Research Group on Nutritional Epidemiology & Cardiovascular Physiopathology, Health Research Institute of the Balearic Islands, University Hospital Son Espases, Palma de Mallorca, Spain.
Centro de Investigación Biomédica en Red Fisiopatología de la Obesidad y la Nutrición, Institute of Health Carlos III, Madrid, Spain.
JAMA Netw Open. 2023 Oct 2;6(10):e2337994. doi: 10.1001/jamanetworkopen.2023.37994.
Strategies targeting body composition may help prevent chronic diseases in persons with excess weight, but randomized clinical trials evaluating lifestyle interventions have rarely reported effects on directly quantified body composition.
To evaluate the effects of a lifestyle weight-loss intervention on changes in overall and regional body composition.
DESIGN, SETTING, AND PARTICIPANTS: The ongoing Prevención con Dieta Mediterránea-Plus (PREDIMED-Plus) randomized clinical trial is designed to test the effect of the intervention on cardiovascular disease prevention after 8 years of follow-up. The trial is being conducted in 23 Spanish research centers and includes men and women (age 55-75 years) with body mass index between 27 and 40 and metabolic syndrome. The trial reported herein is an interim subgroup analysis of the intermediate outcome body composition after 3-year follow-up, and data analysis was conducted from February 1 to November 30, 2022. Of 6874 total PREDIMED-Plus participants, a subsample of 1521 individuals, coming from centers with access to a dual energy x-ray absorptiometry device, underwent body composition measurements at 3 time points.
Participants were randomly allocated to a multifactorial intervention based on an energy-reduced Mediterranean diet (MedDiet) and increased physical activity (PA) or to a control group based on usual care, with advice to follow an ad libitum MedDiet, but no physical activity promotion.
The outcomes (continuous) were 3-year changes in total fat and lean mass (expressed as percentages of body mass) and visceral fat (in grams), tested using multivariable linear mixed-effects models. Clinical relevance of changes in body components (dichotomous) was assessed based on 5% or more improvements in baseline values, using logistic regression. Main analyses were performed in the evaluable population (completers only) and in sensitivity analyses, multiple imputation was performed to include data of participants lost to follow-up (intention-to-treat analyses).
A total of 1521 individuals were included (mean [SD] age, 65.3 [5.0] years; 52.1% men). In comparison with the control group (n=761), participants in the intervention arm (n=760) showed greater reductions in the percentage of total fat (between group differences after 1-year, -0.94% [95% CI, -1.19 to -0.69]; 3 years, -0.38% [95% CI, -0.64 to -0.12] and visceral fat storage after 1 year, -126 g [95% CI, -179 to -73.3 g]; 3 years, -70.4 g [95% CI, -126 to -15.2 g] and greater increases in the percentage of total lean mass at 1 year, 0.88% [95% CI, 0.63%-1.12%]; 3-years 0.34% [95% CI, 0.09%-0.60%]). The intervention group was more likely to show improvements of 5% or more in baseline body components (absolute risk reduction after 1 year, 13% for total fat mass, 11% for total lean mass, and 14% for visceral fat mass; after 3-years: 6% for total fat mass, 6% for total lean mass, and 8% for visceral fat mass). The number of participants needed to treat was between 12 and 17 to attain at least 1 individual with possibly clinically meaningful improvements in body composition.
The findings of this trial suggest a weight-loss lifestyle intervention based on an energy-reduced MedDiet and physical activity significantly reduced total and visceral fat and attenuated age-related losses of lean mass in older adults with overweight or obesity and metabolic syndrome. Continued follow-up is warranted to confirm the long-term consequences of these changes on cardiovascular clinical end points.
isrctn.org Identifier: ISRCTN89898870.
重要性：针对身体成分的策略可能有助于预防超重人群的慢性疾病，但很少有随机临床试验报告对直接量化的身体成分产生影响的生活方式干预措施的效果。
目的：评估生活方式减肥干预对整体和区域身体成分变化的影响。
设计、地点和参与者：正在进行的地中海饮食加预防试验（PREDIMED-Plus）是一项随机临床试验，旨在测试干预措施对 8 年后心血管疾病预防的影响。该试验正在 23 个西班牙研究中心进行，包括年龄在 55-75 岁之间、体重指数在 27 至 40 之间且患有代谢综合征的男性和女性。本文报告的是 3 年随访后中间结果身体成分的亚组分析，数据分析于 2022 年 2 月 1 日至 11 月 30 日进行。在 6874 名 PREDIMED-Plus 总参与者中，有 1521 名个体来自有双能 X 射线吸收仪设备的中心，他们在 3 个时间点进行了身体成分测量。
干预措施：参与者被随机分配到基于能量减少的地中海饮食（MedDiet）和增加体力活动（PA）的多因素干预组或基于常规护理的对照组，建议遵循随意的 MedDiet，但不促进体力活动。
主要结果和措施：结果（连续）是 3 年内总脂肪和瘦体重（表示为体重的百分比）和内脏脂肪（以克为单位）的变化，使用多变量线性混合效应模型进行测试。根据基线值的 5%或更多改善，使用逻辑回归评估身体成分变化的临床意义（二分类）。主要分析在可评估人群（仅完成者）中进行，在敏感性分析中，使用多重插补法包括失随访参与者的数据（意向治疗分析）。
结果：共纳入 1521 名个体（平均[标准差]年龄，65.3[5.0]岁；52.1%为男性）。与对照组（n=761）相比，干预组（n=760）的参与者的总脂肪百分比降低更大（1 年时组间差异，-0.94%[95%CI，-1.19 至-0.69]；3 年时，-0.38%[95%CI，-0.64 至-0.12]和内脏脂肪储存量降低更大，1 年后减少 126 克[95%CI，-179 至-73.3 克]；3 年时减少 70.4 克[95%CI，-126 至-15.2 克]，1 年后总瘦体重百分比增加更大，0.88%[95%CI，0.63%-1.12%]；3 年时增加 0.34%[95%CI，0.09%-0.60%]）。干预组更有可能出现基线身体成分改善 5%或更多（1 年后总脂肪质量绝对风险降低 13%，总瘦质量 11%，内脏脂肪质量 14%；3 年后：总脂肪质量 6%，总瘦质量 6%，内脏脂肪质量 8%）。需要治疗的参与者人数在 12 至 17 人之间，以实现至少 1 名个体的身体成分可能具有临床意义的改善。
结论和相关性：这项试验的结果表明，基于能量减少的 MedDiet 和体力活动的减肥生活方式干预显著减少了超重或肥胖且患有代谢综合征的老年人的总体和内脏脂肪，并减轻了与年龄相关的瘦体重损失。需要继续随访以确认这些变化对心血管临床终点的长期影响。
试验注册：isrctn.org 标识符：ISRCTN89898870。
