Objective: To investigate the effects of three weight loss interventions on cardiometabolic risk factors, including blood pressure, lipids, glucose and markers of insulin resistance and inflammation. We also examined whether categories of incremental weight change conferred greater improvements on these parameters.
Methods: This 2-year trial was conducted in a primary care setting and included 390 obese participants who were randomly assigned to one of three interventions: (1) Usual Care (quarterly primary care provider (PCP) visits that included education about weight management); (2) Brief Lifestyle Counseling (quarterly PCP visits plus monthly behavioral counseling provided by a trained auxiliary health-care provider); or (3) Enhanced Brief Lifestyle Counseling (the same care as described for the previous intervention, plus weight loss medications or meal replacements). The primary outcome was change in cardiometabolic risk factors among groups.
Results: At month 24, participants in Enhanced Brief Lifestyle Counseling lost significantly more weight than those in Usual Care (4.6 vs 1.7 kg), with no other significant differences between groups. Enhanced Brief Lifestyle Counseling produced significantly greater improvements in high-density lipoprotein (HDL) cholesterol and triglyceride levels at one or more assessments, compared with the other two interventions. Markers of insulin resistance also improved significantly more in this group throughout the 2 years. Collapsing across the three groups, greater weight loss was associated with greater improvements in triglycerides, HDL cholesterol and markers of insulin resistance and inflammation at month 24, but was not significantly associated with reductions in blood pressure, total cholesterol and low-density lipoprotein cholesterol at any time.
Conclusions: Enhanced Brief Lifestyle Counseling, which produced the largest weight loss, was generally associated with the greatest improvements in cardiovascular risk factors. These findings suggest that an intensive weight loss intervention, delivered in a primary care setting, can help obese individuals improve some cardiometabolic risk factors.