate

(diethylpropion)

Appetite suppression/satiety

7%

$29

Bontril

(phendimetrazine)

Appetite suppression/satiety

Limited data available

$15

Didrex

(benzphetamine)

Appetite suppression/satiety

Limited data available

$35

Newly Approved Agents (2012-2016)

Belviq

(lorcaserin)

Promotes satiety

3-4%

$264

Qsymia

(phentermine/topiramate)

Appetite suppression/satiety

5-10%

$250

Contrave

(bupropion/naltrexone)

Unknown

5-8%

$250

Saxenda

(liraglutide)

Appetite suppression

5-7%

$1,385

*Select agents only
**Available clinical trial data are extremely limited for traditional agents because most were approved prior to 1960.  Approximated weight-loss values are derived from a variety of resources, including clinical trials, meta-analyses, and review articles.
***Cost may vary based on patient-specific dosing considerations.

MedTrak’s Cost Management Strategy:

Many of MedTrak’s Plans exclude benefit coverage of anti-obesity agents.  For Plans that choose to include this therapeutic category, MedTrak recommends a Prior Authorization (PA) process.  MedTrak’s Clinical Care Center has developed and implemented evidence-based PA criteria that are designed to promote appropriate utilization of anti-obesity agents.  Criteria have recently been revised to reflect clinical trial data surrounding newly approved medications within this category.  As with all of Medtrak’s programs, the goal of this PA process is to ensure cost-effective utilization of medications while simultaneously supporting optimal health outcomes.  Factors considered during the benefit determination process include:

  • Initial assessment of BMI
  • Assessment of comorbid conditions (e.g. hypertension, diabetes, dyslipidemia)
  • Weight-loss achieved during initial period of therapy (typically 4 months)
  • Ongoing assessment of further weight-loss achieved at defined intervals 

 

References:

  1. Bray G.  Obesity in adults: Overview of management.  UpToDate, Waltham, MA.  http://www.uptodate.com  Accessed May 9, 2016
  2. Klish W.  Definition; epidemiology; and etiology of obesity in children and adolescents.  UpToDate, Waltham, MA.  http://www.uptodate.com  Accessed May 9, 2016
  3. Overweight and Obesity.  Centers for Disease Control and Prevention.  http://www.cdc.gov/Obesity/.  Accessed May 9, 2016
  4. Overweight and Obesity statistics. National Institute of Diabetes and Digestive and Kidney Diseases http://www.niddk.nih.gov/health-information/health-statistics/Pages/overweight-obesity-statistics.aspx. Accessed May 9, 2016
  5. Recognition of Obesity as a Disease (Policy H-440.842).  American Medical Association.  https://ssl3.ama-assn.org/apps/ecomm/PolicyFinderForm.pl?site=www.amaassn.org&uri=%2fresources%2fhtml%2fPolicyFinder%2fpolicyfiles%2fHnE%2fH-440.842.HTM.  Accessed May 9, 2016
  6. Finkelstein E, et al.  Annual Medical Spending Attributable to Obesity: Payer-And-Service-Specific Estimates.  Health Affairs.  2009; 28(5): w822-w831
  7. Bray G.  Obesity in adults: Health Hazards.  UpToDate, Waltham, MA.  http://www.uptodate.com  Accessed May 9, 2016
  8. Bray G, Ryan D.  Update on obesity pharmacotherapy.  Annals of the New York Academy of Sciences.  2014; 1311: 1-13
  9. Graham M, Lindsey C.  Overweight and Obesity.  In:  Dipiro, et al.  Pharmacotherapy.  7th ed.  New York:  McGraw Hill; 2008: 1529-1538
  10. Joo J, Lee K.  Pharmacotherapy for Obesity.  Journal of Menopausal Medicine.  2014; 20(3): 90-96
  11. Huizinga M.  Weight-Loss Pharmacotherapy:  A Brief Review.  Clinical Diabetes.  2007; 25(4): 135-140
  12. Belviq Prescribing Information.  Woodcliff Lake, NJ.  Eisai, Inc.  Accessed May 9, 2016
  13. Qsymia Prescribing Information.  Mountain View, CA.  VIVUS, Inc.  Accessed May 9, 2016
  14. Saxenda Prescribing Information.  Plainsboro, NJ.  Novo Nordisk, Inc.  Accessed May 9, 2016
  15. Contrave Prescribing Information.  La Jolla, CA.  Takeda Pharmaceuticals America, Inc.  Accessed May 9, 2016
  16. Phentermine.  Clinical Pharmacology.  Accessed May 9, 2016
  17. Benzphetamine.  Clinical Pharmacology.  Accessed May 9, 2016
  18. Phendimetrazine.  Clinical Pharmacology.  Accessed May 9, 2016
  19. Diethylpropione.  Clinical Pharmacology.  Accessed May 9, 2016 



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