Evidence Review Systematic Review of Impact of Lifestyle-Modification Programs on Metabolic Risks and Patient-Reported Outcomes in Adults With Metabolic Syndrome Chia-Huei Lin, MS • Shang-Lin Chiang, MS • Wen-Chii Tzeng, PhD • Li-Chi Chiang, PhD Keywords lifestyle-modification program, metabolic risks, metabolic syndrome, patient-reported outcome, quality of life, systematic review ABSTRACT Background: Metabolic syndrome (MetS) is primarily attributed to an unhealthy lifestyle, which is a modifiable risk factor. Researchers have been exploring various strategies, including lifestyle- modification programs (LMPs), to prevent the progression of MetS. However, the effectiveness of LMPs on metabolic risks and patient-reported outcomes (PROs) among adults with MetS remains inconclusive. Aim: To evaluate the effectiveness of LMPs on the metabolic risks and PROs among adults with MetS. Methods: A systematic review of randomized controlled trials published from January 1985 to June 2014 was conducted. The review extracted LMP interventions that included outcomes on the metabolic risks and PROs (quality of life and any other psychological health indicators). The quality of the included studies was assessed using the Cochrane Collaboration criteria. Results: Among the five trials included, the most commonly applied intervention components were diet plans, supervised exercise, health education, individual counseling, behavioral modi- fication, and motivational interviewing. Three fifths of the studies were nurse-led, and only one of the selected trials was theory-guided. LMPs can effectively reduce triglyceride levels, waist circumference, and systolic blood pressure. However, few trials consistently confirmed the bene- fits of metabolic risks, and none revealed a significant effect on high-density lipoprotein, fasting blood glucose, or any PRO, except quality of life. The duration of LMPs in the included trials ranged from 4 to 24 weeks, and durations of at least 12 weeks significantly improved quality of life. Linking Evidence to Action: LMPs had positive effects on some metabolic risks and on quality of life, whereas longer-duration LMPs may have highly beneficial effects on quality of life. The es- sential elements of LMPs need to be evaluated more thoroughly to determine their effectiveness. Larger and more rigorous randomized controlled trials are required to assess the effectiveness of LMPs on metabolic risks and PROs among adults with MetS. INTRODUCTION Metabolic syndrome (MetS) can raise the likelihood of type 2 diabetes (Meigs et al., 2006), cardiovascular disease, and mortality (Galassi, Reynolds, & He, 2006; Yasein, Ahmad, Matrook, Nasir, & Froelicher, 2010). The commonly used cri- terion of MetS is defined as the presence of three or more of the following risk components: elevated fasting blood glu- cose (FBG) or the use of antidiabetic medicines, elevated blood pressure (BP) or the use of antihypertensive medicines, ele- vated triglyceride (TG), reduced high-density lipoprotein (HDL) cholesterol, and central obesity (National Cholesterol Educa- tion Program [NCEP] Expert Panel, 2002). The criteria for MetS based on the International Diabetes Federation (IDF) guidelines are similar to the NCEP-Adult Treatment Panel III’s (ATP III) definition, with a key difference being that the former absolutely requires central obesity and includes differ- ent population-specific cut-points (Alberti, Zimmet, & Shaw, 2006). Metabolic risks are associated with sedentary lifestyles and high fat or carbohydrate diet patterns in adults with prediabetes (Chen & Lin, 2010). In response, numerous strategies includ- ing physical activity, healthy diet, and weight control have been proposed to prevent the development of MetS (Oh et al., 2010). Studies have demonstrated that intensive lifestyle modification Worldviews on Evidence-Based Nursing, 2014; 11:6, 361–368. 361 C  2014 Sigma Theta Tau International