Intensive lifestyle intervention program associated with reduced CV risk in overweight/obese adults
Effect of a Lifestyle Intervention Program With Energy-Restricted Mediterranean Diet and Exercise on Weight Loss and Cardiovascular Risk Factors: One-Year Results of the PREDIMED-Plus TrialLiterature - Salas-Salvadó J, Diaz-López A, Ruiz-Canela M et al. - Diabetes Care 2018: published online ahead of print
Introduction and methods
Moderate weight loss through lifestyle intervention (5-10% of initial body weight) is associated with improvement of cardiometabolic abnormalities in overweight/obese individuals [1,2] and reduction in risk of type 2 diabetes . However, the long-term cardiovascular impact of weight loss has never been demonstrated in randomized clinical trials (RCTs).
This sub-analysis of the parallel-group, multicenter, randomized PREvención con DIeta MEDiterránea (PREDIMED)-Plus trial assessed the 12-month effects of an intensive lifestyle intervention on weight loss, adiposity markers, and intermediate markers of CV risk, including overweight/obese (BMI ≥27 and <40 kg/m²) individuals (aged 55-75 years) with metabolic syndrome (MetS) who were randomized 1:1 to receive either the intervention (intervention group [IG]; n=327) or usual care (control group [CG]; n=299). Subjects with a history of CVD were excluded, leaving a study sample of 626 participants.
The lifestyle intervention consisted of an energy restricted Mediterranean diet (erMedDiet), physical activity (PA) promotion, and behavioral support. Questionnaires were used to assess self-reported adherence to the erMedDiet, food frequency, and physical activity.
The primary endpoint was between-group differences in weight loss at 6 and 12 months of intervention. Weight-related secondary endpoints at 6 and 12 months were the between-group differences in the proportions of participants who had either a stable weight or weight below baseline values, those who lost at least 5% or 10% of their initial weight, and those reversing obesity (changing BMI from ≥30 to <30kg/m²).
Compliance with dietary and lifestyle interventions
- At 6 and 12 months, participants in the IG reported a significantly greater achievement in 10/17 items of the questionnaire of adherence to the erMedDiet, with a net increase of two points, compared to the CG at 12 months (3.7 vs. 1.6 points, P<0.001).
- The general food pattern improved significantly in both groups, but the consumption of total cereals and refined cereals improved more in the IG, compared to CG, after 12 months (-34.6 vs. -6.4, P<0.001 and -64.1 vs. -19.7, P<0.001, respectively).
- At 12 months, the IG showed more pronounced reductions in daily energy intake (P=0.05), compared to the CG, with a lower intake of carbohydrates (-4.6% vs. -1.9%, P<0.001) and higher intakes of protein (0.9% vs. -0.01%, P<0.001), total fat (3.6% vs. 2.1%, P=0.01), and monounsaturated fat (4.5% vs. 2.6%, P<0.001).
- In the IG, total leisure time PA was significantly increased at 12 months (361.5-108 METs.min/day), whereas this decreased in the CG (416.4-4.01 METs.min/day) (P=0.001). Proportions of participants meeting recommendations on PA increased in the IG (11.5%), whereas this decreased in CG (-0.7%) at 12 months (P=0.001).
Intention-to-treat analysis: Weight loss and maintenance
- At 6 and 12 months, mean weight losses differed significantly between the IG and CG (6 months: -2.4 [-2.7%] vs. -0.4 kg [-0.5%], P<0.001; 12 months -3.2 [-3.7%] vs. -0.7 kg [-0.8%], P<0.001), with a mean significant difference in weight changes between IG and CG of -2.5 kg (-3.1 to -1.9), which was consistent among subgroups.
- At 6 and 12 months, reductions in BMI were greater in the IG compared to the CG (6 months: -0.9 vs. -0.2 kg/m², P<0.001; 12 months -1.2 vs. -0.3 kg/m², P<0.001), which remained similar after multivariable adjustments.
- Compared to CG, more participants in the IG lost weight below their initial weight at 6 months (81.3% vs. 58.4%, P<0.001) and 12 months (84.1% vs. 57.9%, P<0.001).
- Compared to CG, significantly more participants in the IG attained weight loss of ≥5% (33.7% vs. 11.9%, P<0.001) and ≥10% (6.9% vs. 2.2%, P<0.001) at 12 months.
- Participants in the IG showed a greater reduction in waist circumference than those in the CG at 6 months (-3.0 vs. -0.9 cm, P<0.001) and 12 months (-3.1 vs. -0.7 cm, P<0.001).
- In the IG significant reductions in fasting glucose (-0.23 mmol/L), HbA1c (-1.25 mmol/mol [-0.12%]), insulin (-26.2 pmol/L), and HOMA of insulin resistance (-1.16 in those without insulin treatment [-1.03 in those without diabetes]) were observed after 12 months, whereas no changes were seen in those in the CG.
- At 12 months, IG showed significantly greater improvements in HDL-cholesterol, compared to CG (0.06 vs. 0.0 mmol/L, P<0.001).
- LDL-c decreased in both group, but no between-group differences were observed at 12 months (IG: -0.12 vs. CG: -0.16 mmol/L, P=0.42).
- In participants with diabetes (n=281) improvements in glycemic control (-0.59 vs. 0.22 mmol/L, P<0.001) were observed with the intervention after 12 months, compared to CG.
This study showed clinically meaningful weight loss, high adherence to recommendations, and improvements in MetS components and other intermediate markers of CV risk with the intensive PREDIMED-Plus lifestyle intervention using an erMedDiet, PA promotion, and behavioral support for 12 months in overweight/obese adults with MetS, compared to standard care, after 12 months. Additionally, the interventions resulted in modest improvements in glycemic control, insulin sensitivity, and dyslipidemia in individuals with or at risk for diabetes.