Scenario: A 45 year old male with a BMI of 32 presents to his primary care physician. What
intervention should be suggested to him to reduce his BMI? Should only
behavioral modification be adequate or should orlistat be added to it?
Leblanc ES, O'Connor E, Whitlock EP, Patnode CD, & Kapka T (2011). Effectiveness of primary care-relevant treatments for obesity in adults: a systematic evidence review for the u.s. Preventive services task force. Annals of internal medicine, 155 (7), 434-47 PMID: 21969342
Evidence: A
recent study titled “Effectiveness of Primary Care–Relevant Treatments forObesity in Adults: A Systematic Evidence Review for the U.S. PreventiveServices Task Force" published in the Annals of Internal Medicine looks into
the evidence.
The study tried to answer 4 key questions –
- Is there direct evidence that primary care screening programs for adult obesity or overweight improve health outcomes or result in short-term (12 to 18 mo) or sustained (>18 mo) weight loss or improved physiologic measures? a) How well is weight loss maintained after an intervention is completed?
- Do primary care–relevant interventions (behaviorally based interventions and/or pharmacotherapy) in obese or overweight adults lead to improved health outcomes? a) What are common elements of efficacious interventions? b) Are there differences in efficacy between patient subgroups (i.e., age 65 y or older, sex, race/ethnicity, degree of obesity, baseline cardiovascular risk)?
- Do primary care–relevant interventions in obese or overweight adults lead to short-term or sustained weight loss, with or without improved physiologic measures? a) How well is weight loss maintained after an intervention is completed? b) What are common elements of efficacious interventions? c) Are there differences in efficacy between patient subgroups (i.e., age 65 y or older, sex, race/ethnicity, degree of obesity, baseline cardiovascular risk)?
- Do primary care–relevant interventions in obese or overweight adults lead to short-term or sustained weight loss, with or without improved physiologic measures? a) How well is weight loss maintained after an intervention is completed? b) What are common elements of efficacious interventions? c) Are there differences in efficacy between patient subgroups (i.e., age 65 y or older, sex, race/ethnicity, degree of obesity, baseline cardiovascular risk)?
Outcome: The
first key question remains unanswered as the authors were unable to identify any
study comparing screening vs non-screening of obese individuals.
The second, third and fourth key questions were answered.
The summary –
Behavioral
interventions
Parameter
|
Outcome
|
Weight Loss
|
Weighted mean difference in mean weight change between behavioral intervention
and control group is -3.01 kg 95% CI (-4.02 to -2.01) at 12 to 18 months.
Behavioral interventions lasting longer continued to show weight loss. Weight
los was maintained up to a year following active intervention phase.
|
Mortality
|
No difference in death rate but limited by small number of
trials.
|
Cardiovascular disease
|
No difference in CVD events or CVD related deaths in 3
large good quality trials
|
Hospitalization
|
No difference, limited by low hospitalization rate.
|
Health related quality
of life/depression
|
No difference in depression, small favorable change of
health related quality of life with weight loss
|
Incidence of
diabetes mellitus
|
Weight loss of 4 to 7 kg reduced diabetes incidence by 50%
or more over 2 to 3 years.
|
Glucose tolerance
|
Mean decrease in glucose level = 0.30 mmol/L (5.4 mg/dL)
|
Lipids
|
Weighted mean difference in LDL cholesterol level between treatment
and control group = -4.94 mg/dL 95%CI (-7.32 to -2.56)
|
Blood pressure
|
Weighted mean difference in mean change in blood pressure between
treatment and control group = -2.48 mmHg 95%CI (-3.25 to -1.71)
|
Waist circumference
|
-2.7 cm 95%CI( -4.1 to 1.4)
|
Adverse effects
|
None
|
Orlistat (Note-
Almost all the trials of orlistat had simultaneous behavioral interventions)
Parameter
|
Outcome
|
Weight Loss
|
Weighted mean difference between behavioral intervention
and control group is -2.98 kg 95% CI (-3.92 to -2.05).
|
Mortality
|
There were 4 studies which reported this outcome. Each
study reported 1 death in in the orlistat group, but no clear relationship
with treatment.
|
Cardiovascular disease
|
Not reported.
|
Hospitalization
|
Not reported.
|
Health related quality
of life/depression
|
No difference in depression, Orlistat had greater satisfaction
with treatment, less overweight distress and improvement in the vitality
subscale of SF – 36.
|
Incidence of
diabetes mellitus
|
Decreased incidence by 9-10% but concerns regarding
generalizability and reliability.
|
Glucose tolerance
|
Mean decrease in glucose level = 0.31 mmol/L (5.5 mg/dL).
Glucose reductions are greater in orlistat than placebo possibly because they
were conducted in diabetic patients.
|
Lipids
|
Weighted mean difference in LDL cholesterol level between treatment
and control group = -11.37 mg/dL 95%CI (-15.75 to -7.00)
|
Blood pressure
|
Weighted mean difference in mean change in blood pressure between
treatment and control group = -2.04 mmHg 95%CI (-2.97 to -1.11)
|
Waist circumference
|
-2.3 cm 95%CI( -3.6 to -0.9)
|
Adverse effects
|
Gastrointestinal symptoms of mild to moderate intensity
which resolves spontaneously, liver injury, vitamin E and K deficiency,
increased incidence of hypoglycemia.
|
The authors also examined metformin which had modest effects
on weight loss -2.85 kg 95%CI (-3.52 to -2.18).
Comment
The behavioral interventions included counseling regarding
the importance of diet and exercise. There the interventions were not described
fuly in the study. There was variability in the methods employed for behavioral
modifications in the between the studies. On the other hand, orlistat studies
had high attrition rate and were mostly funded by pharmaceutical companies.
Bottom line
In the primary care setting, behavioral intervention is
effective and safe and should be considered as a first line therapy for weight
loss. Orlistat may be added later. There are significant adverse effects associated
with orlistat. Metformin may be tried in diabetics.