D. Determine Presence of Obesity-Associated Health Conditions that Increase Risk

objective

Identify patients who are overweight and who will benefit from weight loss treatment.

background

Several clinical practice guidelines (including the VA/DoD guidelines) for the management of chronic diseases recommend lifestyle interventions to promote weight loss in all patients with hypertension, type 2 diabetes, or dyslipidemia.  Weight loss has been shown to directly favorably affect outcomes.  Aggressive treatment of these conditions in patients who are overweight will likely result in the greatest benefit.

The decision of which overweight patients to treat is multifaceted.  In formulating this guideline and considering the reality of limited resources, the Working Group determined treatment priorities by stratifying patients according to their risk of disease.  While many medical comorbid conditions are beneficially affected by weight reduction, only a few (hypertension, type 2 diabetes, dyslipidemia, metabolic syndrome and obstructive sleep apnea) have strong evidence that weight loss improves these conditions and that therefore intense weight loss treatment is warranted.  (See Table 2)

* For a definition of Metabolic Syndrome, see Annotation L, Table 5

recommendations

1. Weight loss treatment should be offered to overweight patients (BMI 25 – 29.9 kg/m²) with one or more of the obesity-associated conditions that are directly influenced by weight loss (i.e., hypertension, type 2 diabetes, dyslipidemia, metabolic syndrome, obstructive sleep apnea) [B]; or with degenerative joint disease (DJD). [I]

discussion

There is strong evidence that all obese adults (BMI ≥ 30 kg/m²) should receive weight loss treatment; however, the evidence base for the treatment of overweight (BMI 25 - 29.9 kg/m²) is less clearly defined (National Task Force on the Prevention and Treatment of Obesity, 2000).  The controversy stems from a growing body of evidence that indicates that a modest amount of excess body weight may not impair survival or quality of life (Arterburn et al., 2004b; Flegal et al., 2005; National Task Force on the Prevention and Treatment of Obesity, 2000).  Among adults over 65 years of age, the evidence that overweight is an independent risk factor for mortality is particularly weak (Heiat, 2003; Heiat et al., 2001; Zamboni et al., 2005).  Furthermore, no RCT of weight loss treatment have demonstrated a reduction in mortality in overweight adults (McTigue et al., 2003).  Given this controversy, this guideline does not routinely recommend intensive weight loss treatment for overweight adults who are otherwise healthy.  However, treatment is recommended for overweight adults who have weight-related health conditions for which there is at least grade B evidence that weight loss improves health outcomes.  These conditions include hypertension, dyslipidemia, type 2 diabetes, metabolic syndrome, and obstructive sleep apnea..  Given the current state of the evidence, one can not exclude the possibility that weight loss may improve the health of all overweight adults; therefore, overweight individuals who request assistance with weight loss should also be offered weight loss treatment.  (See Annotation L for a detailed discussion of the supporting evidence).

The Working Group did not find evidence that intensive therapy (i.e., drug therapy) for weight loss directly modifies other vascular conditions such as peripheral vascular disease, abdominal aortic aneurysm, or symptomatic carotid artery disease.  Furthermore, no evidence exists to guide weight loss treatment among overweight adults with other major cardiovascular risk factors that are not directly modifiable by weight loss (i.e., male gender, early family history of CAD, advanced age, tobacco use).  Some providers may deem it reasonable that the presence of these risk factors should warrant a more aggressive approach; however, based on current evidence, the Working Group cannot routinely recommend weight loss treatment for such patients.