Objectives To assess the influence of muscle power and adiposity on all-cause mortality risk and to evaluate the ‘fat but powerful’ (F+P) (or ‘fat but fit’) paradox in older adults. Methods A total of 2563 older adults (65‒91 years old) from the EXERNET multicentre study were included. Adiposity (body mass index (BMI), waist circumference, body fat percentage (BF%) and fat index), allometric and relative power (sit-to-stand muscle power test) and various covariates (age, sex, hypertension, smoking status and walking and sitting times per day) were registered at baseline. All-cause mortality was recorded during a median follow-up of 8.9 years. Participants were classified into four groups: lean and powerful (L+P), F+P, lean but weak and fat and weak (F+W). Cox proportional hazard regression models and adjusted HRs were calculated. Results According to BMI and waist circumference, all-cause mortality risk was reduced in the F+P (HR=0.55 and 0.63, p=0.044 and 0.049, respectively) and L+P (HR=0.57 and 0.58, p=0.043 and 0.025, respectively) groups. According to BF%, all-cause mortality decreased in the L+P group (HR=0.53; p=0.021), and a trend for a reduction was reported in the F+P group (HR=0.57; p=0.060). According to fat index, a survival benefit was only noted in the L+P group (HR=0.50; p=0.049). Higher levels of relative power reduced all-cause mortality risk among older people (HR=0.63 and 0.53, p=0.006 and 0.011, respectively). Conclusion Powerful older people exhibited a reduced 9-year all-cause mortality regardless of BMI, waist circumference and BF%. Obesity according to fat index blunted the survival benefits of being powerful. The data that support the findings of this study are available from the corresponding author on reasonable request.

中文翻译：

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“肥而有力”的悖论：来自 EXERNET 多中心研究的肌肉力量和肥胖标志物与老年人全因死亡率的关联

目的 评估肌肉力量和肥胖对全因死亡风险的影响，并评估老年人的“肥胖但强壮”（F+P）（或“肥胖但健康”）悖论。方法 共纳入 EXERNET 多中心研究的 2563 名老年人（65-91 岁）。肥胖（体重指数 (BMI)、腰围、体脂百分比 (BF%) 和脂肪指数）、异速生长和相对力量（坐到站肌肉力量测试）和各​​种协变量（年龄、性别、高血压、吸烟状况）和每天步行和坐着的时间）在基线处记录。在中位随访 8.9 年期间记录了全因死亡率。参与者被分为四组：瘦而有力（L+P）、F+P、瘦而弱和肥而弱（F+W）。计算了 Cox 比例风险回归模型和调整后的 HR。结果 根据 BMI 和腰围，F+P（HR=0.55 和 0.63，分别 p=0.044 和 0.049）和 L+P（HR=0.57 和 0.58，p=0.043 和0.025，分别）组。根据 BF%，L+P 组的全因死亡率下降（HR=0.53；p=0.021），而 F+P 组报告有下降趋势（HR=0.57；p=0.060）。根据脂肪指数，仅在 L+P 组中观察到生存获益（HR=0.50；p=0.049）。较高水平的相对权力降低了老年人的全因死亡风险（HR=0.63 和 0.53，分别为 p=0.006 和 0.011）。结论 无论 BMI、腰围和 BF%，强壮的老年人的 9 年全因死亡率均降低。根据脂肪指数的肥胖削弱了强大的生存优势。