Muscle distribution in relation to all-cause and cause-specific mortality in young and middle-aged adults

Abstract

Background The relationship between muscle and prognosis, especially that between muscle distribution across different body parts, and the related prognosis is not well established. Objective To investigate the relationship between muscle distribution and all-cause and cause-specific mortality and their potential modifiers. Design Longitudinal cohort study. C-index, IDI, and NRI were used to determine the best indicator of prognosis. COX regression analysis was performed to explore the relationship between variables and outcomes. Interaction and subgroup analyses were applied to identify the potential modifiers. Participants A total of 5052 participants (weighted: 124,841,420) extracted from the NHANES 2003–2006 of median age 45 years and constituting 50.3% men were assessed. For validation, we included 3040 patients from the INSCOC cohort in China. Main measures Muscle mass and distribution. Key Results COX regression analysis revealed that upper limbs (HR = 0.41, 95% CI 0.33–0.51), lower limbs (HR = 0.54, 95% CI 0.47–0.64), trunk (HR = 0.71, 95% CI, 0.59–0.85), gynoid (HR = 0.47, 95% CI 0.38–0.58), and total lean mass (HR = 0.55, 95% CI 0.45–0.66) were all associated with the better survival of participants (P trend < 0.001). The changes in the lean mass ratio of the upper and lower limbs and the lean mass ratio of the android and gynoid attenuated the protective effect of lean mass. Age and sex acted as potential modifiers, and the relationship between lean mass and the prognosis was more significant in men and middle-aged participants when compared to that in other age groups. Sensitive analyses depicted that despite lean mass having a long-term impact on prognosis (15 years), it has a more substantial effect on near-term survival (5 years). Conclusion Muscle mass and its distribution affect the prognosis with a more significant impact on the near-term than that on the long-term prognosis. Age and sex acted as vital modifiers.

Association of weight-adjusted waist index with all-cause mortality among non-Asian individuals: a national population-based cohort study

“…Based on previous studies of the association between body composition and mortality [ 34 , 35 ], we included a variety of covariates that could potentially influence the outcome. These included age (as a continuous variable), gender (male or female), race (categorized into non-Hispanic White, non-Hispanic Black, Mexican American, and other races, the other races includes Multi-Racial individuals), smoking status (current smoker, former smoker, never smoked), alcohol drinking status (current drinker, former drinker, non-drinker), income-to-poverty ratio (PIR) (a continuous variable), and multiple disease conditions (including self-reported heart failure, coronary heart disease, hypertension, renal failure, liver conditions, diabetes, stroke, heart attack, and cancer).…”

Predicted lean body mass trajectories, and cancer risk and cancer‐specific and all‐cause mortality: A prospective cohort study

“…In our previous study, we found a significant sex‐related difference in lean mass 10 . Therefore, in this study, we used the sex‐specific quintile of the predicted lean mass to build the trajectory model.…”

“…In our previous study, we found a significant sex‐related difference in lean mass. 10 Therefore, in this study, we used the sex‐specific quintile of the predicted lean mass to build the trajectory model. Otherwise, women would be in the low lean mass trajectory group, while men would account for the main component in the high lean mass trajectory group, resulting in a sex bias.…”

“…The changes in body composition are highly influenced by various factors, with one of the most significant being aging. As individuals age, mitochondrial function and the synthesis of bodily proteins weaken, while synthetic metabolism resistance increases, consequently, sarcopenia, characterized by the loss of lean mass and a decline in muscle function, has become one of the common chronic diseases associated with aging 9,10 . Furthermore, research indicated that individuals with metabolic disorders such as diabetes experience greater muscle loss compared with those without such conditions 11 .…”

“…As individuals age, mitochondrial function and the synthesis of bodily proteins weaken, while synthetic metabolism resistance increases, consequently, sarcopenia, characterized by the loss of lean mass and a decline in muscle function, has become one of the common chronic diseases associated with aging. 9 , 10 Furthermore, research indicated that individuals with metabolic disorders such as diabetes experience greater muscle loss compared with those without such conditions. 11 Therefore, relying on a single measurement of lean mass during youth or a disease‐free period to predict outcomes over 5 or even 10 years undoubtedly diminishes the rigour and credibility of the study, as we are aware that aging and metabolic changes are ongoing processes.…”